Patent Publication Number: US-11376082-B2

Title: Robotic surgical system with local sensing of functional parameters based on measurements of multiple physical inputs

Description:
BACKGROUND 
     The present disclosure relates to robotic surgical systems. Robotic surgical systems can include a central control unit, a surgeon&#39;s command console, and a robot having one or more robotic arms. Robotic surgical tools can be releasably mounted to the robotic arm(s). The number and type of robotic surgical tools can depend on the type of surgical procedure. Robotic surgical systems can be used in connection with one or more displays and/or one or more handheld surgical instruments during a surgical procedure. 
    
    
     
       FIGURES 
       The features of various aspects are set forth with particularity in the appended claims. The various aspects, however, both as to organization and methods of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in conjunction with the accompanying drawings as follows. 
         FIG. 1  is a block diagram of a computer-implemented interactive surgical system, in accordance with at least one aspect of the present disclosure. 
         FIG. 2  is a surgical system being used to perform a surgical procedure in an operating room, in accordance with at least one aspect of the present disclosure. 
         FIG. 3  is a surgical hub paired with a visualization system, a robotic system, and an intelligent instrument, in accordance with at least one aspect of the present disclosure. 
         FIG. 4  is a schematic of a robotic surgical system, in accordance with at least one aspect of the present disclosure. 
         FIG. 4A  illustrates another exemplification of a robotic arm and another exemplification of a tool assembly releasably coupled to the robotic arm, according to one aspect of the present disclosure. 
         FIG. 5  is a block diagram of control components for the robotic surgical system of  FIG. 4 , in accordance with at least one aspect of the present disclosure. 
         FIG. 6  is a schematic of a robotic surgical system during a surgical procedure including a plurality of hubs and interactive secondary displays, in accordance with at least one aspect of the present disclosure. 
         FIG. 7  is a detail view of the interactive secondary displays of  FIG. 6 , in accordance with at least one aspect of the present disclosure. 
         FIG. 8  illustrates a surgical data network comprising a modular communication hub configured to connect modular devices located in one or more operating theaters of a healthcare facility, or any room in a healthcare facility specially equipped for surgical operations, to the cloud, in accordance with at least one aspect of the present disclosure. 
         FIG. 9  illustrates a computer-implemented interactive surgical system, in accordance with at least one aspect of the present disclosure. 
         FIG. 10  illustrates a surgical hub comprising a plurality of modules coupled to the modular control tower, in accordance with at least one aspect of the present disclosure. 
         FIG. 11  illustrates one aspect of a Universal Serial Bus (USB) network hub device, in accordance with at least one aspect of the present disclosure. 
         FIG. 12  illustrates a logic diagram of a control system of a surgical instrument or tool, in accordance with at least one aspect of the present disclosure. 
         FIG. 13  illustrates a control circuit configured to control aspects of the surgical instrument or tool, in accordance with at least one aspect of the present disclosure. 
         FIG. 14  illustrates a combinational logic circuit configured to control aspects of the surgical instrument or tool, in accordance with at least one aspect of the present disclosure. 
         FIG. 15  illustrates a sequential logic circuit configured to control aspects of the surgical instrument or tool, in accordance with at least one aspect of the present disclosure. 
         FIG. 16  illustrates a surgical instrument or tool comprising a plurality of motors which can be activated to perform various functions, in accordance with at least one aspect of the present disclosure. 
         FIG. 17  is a schematic diagram of a robotic surgical instrument configured to operate a surgical tool described herein, in accordance with at least one aspect of the present disclosure. 
         FIG. 18  illustrates a block diagram of a surgical instrument programmed to control the distal translation of a displacement member, in accordance with at least one aspect of the present disclosure. 
         FIG. 19  is a schematic diagram of a surgical instrument configured to control various functions, in accordance with at least one aspect of the present disclosure. 
         FIG. 20  is a simplified block diagram of a generator configured to provide inductorless tuning, among other benefits, in accordance with at least one aspect of the present disclosure. 
         FIG. 21  illustrates an example of a generator, which is one form of the generator of  FIG. 20 , in accordance with at least one aspect of the present disclosure. 
         FIG. 22  is a schematic of a robotic surgical system, in accordance with one aspect of the present disclosure. 
         FIG. 23  is a graphical illustration of an algorithm implemented in a robotic surgical system for controlling robotic surgical tools based on motor current (I) and externally sensed parameters according to at least one aspect of the present disclosure. 
         FIG. 24  illustrates a distal portion of a motor driven powered robotic surgical tool grasping tissue under low lateral tension according to at least one aspect of the present disclosure. 
         FIG. 25  illustrates a distal portion of the motor driven powered robotic surgical tool grasping tissue under high downward tension according to at least one aspect of the present disclosure. 
         FIG. 26  is a graphical illustration of an algorithm implemented in a robotic surgical system for monitoring a parameter of a control circuit of one motor within a motor pack to influence the control of an adjacent motor control circuit within the motor pack according to at least one aspect of the present disclosure. 
         FIG. 27  illustrates the motor driven powered robotic surgical tool positioned on a linear slide attached to a robotic arm according to at least one aspect of the present disclosure. 
         FIG. 28  illustrates a first robotic arm in a first position A according to at least one aspect of the present disclosure. 
         FIG. 29  illustrates a second robotic arm in a second position B according to at least one aspect of the present disclosure. 
         FIG. 30  illustrates one aspect of the force plate located at the base of the robotic arm or operating room (OR) table to measure reactionary vector loads in x, y, z axis according to at least one aspect of the present disclosure. 
         FIG. 31  is a graphical illustration of an algorithm implemented in a robotic surgical system for comparing reactionary vector loads of the robot base versus x, y, z axis motor loads of the robotic arms according to at least one aspect of the present disclosure. 
         FIG. 32  is a logic flow diagram of a process depicting a control program or a logic configuration for controlling a robotic end-effector actuation motor based on a parameter of a sensed externally applied force to the end-effector according to at least one aspect of the present disclosure. 
         FIG. 33  is a logic flow diagram of a process depicting a control program or a logic configuration for monitoring one motor pack control circuit to adjust the rate, current, or torque of an adjacent motor control circuit according to at least one aspect of the present disclosure. 
         FIG. 34  is a logic flow diagram of a process depicting a control program or a logic configuration for sensing the forces applied by the robotic surgical tool rotation motor or linear slide and the control of jaw to jaw control forces based on that externally applied torsion along with the gripping force generated by the robotic surgical tool actuation motor. 
         FIG. 35  illustrates a robotic surgical system and method for confirming end-effector kinematics with vision system tracking according to at least one aspect of the present disclosure. 
         FIG. 36  illustrates a robotic surgical system and method for confirming end-effector kinematics with vision system tracking according to at least one aspect of the present disclosure. 
         FIG. 37  illustrates a robotic surgical system and method for detecting a location of the distal end of a fixed shaft and a straight-line travel path to an intended position according to at least one aspect of the present disclosure. 
         FIG. 38  illustrates tracking system for a robotic surgical system defining a plurality of travel paths of the distal end of an end-effector based on velocity as the distal end of the end-effector travels form a first location to a second location according to at least one aspect of the present disclosure. 
         FIG. 39  is a graphical illustration of an algorithm for detecting an error in the tracking system depicted in  FIG. 38  and corresponding changes in velocity of the distal end of the end-effector according to at least one aspect of the present disclosure. 
         FIG. 40  illustrates a system for verifying the output of a local control circuit and transmitting a control signal according to at least one aspect of the present disclosure. 
         FIG. 41  is a flow diagram of a process depicting a control program or a logic configuration of a wireless primary and secondary verification feedback system according to at least one aspect of the present disclosure. 
         FIG. 42  is a graphical illustration of an algorithm for comparing motor control signals, safety verification signals, and motor current according to at least aspect of the present disclosure. 
         FIG. 43  is a flow diagram of a process depicting a control program or a logic configuration of a motor controller restart process due to motor controller shutdown due to communication loss according to at least one aspect of the present disclosure. 
         FIG. 44  is a flow diagram of a process depicting a control program or a logic configuration for controlling a motor controller due to command or verification signal loss according to at least one aspect of the present disclosure. 
         FIG. 45  is a flowchart depicting a robotic surgical system utilizing a plurality of independent sensing systems according to at least one aspect of the present disclosure. 
         FIG. 46  is a robotic surgical system for controlling a primary robotic arm and detecting and verifying secondary robotic arms according to at least one aspect of the present disclosure. 
         FIG. 47  is a detailed view of the system depicted in  FIG. 46  according to at least one aspect of the present disclosure 
         FIG. 48  illustrates a positioning and orientation system for a robotic surgical system that includes an end-effector to end-effector positioning and orientation according to at least one aspect of the present disclosure. 
         FIG. 49  is a perspective view of the end-effector to end-effector positioning and orientation system depicted in  FIG. 48  according to at least one aspect of the present disclosure. 
         FIG. 50  illustrates one of the second robotic arm depicted in  FIGS. 48 and 49 , with global and local control of positioning and orientation according to at least one aspect of the present disclosure. 
         FIG. 51  illustrates an electromechanical robotic surgical tool with a shaft having a distal end and an end-effector mounted to the shaft in the vicinity of patient tissue according to at least one aspect of the present disclosure. 
         FIG. 52  illustrates the end-effector in the vicinity of tissue according to at least one aspect of the present disclosure. 
         FIG. 53  is a graphical illustration of jaw temperature and jaw proximity to surrounding tissue as a function of time according to at least one aspect of the present disclosure. 
         FIG. 54  is a cross-sectional view of one aspect of a flexible circuit  67600  comprising RF electrodes and data sensors embedded therein according to at least one aspect of the present disclosure. 
         FIG. 55  illustrates an end-effector with a jaw member, flexible circuits, and segmented electrodes provided on each flexible circuit according to at least one aspect of the present disclosure. 
         FIG. 56  is a cross sectional view of an end-effector comprising a rotatable jaw member, a flexible circuit, and an ultrasonic blade positioned in a vertical orientation relative to the jaw member with tissue located between the jaw member and the ultrasonic blade according to at least one aspect of the present disclosure. 
         FIG. 57A  illustrates an end-effector with a lower jaw or ultrasonic blade, and an upper jaw or clamp member that are configured to clamp tissue therebetween according to at least one aspect of the present disclosure. 
         FIG. 57B  illustrates that the end-effector and thus the blade is lifted, as schematically shown by arrows one of which is labeled as, and the tissue is cut, such that a portion of the tissue is disassociated from the end-effector according to at least one aspect of the present disclosure. 
         FIG. 58  illustrates two examples of graphs of trajectory curves representing impedance values and corresponding curves representing lift velocities of end-effector&#39;s blades for different types of tissues according to at least one aspect of the present disclosure. 
         FIG. 59  illustrates an end-effector of a robotic surgical system according to at least one aspect of the present disclosure. 
         FIG. 60  illustrates a sensor assembly coupled adjacent to an embodiment of an end-effector that includes a cutting robotic surgical tool (e.g., tissue boring robotic surgical tool) according to at least one aspect of the present disclosure. 
         FIG. 61A  illustrates a distal end of a cutting robotic surgical tool that is not in contact with tissue and therefore a force is not applied against the distal end of the cutting robotic surgical tool by the tissue according to at least one aspect of the present disclosure. 
         FIG. 61B  illustrates a distal end of a cutting robotic surgical tool that is in contact with tissue and a force is applied against the distal end of the cutting robotic surgical tool by the tissue according to at least one aspect of the present disclosure. 
         FIG. 61C  illustrates a distal end of a cutting robotic surgical tool that is extending through the tissue and is no longer in contact with the tissue according to at least one aspect of the present disclosure. 
         FIG. 62  illustrates an end-effector being lifted or angled to cause the force applied by tissue to increase against an ultrasonic blade thereby assisting with cutting the tissue as the end-effector is advanced in a direction that cuts the tissue according to at least one aspect of the present disclosure. 
         FIG. 63  illustrates a first end-effector of a first robotic surgical tool assembly coupled to a first robotic arm and a second end-effector of a second robotic surgical tool assembly coupled to a second robotic arm according to at least one aspect of the present disclosure. 
         FIG. 64  illustrates a patient lying on an operating room table with a robot controlled circular stapler inserted in the rectal stump of the patient according to at least one aspect of the present disclosure. 
         FIG. 65  illustrates a limiting robotic surgical tool induced tissue loading relative to a hard anatomic reference according to at least one aspect of the present disclosure. 
         FIG. 66  illustrates a robotic surgical tool improperly inserted at an angle to the proper direction of insertion indicated by the arrow. 
         FIG. 67  illustrates a robotic surgical tool properly inserted in the direction indicated by the arrow. 
         FIG. 68  is a graphical illustration of measured torque T on the operating room table and robotic surgical tool positioning and orientation as a function of time t according to at least one aspect of the present disclosure. 
         FIG. 69A  illustrates a grasper device holding an anvil shaft and applying a first tissue tension F g1  on the colon according to at least one aspect of the present disclosure. 
         FIG. 69B  illustrates the grasper device shown in  FIG. 69A  with the anvil shaft extended into the shaft of the circular stapler, which has been further extended into the colon and the rectal stump according to at least one aspect of the present disclosure. 
         FIG. 69C  illustrates the grasper device shown in  FIG. 69B  with the anvil shaft released and the tissue tension F g3  on the colon reduced according to at least one aspect of the present disclosure. 
         FIG. 69D  illustrates the grasper device shown in  FIG. 69C  with the anvil shaft released and the tissue tension F g4  on the colon within an acceptable range according to at least one aspect of the present disclosure. 
         FIG. 70  is a graphical illustration of control of robotic arms of both internal colon grasper device and a shaft of a circular stapler to achieve acceptable tissue tension according to at least aspect of the present disclosure. 
         FIG. 71  is a graphical illustration of anvil shaft rate and load control of a robotic circular stapler closing system according to at least one aspect of the present disclosure. 
         FIG. 72  is a schematic diagram of an anvil clamping control system of a surgical stapler grasping tissue between an anvil and a staple cartridge and the force Fun/Hon the anvil according to at least one aspect of the present disclosure. 
         FIG. 73  is a schematic diagram of a tissue cutting member control system of the surgical stapler depicted in  FIG. 72  grasping tissue between the anvil and the staple cartridge and the force F knife  on the knife while cutting the tissue according to at least one aspect of the present disclosure. 
         FIG. 74  is a schematic diagram of an anvil motor according to at least one aspect of the present disclosure. 
         FIG. 75  is a schematic diagram of a knife motor according to at least one aspect of the present disclosure. 
         FIG. 76  is a graphical illustration of an algorithm for antagonistic or cooperative control of the anvil clamping control system and the tissue cutting member control system as illustrated in  FIGS. 72-75  according to at least one aspect of the present disclosure. 
         FIG. 77  is a flow diagram of a process depicting a control program or a logic configuration for controlling a first robotic arm relative to a second robotic arm according to at least one aspect of the present disclosure. 
         FIG. 78  is a flow diagram of a process depicting a control program or a logic configuration for verifying a position or velocity of an end-effector jaw of a first surgical tool coupled to a first robotic arm based on a redundant calculation of a resulting movement of the end-effector from a motor application of control parameters of a second robotic arm coupled to a second surgical tool according to at least one aspect of the present disclosure. 
         FIG. 79  is a flow diagram of a process depicting a control program or a logic configuration of controlling at least one operational parameter of a robotic surgical tool driver controlling a circular stapler robotic surgical tool based on another parameter measured within the robotic surgical tool driver controlling the circular stapler according to at least one aspect of the present disclosure. 
         FIG. 80  is a torque transducer having a body connecting a mounting flange and a motor flange according to at least one aspect of the present disclosure. 
         FIG. 81  is a flowchart illustrating a method of controlling an instrument drive unit according to at least one aspect of the present disclosure. 
         FIG. 82  is a front perspective view of an instrument drive unit holder of a robotic surgical assembly with an instrument drive unit and a surgical instrument coupled thereto according to at least one aspect of the present disclosure. 
         FIG. 83A  is a side perspective view of a motor pack of the instrument drive unit of  FIG. 82  with an integrated circuit in a second configuration and separated from the motor assembly according to at least one aspect of the present disclosure. 
         FIG. 83B  is a side perspective view of the motor pack of the instrument drive unit of  FIG. 82  with the integrated circuit in a second configuration and separated from the motor assembly according to at least one aspect of the present disclosure. 
         FIG. 84  is a graphical illustration of limiting combined functional loading on the patient by determining the torques within robotic surgical tool driver and robotic arm/system according to at least one aspect of the present disclosure. 
         FIG. 85  is a flow diagram of a system and method of limiting combined functional loading on the patient by determining the torques within robotic surgical tool driver and robotic arm/system according to at least one aspect of the present disclosure. 
         FIG. 86  illustrates a motor pack according to at least one aspect of the present disclosure. 
         FIG. 87  is a graphical illustration of a temperature control algorithm for monitoring external parameters associated with the operation of a motor according to at least one aspect of the present disclosure. 
         FIG. 88  is a graphical illustration of magnetic field strength (B) of a motor as a function of time t according to at least one aspect of the present disclosure. 
         FIG. 89  is a graphical illustration of motor temperature as a function of time t according to at least one aspect of the present disclosure. 
         FIG. 90  is a graphical illustration of magnetic field strength (B) as a function motor temperature (T) according to at least one aspect of the present disclosure. 
         FIG. 91  illustrates a flex spool assembly that includes a first printed circuit board, a second printed circuit board, and a third printed circuit board according to at least one aspect of the present disclosure. 
         FIG. 92  is a detailed view of the flex spool assembly shown in  FIG. 91  according to at least one aspect of the present disclosure. 
         FIG. 93  illustrates an internal receiver with multiple cavities wire control features to maintain orientation and order of the wiring harness during rotation according to at least one aspect of the present disclosure. 
         FIG. 94  illustrates a wiring harness according to at least one aspect of the present disclosure. 
         FIG. 95  illustrates a semiautonomous motor controller local to a motor pack according to at least aspect of the present disclosure. 
         FIG. 96  is a detailed view of the spring loaded plunger depicted in  FIG. 95  according to at least one aspect of the present disclosure. 
         FIG. 97  illustrates a wireless power system for transmission of electrical power between a surgical robot and a motor pack comprising a plurality of motors according to at least one aspect of the present disclosure 
         FIG. 98  is a diagram of the wireless power system for transmission of electrical power between a robot and a motor pack depicted in  FIG. 97  according to at least one aspect of the present disclosure. 
         FIG. 99  is a block diagram of an information transfer system according to at least one aspect of the present disclosure. 
         FIG. 100  generally depicts system for providing electrical power to a medical device according to at least one aspect of the present disclosure. 
         FIG. 101  illustrates a surgical instrument according to at least one aspect of the present disclosure. 
         FIG. 102  illustrates an electrical interface including a control circuit for transmitting the control signals according to at least one aspect of the present disclosure. 
         FIG. 103  schematically illustrates an electrosurgical system that includes an electric-field capacitive coupler module coupled between a microwave generator assembly and a microwave energy delivery device according to at least one aspect of the present disclosure. 
         FIG. 104  illustrates an elongate link or slide rail that includes a multidirectional movement mechanism configured to axially move a surgical instrument along a longitudinal axis of an elongate link or slide rail and to rotate the surgical instrument about its longitudinal axis according to at least one aspect of the present disclosure. 
         FIGS. 105A and 105B  illustrate first and second motors “M1,” “M2” of a multi-directional movement mechanism actuated to rotate both a left-handed lead screw and a right-handed lead screw in a counter-clockwise direction to cause a cogwheel, and the attached surgical instrument, to rotate in a clockwise direction as indicated by arrow “C” shown in  FIG. 105B , according to at least one aspect of the present disclosure. 
         FIG. 106  illustrates a robotic surgical assembly that is connectable to an interface panel or carriage which is slidably mounted onto the rail according to at least one aspect of the present disclosure. 
         FIG. 107  illustrates a surgical instrument holder of a surgical assembly that functions both to actuate a rotation of a body of an instrument drive unit and to support a housing of a surgical instrument according to at least one aspect of the present disclosure. 
         FIG. 108  illustrates the surgical instrument holder of a surgical assembly shown in  FIG. 107  that functions both to actuate a rotation of a body of an instrument drive unit and to support a housing of a surgical instrument according to at least one aspect of the present disclosure. 
         FIG. 109  illustrates an instrument drive unit according to at least one aspect of the present disclosure. 
         FIG. 110  is a flow diagram of a process depicting a control program or a logic configuration for controlling a robotic arm according to at least one aspect of the present disclosure. 
     
    
    
     DESCRIPTION 
     Applicant of the present application owns the following U.S. patent applications, filed on even date herewith, the disclosure of each of which is herein incorporated by reference in its entirety:
         Ser. No. 16/,454,702, titled METHOD OF USING A SURGICAL MODULAR ROBOTIC ASSEMBLY;   Ser. No. 16/454,710, titled SURGICAL SYSTEMS WITH INTERCHANGEABLE MOTOR PACKS;   Ser. No. 16/454,715, titled COOPERATIVE ROBOTIC SURGICAL SYSTEMS;   Ser. No. 16/454,740, titled HEAT EXCHANGE SYSTEMS FOR ROBOTIC SURGICAL SYSTEMS;   Ser. No. 16/454,757, titled DETERMINING ROBOTIC SURGICAL ASSEMBLY COUPLING STATUS;   Ser. No. 16/454,780, titled ROBOTIC SURGICAL ASSEMBLY COUPLING SAFETY MECHANISMS;   Ser. No. 16/454,707, titled ROBOTIC SURGICAL SYSTEM WITH SAFETY AND COOPERATIVE SENSING CONTROL;   Ser. No. 16/454,726, titled ROBOTIC SURGICAL SYSTEM FOR CONTROLLING CLOSE OPERATION OF END-EFFECTORS;   Ser. No. 16/454,751, titled COOPERATIVE OPERATION OF ROBOTIC ARMS;   Ser. No. 16/454,760, titled SURGICAL INSTRUMENT DRIVE SYSTEMS;   Ser. No. 16/454,769, titled SURGICAL INSTRUMENT DRIVE SYSTEMS WITH CABLE-TIGHTENING SYSTEM;   Ser. No. 16/454,727, titled VISUALIZATION SYSTEM WITH AUTOMATIC CONTAMINATION DETECTION AND CLEANING CONTROLS; and   Ser. No. 16/454,741, titled MULTI-ACCESS PORT FOR SURGICAL ROBOTIC SYSTEMS.       

     Applicant of the present application owns the following U.S. patent applications, filed on Dec. 4, 2018, the disclosure of each of which is herein incorporated by reference in its entirety:
         U.S. patent application Ser. No. 16/209,385, titled METHOD OF HUB COMMUNICATION, PROCESSING, STORAGE AND DISPLAY;   U.S. patent application Ser. No. 16/209,395, titled METHOD OF HUB COMMUNICATION;   U.S. patent application Ser. No. 16/209,403, titled METHOD OF CLOUD BASED DATA ANALYTICS FOR USE WITH THE HUB;   U.S. patent application Ser. No. 16/209,407, titled METHOD OF ROBOTIC HUB COMMUNICATION, DETECTION, AND CONTROL;   U.S. patent application Ser. No. 16/209,416, titled METHOD OF HUB COMMUNICATION, PROCESSING, DISPLAY, AND CLOUD ANALYTICS;   U.S. patent application Ser. No. 16/209,423, titled METHOD OF COMPRESSING TISSUE WITHIN A STAPLING DEVICE AND SIMULTANEOUSLY DISPLAYING THE LOCATION OF THE TISSUE WITHIN THE JAWS;   U.S. patent application Ser. No. 16/209,427, titled METHOD OF USING REINFORCED FLEXIBLE CIRCUITS WITH MULTIPLE SENSORS TO OPTIMIZE PERFORMANCE OF RADIO FREQUENCY DEVICES;   U.S. patent application Ser. No. 16/209,433, titled METHOD OF SENSING PARTICULATE FROM SMOKE EVACUATED FROM A PATIENT, ADJUSTING THE PUMP SPEED BASED ON THE SENSED INFORMATION, AND COMMUNICATING THE FUNCTIONAL PARAMETERS OF THE SYSTEM TO THE HUB;   U.S. patent application Ser. No. 16/209,447, titled METHOD FOR SMOKE EVACUATION FOR SURGICAL HUB;   U.S. patent application Ser. No. 16/209,453, titled METHOD FOR CONTROLLING SMART ENERGY DEVICES;   U.S. patent application Ser. No. 16/209,458, titled METHOD FOR SMART ENERGY DEVICE INFRASTRUCTURE;   U.S. patent application Ser. No. 16/209,465, titled METHOD FOR ADAPTIVE CONTROL SCHEMES FOR SURGICAL NETWORK CONTROL AND INTERACTION;   U.S. patent application Ser. No. 16/209,478, titled METHOD FOR SITUATIONAL AWARENESS FOR SURGICAL NETWORK OR SURGICAL NETWORK CONNECTED DEVICE CAPABLE OF ADJUSTING FUNCTION BASED ON A SENSED SITUATION OR USAGE;   U.S. patent application Ser. No. 16/209,490, titled METHOD FOR FACILITY DATA COLLECTION AND INTERPRETATION; and   U.S. patent application Ser. No. 16/209,491, titled METHOD FOR CIRCULAR STAPLER CONTROL ALGORITHM ADJUSTMENT BASED ON SITUATIONAL AWARENESS.       

     Before explaining various aspects of surgical devices and generators in detail, it should be noted that the illustrative examples are not limited in application or use to the details of construction and arrangement of parts illustrated in the accompanying drawings and description. The illustrative examples may be implemented or incorporated in other aspects, variations and modifications, and may be practiced or carried out in various ways. Further, unless otherwise indicated, the terms and expressions employed herein have been chosen for the purpose of describing the illustrative examples for the convenience of the reader and are not for the purpose of limitation thereof. Also, it will be appreciated that one or more of the following-described aspects, expressions of aspects, and/or examples, can be combined with any one or more of the other following-described aspects, expressions of aspects and/or examples. 
     Referring to  FIG. 1 , a computer-implemented interactive surgical system  100  includes one or more surgical systems  102  and a cloud-based system (e.g., the cloud  104  that may include a remote server  113  coupled to a storage device  105 ). Each surgical system  102  includes at least one surgical hub  106  in communication with the cloud  104  that may include a remote server  113 . In one example, as illustrated in FIG.  1 , the surgical system  102  includes a visualization system  108 , a robotic system  110 , and a handheld intelligent surgical instrument  112 , which are configured to communicate with one another and/or the hub  106 . In some aspects, a surgical system  102  may include an M number of hubs  106 , an N number of visualization systems  108 , an O number of robotic systems  110 , and a P number of handheld intelligent surgical instruments  112 , where M, N, O, and P are integers greater than or equal to one. 
       FIG. 3  depicts an example of a surgical system  102  being used to perform a surgical procedure on a patient who is lying down on an operating table  114  in a surgical operating room  116 . A robotic system  110  is used in the surgical procedure as a part of the surgical system  102 . The robotic system  110  includes a surgeon&#39;s console  118 , a patient side cart  120  (surgical robot), and a surgical robotic hub  122 . The patient side cart  120  can manipulate at least one removably coupled surgical tool  117  through a minimally invasive incision in the body of the patient while the surgeon views the surgical site through the surgeon&#39;s console  118 . An image of the surgical site can be obtained by a medical imaging device  124 , which can be manipulated by the patient side cart  120  to orient the imaging device  124 . The robotic hub  122  can be used to process the images of the surgical site for subsequent display to the surgeon through the surgeon&#39;s console  118 . 
     Other types of robotic systems can be readily adapted for use with the surgical system  102 . Various examples of robotic systems and surgical tools that are suitable for use with the present disclosure are described in U.S. Provisional Patent Application Ser. No. 62/611,339, titled ROBOT ASSISTED SURGICAL PLATFORM, filed Dec. 28, 2017, the disclosure of which is herein incorporated by reference in its entirety. 
     Various examples of cloud-based analytics that are performed by the cloud  104 , and are suitable for use with the present disclosure, are described in U.S. Provisional Patent Application Ser. No. 62/611,340, titled CLOUD-BASED MEDICAL ANALYTICS, filed Dec. 28, 2017, the disclosure of which is herein incorporated by reference in its entirety. 
     In various aspects, the imaging device  124  includes at least one image sensor and one or more optical components. Suitable image sensors include, but are not limited to, Charge-Coupled Device (CCD) sensors and Complementary Metal-Oxide Semiconductor (CMOS) sensors. 
     The optical components of the imaging device  124  may include one or more illumination sources and/or one or more lenses. The one or more illumination sources may be directed to illuminate portions of the surgical field. The one or more image sensors may receive light reflected or refracted from the surgical field, including light reflected or refracted from tissue and/or surgical instruments. 
     The one or more illumination sources may be configured to radiate electromagnetic energy in the visible spectrum as well as the invisible spectrum. The visible spectrum, sometimes referred to as the optical spectrum or luminous spectrum, is that portion of the electromagnetic spectrum that is visible to (i.e., can be detected by) the human eye and may be referred to as visible light or simply light. A typical human eye will respond to wavelengths in air that are from about 380 nm to about 750 nm. 
     The invisible spectrum (i.e., the non-luminous spectrum) is that portion of the electromagnetic spectrum that lies below and above the visible spectrum (i.e., wavelengths below about 380 nm and above about 750 nm). The invisible spectrum is not detectable by the human eye. Wavelengths greater than about 750 nm are longer than the red visible spectrum, and they become invisible infrared (IR), microwave, and radio electromagnetic radiation. Wavelengths less than about 380 nm are shorter than the violet spectrum, and they become invisible ultraviolet, x-ray, and gamma ray electromagnetic radiation. 
     In various aspects, the imaging device  124  is configured for use in a minimally invasive procedure. Examples of imaging devices suitable for use with the present disclosure include, but not limited to, an arthroscope, angioscope, bronchoscope, choledochoscope, colonoscope, cytoscope, duodenoscope, enteroscope, esophagogastro-duodenoscope (gastroscope), endoscope, laryngoscope, nasopharyngo-neproscope, sigmoidoscope, thoracoscope, and ureteroscope. 
     In one aspect, the imaging device employs multi-spectrum monitoring to discriminate topography and underlying structures. A multi-spectral image is one that captures image data within specific wavelength ranges across the electromagnetic spectrum. The wavelengths may be separated by filters or by the use of instruments that are sensitive to particular wavelengths, including light from frequencies beyond the visible light range, e.g., IR and ultraviolet. Spectral imaging can allow extraction of additional information the human eye fails to capture with its receptors for red, green, and blue. The use of multi-spectral imaging is described in greater detail under the heading “Advanced Imaging Acquisition Module” in U.S. Provisional Patent Application Ser. No. 62/611,341, titled INTERACTIVE SURGICAL PLATFORM, filed Dec. 28, 2017, the disclosure of which is herein incorporated by reference in its entirety. Multi-spectrum monitoring can be a useful tool in relocating a surgical field after a surgical task is completed to perform one or more of the previously described tests on the treated tissue. 
     It is axiomatic that strict sterilization of the operating room and surgical equipment is required during any surgery. The strict hygiene and sterilization conditions required in a “surgical theater,” i.e., an operating or treatment room, necessitate the highest possible sterility of all medical devices and equipment. Part of that sterilization process is the need to sterilize anything that comes in contact with the patient or penetrates the sterile field, including the imaging device  124  and its attachments and components. It will be appreciated that the sterile field may be considered a specified area, such as within a tray or on a sterile towel, that is considered free of microorganisms, or the sterile field may be considered an area, immediately around a patient, who has been prepared for a surgical procedure. The sterile field may include the scrubbed team members, who are properly attired, and all furniture and fixtures in the area. 
     In various aspects, the visualization system  108  includes one or more imaging sensors, one or more image processing units, one or more storage arrays, and one or more displays that are strategically arranged with respect to the sterile field, as illustrated in  FIG. 2 . In one aspect, the visualization system  108  includes an interface for HL7, PACS, and EMR. Various components of the visualization system  108  are described under the heading “Advanced Imaging Acquisition Module” in U.S. Provisional Patent Application Ser. No. 62/611,341, titled INTERACTIVE SURGICAL PLATFORM, filed Dec. 28, 2017, the disclosure of which is herein incorporated by reference in its entirety. 
     As illustrated in  FIG. 2 , a primary display  119  is positioned in the sterile field to be visible to an operator at the operating table  114 . In addition, a visualization tower  111  is positioned outside the sterile field. The visualization tower  111  includes a first non-sterile display  107  and a second non-sterile display  109 , which face away from each other. The visualization system  108 , guided by the hub  106 , is configured to utilize the displays  107 ,  109 , and  119  to coordinate information flow to operators inside and outside the sterile field. For example, the hub  106  may cause the visualization system  108  to display a snap-shot of a surgical site, as recorded by an imaging device  124 , on a non-sterile display  107  or  109 , while maintaining a live feed of the surgical site on the primary display  119 . The snap-shot on the non-sterile display  107  or  109  can permit a non-sterile operator to perform a diagnostic step relevant to the surgical procedure, for example. 
     In one aspect, the hub  106  is also configured to route a diagnostic input or feedback entered by a non-sterile operator at the visualization tower  111  to the primary display  119  within the sterile field, where it can be viewed by a sterile operator at the operating table. In one example, the input can be in the form of a modification to the snap-shot displayed on the non-sterile display  107  or  109 , which can be routed to the primary display  119  by the hub  106 . 
     Referring to  FIG. 2 , a surgical instrument  112  is being used in the surgical procedure as part of the surgical system  102 . The hub  106  is also configured to coordinate information flow to a display of the surgical instrument  112 . For example, in U.S. Provisional Patent Application Ser. No. 62/611,341, titled INTERACTIVE SURGICAL PLATFORM, filed Dec. 28, 2017, the disclosure of which is herein incorporated by reference in its entirety. A diagnostic input or feedback entered by a non-sterile operator at the visualization tower  111  can be routed by the hub  106  to the surgical instrument display  115  within the sterile field, where it can be viewed by the operator of the surgical instrument  112 . Example surgical instruments that are suitable for use with the surgical system  102  are described under the heading “Surgical Instrument Hardware” and in U.S. Provisional Patent Application Ser. No. 62/611,341, titled INTERACTIVE SURGICAL PLATFORM, filed Dec. 28, 2017, the disclosure of which is herein incorporated by reference in its entirety, for example. 
     Referring now to  FIG. 3 , a hub  106  is depicted in communication with a visualization system  108 , a robotic system  110 , and a handheld intelligent surgical instrument  112 . The hub  106  includes a hub display  135 , an imaging module  138 , a generator module  140 , a communication module  130 , a processor module  132 , and a storage array  134 . In certain aspects, as illustrated in  FIG. 3 , the hub  106  further includes a smoke evacuation module  126  and/or a suction/irrigation module  128 . 
     During a surgical procedure, energy application to tissue, for sealing and/or cutting, is generally associated with smoke evacuation, suction of excess fluid, and/or irrigation of the tissue. Fluid, power, and/or data lines from different sources are often entangled during the surgical procedure. Valuable time can be lost addressing this issue during a surgical procedure. Detangling the lines may necessitate disconnecting the lines from their respective modules, which may require resetting the modules. The hub modular enclosure  136  offers a unified environment for managing the power, data, and fluid lines, which reduces the frequency of entanglement between such lines. 
     Aspects of the present disclosure present a surgical hub for use in a surgical procedure that involves energy application to tissue at a surgical site. The surgical hub includes a hub enclosure and a combo generator module slidably receivable in a docking station of the hub enclosure. The docking station includes data and power contacts. The combo generator module includes two or more of an ultrasonic energy generator component, a bipolar RF energy generator component, and a monopolar RF energy generator component that are housed in a single unit. In one aspect, the combo generator module also includes a smoke evacuation component, at least one energy delivery cable for connecting the combo generator module to a surgical instrument, at least one smoke evacuation component configured to evacuate smoke, fluid, and/or particulates generated by the application of therapeutic energy to the tissue, and a fluid line extending from the remote surgical site to the smoke evacuation component. 
     In one aspect, the fluid line is a first fluid line and a second fluid line extends from the remote surgical site to a suction and irrigation module slidably received in the hub enclosure. In one aspect, the hub enclosure comprises a fluid interface. 
     Certain surgical procedures may require the application of more than one energy type to the tissue. One energy type may be more beneficial for cutting the tissue, while another different energy type may be more beneficial for sealing the tissue. For example, a bipolar generator can be used to seal the tissue while an ultrasonic generator can be used to cut the sealed tissue. Aspects of the present disclosure present a solution where a hub modular enclosure  136  is configured to accommodate different generators, and facilitate an interactive communication therebetween. One of the advantages of the hub modular enclosure  136  is enabling the quick removal and/or replacement of various modules. 
     Aspects of the present disclosure present a modular surgical enclosure for use in a surgical procedure that involves energy application to tissue. The modular surgical enclosure includes a first energy-generator module, configured to generate a first energy for application to the tissue, and a first docking station comprising a first docking port that includes first data and power contacts, wherein the first energy-generator module is slidably movable into an electrical engagement with the power and data contacts and wherein the first energy-generator module is slidably movable out of the electrical engagement with the first power and data contacts, 
     Further to the above, the modular surgical enclosure also includes a second energy-generator module configured to generate a second energy, different than the first energy, for application to the tissue, and a second docking station comprising a second docking port that includes second data and power contacts, wherein the second energy-generator module is slidably movable into an electrical engagement with the power and data contacts, and wherein the second energy-generator module is slidably movable out of the electrical engagement with the second power and data contacts. 
     In addition, the modular surgical enclosure also includes a communication bus between the first docking port and the second docking port, configured to facilitate communication between the first energy-generator module and the second energy-generator module. 
     Referring to  FIG. 3 , aspects of the present disclosure are presented for a hub modular enclosure  136  that allows the modular integration of a generator module  140 , a smoke evacuation module  126 , and a suction/irrigation module  128 . The hub modular enclosure  136  further facilitates interactive communication between the modules  140 ,  126 ,  128 . The generator module  140  can be a generator module with integrated monopolar, bipolar, and ultrasonic components supported in a single housing unit slidably insertable into the hub modular enclosure  136 . In various aspects, the hub modular enclosure  136  can be configured to facilitate the insertion of multiple generators and interactive communication between the generators docked into the hub modular enclosure  136  so that the generators would act as a single generator. 
     In one aspect, the hub modular enclosure  136  comprises a modular power and communication backplane with external and wireless communication headers to enable the removable attachment of the modules  140 ,  126 ,  128  and interactive communication therebetween. 
     In various aspects, the imaging module  138  comprises an integrated video processor and a modular light source and is adapted for use with various imaging devices. In one aspect, the imaging device is comprised of a modular housing that can be assembled with a light source module and a camera module. The housing can be a disposable housing. In at least one example, the disposable housing is removably coupled to a reusable controller, a light source module, and a camera module. The light source module and/or the camera module can be selectively chosen depending on the type of surgical procedure. In one aspect, the camera module comprises a CCD sensor. In another aspect, the camera module comprises a CMOS sensor. In another aspect, the camera module is configured for scanned beam imaging. Likewise, the light source module can be configured to deliver a white light or a different light, depending on the surgical procedure. 
     During a surgical procedure, removing a surgical device from the surgical field and replacing it with another surgical device that includes a different camera or a different light source can be inefficient. Temporarily losing sight of the surgical field may lead to undesirable consequences. The module imaging device of the present disclosure is configured to permit the replacement of a light source module or a camera module midstream during a surgical procedure, without having to remove the imaging device from the surgical field. 
     In one aspect, the imaging device comprises a tubular housing that includes a plurality of channels. A first channel is configured to slidably receive the camera module, which can be configured for a snap-fit engagement with the first channel. A second channel is configured to slidably receive the light source module, which can be configured for a snap-fit engagement with the second channel. In another example, the camera module and/or the light source module can be rotated into a final position within their respective channels. A threaded engagement can be employed in lieu of the snap-fit engagement. 
     In various examples, multiple imaging devices are placed at different positions in the surgical field to provide multiple views. The imaging module  138  can be configured to switch between the imaging devices to provide an optimal view. In various aspects, the imaging module  138  can be configured to integrate the images from the different imaging device. 
     Various image processors and imaging devices suitable for use with the present disclosure are described in U.S. Pat. No. 7,995,045, titled COMBINED SBI AND CONVENTIONAL IMAGE PROCESSOR, which issued on Aug. 9, 2011, which is herein incorporated by reference in its entirety. In addition, U.S. Pat. No. 7,982,776, titled SBI MOTION ARTIFACT REMOVAL APPARATUS AND METHOD, which issued on Jul. 19, 2011, which is herein incorporated by reference in its entirety, describes various systems for removing motion artifacts from image data. Such systems can be integrated with the imaging module  138 . Furthermore, U.S. Patent Application Publication No. 2011/0306840, titled CONTROLLABLE MAGNETIC SOURCE TO FIXTURE INTRACORPOREAL APPARATUS, which published on Dec. 15, 2011, and U.S. Patent Application Publication No. 2014/0243597, titled SYSTEM FOR PERFORMING A MINIMALLY INVASIVE SURGICAL PROCEDURE, which published on Aug. 28, 2014, each of which is herein incorporated by reference in its entirety. 
     Robotic Surgical System 
     An example robotic surgical system is depicted in  FIGS. 4 and 5 . With reference to  FIG. 4 , the robotic surgical system  13000  includes robotic arms  13002 ,  13003 , a control device  13004 , and a console  13005  coupled to the control device  13004 . As illustrated in  FIG. 4 , the surgical system  13000  is configured for use on a patient  13013  lying on a patient table  13012  for performance of a minimally invasive surgical operation. The console  13005  includes a display device  13006  and input devices  13007 ,  13008 . The display device  13006  is set up to display three-dimensional images, and the manual input devices  13007 ,  13008  are configured to allow a clinician to telemanipulate the robotic arms  13002 ,  13003 . Controls for a surgeon&#39;s console, such as the console  13005 , are further described in International Patent Publication No. WO2017/075121, filed Oct. 27, 2016, titled HAPTIC FEEDBACK FOR A ROBOTIC SURGICAL SYSTEM INTERFACE, which is herein incorporated by reference in its entirety. 
     Each of the robotic arms  13002 ,  13003  is made up of a plurality of members connected through joints and includes a surgical assembly  13010  connected to a distal end of a corresponding robotic arm  13002 ,  13003 . Support of multiple arms is further described in U.S. Patent Application Publication No. 2017/0071693, filed Nov. 11, 2016, titled SURGICAL ROBOTIC ARM SUPPORT SYSTEMS AND METHODS OF USE, which is herein incorporated by reference in its entirety. Various robotic arm configurations are further described in International Patent Publication No. WO2017/044406, filed Sep. 6, 2016, titled ROBOTIC SURGICAL CONTROL SCHEME FOR MANIPULATING ROBOTIC END EFFECTORS, which is herein incorporated by reference in its entirety. In an exemplification, the surgical assembly  13010  includes a surgical instrument  13020  supporting an end effector  13023 . Although two robotic arms  13002 ,  13003 , are depicted, the surgical system  13000  may include a single robotic arm or more than two robotic arms  13002 ,  13003 . Additional robotic arms are likewise connected to the control device  13004  and are telemanipulatable via the console  13005 . Accordingly, one or more additional surgical assemblies  13010  and/or surgical instruments  13020  may also be attached to the additional robotic arm(s). 
     The robotic arms  13002 ,  13003  may be driven by electric drives that are connected to the control device  13004 . According to an exemplification, the control device  13004  is configured to activate drives, for example, via a computer program, such that the robotic arms  13002 ,  13003  and the surgical assemblies  13010  and/or surgical instruments  13020  corresponding to the robotic arms  13002 ,  13003 , execute a desired movement received through the manual input devices  13007 ,  13008 . The control device  13004  may also be configured to regulate movement of the robotic arms  13002 ,  13003  and/or of the drives. 
     The control device  13004  may control a plurality of motors (for example, Motor I . . . n) with each motor configured to drive a pushing or a pulling of one or more cables, such as cables coupled to the end effector  13023  of the surgical instrument  13020 . In use, as these cables are pushed and/or pulled, the one or more cables affect operation and/or movement of the end effector  13023 . The control device  13004  coordinates the activation of the various motors to coordinate a pushing or a pulling motion of one or more cables in order to coordinate an operation and/or movement of one or more end effectors  13023 . For example, articulation of an end effector by a robotic assembly such as the surgical assembly  13010  is further described in U.S. Patent Application Publication No. 2016/0303743, filed Jun. 6, 2016, titled WRIST AND JAW ASSEMBLIES FOR ROBOTIC SURGICAL SYSTEMS and in International Patent Publication No. WO2016/144937, filed Mar. 8, 2016, titled MEASURING HEALTH OF A CONNECTOR MEMBER OF A ROBOTIC SURGICAL SYSTEM, each of which is herein incorporated by reference in its entirety. In an exemplification, each motor is configured to actuate a drive rod or a lever arm to affect operation and/or movement of end effectors  13023  in addition to, or instead of, one or more cables. 
     Driver configurations for surgical instruments, such as drive arrangements for a surgical end effector, are further described in International Patent Publication No. WO2016/183054, filed May 10, 2016, titled COUPLING INSTRUMENT DRIVE UNIT AND ROBOTIC SURGICAL INSTRUMENT, International Patent Publication No. WO2016/205266, filed Jun. 15, 2016, titled ROBOTIC SURGICAL SYSTEM TORQUE TRANSDUCTION SENSING, International Patent Publication No. WO2016/205452, filed Jun. 16, 2016, titled CONTROLLING ROBOTIC SURGICAL INSTRUMENTS WITH BIDIRECTIONAL COUPLING, and International Patent Publication No. WO2017/053507, filed Sep. 22, 2016, titled ELASTIC SURGICAL INTERFACE FOR ROBOTIC SURGICAL SYSTEMS, each of which is herein incorporated by reference in its entirety. The modular attachment of surgical instruments to a driver is further described in International Patent Publication No. WO2016/209769, filed Jun. 20, 2016, titled ROBOTIC SURGICAL ASSEMBLIES, which is herein incorporated by reference in its entirety. Housing configurations for a surgical instrument driver and interface are further described in International Patent Publication No. WO2016/144998, filed Mar. 9, 2016, titled ROBOTIC SURGICAL SYSTEMS, INSTRUMENT DRIVE UNITS, AND DRIVE ASSEMBLIES, which is herein incorporated by reference in its entirety. Various surgical instrument configurations for use with the robotic arms  13002 ,  13003  are further described in International Patent Publication No. WO2017/053358, filed Sep. 21, 2016, titled SURGICAL ROBOTIC ASSEMBLIES AND INSTRUMENT ADAPTERS THEREOF and International Patent Publication No. WO2017/053363, filed Sep. 21, 2016, titled ROBOTIC SURGICAL ASSEMBLIES AND INSTRUMENT DRIVE CONNECTORS THEREOF, each of which is herein incorporated by reference in its entirety. Bipolar instrument configurations for use with the robotic arms  13002 ,  13003  are further described in International Patent Publication No. WO2017/053698, filed Sep. 23, 2016, titled ROBOTIC SURGICAL ASSEMBLIES AND ELECTROMECHANICAL INSTRUMENTS THEREOF, which is herein incorporated by reference in its entirety. Shaft arrangements for use with the robotic arms  13002 ,  13003  are further described in International Patent Publication No. WO2017/116793, filed Dec. 19, 2016, titled ROBOTIC SURGICAL SYSTEMS AND INSTRUMENT DRIVE ASSEMBLIES, which is herein incorporated by reference in its entirety. 
     The control device  13004  includes any suitable logic control circuit adapted to perform calculations and/or operate according to a set of instructions. The control device  13004  can be configured to communicate with a remote system “RS,” either via a wireless (e.g., Wi-Fi, Bluetooth, LTE, etc.) and/or wired connection. The remote system “RS” can include data, instructions and/or information related to the various components, algorithms, and/or operations of system  13000 . The remote system “RS” can include any suitable electronic service, database, platform, cloud “C” (see  FIG. 4 ), or the like. The control device  13004  may include a central processing unit operably connected to memory. The memory may include transitory type memory (e.g., RAM) and/or non-transitory type memory (e.g., flash media, disk media, etc.). In some exemplifications, the memory is part of, and/or operably coupled to, the remote system “RS.” 
     The control device  13004  can include a plurality of inputs and outputs for interfacing with the components of the system  13000 , such as through a driver circuit. The control device  13004  can be configured to receive input signals and/or generate output signals to control one or more of the various components (e.g., one or more motors) of the system  13000 . The output signals can include, and/or can be based upon, algorithmic instructions which may be pre-programmed and/or input by a user. The control device  13004  can be configured to accept a plurality of user inputs from a user interface (e.g., switches, buttons, touch screen, etc. of operating the console  13005 ) which may be coupled to remote system “RS.” 
     A memory  13014  can be directly and/or indirectly coupled to the control device  13004  to store instructions and/or databases including pre-operative data from living being(s) and/or anatomical atlas(es). The memory  13014  can be part of, and/or or operatively coupled to, remote system “RS.” 
     In accordance with an exemplification, the distal end of each robotic arm  13002 ,  13003  is configured to releasably secure the end effector  13023  (or other surgical tool) therein and may be configured to receive any number of surgical tools or instruments, such as a trocar or retractor, for example. 
     A simplified functional block diagram of a system architecture  13400  of the robotic surgical system  13010  is depicted in  FIG. 5 . The system architecture  13400  includes a core module  13420 , a surgeon master module  13430 , a robotic arm module  13440 , and an instrument module  13450 . The core module  13420  serves as a central controller for the robotic surgical system  13000  and coordinates operations of all of the other modules  13430 ,  13440 ,  13450 . For example, the core module  13420  maps control devices to the arms  13002 ,  13003 , determines current status, performs all kinematics and frame transformations, and relays resulting movement commands. In this regard, the core module  13420  receives and analyzes data from each of the other modules  13430 ,  13440 ,  13450  in order to provide instructions or commands to the other modules  13430 ,  13440 ,  13450  for execution within the robotic surgical system  13000 . Although depicted as separate modules, one or more of the modules  13420 ,  13430 ,  13440 , and  13450  are a single component in other exemplifications. 
     The core module  13420  includes models  13422 , observers  13424 , a collision manager  13426 , controllers  13428 , and a skeleton  13429 . The models  13422  include units that provide abstracted representations (base classes) for controlled components, such as the motors (for example, Motor I . . . n) and/or the arms  13002 ,  13003 . The observers  13424  create state estimates based on input and output signals received from the other modules  13430 ,  13440 ,  13450 . The collision manager  13426  prevents collisions between components that have been registered within the system  13010 . The skeleton  13429  tracks the system  13010  from a kinematic and dynamics point of view. For example, the kinematics item may be implemented either as forward or inverse kinematics, in an exemplification. The dynamics item may be implemented as algorithms used to model dynamics of the system&#39;s components. 
     The surgeon master module  13430  communicates with surgeon control devices at the console  13005  and relays inputs received from the console  13005  to the core module  13420 . In accordance with an exemplification, the surgeon master module  13430  communicates button status and control device positions to the core module  13420  and includes a node controller  13432  that includes a state/mode manager  13434 , a fail-over controller  13436 , and a N-degree of freedom (“DOF”) actuator  13438 . 
     The robotic arm module  13440  coordinates operation of a robotic arm subsystem, an arm cart subsystem, a set up arm, and an instrument subsystem in order to control movement of a corresponding arm  13002 ,  13003 . Although a single robotic arm module  13440  is included, it will be appreciated that the robotic arm module  13440  corresponds to and controls a single arm. As such, additional robotic arm modules  13440  are included in configurations in which the system  13010  includes multiple arms  13002 ,  13003 . The robotic arm module  13440  includes a node controller  13442 , a state/mode manager  13444 , a fail-over controller  13446 , and a N-degree of freedom (“DOF”) actuator  13348 . 
     The instrument module  13450  controls movement of an instrument and/or tool component attached to the arm  13002 ,  13003 . The instrument module  13450  is configured to correspond to and control a single instrument. Thus, in configurations in which multiple instruments are included, additional instrument modules  13450  are likewise included. In an exemplification, the instrument module  13450  obtains and communicates data related to the position of the end effector or jaw assembly (which may include the pitch and yaw angle of the jaws), the width of or the angle between the jaws, and the position of an access port. The instrument module  13450  has a node controller  13452 , a state/mode manager  13454 , a fail-over controller  13456 , and a N-degree of freedom (“DOF”) actuator  13458 . 
     The position data collected by the instrument module  13450  is used by the core module  13420  to determine when the instrument is within the surgical site, within a cannula, adjacent to an access port, or above an access port in free space. The core module  13420  can determine whether to provide instructions to open or close the jaws of the instrument based on the positioning thereof. For example, when the position of the instrument indicates that the instrument is within a cannula, instructions are provided to maintain a jaw assembly in a closed position. When the position of the instrument indicates that the instrument is outside of an access port, instructions are provided to open the jaw assembly. 
     Additional features and operations of a robotic surgical system, such as the surgical robot system depicted in  FIGS. 4 and 5 , are further described in the following references, each of which is herein incorporated by reference in its entirety:
         U.S. Patent Application Publication No. 2016/0303743, filed Jun. 6, 2016, titled WRIST AND JAW ASSEMBLIES FOR ROBOTIC SURGICAL SYSTEMS;   U.S. Patent Application Publication No. 2017/0071693, filed Nov. 11, 2016, titled SURGICAL ROBOTIC ARM SUPPORT SYSTEMS AND METHODS OF USE;   International Patent Publication No. WO2016/144937, filed Mar. 8, 2016, titled MEASURING HEALTH OF A CONNECTOR MEMBER OF A ROBOTIC SURGICAL SYSTEM;   International Patent Publication No. WO2016/144998, filed Mar. 9, 2016, titled ROBOTIC SURGICAL SYSTEMS, INSTRUMENT DRIVE UNITS, AND DRIVE ASSEMBLIES;   International Patent Publication No. WO2016/183054, filed May 10, 2016, titled COUPLING INSTRUMENT DRIVE UNIT AND ROBOTIC SURGICAL INSTRUMENT;   International Patent Publication No. WO2016/205266, filed Jun. 15, 2016, titled ROBOTIC SURGICAL SYSTEM TORQUE TRANSDUCTION SENSING;   International Patent Publication No. WO2016/205452, filed Jun. 16, 2016, titled CONTROLLING ROBOTIC SURGICAL INSTRUMENTS WITH BIDIRECTIONAL COUPLING;   International Patent Publication No. WO2016/209769, filed Jun. 20, 2016, titled ROBOTIC SURGICAL ASSEMBLIES;   International Patent Publication No. WO2017/044406, filed Sep. 6, 2016, titled ROBOTIC SURGICAL CONTROL SCHEME FOR MANIPULATING ROBOTIC END EFFECTORS;   International Patent Publication No. WO2017/053358, filed Sep. 21, 2016, titled SURGICAL ROBOTIC ASSEMBLIES AND INSTRUMENT ADAPTERS THEREOF;   International Patent Publication No. WO2017/053363, filed Sep. 21, 2016, titled ROBOTIC SURGICAL ASSEMBLIES AND INSTRUMENT DRIVE CONNECTORS THEREOF;   International Patent Publication No. WO2017/053507, filed Sep. 22, 2016, titled ELASTIC SURGICAL INTERFACE FOR ROBOTIC SURGICAL SYSTEMS;   International Patent Publication No. WO2017/053698, filed Sep. 23, 2016, titled ROBOTIC SURGICAL ASSEMBLIES AND ELECTROMECHANICAL INSTRUMENTS THEREOF;   International Patent Publication No. WO2017/075121, filed Oct. 27, 2016, titled HAPTIC FEEDBACK CONTROLS FOR A ROBOTIC SURGICAL SYSTEM INTERFACE;   International Patent Publication No. WO2017/116793, filed Dec. 19, 2016, titled ROBOTIC SURGICAL SYSTEMS AND INSTRUMENT DRIVE ASSEMBLIES.       

     The robotic surgical systems and features disclosed herein can be employed with the robotic surgical system of  FIGS. 4 and 5 . The reader will further appreciate that various systems and/or features disclosed herein can also be employed with alternative surgical systems including the computer-implemented interactive surgical system  100 , the computer-implemented interactive surgical system  200 , the robotic surgical system  110 , the robotic hub  122 , and/or the robotic hub  222 , for example. 
     In various instances, a robotic surgical system can include a robotic control tower, which can house the control unit of the system. For example, the control unit  13004  of the robotic surgical system  13000  ( FIG. 4 ) can be housed within a robotic control tower. The robotic control tower can include a robotic hub such as the robotic hub  122  ( FIG. 2 ) or the robotic hub  222  ( FIG. 9 ), for example. Such a robotic hub can include a modular interface for coupling with one or more generators, such as an ultrasonic generator and/or a radio frequency generator, and/or one or more modules, such as an imaging module, suction module, an irrigation module, a smoke evacuation module, and/or a communication module. 
     A robotic hub can include a situational awareness module, which can be configured to synthesize data from multiple sources to determine an appropriate response to a surgical event. For example, a situational awareness module can determine the type of surgical procedure, step in the surgical procedure, type of tissue, and/or tissue characteristics, as further described herein. Moreover, such a module can recommend a particular course of action or possible choices to the robotic system based on the synthesized data. In various instances, a sensor system encompassing a plurality of sensors distributed throughout the robotic system can provide data, images, and/or other information to the situational awareness module. Such a situational awareness module can be incorporated into a control unit, such as the control unit  13004 , for example. In various instances, the situational awareness module can obtain data and/or information from a non-robotic surgical hub and/or a cloud, such as the surgical hub  106  ( FIG. 1 ), the surgical hub  206  ( FIG. 10 ), the cloud  104  ( FIG. 1 ), and/or the cloud  204  ( FIG. 9 ), for example. Situational awareness of a surgical system is further disclosed herein and in U.S. Provisional Patent Application Ser. No. 62/611,341, titled INTERACTIVE SURGICAL PLATFORM, filed Dec. 28, 2017, and U.S. Provisional Patent Application Ser. No. 62/611,340, titled CLOUD-BASED MEDICAL ANALYTICS, filed Dec. 28, 2017, the disclosure of each of which is herein incorporated by reference in its entirety. 
     In certain instances, the activation of a surgical tool at certain times during a surgical procedure and/or for certain durations may cause tissue trauma and/or may prolong a surgical procedure. For example, a robotic surgical system can utilize an electrosurgical tool having an energy delivery surface that should only be energized when a threshold condition is met. In one example, the energy delivery surface should only be activated when the energy delivery surface is in contact with the appropriate, or targeted, tissue. As another example, a robotic surgical system can utilize a suction element that should only be activated when a threshold condition is met, such as when an appropriate volume of fluid is present. Due to visibility restrictions, evolving situations, and the multitude of moving parts during a robotic surgical procedure, it can be difficult for a clinician to determine and/or monitor certain conditions at the surgical site. For example, it can be difficult to determine if an energy delivery surface of an electrosurgical tool is in contact with tissue. It can also be difficult to determine if a particular suctioning pressure is sufficient for the volume of fluid in the proximity of the suctioning port. 
     Moreover, a plurality of surgical devices can be used in certain robotic surgical procedures. For example, a robotic surgical system can use one or more surgical tools during the surgical procedure. Additionally, one or more handheld instruments can also be used during the surgical procedure. One or more of the surgical devices can include a sensor. For example, multiple sensors can be positioned around the surgical site and/or the operating room. A sensor system including the one or more sensors can be configured to detect one or more conditions at the surgical site. For example, data from the sensor system can determine if a surgical tool mounted to the surgical robot is being used and/or if a feature of the surgical tool should be activated. More specifically, a sensor system can detect if an electrosurgical device is positioned in abutting contact with tissue, for example. As another example, a sensor system can detect if a suctioning element of a surgical tool is applying a sufficient suctioning force to fluid at the surgical site. 
     When in an automatic activation mode, the robotic surgical system can automatically activate one or more features of one or more surgical tools based on data, images, and/or other information received from the sensor system. For example, an energy delivery surface of an electrosurgical tool can be activated upon detecting that the electrosurgical tool is in use (e.g. positioned in abutting contact with tissue). As another example, a suctioning element on a surgical tool can be activated when the suction port is moved into contact with a fluid. In certain instances, the surgical tool can be adjusted based on the sensed conditions. 
     A robotic surgical system incorporating an automatic activation mode can automatically provide a scenario-specific result based on detected condition(s) at the surgical site. The scenario-specific result can be outcome-based, for example, and can streamline the decision-making process of the clinician. In certain instances, such an automatic activation mode can improve the efficiency and/or effectiveness of the clinician. For example, the robotic surgical system can aggregate data to compile a more complete view of the surgical site and/or the surgical procedure in order to determine the best possible course of action. Additionally or alternatively, in instances in which the clinician makes fewer decisions, the clinician can be better focused on other tasks and/or can process other information more effectively. 
     Referring primarily to  FIGS. 6 and 7 , hubs  13380 ,  13382  include wireless communication modules such that a wireless communication link is established between the two hubs  13380 ,  13382 . Additionally, the robotic hub  13380  is in signal communication with the interactive secondary displays  13362 ,  13364  within the sterile field. The hub  13382  is in signal communication with the handheld surgical instrument  13366 . If the surgeon  13371  moves over towards the patient  13361  and within the sterile field (as indicated by the reference character  13371 ′), the surgeon  13371  can use one of the wireless interactive displays  13362 ,  13364  to operate the robot  13372  away from the remote command console  13370 . The plurality of secondary displays  13362 ,  13364  within the sterile field allows the surgeon  13371  to move away from the remote command console  13370  without losing sight of important information for the surgical procedure and controls for the robotic tools utilized therein. 
     The interactive secondary displays  13362 ,  13364  permit the clinician to step away from the remote command console  13370  and into the sterile field while maintaining control of the robot  13372 . For example, the interactive secondary displays  13362 ,  13364  allow the clinician to maintain cooperative and/or coordinated control over the powered handheld surgical instrument(s)  13366  and the robotic surgical system at the same time. In various instances, information is communicated between the robotic surgical system, one or more powered handheld surgical instruments  13366 , surgical hubs  13380 ,  13382 , and the interactive secondary displays  13362 ,  13364 . Such information may include, for example, the images on the display of the robotic surgical system and/or the powered handheld surgical instruments, a parameter of the robotic surgical system and/or the powered handheld surgical instruments, and/or a control command for the robotic surgical system and/or the powered handheld surgical instruments. 
     In various instances, the control unit of the robotic surgical system (e.g. the control unit  13113  of the robotic surgical system  13110 ) is configured to communicate at least one display element from the surgeon&#39;s command console (e.g. the console  13116 ) to an interactive secondary display (e.g. the displays  13362 ,  13364 ). In other words, a portion of the display at the surgeon&#39;s console is replicated on the display of the interactive secondary display, integrating the robot display with the interactive secondary display. The replication of the robot display on to the display of the interactive secondary display allows the clinician to step away from the remote command console without losing the visual image that is displayed there. For example, at least one of the interactive secondary displays  13362 ,  13364  can display information from the robot, such as information from the robot display and/or the surgeon&#39;s command console  13370 . 
     In various instances, the interactive secondary displays  13362 ,  13364  are configured to control and/or adjust at least one operating parameter of the robotic surgical system. Such control can occur automatically and/or in response to a clinician input. Interacting with a touch-sensitive screen and/or buttons on the interactive secondary display(s)  13362 ,  13364 , the clinician is able to input a command to control movement and/or functionality of the one or more robotic tools. For example, when utilizing a handheld surgical instrument  13366 , the clinician may want to move the robotic tool  13374  to a different position. To control the robotic tool  13374 , the clinician applies an input to the interactive secondary display(s)  13362 ,  13364 , and the respective interactive secondary display(s)  13362 ,  13364  communicates the clinician input to the control unit of the robotic surgical system in the robotic hub  13380 . 
     In various instances, a clinician positioned at the remote command console  13370  of the robotic surgical system can manually override any robot command initiated by a clinician input on the one or more interactive secondary displays  13362 ,  13364 . For example, when a clinician input is received from the one or more interactive secondary displays  13362 ,  13364 , a clinician positioned at the remote command console  13370  can either allow the command to be issued and the desired function performed or the clinician can override the command by interacting with the remote command console  13370  and prohibiting the command from being issued. 
     In certain instances, a clinician within the sterile field can be required to request permission to control the robot  13372  and/or the robotic tool  13374  mounted thereto. The surgeon  13371  at the remote command console  13370  can grant or deny the clinician&#39;s request. For example, the surgeon can receive a pop-up or other notification indicating the permission is being requested by another clinician operating a handheld surgical instrument and/or interacting with an interactive secondary display  13362 ,  13364 . 
     In various instances, the processor of a robotic surgical system, such as the robotic surgical systems  13000  ( FIG. 4 ),  13400  ( FIG. 5 ),  13360  ( FIG. 6 ), and/or the surgical hub  13380 ,  13382 , for example, is programmed with pre-approved functions of the robotic surgical system. For example, if a clinician input from the interactive secondary display  13362 ,  13364  corresponds to a pre-approved function, the robotic surgical system allows for the interactive secondary display  13362 ,  13364  to control the robotic surgical system and/or does not prohibit the interactive secondary display  13362 ,  13364  from controlling the robotic surgical system. If a clinician input from the interactive secondary display  13362 ,  13364  does not correspond to a pre-approved function, the interactive secondary display  13362 ,  13364  is unable to command the robotic surgical system to perform the desired function. In one instances, a situational awareness module in the robotic hub  13370  and/or the surgical hub  13382  is configured to dictate and/or influence when the interactive secondary display can issue control motions to the robot surgical system. 
     In various instances, an interactive secondary display  13362 ,  13364  has control over a portion of the robotic surgical system upon making contact with the portion of the robotic surgical system. For example, when the interactive secondary display  13362 ,  13364  is brought into contact with the robotic tool  13374 , control of the contacted robotic tool  13374  is granted to the interactive secondary display  13362 ,  13364 . A clinician can then utilize a touch-sensitive screen and/or buttons on the interactive secondary display  13362 ,  13364  to input a command to control movement and/or functionality of the contacted robotic tool  13374 . This control scheme allows for a clinician to reposition a robotic arm, reload a robotic tool, and/or otherwise reconfigure the robotic surgical system. In a similar manner as discussed above, the clinician  13371  positioned at the remote command console  13370  of the robotic surgical system can manually override any robot command initiated by the interactive secondary display  13362 ,  13364 . 
     In one aspect, the robotic surgical system includes a processor and a memory communicatively coupled to the processor, as described herein. The memory stores instructions executable by the processor to receive a first user input from a console and to receive a second user input from a mobile wireless control module for controlling a function of a robotic surgical tool, as described herein. 
     In various aspects, the present disclosure provides a control circuit to receive a first user input from a console and to receive a second user input from a mobile wireless control module for controlling a function of a robotic surgical tool, as described herein. In various aspects, the present disclosure provides a non-transitory computer readable medium storing computer readable instructions which, when executed, cause a machine to receive a first user input from a console and to receive a second user input from a mobile wireless control module for controlling a function of a robotic surgical tool, as described herein. 
     A robotic surgical system may include multiple robotic arms that are configured to assist the clinician during a surgical procedure. Each robotic arm may be operable independently of the others. A lack of communication may exist between each of the robotic arms as they are independently operated, which may increase the risk of tissue trauma. For example, in a scenario where one robotic arm is configured to apply a force that is stronger and in a different direction than a force configured to be applied by a second robotic arm, tissue trauma can result. For example, tissue trauma and/or tearing may occur when a first robotic arm applies a strong retracting force to the tissue while a second robotic arm is configured to rigidly hold the tissue in place. 
     In various instances, one or more sensors are attached to each robotic arm of a robotic surgical system. The one or more sensors are configured to sense a force applied to the surrounding tissue during the operation of the robotic arm. Such forces can include, for example, a holding force, a retracting force, and/or a dragging force. The sensor from each robotic arm is configured to communicate the magnitude and direction of the detected force to a control unit of the robotic surgical system. The control unit is configured to analyze the communicated forces and set limits for maximum loads to avoid causing trauma to the tissue in a surgical site. For example, the control unit may minimize the holding force applied by a first robotic arm if the retracting or dragging force applied by a second robotic arm increases. 
       FIG. 4 a    illustrates an exemplification of a robotic arm  13120  and a tool assembly  13130  releasably coupled to the robotic arm  13120 . The robotic arm  13120  can support and move the associated tool assembly  13130  along one or more mechanical degrees of freedom (e.g., all six Cartesian degrees of freedom, five or fewer Cartesian degrees of freedom, etc.). 
     The robotic arm  13120  can include a tool driver  13140  at a distal end of the robotic arm  13120 , which can assist with controlling features associated with the tool assembly  13130 . The robotic arm  13120  can also include a movable tool guide  13132  that can retract and extend relative to the tool driver  13140 . A shaft of the tool assembly  13130  can extend parallel to a threaded shaft of the movable tool guide  13132  and can extend through a distal end feature  13133  (e.g., a ring) of the movable tool guide  13132  and into a patient. 
     In order to provide a sterile operation area while using the surgical system, a barrier can be placed between the actuating portion of the surgical system (e.g., the robotic arm  13120 ) and the surgical instruments (e.g., the tool assembly  13130 ) in the sterile surgical field. A sterile component, such as an instrument sterile adapter (ISA), can also be placed at the connecting interface between the tool assembly  13130  and the robotic arm  13120 . The placement of an ISA between the tool assembly  13130  and the robotic arm  13120  can ensure a sterile coupling point for the tool assembly  13130  and the robotic arm  13120 . This permits removal of tool assemblies  13130  from the robotic arm  13120  to exchange with other tool assemblies  13130  during the course of a surgery without compromising the sterile surgical field. 
     The tool assembly  13130  can be loaded from a top side of the tool driver  13140  with the shaft of the tool assembly  13130  being positioned in a shaft-receiving channel  13144  formed along the side of the tool driver  13140 . The shaft-receiving channel  13144  allows the shaft, which extends along a central axis of the tool assembly  13130 , to extend along a central axis of the tool driver  13140  when the tool assembly  13130  is coupled to the tool driver  13140 . In other exemplifications, the shaft can extend through on opening in the tool driver  13140 , or the two components can mate in various other configurations. 
     As discussed above, the robotic surgical system can include one or more robotic arms with each robotic arm having a tool assembly coupled thereto. Each tool assembly can include an end effector that has one or more of a variety of features, such as one or more tools for assisting with performing a surgical procedure. For example, the end effector can include a cutting or boring tool that can be used to perforate or cut through tissue (e.g., create an incision). 
     Furthermore, some end effectors include one or more sensors that can sense a variety of characteristics associated with either the end effector or the tissue. Each robotic arm and end effector can be controlled by a control system to assist with creating a desired cut or bore and prevent against undesired cutting of tissue. As an alternative to (or in addition to) controlling the robotic arm, it is understood that the control system can control either the tool itself or the tool assembly. 
     One or more aspects associated with the movement of the robotic arm can be controlled by the control system, such as either a direction or a velocity of movement. For example, when boring through tissue, the robotic arm can be controlled to perform jackhammer-like movements with the cutting tool. Such jackhammer movements can include the robotic arm moving up and down along an axis (e.g., an axis that is approximately perpendicular to the tissue being perforated) in a rapid motion while also advancing the cutting tool in a downward direction towards the tissue to eventually perforate the tissue with the cutting tool (e.g. an ultrasonic blade). While performing such movements in a robotic surgical procedure, not only can it be difficult to see the tissue being perforated to thereby determine a relative position of the cutting tool, but it can also be difficult to determine when the cutting tool has completed perforating the tissue. Such position of the cutting tool relative to the tissue can include the cutting tool approaching or not yet in contact with the tissue, the cutting tool drilling down or cutting into the tissue, and the cutting tool extending through or having perforated the tissue. These positions can be difficult for either a user controlling the robotic arm or the robotic surgical system to determine which can result in potential harm to the patient due to over or under-penetrating the tissue, as well as result in longer procedure times. As such, in order to reduce procedure time and surgical errors, the robotic surgical system includes a control system that communicates with at least one sensor assembly configured to sense a force applied at a distal end of the end effector or cutting tool. The control system can thereby determine and control, based on such sensed forces, one or more appropriate aspects associated with the movement of the robotic arm, such as when boring or cutting into tissue, as will be described in greater detail below. 
     Although a cutting tool for perforating tissue is described in detail herein, the sensor assembly of the present disclosure that is in communication with the control system can be implemented in any number of robotic surgical systems for detecting any number of a variety of tools and/or end effectors used for performing any number of a variety of procedures without departing from the scope of this disclosure. Furthermore, any number of movements can be performed by the robotic arm to perforate or cut tissue using the robotic surgical system including the sensor assembly and control system described herein and is not limited to the jackhammering or boring of tissue. 
       FIG. 4 a    and additional exemplifications are further described in U.S. patent application Ser. No. 15/237,753, entitled CONTROL OF ADVANCEMENT RATE AND APPLICATION FORCE BASED ON MEASURED FORCES, filed Aug. 16, 2016, the entire disclosure of which is incorporated by reference herein. 
     The entire disclosures of:
         U.S. Pat. No. 9,072,535, filed May 27, 2011, entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS, which issued Jul. 7, 2015;   U.S. Pat. No. 9,072,536, filed Jun. 28, 2012, entitled DIFFERENTIAL LOCKING ARRANGEMENTS FOR ROTARY POWERED SURGICAL INSTRUMENTS, which issued Jul. 7, 2015;   U.S. Pat. No. 9,204,879, filed Jun. 28, 2012, entitled FLEXIBLE DRIVE MEMBER, which issued on Dec. 8, 2015;   U.S. Pat. No. 9,561,038, filed Jun. 28, 2012, entitled INTERCHANGEABLE CLIP APPLIER, which issued on Feb. 7, 2017;   U.S. Pat. No. 9,757,128, filed Sep. 5, 2014, entitled MULTIPLE SENSORS WITH ONE SENSOR AFFECTING A SECOND SENSOR&#39;S OUTPUT OR INTERPRETATION, which issued on Sep. 12, 2017;   U.S. patent application Ser. No. 14/640,935, entitled OVERLAID MULTI SENSOR RADIO FREQUENCY (RF) ELECTRODE SYSTEM TO MEASURE TISSUE COMPRESSION, filed Mar. 6, 2015, now U.S. Patent Application Publication No. 2016/0256071;   U.S. patent application Ser. No. 15/382,238, entitled MODULAR BATTERY POWERED HANDHELD SURGICAL INSTRUMENT WITH SELECTIVE APPLICATION OF ENERGY BASED ON TISSUE CHARACTERIZATION, filed Dec. 16, 2016, now U.S. Patent Application Publication No. 2017/0202591; and   U.S. patent application Ser. No. 15/237,753, entitled CONTROL OF ADVANCEMENT RATE AND APPLICATION FORCE BASED ON MEASURED FORCES, filed Aug. 16, 2016 are hereby incorporated by reference herein in their respective entireties.       

     The surgical devices, systems, and methods disclosed herein can be implemented with a variety of different robotic surgical systems and surgical devices. Surgical devices include robotic surgical tools and handheld surgical instruments. The reader will readily appreciate that certain devices, systems, and methods disclosed herein are not limited to applications within a robotic surgical system. For example, certain systems, devices, and methods for communicating, detecting, and/or control a surgical device can be implemented without a robotic surgical system. 
     Surgical Network 
       FIG. 8  illustrates a surgical data network  201  comprising a modular communication hub  203  configured to connect modular devices located in one or more operating theaters of a healthcare facility, or any room in a healthcare facility specially equipped for surgical operations, to a cloud-based system (e.g., the cloud  204  that may include a remote server  213  coupled to a storage device  205 ). In one aspect, the modular communication hub  203  comprises a network hub  207  and/or a network switch  209  in communication with a network router. The modular communication hub  203  also can be coupled to a local computer system  210  to provide local computer processing and data manipulation. The surgical data network  201  may be configured as passive, intelligent, or switching. A passive surgical data network serves as a conduit for the data, enabling it to go from one device (or segment) to another and to the cloud computing resources. An intelligent surgical data network includes additional features to enable the traffic passing through the surgical data network to be monitored and to configure each port in the network hub  207  or network switch  209 . An intelligent surgical data network may be referred to as a manageable hub or switch. A switching hub reads the destination address of each packet and then forwards the packet to the correct port. 
     Modular devices  1   a - 1   n  located in the operating theater may be coupled to the modular communication hub  203 . The network hub  207  and/or the network switch  209  may be coupled to a network router  211  to connect the devices  1   a - 1   n  to the cloud  204  or the local computer system  210 . Data associated with the devices  1   a - 1   n  may be transferred to cloud-based computers via the router for remote data processing and manipulation. Data associated with the devices  1   a - 1   n  may also be transferred to the local computer system  210  for local data processing and manipulation. Modular devices  2   a - 2   m  located in the same operating theater also may be coupled to a network switch  209 . The network switch  209  may be coupled to the network hub  207  and/or the network router  211  to connect to the devices  2   a - 2   m  to the cloud  204 . Data associated with the devices  2   a - 2   n  may be transferred to the cloud  204  via the network router  211  for data processing and manipulation. Data associated with the devices  2   a - 2   m  may also be transferred to the local computer system  210  for local data processing and manipulation. 
     It will be appreciated that the surgical data network  201  may be expanded by interconnecting multiple network hubs  207  and/or multiple network switches  209  with multiple network routers  211 . The modular communication hub  203  may be contained in a modular control tower configured to receive multiple devices  1   a - 1   n / 2   a - 2   m . The local computer system  210  also may be contained in a modular control tower. The modular communication hub  203  is connected to a display  212  to display images obtained by some of the devices  1   a - 1   n / 2   a - 2   m , for example during surgical procedures. In various aspects, the devices  1   a - 1   n / 2   a - 2   m  may include, for example, various modules such as an imaging module  138  coupled to an endoscope, a generator module  140  coupled to an energy-based surgical device, a smoke evacuation module  126 , a suction/irrigation module  128 , a communication module  130 , a processor module  132 , a storage array  134 , a surgical device coupled to a display, and/or a non-contact sensor module, among other modular devices that may be connected to the modular communication hub  203  of the surgical data network  201 . 
     In one aspect, the surgical data network  201  may comprise a combination of network hub(s), network switch(es), and network router(s) connecting the devices  1   a - 1   n / 2   a - 2   m  to the cloud. Any one of or all of the devices  1   a - 1   n / 2   a - 2   m  coupled to the network hub or network switch may collect data in real time and transfer the data to cloud computers for data processing and manipulation. It will be appreciated that cloud computing relies on sharing computing resources rather than having local servers or personal devices to handle software applications. The word “cloud” may be used as a metaphor for “the Internet,” although the term is not limited as such. Accordingly, the term “cloud computing” may be used herein to refer to “a type of Internet-based computing,” where different services—such as servers, storage, and applications—are delivered to the modular communication hub  203  and/or computer system  210  located in the surgical theater (e.g., a fixed, mobile, temporary, or field operating room or space) and to devices connected to the modular communication hub  203  and/or computer system  210  through the Internet. The cloud infrastructure may be maintained by a cloud service provider. In this context, the cloud service provider may be the entity that coordinates the usage and control of the devices  1   a - 1   n / 2   a - 2   m  located in one or more operating theaters. The cloud computing services can perform a large number of calculations based on the data gathered by smart surgical instruments, robots, and other computerized devices located in the operating theater. The hub hardware enables multiple devices or connections to be connected to a computer that communicates with the cloud computing resources and storage. 
     Applying cloud computer data processing techniques on the data collected by the devices  1   a - 1   n / 2   a - 2   m , the surgical data network provides improved surgical outcomes, reduced costs, and improved patient satisfaction. At least some of the devices  1   a - 1   n / 2   a - 2   m  may be employed to view tissue states to assess leaks or perfusion of sealed tissue after a tissue sealing and cutting procedure. At least some of the devices  1   a - 1   n / 2   a - 2   m  may be employed to identify pathology, such as the effects of diseases, using the cloud-based computing to examine data including images of samples of body tissue for diagnostic purposes. This includes localization and margin confirmation of tissue and phenotypes. At least some of the devices  1   a - 1   n / 2   a - 2   m  may be employed to identify anatomical structures of the body using a variety of sensors integrated with imaging devices and techniques such as overlaying images captured by multiple imaging devices. The data gathered by the devices  1   a - 1   n / 2   a - 2   m , including image data, may be transferred to the cloud  204  or the local computer system  210  or both for data processing and manipulation including image processing and manipulation. The data may be analyzed to improve surgical procedure outcomes by determining if further treatment, such as the application of endoscopic intervention, emerging technologies, a targeted radiation, targeted intervention, and precise robotics to tissue-specific sites and conditions, may be pursued. Such data analysis may further employ outcome analytics processing, and using standardized approaches may provide beneficial feedback to either confirm surgical treatments and the behavior of the surgeon or suggest modifications to surgical treatments and the behavior of the surgeon. 
     In one implementation, the operating theater devices  1   a - 1   n  may be connected to the modular communication hub  203  over a wired channel or a wireless channel depending on the configuration of the devices  1   a - 1   n  to a network hub. The network hub  207  may be implemented, in one aspect, as a local network broadcast device that works on the physical layer of the Open System Interconnection (OSI) model. The network hub provides connectivity to the devices  1   a - 1   n  located in the same operating theater network. The network hub  207  collects data in the form of packets and sends them to the router in half duplex mode. The network hub  207  does not store any media access control/internet protocol (MAC/IP) to transfer the device data. Only one of the devices  1   a - 1   n  can send data at a time through the network hub  207 . The network hub  207  has no routing tables or intelligence regarding where to send information and broadcasts all network data across each connection and to a remote server  213  ( FIG. 9 ) over the cloud  204 . The network hub  207  can detect basic network errors such as collisions, but having all information broadcast to multiple ports can be a security risk and cause bottlenecks. 
     In another implementation, the operating theater devices  2   a - 2   m  may be connected to a network switch  209  over a wired channel or a wireless channel. The network switch  209  works in the data link layer of the OSI model. The network switch  209  is a multicast device for connecting the devices  2   a - 2   m  located in the same operating theater to the network. The network switch  209  sends data in the form of frames to the network router  211  and works in full duplex mode. Multiple devices  2   a - 2   m  can send data at the same time through the network switch  209 . The network switch  209  stores and uses MAC addresses of the devices  2   a - 2   m  to transfer data. 
     The network hub  207  and/or the network switch  209  are coupled to the network router  211  for connection to the cloud  204 . The network router  211  works in the network layer of the OSI model. The network router  211  creates a route for transmitting data packets received from the network hub  207  and/or network switch  211  to cloud-based computer resources for further processing and manipulation of the data collected by any one of or all the devices  1   a - 1   n / 2   a - 2   m . The network router  211  may be employed to connect two or more different networks located in different locations, such as, for example, different operating theaters of the same healthcare facility or different networks located in different operating theaters of different healthcare facilities. The network router  211  sends data in the form of packets to the cloud  204  and works in full duplex mode. Multiple devices can send data at the same time. The network router  211  uses IP addresses to transfer data. 
     In one example, the network hub  207  may be implemented as a USB hub, which allows multiple USB devices to be connected to a host computer. The USB hub may expand a single USB port into several tiers so that there are more ports available to connect devices to the host system computer. The network hub  207  may include wired or wireless capabilities to receive information over a wired channel or a wireless channel. In one aspect, a wireless USB short-range, high-bandwidth wireless radio communication protocol may be employed for communication between the devices  1   a - 1   n  and devices  2   a - 2   m  located in the operating theater. 
     In other examples, the operating theater devices  1   a - 1   n / 2   a - 2   m  may communicate to the modular communication hub  203  via Bluetooth wireless technology standard for exchanging data over short distances (using short-wavelength UHF radio waves in the ISM band from 2.4 to 2.485 GHz) from fixed and mobile devices and building personal area networks (PANs). In other aspects, the operating theater devices  1   a - 1   n / 2   a - 2   m  may communicate to the modular communication hub  203  via a number of wireless or wired communication standards or protocols, including but not limited to Wi-Fi (IEEE 802.11 family), WiMAX (IEEE 802.16 family), IEEE 802.20, long-term evolution (LTE), and Ev-DO, HSPA+, HSDPA+, HSUPA+, EDGE, GSM, GPRS, CDMA, TDMA, DECT, and Ethernet derivatives thereof, as well as any other wireless and wired protocols that are designated as 3G, 4G, 5G, and beyond. The computing module may include a plurality of communication modules. For instance, a first communication module may be dedicated to shorter-range wireless communications such as Wi-Fi and Bluetooth, and a second communication module may be dedicated to longer-range wireless communications such as GPS, EDGE, GPRS, CDMA, WiMAX, LTE, Ev-DO, and others. 
     The modular communication hub  203  may serve as a central connection for one or all of the operating theater devices  1   a - 1   n / 2   a - 2   m  and handles a data type known as frames. Frames carry the data generated by the devices  1   a - 1   n / 2   a - 2   m . When a frame is received by the modular communication hub  203 , it is amplified and transmitted to the network router  211 , which transfers the data to the cloud computing resources by using a number of wireless or wired communication standards or protocols, as described herein. 
     The modular communication hub  203  can be used as a standalone device or be connected to compatible network hubs and network switches to form a larger network. The modular communication hub  203  is generally easy to install, configure, and maintain, making it a good option for networking the operating theater devices  1   a - 1   n / 2   a - 2   m.    
       FIG. 9  illustrates a computer-implemented interactive surgical system  200 . The computer-implemented interactive surgical system  200  is similar in many respects to the computer-implemented interactive surgical system  100 . For example, the computer-implemented interactive surgical system  200  includes one or more surgical systems  202 , which are similar in many respects to the surgical systems  102 . Each surgical system  202  includes at least one surgical hub  206  in communication with a cloud  204  that may include a remote server  213 . In one aspect, the computer-implemented interactive surgical system  200  comprises a modular control tower  236  connected to multiple operating theater devices such as, for example, intelligent surgical instruments, robots, and other computerized devices located in the operating theater. As shown in  FIG. 10 , the modular control tower  236  comprises a modular communication hub  203  coupled to a computer system  210 . As illustrated in the example of  FIG. 9 , the modular control tower  236  is coupled to an imaging module  238  that is coupled to an endoscope  239 , a generator module  240  that is coupled to an energy device  241 , a smoke evacuator module  226 , a suction/irrigation module  228 , a communication module  230 , a processor module  232 , a storage array  234 , a smart device/instrument  235  optionally coupled to a display  237 , and a non-contact sensor module  242 . The operating theater devices are coupled to cloud computing resources and data storage via the modular control tower  236 . A robot hub  222  also may be connected to the modular control tower  236  and to the cloud computing resources. The devices/instruments  235 , visualization systems  208 , among others, may be coupled to the modular control tower  236  via wired or wireless communication standards or protocols, as described herein. The modular control tower  236  may be coupled to a hub display  215  (e.g., monitor, screen) to display and overlay images received from the imaging module, device/instrument display, and/or other visualization systems  208 . The hub display also may display data received from devices connected to the modular control tower in conjunction with images and overlaid images. 
       FIG. 10  illustrates a surgical hub  206  comprising a plurality of modules coupled to the modular control tower  236 . The modular control tower  236  comprises a modular communication hub  203 , e.g., a network connectivity device, and a computer system  210  to provide local processing, visualization, and imaging, for example. As shown in  FIG. 10 , the modular communication hub  203  may be connected in a tiered configuration to expand the number of modules (e.g., devices) that may be connected to the modular communication hub  203  and transfer data associated with the modules to the computer system  210 , cloud computing resources, or both. As shown in  FIG. 10 , each of the network hubs/switches in the modular communication hub  203  includes three downstream ports and one upstream port. The upstream network hub/switch is connected to a processor to provide a communication connection to the cloud computing resources and a local display  217 . Communication to the cloud  204  may be made either through a wired or a wireless communication channel. 
     The surgical hub  206  employs a non-contact sensor module  242  to measure the dimensions of the operating theater and generate a map of the surgical theater using either ultrasonic or laser-type non-contact measurement devices. An ultrasound-based non-contact sensor module scans the operating theater by transmitting a burst of ultrasound and receiving the echo when it bounces off the perimeter walls of an operating theater as described under the heading “Surgical Hub Spatial Awareness Within an Operating Room” in U.S. Provisional Patent Application Ser. No. 62/611,341, titled INTERACTIVE SURGICAL PLATFORM, filed Dec. 28, 2017, the disclosure of which is herein incorporated by reference in its entirety, in which the sensor module is configured to determine the size of the operating theater and to adjust Bluetooth-pairing distance limits. A laser-based non-contact sensor module scans the operating theater by transmitting laser light pulses, receiving laser light pulses that bounce off the perimeter walls of the operating theater, and comparing the phase of the transmitted pulse to the received pulse to determine the size of the operating theater and to adjust Bluetooth pairing distance limits, for example. 
     The computer system  210  comprises a processor  244  and a network interface  245 . The processor  244  is coupled to a communication module  247 , storage  248 , memory  249 , non-volatile memory  250 , and input/output interface  251  via a system bus. The system bus can be any of several types of bus structure(s) including the memory bus or memory controller, a peripheral bus or external bus, and/or a local bus using any variety of available bus architectures including, but not limited to, 9-bit bus, Industrial Standard Architecture (ISA), Micro-Charmel Architecture (MSA), Extended ISA (EISA), Intelligent Drive Electronics (IDE), VESA Local Bus (VLB), Peripheral Component Interconnect (PCI), USB, Advanced Graphics Port (AGP), Personal Computer Memory Card International Association bus (PCMCIA), Small Computer Systems Interface (SCSI), or any other proprietary bus. 
     The processor  244  may be any single-core or multicore processor such as those known under the trade name ARM Cortex by Texas Instruments. In one aspect, the processor may be an LM4F230H5QR ARM Cortex-M4F Processor Core, available from Texas Instruments, for example, comprising an on-chip memory of 256 KB single-cycle flash memory, or other non-volatile memory, up to 40 MHz, a prefetch buffer to improve performance above 40 MHz, a 32 KB single-cycle serial random access memory (SRAM), an internal read-only memory (ROM) loaded with StellarisWare® software, a 2 KB electrically erasable programmable read-only memory (EEPROM), and/or one or more pulse width modulation (PWM) modules, one or more quadrature encoder inputs (QEI) analogs, one or more 12-bit analog-to-digital converters (ADCs) with 12 analog input channels, details of which are available for the product datasheet. 
     In one aspect, the processor  244  may comprise a safety controller comprising two controller-based families such as TMS570 and RM4x, known under the trade name Hercules ARM Cortex R4, also by Texas Instruments. The safety controller may be configured specifically for IEC 61508 and ISO 26262 safety critical applications, among others, to provide advanced integrated safety features while delivering scalable performance, connectivity, and memory options. 
     The system memory includes volatile memory and non-volatile memory. The basic input/output system (BIOS), containing the basic routines to transfer information between elements within the computer system, such as during start-up, is stored in non-volatile memory. For example, the non-volatile memory can include ROM, programmable ROM (PROM), electrically programmable ROM (EPROM), EEPROM, or flash memory. Volatile memory includes random-access memory (RAM), which acts as external cache memory. Moreover, RAM is available in many forms such as SRAM, dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), Synchlink DRAM (SLDRAM), and direct Rambus RAM (DRRAM). 
     The computer system  210  also includes removable/non-removable, volatile/non-volatile computer storage media, such as for example disk storage. The disk storage includes, but is not limited to, devices like a magnetic disk drive, floppy disk drive, tape drive, Jaz drive, Zip drive, LS-60 drive, flash memory card, or memory stick. In addition, the disk storage can include storage media separately or in combination with other storage media including, but not limited to, an optical disc drive such as a compact disc ROM device (CD-ROM), compact disc recordable drive (CD-R Drive), compact disc rewritable drive (CD-RW Drive), or a digital versatile disc ROM drive (DVD-ROM). To facilitate the connection of the disk storage devices to the system bus, a removable or non-removable interface may be employed. 
     It is to be appreciated that the computer system  210  includes software that acts as an intermediary between users and the basic computer resources described in a suitable operating environment. Such software includes an operating system. The operating system, which can be stored on the disk storage, acts to control and allocate resources of the computer system. System applications take advantage of the management of resources by the operating system through program modules and program data stored either in the system memory or on the disk storage. It is to be appreciated that various components described herein can be implemented with various operating systems or combinations of operating systems. 
     A user enters commands or information into the computer system  210  through input device(s) coupled to the I/O interface  251 . The input devices include, but are not limited to, a pointing device such as a mouse, trackball, stylus, touch pad, keyboard, microphone, joystick, game pad, satellite dish, scanner, TV tuner card, digital camera, digital video camera, web camera, and the like. These and other input devices connect to the processor through the system bus via interface port(s). The interface port(s) include, for example, a serial port, a parallel port, a game port, and a USB. The output device(s) use some of the same types of ports as input device(s). Thus, for example, a USB port may be used to provide input to the computer system and to output information from the computer system to an output device. An output adapter is provided to illustrate that there are some output devices like monitors, displays, speakers, and printers, among other output devices that require special adapters. The output adapters include, by way of illustration and not limitation, video and sound cards that provide a means of connection between the output device and the system bus. It should be noted that other devices and/or systems of devices, such as remote computer(s), provide both input and output capabilities. 
     The computer system  210  can operate in a networked environment using logical connections to one or more remote computers, such as cloud computer(s), or local computers. The remote cloud computer(s) can be a personal computer, server, router, network PC, workstation, microprocessor-based appliance, peer device, or other common network node, and the like, and typically includes many or all of the elements described relative to the computer system. For purposes of brevity, only a memory storage device is illustrated with the remote computer(s). The remote computer(s) is logically connected to the computer system through a network interface and then physically connected via a communication connection. The network interface encompasses communication networks such as local area networks (LANs) and wide area networks (WANs). LAN technologies include Fiber Distributed Data Interface (FDDI), Copper Distributed Data Interface (CDDI), Ethernet/IEEE 802.3, Token Ring/IEEE 802.5 and the like. WAN technologies include, but are not limited to, point-to-point links, circuit-switching networks like Integrated Services Digital Networks (ISDN) and variations thereon, packet-switching networks, and Digital Subscriber Lines (DSL). 
     In various aspects, the computer system  210  of  FIG. 10 , the imaging module  238  and/or visualization system  208 , and/or the processor module  232  of  FIGS. 9-10 , may comprise an image processor, image processing engine, media processor, or any specialized digital signal processor (DSP) used for the processing of digital images. The image processor may employ parallel computing with single instruction, multiple data (SIMD) or multiple instruction, multiple data (MIMD) technologies to increase speed and efficiency. The digital image processing engine can perform a range of tasks. The image processor may be a system on a chip with multicore processor architecture. 
     The communication connection(s) refers to the hardware/software employed to connect the network interface to the bus. While the communication connection is shown for illustrative clarity inside the computer system, it can also be external to the computer system  210 . The hardware/software necessary for connection to the network interface includes, for illustrative purposes only, internal and external technologies such as modems, including regular telephone-grade modems, cable modems, and DSL modems, ISDN adapters, and Ethernet cards. 
       FIG. 11  illustrates a functional block diagram of one aspect of a USB network hub  300  device, according to one aspect of the present disclosure. In the illustrated aspect, the USB network hub device  300  employs a TUSB2036 integrated circuit hub by Texas Instruments. The USB network hub  300  is a CMOS device that provides an upstream USB transceiver port  302  and up to three downstream USB transceiver ports  304 ,  306 ,  308  in compliance with the USB 2.0 specification. The upstream USB transceiver port  302  is a differential root data port comprising a differential data minus (DM0) input paired with a differential data plus (DP0) input. The three downstream USB transceiver ports  304 ,  306 ,  308  are differential data ports where each port includes differential data plus (DP1-DP3) outputs paired with differential data minus (DM1-DM3) outputs. 
     The USB network hub  300  device is implemented with a digital state machine instead of a microcontroller, and no firmware programming is required. Fully compliant USB transceivers are integrated into the circuit for the upstream USB transceiver port  302  and all downstream USB transceiver ports  304 ,  306 ,  308 . The downstream USB transceiver ports  304 ,  306 ,  308  support both full-speed and low-speed devices by automatically setting the slew rate according to the speed of the device attached to the ports. The USB network hub  300  device may be configured either in bus-powered or self-powered mode and includes a hub power logic  312  to manage power. 
     The USB network hub  300  device includes a serial interface engine  310  (SIE). The SIE  310  is the front end of the USB network hub  300  hardware and handles most of the protocol described in chapter 8 of the USB specification. The SIE  310  typically comprehends signaling up to the transaction level. The functions that it handles could include: packet recognition, transaction sequencing, SOP, EOP, RESET, and RESUME signal detection/generation, clock/data separation, non-return-to-zero invert (NRZI) data encoding/decoding and bit-stuffing, CRC generation and checking (token and data), packet ID (PID) generation and checking/decoding, and/or serial-parallel/parallel-serial conversion. The  310  receives a clock input  314  and is coupled to a suspend/resume logic and frame timer  316  circuit and a hub repeater circuit  318  to control communication between the upstream USB transceiver port  302  and the downstream USB transceiver ports  304 ,  306 ,  308  through port logic circuits  320 ,  322 ,  324 . The SIE  310  is coupled to a command decoder  326  via interface logic to control commands from a serial EEPROM via a serial EEPROM interface  330 . 
     In various aspects, the USB network hub  300  can connect  127  functions configured in up to six logical layers (tiers) to a single computer. Further, the USB network hub  300  can connect to all peripherals using a standardized four-wire cable that provides both communication and power distribution. The power configurations are bus-powered and self-powered modes. The USB network hub  300  may be configured to support four modes of power management: a bus-powered hub, with either individual-port power management or ganged-port power management, and the self-powered hub, with either individual-port power management or ganged-port power management. In one aspect, using a USB cable, the USB network hub  300 , the upstream USB transceiver port  302  is plugged into a USB host controller, and the downstream USB transceiver ports  304 ,  306 ,  308  are exposed for connecting USB compatible devices, and so forth. 
     Surgical Instrument Hardware 
       FIG. 12  illustrates a logic diagram of a control system  470  of a surgical instrument or tool in accordance with one or more aspects of the present disclosure. The system  470  comprises a control circuit. The control circuit includes a microcontroller  461  comprising a processor  462  and a memory  468 . One or more of sensors  472 ,  474 ,  476 , for example, provide real-time feedback to the processor  462 . A motor  482 , driven by a motor driver  492 , operably couples a longitudinally movable displacement member to drive the I-beam knife element. A tracking system  480  is configured to determine the position of the longitudinally movable displacement member. The position information is provided to the processor  462 , which can be programmed or configured to determine the position of the longitudinally movable drive member as well as the position of a firing member, firing bar, and I-beam knife element. Additional motors may be provided at the tool driver interface to control I-beam firing, closure tube travel, shaft rotation, and articulation. A display  473  displays a variety of operating conditions of the instruments and may include touch screen functionality for data input. Information displayed on the display  473  may be overlaid with images acquired via endoscopic imaging modules. 
     In one aspect, the microcontroller  461  may be any single-core or multicore processor such as those known under the trade name ARM Cortex by Texas Instruments. In one aspect, the main microcontroller  461  may be an LM4F230H5QR ARM Cortex-M4F Processor Core, available from Texas Instruments, for example, comprising an on-chip memory of 256 KB single-cycle flash memory, or other non-volatile memory, up to 40 MHz, a prefetch buffer to improve performance above 40 MHz, a 32 KB single-cycle SRAM, and internal ROM loaded with StellarisWare® software, a 2 KB EEPROM, one or more PWM modules, one or more QEI analogs, and/or one or more 12-bit ADCs with 12 analog input channels, details of which are available for the product datasheet. 
     In one aspect, the microcontroller  461  may comprise a safety controller comprising two controller-based families such as TMS570 and RM4x, known under the trade name Hercules ARM Cortex R4, also by Texas Instruments. The safety controller may be configured specifically for IEC 61508 and ISO 26262 safety critical applications, among others, to provide advanced integrated safety features while delivering scalable performance, connectivity, and memory options. 
     The microcontroller  461  may be programmed to perform various functions such as precise control over the speed and position of the knife and articulation systems. In one aspect, the microcontroller  461  includes a processor  462  and a memory  468 . The electric motor  482  may be a brushed direct current (DC) motor with a gearbox and mechanical links to an articulation or knife system. In one aspect, a motor driver  492  may be an A3941 available from Allegro Microsystems, Inc. Other motor drivers may be readily substituted for use in the tracking system  480  comprising an absolute positioning system. A detailed description of an absolute positioning system is described in U.S. Patent Application Publication No. 2017/0296213, titled SYSTEMS AND METHODS FOR CONTROLLING A SURGICAL STAPLING AND CUTTING INSTRUMENT, which published on Oct. 19, 2017, which is herein incorporated by reference in its entirety. 
     The microcontroller  461  may be programmed to provide precise control over the speed and position of displacement members and articulation systems. The microcontroller  461  may be configured to compute a response in the software of the microcontroller  461 . The computed response is compared to a measured response of the actual system to obtain an “observed” response, which is used for actual feedback decisions. The observed response is a favorable, tuned value that balances the smooth, continuous nature of the simulated response with the measured response, which can detect outside influences on the system. 
     In one aspect, the motor  482  may be controlled by the motor driver  492  and can be employed by the firing system of the surgical instrument or tool. In various forms, the motor  482  may be a brushed DC driving motor having a maximum rotational speed of approximately 25,000 RPM. In other arrangements, the motor  482  may include a brushless motor, a cordless motor, a synchronous motor, a stepper motor, or any other suitable electric motor. The motor driver  492  may comprise an H-bridge driver comprising field-effect transistors (FETs), for example. The motor  482  can be powered by a power assembly releasably mounted to the handle assembly or tool housing for supplying control power to the surgical instrument or tool. The power assembly may comprise a battery which may include a number of battery cells connected in series that can be used as the power source to power the surgical instrument or tool. In certain circumstances, the battery cells of the power assembly may be replaceable and/or rechargeable. In at least one example, the battery cells can be lithium-ion batteries which can be couplable to and separable from the power assembly. 
     The motor driver  492  may be an A3941 available from Allegro Microsystems, Inc. The A3941  492  is a full-bridge controller for use with external N-channel power metal-oxide semiconductor field-effect transistors (MOSFETs) specifically designed for inductive loads, such as brush DC motors. The driver  492  comprises a unique charge pump regulator that provides full (&gt;10 V) gate drive for battery voltages down to 7 V and allows the A3941 to operate with a reduced gate drive, down to 5.5 V. A bootstrap capacitor may be employed to provide the above battery supply voltage required for N-channel MOSFETs. An internal charge pump for the high-side drive allows DC (100% duty cycle) operation. The full bridge can be driven in fast or slow decay modes using diode or synchronous rectification. In the slow decay mode, current recirculation can be through the high-side or the lowside FETs. The power FETs are protected from shoot-through by resistor-adjustable dead time. Integrated diagnostics provide indications of undervoltage, overtemperature, and power bridge faults and can be configured to protect the power MOSFETs under most short circuit conditions. Other motor drivers may be readily substituted for use in the tracking system  480  comprising an absolute positioning system. 
     The tracking system  480  comprises a controlled motor drive circuit arrangement comprising a position sensor  472  according to one aspect of this disclosure. The position sensor  472  for an absolute positioning system provides a unique position signal corresponding to the location of a displacement member. In one aspect, the displacement member represents a longitudinally movable drive member comprising a rack of drive teeth for meshing engagement with a corresponding drive gear of a gear reducer assembly. In other aspects, the displacement member represents the firing member, which could be adapted and configured to include a rack of drive teeth. In yet another aspect, the displacement member represents a firing bar or the I-beam, each of which can be adapted and configured to include a rack of drive teeth. Accordingly, as used herein, the term displacement member is used generically to refer to any movable member of the surgical instrument or tool such as the drive member, the firing member, the firing bar, the I-beam, or any element that can be displaced. In one aspect, the longitudinally movable drive member is coupled to the firing member, the firing bar, and the I-beam. Accordingly, the absolute positioning system can, in effect, track the linear displacement of the I-beam by tracking the linear displacement of the longitudinally movable drive member. In various other aspects, the displacement member may be coupled to any position sensor  472  suitable for measuring linear displacement. Thus, the longitudinally movable drive member, the firing member, the firing bar, or the I-beam, or combinations thereof, may be coupled to any suitable linear displacement sensor. Linear displacement sensors may include contact or non-contact displacement sensors. Linear displacement sensors may comprise linear variable differential transformers (LVDT), differential variable reluctance transducers (DVRT), a slide potentiometer, a magnetic sensing system comprising a movable magnet and a series of linearly arranged Hall effect sensors, a magnetic sensing system comprising a fixed magnet and a series of movable, linearly arranged Hall effect sensors, an optical sensing system comprising a movable light source and a series of linearly arranged photo diodes or photo detectors, an optical sensing system comprising a fixed light source and a series of movable linearly, arranged photo diodes or photo detectors, or any combination thereof. 
     The electric motor  482  can include a rotatable shaft that operably interfaces with a gear assembly that is mounted in meshing engagement with a set, or rack, of drive teeth on the displacement member. A sensor element may be operably coupled to a gear assembly such that a single revolution of the position sensor  472  element corresponds to some linear longitudinal translation of the displacement member. An arrangement of gearing and sensors can be connected to the linear actuator, via a rack and pinion arrangement, or a rotary actuator, via a spur gear or other connection. A power source supplies power to the absolute positioning system and an output indicator may display the output of the absolute positioning system. The displacement member represents the longitudinally movable drive member comprising a rack of drive teeth formed thereon for meshing engagement with a corresponding drive gear of the gear reducer assembly. The displacement member represents the longitudinally movable firing member, firing bar, I-beam, or combinations thereof. 
     A single revolution of the sensor element associated with the position sensor  472  is equivalent to a longitudinal linear displacement d1 of the of the displacement member, where d1 is the longitudinal linear distance that the displacement member moves from point “a” to point “b” after a single revolution of the sensor element coupled to the displacement member. The sensor arrangement may be connected via a gear reduction that results in the position sensor  472  completing one or more revolutions for the full stroke of the displacement member. The position sensor  472  may complete multiple revolutions for the full stroke of the displacement member. 
     A series of switches, where n is an integer greater than one, may be employed alone or in combination with a gear reduction to provide a unique position signal for more than one revolution of the position sensor  472 . The state of the switches are fed back to the microcontroller  461  that applies logic to determine a unique position signal corresponding to the longitudinal linear displacement d1+d2+ . . . dn of the displacement member. The output of the position sensor  472  is provided to the microcontroller  461 . The position sensor  472  of the sensor arrangement may comprise a magnetic sensor, an analog rotary sensor like a potentiometer, or an array of analog Hall-effect elements, which output a unique combination of position signals or values. 
     The position sensor  472  may comprise any number of magnetic sensing elements, such as, for example, magnetic sensors classified according to whether they measure the total magnetic field or the vector components of the magnetic field. The techniques used to produce both types of magnetic sensors encompass many aspects of physics and electronics. The technologies used for magnetic field sensing include search coil, fluxgate, optically pumped, nuclear precession, SQUID, Hall-effect, anisotropic magnetoresistance, giant magnetoresistance, magnetic tunnel junctions, giant magnetoimpedance, magnetostrictive/piezoelectric composites, magnetodiode, magnetotransistor, fiber-optic, magneto-optic, and microelectromechanical systems-based magnetic sensors, among others. 
     In one aspect, the position sensor  472  for the tracking system  480  comprising an absolute positioning system comprises a magnetic rotary absolute positioning system. The position sensor  472  may be implemented as an AS5055EQFT single-chip magnetic rotary position sensor available from Austria Microsystems, AG. The position sensor  472  is interfaced with the microcontroller  461  to provide an absolute positioning system. The position sensor  472  is a low-voltage and low-power component and includes four Hall-effect elements in an area of the position sensor  472  that is located above a magnet. A high-resolution ADC and a smart power management controller are also provided on the chip. A coordinate rotation digital computer (CORDIC) processor, also known as the digit-by-digit method and Volder&#39;s algorithm, is provided to implement a simple and efficient algorithm to calculate hyperbolic and trigonometric functions that require only addition, subtraction, bitshift, and table lookup operations. The angle position, alarm bits, and magnetic field information are transmitted over a standard serial communication interface, such as a serial peripheral interface (SPI) interface, to the microcontroller  461 . The position sensor  472  provides 12 or 14 bits of resolution. The position sensor  472  may be an AS5055 chip provided in a small QFN 16-pin 4×4×0.85 mm package. 
     The tracking system  480  comprising an absolute positioning system may comprise and/or be programmed to implement a feedback controller, such as a PID, state feedback, and adaptive controller. A power source converts the signal from the feedback controller into a physical input to the system: in this case the voltage. Other examples include a PWM of the voltage, current, and force. Other sensor(s) may be provided to measure physical parameters of the physical system in addition to the position measured by the position sensor  472 . In some aspects, the other sensor(s) can include sensor arrangements such as those described in U.S. Pat. No. 9,345,481, titled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, which issued on May 24, 2016, which is herein incorporated by reference in its entirety; U.S. Patent Application Publication No. 2014/0263552, titled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, which published on Sep. 18, 2014, which is herein incorporated by reference in its entirety; and U.S. patent application Ser. No. 15/628,175, titled TECHNIQUES FOR ADAPTIVE CONTROL OF MOTOR VELOCITY OF A SURGICAL STAPLING AND CUTTING INSTRUMENT, filed Jun. 20, 2017, which is herein incorporated by reference in its entirety. In a digital signal processing system, an absolute positioning system is coupled to a digital data acquisition system where the output of the absolute positioning system will have a finite resolution and sampling frequency. The absolute positioning system may comprise a compare-and-combine circuit to combine a computed response with a measured response using algorithms, such as a weighted average and a theoretical control loop, that drive the computed response towards the measured response. The computed response of the physical system takes into account properties like mass, inertial, viscous friction, inductance resistance, etc., to predict what the states and outputs of the physical system will be by knowing the input. 
     The absolute positioning system provides an absolute position of the displacement member upon power-up of the instrument, without retracting or advancing the displacement member to a reset (zero or home) position as may be required with conventional rotary encoders that merely count the number of steps forwards or backwards that the motor  482  has taken to infer the position of a device actuator, drive bar, knife, or the like. 
     A sensor  474 , such as, for example, a strain gauge or a micro-strain gauge, is configured to measure one or more parameters of the end effector, such as, for example, the amplitude of the strain exerted on the anvil during a clamping operation, which can be indicative of the closure forces applied to the anvil. The measured strain is converted to a digital signal and provided to the processor  462 . Alternatively, or in addition to the sensor  474 , a sensor  476 , such as, for example, a load sensor, can measure the closure force applied by the closure drive system to the anvil. The sensor  476 , such as, for example, a load sensor, can measure the firing force applied to an I-beam in a firing stroke of the surgical instrument or tool. The I-beam is configured to engage a wedge sled, which is configured to upwardly cam staple drivers to force out staples into deforming contact with an anvil. The I-beam also includes a sharpened cutting edge that can be used to sever tissue as the I-beam is advanced distally by the firing bar. Alternatively, a current sensor  478  can be employed to measure the current drawn by the motor  482 . The force required to advance the firing member can correspond to the current drawn by the motor  482 , for example. The measured force is converted to a digital signal and provided to the processor  462 . 
     In one form, the strain gauge sensor  474  can be used to measure the force applied to the tissue by the end effector. A strain gauge can be coupled to the end effector to measure the force on the tissue being treated by the end effector. A system for measuring forces applied to the tissue grasped by the end effector comprises a strain gauge sensor  474 , such as, for example, a micro-strain gauge, that is configured to measure one or more parameters of the end effector, for example. In one aspect, the strain gauge sensor  474  can measure the amplitude or magnitude of the strain exerted on a jaw member of an end effector during a clamping operation, which can be indicative of the tissue compression. The measured strain is converted to a digital signal and provided to a processor  462  of the microcontroller  461 . A load sensor  476  can measure the force used to operate the knife element, for example, to cut the tissue captured between the anvil and the staple cartridge. A magnetic field sensor can be employed to measure the thickness of the captured tissue. The measurement of the magnetic field sensor also may be converted to a digital signal and provided to the processor  462 . 
     The measurements of the tissue compression, the tissue thickness, and/or the force required to close the end effector on the tissue, as respectively measured by the sensors  474 ,  476 , can be used by the microcontroller  461  to characterize the selected position of the firing member and/or the corresponding value of the speed of the firing member. In one instance, a memory  468  may store a technique, an equation, and/or a lookup table which can be employed by the microcontroller  461  in the assessment. 
     The control system  470  of the surgical instrument or tool also may comprise wired or wireless communication circuits to communicate with the modular communication hub as shown in  FIGS. 8-11 . 
       FIG. 13  illustrates a control circuit  500  configured to control aspects of the surgical instrument or tool according to one aspect of this disclosure. The control circuit  500  can be configured to implement various processes described herein. The control circuit  500  may comprise a microcontroller comprising one or more processors  502  (e.g., microprocessor, microcontroller) coupled to at least one memory circuit  504 . The memory circuit  504  stores machine-executable instructions that, when executed by the processor  502 , cause the processor  502  to execute machine instructions to implement various processes described herein. The processor  502  may be any one of a number of single-core or multicore processors known in the art. The memory circuit  504  may comprise volatile and non-volatile storage media. The processor  502  may include an instruction processing unit  506  and an arithmetic unit  508 . The instruction processing unit may be configured to receive instructions from the memory circuit  504  of this disclosure. 
       FIG. 14  illustrates a combinational logic circuit  510  configured to control aspects of the surgical instrument or tool according to one aspect of this disclosure. The combinational logic circuit  510  can be configured to implement various processes described herein. The combinational logic circuit  510  may comprise a finite state machine comprising a combinational logic  512  configured to receive data associated with the surgical instrument or tool at an input  514 , process the data by the combinational logic  512 , and provide an output  516 . 
       FIG. 15  illustrates a sequential logic circuit  520  configured to control aspects of the surgical instrument or tool according to one aspect of this disclosure. The sequential logic circuit  520  or the combinational logic  522  can be configured to implement various processes described herein. The sequential logic circuit  520  may comprise a finite state machine. The sequential logic circuit  520  may comprise a combinational logic  522 , at least one memory circuit  524 , and a clock  529 , for example. The at least one memory circuit  524  can store a current state of the finite state machine. In certain instances, the sequential logic circuit  520  may be synchronous or asynchronous. The combinational logic  522  is configured to receive data associated with the surgical instrument or tool from an input  526 , process the data by the combinational logic  522 , and provide an output  528 . In other aspects, the circuit may comprise a combination of a processor (e.g., processor  502 ,  FIG. 13 ) and a finite state machine to implement various processes herein. In other aspects, the finite state machine may comprise a combination of a combinational logic circuit (e.g., combinational logic circuit  510 ,  FIG. 14 ) and the sequential logic circuit  520 . 
       FIG. 16  illustrates a surgical instrument or tool comprising a plurality of motors which can be activated to perform various functions. In certain instances, a first motor can be activated to perform a first function, a second motor can be activated to perform a second function, a third motor can be activated to perform a third function, a fourth motor can be activated to perform a fourth function, and so on. In certain instances, the plurality of motors of robotic surgical instrument  600  can be individually activated to cause firing, closure, and/or articulation motions in the end effector. The firing, closure, and/or articulation motions can be transmitted to the end effector through a shaft assembly, for example. 
     In certain instances, the surgical instrument system or tool may include a firing motor  602 . The firing motor  602  may be operably coupled to a firing motor drive assembly  604  which can be configured to transmit firing motions, generated by the motor  602  to the end effector, in particular to displace the I-beam element. In certain instances, the firing motions generated by the motor  602  may cause the staples to be deployed from the staple cartridge into tissue captured by the end effector and/or the cutting edge of the I-beam element to be advanced to cut the captured tissue, for example. The I-beam element may be retracted by reversing the direction of the motor  602 . 
     In certain instances, the surgical instrument or tool may include a closure motor  603 . The closure motor  603  may be operably coupled to a closure motor drive assembly  605  which can be configured to transmit closure motions, generated by the motor  603  to the end effector, in particular to displace a closure tube to close the anvil and compress tissue between the anvil and the staple cartridge. The closure motions may cause the end effector to transition from an open configuration to an approximated configuration to capture tissue, for example. The end effector may be transitioned to an open position by reversing the direction of the motor  603 . 
     In certain instances, the surgical instrument or tool may include one or more articulation motors  606   a ,  606   b , for example. The motors  606   a ,  606   b  may be operably coupled to respective articulation motor drive assemblies  608   a ,  608   b , which can be configured to transmit articulation motions generated by the motors  606   a ,  606   b  to the end effector. In certain instances, the articulation motions may cause the end effector to articulate relative to the shaft, for example. 
     As described above, the surgical instrument or tool may include a plurality of motors which may be configured to perform various independent functions. In certain instances, the plurality of motors of the surgical instrument or tool can be individually or separately activated to perform one or more functions while the other motors remain inactive. For example, the articulation motors  606   a ,  606   b  can be activated to cause the end effector to be articulated while the firing motor  602  remains inactive. Alternatively, the firing motor  602  can be activated to fire the plurality of staples, and/or to advance the cutting edge, while the articulation motor  606  remains inactive. Furthermore the closure motor  603  may be activated simultaneously with the firing motor  602  to cause the closure tube and the I-beam element to advance distally as described in more detail hereinbelow. 
     In certain instances, the surgical instrument or tool may include a common control module  610  which can be employed with a plurality of motors of the surgical instrument or tool. In certain instances, the common control module  610  may accommodate one of the plurality of motors at a time. For example, the common control module  610  can be couplable to and separable from the plurality of motors of the robotic surgical instrument individually. In certain instances, a plurality of the motors of the surgical instrument or tool may share one or more common control modules such as the common control module  610 . In certain instances, a plurality of motors of the surgical instrument or tool can be individually and selectively engaged with the common control module  610 . In certain instances, the common control module  610  can be selectively switched from interfacing with one of a plurality of motors of the surgical instrument or tool to interfacing with another one of the plurality of motors of the surgical instrument or tool. 
     In at least one example, the common control module  610  can be selectively switched between operable engagement with the articulation motors  606   a ,  606   b  and operable engagement with either the firing motor  602  or the closure motor  603 . In at least one example, as illustrated in  FIG. 16 , a switch  614  can be moved or transitioned between a plurality of positions and/or states. In a first position  616 , the switch  614  may electrically couple the common control module  610  to the firing motor  602 ; in a second position  617 , the switch  614  may electrically couple the common control module  610  to the closure motor  603 ; in a third position  618   a , the switch  614  may electrically couple the common control module  610  to the first articulation motor  606   a ; and in a fourth position  618   b , the switch  614  may electrically couple the common control module  610  to the second articulation motor  606   b , for example. In certain instances, separate common control modules  610  can be electrically coupled to the firing motor  602 , the closure motor  603 , and the articulations motor  606   a ,  606   b  at the same time. In certain instances, the switch  614  may be a mechanical switch, an electromechanical switch, a solid-state switch, or any suitable switching mechanism. 
     Each of the motors  602 ,  603 ,  606   a ,  606   b  may comprise a torque sensor to measure the output torque on the shaft of the motor. The force on an end effector may be sensed in any conventional manner, such as by force sensors on the outer sides of the jaws or by a torque sensor for the motor actuating the jaws. 
     In various instances, as illustrated in  FIG. 16 , the common control module  610  may comprise a motor driver  626  which may comprise one or more H-Bridge FETs. The motor driver  626  may modulate the power transmitted from a power source  628  to a motor coupled to the common control module  610  based on input from a microcontroller  620  (the “controller”), for example. In certain instances, the microcontroller  620  can be employed to determine the current drawn by the motor, for example, while the motor is coupled to the common control module  610 , as described above. 
     In certain instances, the microcontroller  620  may include a microprocessor  622  (the “processor”) and one or more non-transitory computer-readable mediums or memory units  624  (the “memory”). In certain instances, the memory  624  may store various program instructions, which when executed may cause the processor  622  to perform a plurality of functions and/or calculations described herein. In certain instances, one or more of the memory units  624  may be coupled to the processor  622 , for example. 
     In certain instances, the power source  628  can be employed to supply power to the microcontroller  620 , for example. In certain instances, the power source  628  may comprise a battery (or “battery pack” or “power pack”), such as a lithium-ion battery, for example. In certain instances, the battery pack may be configured to be releasably mounted to a handle for supplying power to the surgical instrument  600 . A number of battery cells connected in series may be used as the power source  628 . In certain instances, the power source  628  may be replaceable and/or rechargeable, for example. 
     In various instances, the processor  622  may control the motor driver  626  to control the position, direction of rotation, and/or velocity of a motor that is coupled to the common control module  610 . In certain instances, the processor  622  can signal the motor driver  626  to stop and/or disable a motor that is coupled to the common control module  610 . It should be understood that the term “processor” as used herein includes any suitable microprocessor, microcontroller, or other basic computing device that incorporates the functions of a computer&#39;s central processing unit (CPU) on an integrated circuit or, at most, a few integrated circuits. The processor is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and provides results as output. It is an example of sequential digital logic, as it has internal memory. Processors operate on numbers and symbols represented in the binary numeral system. 
     In one instance, the processor  622  may be any single-core or multicore processor such as those known under the trade name ARM Cortex by Texas Instruments. In certain instances, the microcontroller  620  may be an LM 4F230H5QR, available from Texas Instruments, for example. In at least one example, the Texas Instruments LM4F230H5QR is an ARM Cortex-M4F Processor Core comprising an on-chip memory of 256 KB single-cycle flash memory, or other non-volatile memory, up to 40 MHz, a prefetch buffer to improve performance above 40 MHz, a 32 KB single-cycle SRAM, an internal ROM loaded with StellarisWare® software, a 2 KB EEPROM, one or more PWM modules, one or more QEI analogs, one or more 12-bit ADCs with 12 analog input channels, among other features that are readily available for the product datasheet. Other microcontrollers may be readily substituted for use with the module  4410 . Accordingly, the present disclosure should not be limited in this context. 
     In certain instances, the memory  624  may include program instructions for controlling each of the motors of the surgical instrument  600  that are couplable to the common control module  610 . For example, the memory  624  may include program instructions for controlling the firing motor  602 , the closure motor  603 , and the articulation motors  606   a ,  606   b . Such program instructions may cause the processor  622  to control the firing, closure, and articulation functions in accordance with inputs from algorithms or control programs of the surgical instrument or tool. 
     In certain instances, one or more mechanisms and/or sensors such as, for example, sensors  630  can be employed to alert the processor  622  to the program instructions that should be used in a particular setting. For example, the sensors  630  may alert the processor  622  to use the program instructions associated with firing, closing, and articulating the end effector. In certain instances, the sensors  630  may comprise position sensors which can be employed to sense the position of the switch  614 , for example. Accordingly, the processor  622  may use the program instructions associated with firing the I-beam of the end effector upon detecting, through the sensors  630  for example, that the switch  614  is in the first position  616 ; the processor  622  may use the program instructions associated with closing the anvil upon detecting, through the sensors  630  for example, that the switch  614  is in the second position  617 ; and the processor  622  may use the program instructions associated with articulating the end effector upon detecting, through the sensors  630  for example, that the switch  614  is in the third or fourth position  618   a ,  618   b.    
       FIG. 17  is a schematic diagram of a robotic surgical instrument  700  configured to operate a surgical tool described herein according to one aspect of this disclosure. The robotic surgical instrument  700  may be programmed or configured to control distal/proximal translation of a displacement member, distal/proximal displacement of a closure tube, shaft rotation, and articulation, either with single or multiple articulation drive links. In one aspect, the surgical instrument  700  may be programmed or configured to individually control a firing member, a closure member, a shaft member, and/or one or more articulation members. The surgical instrument  700  comprises a control circuit  710  configured to control motor-driven firing members, closure members, shaft members, and/or one or more articulation members. 
     In one aspect, the robotic surgical instrument  700  comprises a control circuit  710  configured to control an anvil  716  and an I-beam  714  (including a sharp cutting edge) portion of an end effector  702 , a removable staple cartridge  718 , a shaft  740 , and one or more articulation members  742   a ,  742   b  via a plurality of motors  704   a - 704   e . A position sensor  734  may be configured to provide position feedback of the I-beam  714  to the control circuit  710 . Other sensors  738  may be configured to provide feedback to the control circuit  710 . A timer/counter  731  provides timing and counting information to the control circuit  710 . An energy source  712  may be provided to operate the motors  704   a - 704   e , and a current sensor  736  provides motor current feedback to the control circuit  710 . The motors  704   a - 704   e  can be operated individually by the control circuit  710  in an open-loop or closed-loop feedback control. 
     In one aspect, the control circuit  710  may comprise one or more microcontrollers, microprocessors, or other suitable processors for executing instructions that cause the processor or processors to perform one or more tasks. In one aspect, a timer/counter  731  provides an output signal, such as the elapsed time or a digital count, to the control circuit  710  to correlate the position of the I-beam  714  as determined by the position sensor  734  with the output of the timer/counter  731  such that the control circuit  710  can determine the position of the I-beam  714  at a specific time (t) relative to a starting position or the time (t) when the I-beam  714  is at a specific position relative to a starting position. The timer/counter  731  may be configured to measure elapsed time, count external events, or time external events. 
     In one aspect, the control circuit  710  may be programmed to control functions of the end effector  702  based on one or more tissue conditions. The control circuit  710  may be programmed to sense tissue conditions, such as thickness, either directly or indirectly, as described herein. The control circuit  710  may be programmed to select a firing control program or closure control program based on tissue conditions. A firing control program may describe the distal motion of the displacement member. Different firing control programs may be selected to better treat different tissue conditions. For example, when thicker tissue is present, the control circuit  710  may be programmed to translate the displacement member at a lower velocity and/or with lower power. When thinner tissue is present, the control circuit  710  may be programmed to translate the displacement member at a higher velocity and/or with higher power. A closure control program may control the closure force applied to the tissue by the anvil  716 . Other control programs control the rotation of the shaft  740  and the articulation members  742   a ,  742   b.    
     In one aspect, the control circuit  710  may generate motor set point signals. The motor set point signals may be provided to various motor controllers  708   a - 708   e . The motor controllers  708   a - 708   e  may comprise one or more circuits configured to provide motor drive signals to the motors  704   a - 704   e  to drive the motors  704   a - 704   e  as described herein. In some examples, the motors  704   a - 704   e  may be brushed DC electric motors. For example, the velocity of the motors  704   a - 704   e  may be proportional to the respective motor drive signals. In some examples, the motors  704   a - 704   e  may be brushless DC electric motors, and the respective motor drive signals may comprise a PWM signal provided to one or more stator windings of the motors  704   a - 704   e . Also, in some examples, the motor controllers  708   a - 708   e  may be omitted and the control circuit  710  may generate the motor drive signals directly. 
     In one aspect, the control circuit  710  may initially operate each of the motors  704   a - 704   e  in an open-loop configuration for a first open-loop portion of a stroke of the displacement member. Based on the response of the robotic surgical instrument  700  during the open-loop portion of the stroke, the control circuit  710  may select a firing control program in a closed-loop configuration. The response of the instrument may include a translation distance of the displacement member during the open-loop portion, a time elapsed during the open-loop portion, the energy provided to one of the motors  704   a - 704   e  during the open-loop portion, a sum of pulse widths of a motor drive signal, etc. After the open-loop portion, the control circuit  710  may implement the selected firing control program for a second portion of the displacement member stroke. For example, during a closed-loop portion of the stroke, the control circuit  710  may modulate one of the motors  704   a - 704   e  based on translation data describing a position of the displacement member in a closed-loop manner to translate the displacement member at a constant velocity. 
     In one aspect, the motors  704   a - 704   e  may receive power from an energy source  712 . The energy source  712  may be a DC power supply driven by a main alternating current power source, a battery, a super capacitor, or any other suitable energy source. The motors  704   a - 704   e  may be mechanically coupled to individual movable mechanical elements such as the I-beam  714 , anvil  716 , shaft  740 , articulation  742   a , and articulation  742   b  via respective transmissions  706   a - 706   e . The transmissions  706   a - 706   e  may include one or more gears or other linkage components to couple the motors  704   a - 704   e  to movable mechanical elements. A position sensor  734  may sense a position of the I-beam  714 . The position sensor  734  may be or include any type of sensor that is capable of generating position data that indicate a position of the I-beam  714 . In some examples, the position sensor  734  may include an encoder configured to provide a series of pulses to the control circuit  710  as the I-beam  714  translates distally and proximally. The control circuit  710  may track the pulses to determine the position of the I-beam  714 . Other suitable position sensors may be used, including, for example, a proximity sensor. Other types of position sensors may provide other signals indicating motion of the I-beam  714 . Also, in some examples, the position sensor  734  may be omitted. Where any of the motors  704   a - 704   e  is a stepper motor, the control circuit  710  may track the position of the I-beam  714  by aggregating the number and direction of steps that the motor  704  has been instructed to execute. The position sensor  734  may be located in the end effector  702  or at any other portion of the instrument. The outputs of each of the motors  704   a - 704   e  include a torque sensor  744   a - 744   e  to sense force and have an encoder to sense rotation of the drive shaft. 
     In one aspect, the control circuit  710  is configured to drive a firing member such as the I-beam  714  portion of the end effector  702 . The control circuit  710  provides a motor set point to a motor control  708   a , which provides a drive signal to the motor  704   a . The output shaft of the motor  704   a  is coupled to a torque sensor  744   a . The torque sensor  744   a  is coupled to a transmission  706   a  which is coupled to the I-beam  714 . The transmission  706   a  comprises movable mechanical elements such as rotating elements and a firing member to control the movement of the I-beam  714  distally and proximally along a longitudinal axis of the end effector  702 . In one aspect, the motor  704   a  may be coupled to the knife gear assembly, which includes a knife gear reduction set that includes a first knife drive gear and a second knife drive gear. A torque sensor  744   a  provides a firing force feedback signal to the control circuit  710 . The firing force signal represents the force required to fire or displace the I-beam  714 . A position sensor  734  may be configured to provide the position of the I-beam  714  along the firing stroke or the position of the firing member as a feedback signal to the control circuit  710 . The end effector  702  may include additional sensors  738  configured to provide feedback signals to the control circuit  710 . When ready to use, the control circuit  710  may provide a firing signal to the motor control  708   a . In response to the firing signal, the motor  704   a  may drive the firing member distally along the longitudinal axis of the end effector  702  from a proximal stroke start position to a stroke end position distal to the stroke start position. As the firing member translates distally, an I-beam  714 , with a cutting element positioned at a distal end, advances distally to cut tissue located between the staple cartridge  718  and the anvil  716 . 
     In one aspect, the control circuit  710  is configured to drive a closure member such as the anvil  716  portion of the end effector  702 . The control circuit  710  provides a motor set point to a motor control  708   b , which provides a drive signal to the motor  704   b . The output shaft of the motor  704   b  is coupled to a torque sensor  744   b . The torque sensor  744   b  is coupled to a transmission  706   b  which is coupled to the anvil  716 . The transmission  706   b  comprises movable mechanical elements such as rotating elements and a closure member to control the movement of the anvil  716  from the open and closed positions. In one aspect, the motor  704   b  is coupled to a closure gear assembly, which includes a closure reduction gear set that is supported in meshing engagement with the closure spur gear. The torque sensor  744   b  provides a closure force feedback signal to the control circuit  710 . The closure force feedback signal represents the closure force applied to the anvil  716 . The position sensor  734  may be configured to provide the position of the closure member as a feedback signal to the control circuit  710 . Additional sensors  738  in the end effector  702  may provide the closure force feedback signal to the control circuit  710 . The pivotable anvil  716  is positioned opposite the staple cartridge  718 . When ready to use, the control circuit  710  may provide a closure signal to the motor control  708   b . In response to the closure signal, the motor  704   b  advances a closure member to grasp tissue between the anvil  716  and the staple cartridge  718 . 
     In one aspect, the control circuit  710  is configured to rotate a shaft member such as the shaft  740  to rotate the end effector  702 . The control circuit  710  provides a motor set point to a motor control  708   c , which provides a drive signal to the motor  704   c . The output shaft of the motor  704   c  is coupled to a torque sensor  744   c . The torque sensor  744   c  is coupled to a transmission  706   c  which is coupled to the shaft  740 . The transmission  706   c  comprises movable mechanical elements such as rotating elements to control the rotation of the shaft  740  clockwise or counterclockwise up to and over 360°. In one aspect, the motor  704   c  is coupled to the rotational transmission assembly, which includes a tube gear segment that is formed on (or attached to) the proximal end of the proximal closure tube for operable engagement by a rotational gear assembly that is operably supported on the tool mounting plate. The torque sensor  744   c  provides a rotation force feedback signal to the control circuit  710 . The rotation force feedback signal represents the rotation force applied to the shaft  740 . The position sensor  734  may be configured to provide the position of the closure member as a feedback signal to the control circuit  710 . Additional sensors  738  such as a shaft encoder may provide the rotational position of the shaft  740  to the control circuit  710 . 
     In one aspect, the control circuit  710  is configured to articulate the end effector  702 . The control circuit  710  provides a motor set point to a motor control  708   d , which provides a drive signal to the motor  704   d . The output shaft of the motor  704   d  is coupled to a torque sensor  744   d . The torque sensor  744   d  is coupled to a transmission  706   d  which is coupled to an articulation member  742   a . The transmission  706   d  comprises movable mechanical elements such as articulation elements to control the articulation of the end effector  702  ±65°. In one aspect, the motor  704   d  is coupled to an articulation nut, which is rotatably journaled on the proximal end portion of the distal spine portion and is rotatably driven thereon by an articulation gear assembly. The torque sensor  744   d  provides an articulation force feedback signal to the control circuit  710 . The articulation force feedback signal represents the articulation force applied to the end effector  702 . Sensors  738 , such as an articulation encoder, may provide the articulation position of the end effector  702  to the control circuit  710 . 
     In another aspect, the articulation function of the robotic surgical system  700  may comprise two articulation members, or links,  742   a ,  742   b . These articulation members  742   a ,  742   b  are driven by separate disks on the robot interface (the rack) which are driven by the two motors  708   d ,  708   e . When the separate firing motor  704   a  is provided, each of articulation links  742   a ,  742   b  can be antagonistically driven with respect to the other link in order to provide a resistive holding motion and a load to the head when it is not moving and to provide an articulation motion as the head is articulated. The articulation members  742   a ,  742   b  attach to the head at a fixed radius as the head is rotated. Accordingly, the mechanical advantage of the push-and-pull link changes as the head is rotated. This change in the mechanical advantage may be more pronounced with other articulation link drive systems. 
     In one aspect, the one or more motors  704   a - 704   e  may comprise a brushed DC motor with a gearbox and mechanical links to a firing member, closure member, or articulation member. Another example includes electric motors  704   a - 704   e  that operate the movable mechanical elements such as the displacement member, articulation links, closure tube, and shaft. An outside influence is an unmeasured, unpredictable influence of things like tissue, surrounding bodies, and friction on the physical system. Such outside influence can be referred to as drag, which acts in opposition to one of electric motors  704   a - 704   e . The outside influence, such as drag, may cause the operation of the physical system to deviate from a desired operation of the physical system. 
     In one aspect, the position sensor  734  may be implemented as an absolute positioning system. In one aspect, the position sensor  734  may comprise a magnetic rotary absolute positioning system implemented as an AS5055EQFT single-chip magnetic rotary position sensor available from Austria Microsystems, AG. The position sensor  734  may interface with the control circuit  710  to provide an absolute positioning system. The position may include multiple Hall-effect elements located above a magnet and coupled to a CORDIC processor, also known as the digit-by-digit method and Volder&#39;s algorithm, that is provided to implement a simple and efficient algorithm to calculate hyperbolic and trigonometric functions that require only addition, subtraction, bitshift, and table lookup operations. 
     In one aspect, the control circuit  710  may be in communication with one or more sensors  738 . The sensors  738  may be positioned on the end effector  702  and adapted to operate with the robotic surgical instrument  700  to measure the various derived parameters such as the gap distance versus time, tissue compression versus time, and anvil strain versus time. The sensors  738  may comprise a magnetic sensor, a magnetic field sensor, a strain gauge, a load cell, a pressure sensor, a force sensor, a torque sensor, an inductive sensor such as an eddy current sensor, a resistive sensor, a capacitive sensor, an optical sensor, and/or any other suitable sensor for measuring one or more parameters of the end effector  702 . The sensors  738  may include one or more sensors. The sensors  738  may be located on the staple cartridge  718  deck to determine tissue location using segmented electrodes. The torque sensors  744   a - 744   e  may be configured to sense force such as firing force, closure force, and/or articulation force, among others. Accordingly, the control circuit  710  can sense (1) the closure load experienced by the distal closure tube and its position, (2) the firing member at the rack and its position, (3) what portion of the staple cartridge  718  has tissue on it, and (4) the load and position on both articulation rods. 
     In one aspect, the one or more sensors  738  may comprise a strain gauge, such as a micro-strain gauge, configured to measure the magnitude of the strain in the anvil  716  during a clamped condition. The strain gauge provides an electrical signal whose amplitude varies with the magnitude of the strain. The sensors  738  may comprise a pressure sensor configured to detect a pressure generated by the presence of compressed tissue between the anvil  716  and the staple cartridge  718 . The sensors  738  may be configured to detect impedance of a tissue section located between the anvil  716  and the staple cartridge  718  that is indicative of the thickness and/or fullness of tissue located therebetween. 
     In one aspect, the sensors  738  may be implemented as one or more limit switches, electromechanical devices, solid-state switches, Hall-effect devices, magneto-resistive (MR) devices, giant magneto-resistive (GMR) devices, magnetometers, among others. In other implementations, the sensors  738  may be implemented as solid-state switches that operate under the influence of light, such as optical sensors, IR sensors, ultraviolet sensors, among others. Still, the switches may be solid-state devices such as transistors (e.g., FET, junction FET, MOSFET, bipolar, and the like). In other implementations, the sensors  738  may include electrical conductorless switches, ultrasonic switches, accelerometers, and inertial sensors, among others. 
     In one aspect, the sensors  738  may be configured to measure forces exerted on the anvil  716  by the closure drive system. For example, one or more sensors  738  can be at an interaction point between the closure tube and the anvil  716  to detect the closure forces applied by the closure tube to the anvil  716 . The forces exerted on the anvil  716  can be representative of the tissue compression experienced by the tissue section captured between the anvil  716  and the staple cartridge  718 . The one or more sensors  738  can be positioned at various interaction points along the closure drive system to detect the closure forces applied to the anvil  716  by the closure drive system. The one or more sensors  738  may be sampled in real time during a clamping operation by the processor of the control circuit  710 . The control circuit  710  receives real-time sample measurements to provide and analyze time-based information and assess, in real time, closure forces applied to the anvil  716 . 
     In one aspect, a current sensor  736  can be employed to measure the current drawn by each of the motors  704   a - 704   e . The force required to advance any of the movable mechanical elements such as the I-beam  714  corresponds to the current drawn by one of the motors  704   a - 704   e . The force is converted to a digital signal and provided to the control circuit  710 . The control circuit  710  can be configured to simulate the response of the actual system of the instrument in the software of the controller. A displacement member can be actuated to move an I-beam  714  in the end effector  702  at or near a target velocity. The robotic surgical instrument  700  can include a feedback controller, which can be one of any feedback controllers, including, but not limited to a PID, a state feedback, a linear-quadratic (LQR), and/or an adaptive controller, for example. The robotic surgical instrument  700  can include a power source to convert the signal from the feedback controller into a physical input such as case voltage, PWM voltage, frequency modulated voltage, current, torque, and/or force, for example. Additional details are disclosed in U.S. patent application Ser. No. 15/636,829, titled CLOSED LOOP VELOCITY CONTROL TECHNIQUES FOR ROBOTIC SURGICAL INSTRUMENT, filed Jun. 29, 2017, which is herein incorporated by reference in its entirety. 
       FIG. 18  illustrates a block diagram of a surgical instrument  750  programmed to control the distal translation of a displacement member according to one aspect of this disclosure. In one aspect, the surgical instrument  750  is programmed to control the distal translation of a displacement member such as the I-beam  764 . The surgical instrument  750  comprises an end effector  752  that may comprise an anvil  766 , an I-beam  764  (including a sharp cutting edge), and a removable staple cartridge  768 . 
     The position, movement, displacement, and/or translation of a linear displacement member, such as the I-beam  764 , can be measured by an absolute positioning system, sensor arrangement, and position sensor  784 . Because the I-beam  764  is coupled to a longitudinally movable drive member, the position of the I-beam  764  can be determined by measuring the position of the longitudinally movable drive member employing the position sensor  784 . Accordingly, in the following description, the position, displacement, and/or translation of the I-beam  764  can be achieved by the position sensor  784  as described herein. A control circuit  760  may be programmed to control the translation of the displacement member, such as the I-beam  764 . The control circuit  760 , in some examples, may comprise one or more microcontrollers, microprocessors, or other suitable processors for executing instructions that cause the processor or processors to control the displacement member, e.g., the I-beam  764 , in the manner described. In one aspect, a timer/counter  781  provides an output signal, such as the elapsed time or a digital count, to the control circuit  760  to correlate the position of the I-beam  764  as determined by the position sensor  784  with the output of the timer/counter  781  such that the control circuit  760  can determine the position of the I-beam  764  at a specific time (t) relative to a starting position. The timer/counter  781  may be configured to measure elapsed time, count external events, or time external events. 
     The control circuit  760  may generate a motor set point signal  772 . The motor set point signal  772  may be provided to a motor controller  758 . The motor controller  758  may comprise one or more circuits configured to provide a motor drive signal  774  to the motor  754  to drive the motor  754  as described herein. In some examples, the motor  754  may be a brushed DC electric motor. For example, the velocity of the motor  754  may be proportional to the motor drive signal  774 . In some examples, the motor  754  may be a brushless DC electric motor and the motor drive signal  774  may comprise a PWM signal provided to one or more stator windings of the motor  754 . Also, in some examples, the motor controller  758  may be omitted, and the control circuit  760  may generate the motor drive signal  774  directly. 
     The motor  754  may receive power from an energy source  762 . The energy source  762  may be or include a battery, a super capacitor, or any other suitable energy source. The motor  754  may be mechanically coupled to the I-beam  764  via a transmission  756 . The transmission  756  may include one or more gears or other linkage components to couple the motor  754  to the I-beam  764 . A position sensor  784  may sense a position of the I-beam  764 . The position sensor  784  may be or include any type of sensor that is capable of generating position data that indicate a position of the !-beam  764 . In some examples, the position sensor  784  may include an encoder configured to provide a series of pulses to the control circuit  760  as the I-beam  764  translates distally and proximally. The control circuit  760  may track the pulses to determine the position of the I-beam  764 . Other suitable position sensors may be used, including, for example, a proximity sensor. Other types of position sensors may provide other signals indicating motion of the I-beam  764 . Also, in some examples, the position sensor  784  may be omitted. Where the motor  754  is a stepper motor, the control circuit  760  may track the position of the I-beam  764  by aggregating the number and direction of steps that the motor  754  has been instructed to execute. The position sensor  784  may be located in the end effector  752  or at any other portion of the instrument. 
     The control circuit  760  may be in communication with one or more sensors  788 . The sensors  788  may be positioned on the end effector  752  and adapted to operate with the surgical instrument  750  to measure the various derived parameters such as gap distance versus time, tissue compression versus time, and anvil strain versus time. The sensors  788  may comprise a magnetic sensor, a magnetic field sensor, a strain gauge, a pressure sensor, a force sensor, an inductive sensor such as an eddy current sensor, a resistive sensor, a capacitive sensor, an optical sensor, and/or any other suitable sensor for measuring one or more parameters of the end effector  752 . The sensors  788  may include one or more sensors. 
     The one or more sensors  788  may comprise a strain gauge, such as a micro-strain gauge, configured to measure the magnitude of the strain in the anvil  766  during a clamped condition. The strain gauge provides an electrical signal whose amplitude varies with the magnitude of the strain. The sensors  788  may comprise a pressure sensor configured to detect a pressure generated by the presence of compressed tissue between the anvil  766  and the staple cartridge  768 . The sensors  788  may be configured to detect impedance of a tissue section located between the anvil  766  and the staple cartridge  768  that is indicative of the thickness and/or fullness of tissue located therebetween. 
     The sensors  788  may be is configured to measure forces exerted on the anvil  766  by a closure drive system. For example, one or more sensors  788  can be at an interaction point between a closure tube and the anvil  766  to detect the closure forces applied by a closure tube to the anvil  766 . The forces exerted on the anvil  766  can be representative of the tissue compression experienced by the tissue section captured between the anvil  766  and the staple cartridge  768 . The one or more sensors  788  can be positioned at various interaction points along the closure drive system to detect the closure forces applied to the anvil  766  by the closure drive system. The one or more sensors  788  may be sampled in real time during a clamping operation by a processor of the control circuit  760 . The control circuit  760  receives real-time sample measurements to provide and analyze time-based information and assess, in real time, closure forces applied to the anvil  766 . 
     A current sensor  786  can be employed to measure the current drawn by the motor  754 . The force required to advance the I-beam  764  corresponds to the current drawn by the motor  754 . The force is converted to a digital signal and provided to the control circuit  760 . 
     The control circuit  760  can be configured to simulate the response of the actual system of the instrument in the software of the controller. A displacement member can be actuated to move an I-beam  764  in the end effector  752  at or near a target velocity. The surgical instrument  750  can include a feedback controller, which can be one of any feedback controllers, including, but not limited to a PID, a state feedback, LQR, and/or an adaptive controller, for example. The surgical instrument  750  can include a power source to convert the signal from the feedback controller into a physical input such as case voltage, PWM voltage, frequency modulated voltage, current, torque, and/or force, for example. 
     The actual drive system of the surgical instrument  750  is configured to drive the displacement member, cutting member, or I-beam  764 , by a brushed DC motor with gearbox and mechanical links to an articulation and/or knife system. Another example is the electric motor  754  that operates the displacement member and the articulation driver, for example, of an interchangeable shaft assembly. An outside influence is an unmeasured, unpredictable influence of things like tissue, surrounding bodies and friction on the physical system. Such outside influence can be referred to as drag which acts in opposition to the electric motor  754 . The outside influence, such as drag, may cause the operation of the physical system to deviate from a desired operation of the physical system. 
     Various example aspects are directed to a surgical instrument  750  comprising an end effector  752  with motor-driven surgical stapling and cutting implements. For example, a motor  754  may drive a displacement member distally and proximally along a longitudinal axis of the end effector  752 . The end effector  752  may comprise a pivotable anvil  766  and, when configured for use, a staple cartridge  768  positioned opposite the anvil  766 . A clinician may grasp tissue between the anvil  766  and the staple cartridge  768 , as described herein. When ready to use the instrument  750 , the clinician may provide a firing signal, for example by depressing a trigger of the instrument  750 . In response to the firing signal, the motor  754  may drive the displacement member distally along the longitudinal axis of the end effector  752  from a proximal stroke begin position to a stroke end position distal of the stroke begin position. As the displacement member translates distally, an I-beam  764  with a cutting element positioned at a distal end, may cut the tissue between the staple cartridge  768  and the anvil  766 . 
     In various examples, the surgical instrument  750  may comprise a control circuit  760  programmed to control the distal translation of the displacement member, such as the I-beam  764 , for example, based on one or more tissue conditions. The control circuit  760  may be programmed to sense tissue conditions, such as thickness, either directly or indirectly, as described herein. The control circuit  760  may be programmed to select a firing control program based on tissue conditions. A firing control program may describe the distal motion of the displacement member. Different firing control programs may be selected to better treat different tissue conditions. For example, when thicker tissue is present, the control circuit  760  may be programmed to translate the displacement member at a lower velocity and/or with lower power. When thinner tissue is present, the control circuit  760  may be programmed to translate the displacement member at a higher velocity and/or with higher power. 
     In some examples, the control circuit  760  may initially operate the motor  754  in an open loop configuration for a first open loop portion of a stroke of the displacement member. Based on a response of the instrument  750  during the open loop portion of the stroke, the control circuit  760  may select a firing control program. The response of the instrument may include, a translation distance of the displacement member during the open loop portion, a time elapsed during the open loop portion, energy provided to the motor  754  during the open loop portion, a sum of pulse widths of a motor drive signal, etc. After the open loop portion, the control circuit  760  may implement the selected firing control program for a second portion of the displacement member stroke. For example, during the closed loop portion of the stroke, the control circuit  760  may modulate the motor  754  based on translation data describing a position of the displacement member in a closed loop manner to translate the displacement member at a constant velocity. Additional details are disclosed in U.S. patent application Ser. No. 15/720,852, titled SYSTEM AND METHODS FOR CONTROLLING A DISPLAY OF A SURGICAL INSTRUMENT, filed Sep. 29, 2017, which is herein incorporated by reference in its entirety. 
       FIG. 19  is a schematic diagram of a surgical instrument  790  configured to control various functions according to one aspect of this disclosure. In one aspect, the surgical instrument  790  is programmed to control distal translation of a displacement member such as the I-beam  764 . The surgical instrument  790  comprises an end effector  792  that may comprise an anvil  766 , an I-beam  764 , and a removable staple cartridge  768  which may be interchanged with an RF cartridge  796  (shown in dashed line). 
     In one aspect, sensors  788  may be implemented as a limit switch, electromechanical device, solid-state switches, Hall-effect devices, MR devices, GMR devices, magnetometers, among others. In other implementations, the sensors  638  may be solid-state switches that operate under the influence of light, such as optical sensors, IR sensors, ultraviolet sensors, among others. Still, the switches may be solid-state devices such as transistors (e.g., FET, junction FET, MOSFET, bipolar, and the like). In other implementations, the sensors  788  may include electrical conductorless switches, ultrasonic switches, accelerometers, and inertial sensors, among others. 
     In one aspect, the position sensor  784  may be implemented as an absolute positioning system comprising a magnetic rotary absolute positioning system implemented as an AS5055EQFT single-chip magnetic rotary position sensor available from Austria Microsystems, AG. The position sensor  784  may interface with the control circuit  760  to provide an absolute positioning system. The position may include multiple Hall-effect elements located above a magnet and coupled to a CORDIC processor, also known as the digit-by-digit method and Volder&#39;s algorithm, that is provided to implement a simple and efficient algorithm to calculate hyperbolic and trigonometric functions that require only addition, subtraction, bitshift, and table lookup operations. 
     In one aspect, the I-beam  764  may be implemented as a knife member comprising a knife body that operably supports a tissue cutting blade thereon and may further include anvil engagement tabs or features and channel engagement features or a foot. In one aspect, the staple cartridge  768  may be implemented as a standard (mechanical) surgical fastener cartridge. In one aspect, the RF cartridge  796  may be implemented as an RF cartridge. These and other sensors arrangements are described in commonly owned U.S. patent application Ser. No. 15/628,175, titled TECHNIQUES FOR ADAPTIVE CONTROL OF MOTOR VELOCITY OF A SURGICAL STAPLING AND CUTTING INSTRUMENT, filed Jun. 20, 2017, which is herein incorporated by reference in its entirety. 
     The position, movement, displacement, and/or translation of a linear displacement member, such as the I-beam  764 , can be measured by an absolute positioning system, sensor arrangement, and position sensor represented as position sensor  784 . Because the I-beam  764  is coupled to the longitudinally movable drive member, the position of the I-beam  764  can be determined by measuring the position of the longitudinally movable drive member employing the position sensor  784 . Accordingly, in the following description, the position, displacement, and/or translation of the I-beam  764  can be achieved by the position sensor  784  as described herein. A control circuit  760  may be programmed to control the translation of the displacement member, such as the I-beam  764 , as described herein. The control circuit  760 , in some examples, may comprise one or more microcontrollers, microprocessors, or other suitable processors for executing instructions that cause the processor or processors to control the displacement member, e.g., the I-beam  764 , in the manner described. In one aspect, a timer/counter  781  provides an output signal, such as the elapsed time or a digital count, to the control circuit  760  to correlate the position of the I-beam  764  as determined by the position sensor  784  with the output of the timer/counter  781  such that the control circuit  760  can determine the position of the I-beam  764  at a specific time (t) relative to a starting position. The timer/counter  781  may be configured to measure elapsed time, count external events, or time external events. 
     The control circuit  760  may generate a motor set point signal  772 . The motor set point signal  772  may be provided to a motor controller  758 . The motor controller  758  may comprise one or more circuits configured to provide a motor drive signal  774  to the motor  754  to drive the motor  754  as described herein. In some examples, the motor  754  may be a brushed DC electric motor. For example, the velocity of the motor  754  may be proportional to the motor drive signal  774 . In some examples, the motor  754  may be a brushless DC electric motor and the motor drive signal  774  may comprise a PWM signal provided to one or more stator windings of the motor  754 . Also, in some examples, the motor controller  758  may be omitted, and the control circuit  760  may generate the motor drive signal  774  directly. 
     The motor  754  may receive power from an energy source  762 . The energy source  762  may be or include a battery, a super capacitor, or any other suitable energy source. The motor  754  may be mechanically coupled to the I-beam  764  via a transmission  756 . The transmission  756  may include one or more gears or other linkage components to couple the motor  754  to the I-beam  764 . A position sensor  784  may sense a position of the I-beam  764 . The position sensor  784  may be or include any type of sensor that is capable of generating position data that indicate a position of the I-beam  764 . In some examples, the position sensor  784  may include an encoder configured to provide a series of pulses to the control circuit  760  as the I-beam  764  translates distally and proximally. The control circuit  760  may track the pulses to determine the position of the I-beam  764 . Other suitable position sensors may be used, including, for example, a proximity sensor. Other types of position sensors may provide other signals indicating motion of the I-beam  764 . Also, in some examples, the position sensor  784  may be omitted. Where the motor  754  is a stepper motor, the control circuit  760  may track the position of the I-beam  764  by aggregating the number and direction of steps that the motor has been instructed to execute. The position sensor  784  may be located in the end effector  792  or at any other portion of the instrument. 
     The control circuit  760  may be in communication with one or more sensors  788 . The sensors  788  may be positioned on the end effector  792  and adapted to operate with the surgical instrument  790  to measure the various derived parameters such as gap distance versus time, tissue compression versus time, and anvil strain versus time. The sensors  788  may comprise a magnetic sensor, a magnetic field sensor, a strain gauge, a pressure sensor, a force sensor, an inductive sensor such as an eddy current sensor, a resistive sensor, a capacitive sensor, an optical sensor, and/or any other suitable sensor for measuring one or more parameters of the end effector  792 . The sensors  788  may include one or more sensors. 
     The one or more sensors  788  may comprise a strain gauge, such as a micro-strain gauge, configured to measure the magnitude of the strain in the anvil  766  during a clamped condition. The strain gauge provides an electrical signal whose amplitude varies with the magnitude of the strain. The sensors  788  may comprise a pressure sensor configured to detect a pressure generated by the presence of compressed tissue between the anvil  766  and the staple cartridge  768 . The sensors  788  may be configured to detect impedance of a tissue section located between the anvil  766  and the staple cartridge  768  that is indicative of the thickness and/or fullness of tissue located therebetween. 
     The sensors  788  may be is configured to measure forces exerted on the anvil  766  by the closure drive system. For example, one or more sensors  788  can be at an interaction point between a closure tube and the anvil  766  to detect the closure forces applied by a closure tube to the anvil  766 . The forces exerted on the anvil  766  can be representative of the tissue compression experienced by the tissue section captured between the anvil  766  and the staple cartridge  768 . The one or more sensors  788  can be positioned at various interaction points along the closure drive system to detect the closure forces applied to the anvil  766  by the closure drive system. The one or more sensors  788  may be sampled in real time during a clamping operation by a processor portion of the control circuit  760 . The control circuit  760  receives real-time sample measurements to provide and analyze time-based information and assess, in real time, closure forces applied to the anvil  766 . 
     A current sensor  786  can be employed to measure the current drawn by the motor  754 . The force required to advance the I-beam  764  corresponds to the current drawn by the motor  754 . The force is converted to a digital signal and provided to the control circuit  760 . 
     An RF energy source  794  is coupled to the end effector  792  and is applied to the RF cartridge  796  when the RF cartridge  796  is loaded in the end effector  792  in place of the staple cartridge  768 . The control circuit  760  controls the delivery of the RF energy to the RF cartridge  796 . 
     Additional details are disclosed in U.S. patent application Ser. No. 15/636,096, titled SURGICAL SYSTEM COUPLABLE WITH STAPLE CARTRIDGE AND RADIO FREQUENCY CARTRIDGE, AND METHOD OF USING SAME, filed Jun. 28, 2017, which is herein incorporated by reference in its entirety. 
       FIG. 20  is a simplified block diagram of a generator  800  configured to provide inductorless tuning, among other benefits. Additional details of the generator  800  are described in U.S. Pat. No. 9,060,775, titled SURGICAL GENERATOR FOR ULTRASONIC AND ELECTROSURGICAL DEVICES, which issued on Jun. 23, 2015, which is herein incorporated by reference in its entirety. The generator  800  may comprise a patient isolated stage  802  in communication with a non-isolated stage  804  via a power transformer  806 . A secondary winding  808  of the power transformer  806  is contained in the isolated stage  802  and may comprise a tapped configuration (e.g., a center-tapped or a non-center-tapped configuration) to define drive signal outputs  810   a ,  810   b ,  810   c  for delivering drive signals to different surgical instruments, such as, for example, an ultrasonic surgical instrument, an RF electrosurgical instrument, and a multifunction surgical instrument which includes ultrasonic and RF energy modes that can be delivered alone or simultaneously. In particular, drive signal outputs  810   a ,  810   c  may output an ultrasonic drive signal (e.g., a 420V root-mean-square (RMS) drive signal) to an ultrasonic surgical instrument, and drive signal outputs  810   b ,  810   c  may output an RF electrosurgical drive signal (e.g., a 100V RMS drive signal) to an RF electrosurgical instrument, with the drive signal output  810   b  corresponding to the center tap of the power transformer  806 . 
     In certain forms, the ultrasonic and electrosurgical drive signals may be provided simultaneously to distinct surgical instruments and/or to a single surgical instrument, such as the multifunction surgical instrument, having the capability to deliver both ultrasonic and electrosurgical energy to tissue. It will be appreciated that the electrosurgical signal, provided either to a dedicated electrosurgical instrument and/or to a combined multifunction ultrasonic/electrosurgical instrument may be either a therapeutic or sub-therapeutic level signal where the sub-therapeutic signal can be used, for example, to monitor tissue or instrument conditions and provide feedback to the generator. For example, the ultrasonic and RF signals can be delivered separately or simultaneously from a generator with a single output port in order to provide the desired output signal to the surgical instrument, as will be discussed in more detail below. Accordingly, the generator can combine the ultrasonic and electrosurgical RF energies and deliver the combined energies to the multifunction ultrasonic/electrosurgical instrument. Bipolar electrodes can be placed on one or both jaws of the end effector. One jaw may be driven by ultrasonic energy in addition to electrosurgical RF energy, working simultaneously. The ultrasonic energy may be employed to dissect tissue, while the electrosurgical RF energy may be employed for vessel sealing. 
     The non-isolated stage  804  may comprise a power amplifier  812  having an output connected to a primary winding  814  of the power transformer  806 . In certain forms, the power amplifier  812  may comprise a push-pull amplifier. For example, the non-isolated stage  804  may further comprise a logic device  816  for supplying a digital output to a digital-to-analog converter (DAC) circuit  818 , which in turn supplies a corresponding analog signal to an input of the power amplifier  812 . In certain forms, the logic device  816  may comprise a programmable gate array (PGA), a FPGA, programmable logic device (PLD), among other logic circuits, for example. The logic device  816 , by virtue of controlling the input of the power amplifier  812  via the DAC circuit  818 , may therefore control any of a number of parameters (e.g., frequency, waveform shape, waveform amplitude) of drive signals appearing at the drive signal outputs  810   a ,  810   b ,  810   c . In certain forms and as discussed below, the logic device  816 , in conjunction with a processor (e.g., a DSP discussed below), may implement a number of DSP-based and/or other control algorithms to control parameters of the drive signals output by the generator  800 . 
     Power may be supplied to a power rail of the power amplifier  812  by a switch-mode regulator  820 , e.g., a power converter. In certain forms, the switch-mode regulator  820  may comprise an adjustable buck regulator, for example. The non-isolated stage  804  may further comprise a first processor  822 , which in one form may comprise a DSP processor such as an Analog Devices ADSP-21469 SHARC DSP, available from Analog Devices, Norwood, Mass., for example, although in various forms any suitable processor may be employed. In certain forms the DSP processor  822  may control the operation of the switch-mode regulator  820  responsive to voltage feedback data received from the power amplifier  812  by the DSP processor  822  via an ADC circuit  824 . In one form, for example, the DSP processor  822  may receive as input, via the ADC circuit  824 , the waveform envelope of a signal (e.g., an RF signal) being amplified by the power amplifier  812 . The DSP processor  822  may then control the switch-mode regulator  820  (e.g., via a PWM output) such that the rail voltage supplied to the power amplifier  812  tracks the waveform envelope of the amplified signal. By dynamically modulating the rail voltage of the power amplifier  812  based on the waveform envelope, the efficiency of the power amplifier  812  may be significantly improved relative to a fixed rail voltage amplifier schemes. 
     In certain forms, the logic device  816 , in conjunction with the DSP processor  822 , may implement a digital synthesis circuit such as a direct digital synthesizer control scheme to control the waveform shape, frequency, and/or amplitude of drive signals output by the generator  800 . In one form, for example, the logic device  816  may implement a DDS control algorithm by recalling waveform samples stored in a dynamically updated lookup table (LUT), such as a RAM LUT, which may be embedded in an FPGA. This control algorithm is particularly useful for ultrasonic applications in which an ultrasonic transducer, such as an ultrasonic transducer, may be driven by a clean sinusoidal current at its resonant frequency. Because other frequencies may excite parasitic resonances, minimizing or reducing the total distortion of the motional branch current may correspondingly minimize or reduce undesirable resonance effects. Because the waveform shape of a drive signal output by the generator  800  is impacted by various sources of distortion present in the output drive circuit (e.g., the power transformer  806 , the power amplifier  812 ), voltage and current feedback data based on the drive signal may be input into an algorithm, such as an error control algorithm implemented by the DSP processor  822 , which compensates for distortion by suitably pre-distorting or modifying the waveform samples stored in the LUT on a dynamic, ongoing basis (e.g., in real time). In one form, the amount or degree of pre-distortion applied to the LUT samples may be based on the error between a computed motional branch current and a desired current waveform shape, with the error being determined on a sample-by-sample basis. In this way, the pre-distorted LUT samples, when processed through the drive circuit, may result in a motional branch drive signal having the desired waveform shape (e.g., sinusoidal) for optimally driving the ultrasonic transducer. In such forms, the LUT waveform samples will therefore not represent the desired waveform shape of the drive signal, but rather the waveform shape that is required to ultimately produce the desired waveform shape of the motional branch drive signal when distortion effects are taken into account. 
     The non-isolated stage  804  may further comprise a first ADC circuit  826  and a second ADC circuit  828  coupled to the output of the power transformer  806  via respective isolation transformers  830 ,  832  for respectively sampling the voltage and current of drive signals output by the generator  800 . In certain forms, the ADC circuits  826 ,  828  may be configured to sample at high speeds (e.g., 80 mega samples per second (MSPS)) to enable oversampling of the drive signals. In one form, for example, the sampling speed of the ADC circuits  826 ,  828  may enable approximately 200× (depending on frequency) oversampling of the drive signals. In certain forms, the sampling operations of the ADC circuit  826 ,  828  may be performed by a single ADC circuit receiving input voltage and current signals via a two-way multiplexer. The use of high-speed sampling in forms of the generator  800  may enable, among other things, calculation of the complex current flowing through the motional branch (which may be used in certain forms to implement DDS-based waveform shape control described above), accurate digital filtering of the sampled signals, and calculation of real power consumption with a high degree of precision. Voltage and current feedback data output by the ADC circuits  826 ,  828  may be received and processed (e.g., first-in-first-out (FIFO) buffer, multiplexer) by the logic device  816  and stored in data memory for subsequent retrieval by, for example, the DSP processor  822 . As noted above, voltage and current feedback data may be used as input to an algorithm for pre-distorting or modifying LUT waveform samples on a dynamic and ongoing basis. In certain forms, this may require each stored voltage and current feedback data pair to be indexed based on, or otherwise associated with, a corresponding LUT sample that was output by the logic device  816  when the voltage and current feedback data pair was acquired. Synchronization of the LUT samples and the voltage and current feedback data in this manner contributes to the correct timing and stability of the pre-distortion algorithm. 
     In certain forms, the voltage and current feedback data may be used to control the frequency and/or amplitude (e.g., current amplitude) of the drive signals. In one form, for example, voltage and current feedback data may be used to determine impedance phase. The frequency of the drive signal may then be controlled to minimize or reduce the difference between the determined impedance phase and an impedance phase setpoint (e.g., 0°), thereby minimizing or reducing the effects of harmonic distortion and correspondingly enhancing impedance phase measurement accuracy. The determination of phase impedance and a frequency control signal may be implemented in the DSP processor  822 , for example, with the frequency control signal being supplied as input to a DDS control algorithm implemented by the logic device  816 . 
     In another form, for example, the current feedback data may be monitored in order to maintain the current amplitude of the drive signal at a current amplitude setpoint. The current amplitude setpoint may be specified directly or determined indirectly based on specified voltage amplitude and power setpoints. In certain forms, control of the current amplitude may be implemented by control algorithm, such as, for example, a proportional-integral-derivative (PID) control algorithm, in the DSP processor  822 . Variables controlled by the control algorithm to suitably control the current amplitude of the drive signal may include, for example, the scaling of the LUT waveform samples stored in the logic device  816  and/or the full-scale output voltage of the DAC circuit  818  (which supplies the input to the power amplifier  812 ) via a DAC circuit  834 . 
     The non-isolated stage  804  may further comprise a second processor  836  for providing, among other things user interface (UI) functionality. In one form, the UI processor  836  may comprise an Atmel AT91SAM9263 processor having an ARM 926EJ-S core, available from Atmel Corporation, San Jose, Calif., for example. Examples of UI functionality supported by the UI processor  836  may include audible and visual user feedback, communication with peripheral devices (e.g., via a USB interface), communication with a foot switch, communication with an input device (e.g., a touch screen display) and communication with an output device (e.g., a speaker). The UI processor  836  may communicate with the DSP processor  822  and the logic device  816  (e.g., via SPI buses). Although the UI processor  836  may primarily support UI functionality, it may also coordinate with the DSP processor  822  to implement hazard mitigation in certain forms. For example, the UI processor  836  may be programmed to monitor various aspects of user input and/or other inputs (e.g., touch screen inputs, foot switch inputs, temperature sensor inputs) and may disable the drive output of the generator  800  when an erroneous condition is detected. 
     In certain forms, both the DSP processor  822  and the UI processor  836 , for example, may determine and monitor the operating state of the generator  800 . For the DSP processor  822 , the operating state of the generator  800  may dictate, for example, which control and/or diagnostic processes are implemented by the DSP processor  822 . For the UI processor  836 , the operating state of the generator  800  may dictate, for example, which elements of a UI (e.g., display screens, sounds) are presented to a user. The respective DSP and UI processors  822 ,  836  may independently maintain the current operating state of the generator  800  and recognize and evaluate possible transitions out of the current operating state. The DSP processor  822  may function as the master in this relationship and determine when transitions between operating states are to occur. The UI processor  836  may be aware of valid transitions between operating states and may confirm if a particular transition is appropriate. For example, when the DSP processor  822  instructs the UI processor  836  to transition to a specific state, the UI processor  836  may verify that requested transition is valid. In the event that a requested transition between states is determined to be invalid by the UI processor  836 , the UI processor  836  may cause the generator  800  to enter a failure mode. 
     The non-isolated stage  804  may further comprise a controller  838  for monitoring input devices (e.g., a capacitive touch sensor used for turning the generator  800  on and off, a capacitive touch screen). In certain forms, the controller  838  may comprise at least one processor and/or other controller device in communication with the UI processor  836 . In one form, for example, the controller  838  may comprise a processor (e.g., a Meg168 8-bit controller available from Atmel) configured to monitor user input provided via one or more capacitive touch sensors. In one form, the controller  838  may comprise a touch screen controller (e.g., a QT5480 touch screen controller available from Atmel) to control and manage the acquisition of touch data from a capacitive touch screen. 
     In certain forms, when the generator  800  is in a “power off” state, the controller  838  may continue to receive operating power (e.g., via a line from a power supply of the generator  800 , such as the power supply  854  discussed below). In this way, the controller  838  may continue to monitor an input device (e.g., a capacitive touch sensor located on a front panel of the generator  800 ) for turning the generator  800  on and off. When the generator  800  is in the power off state, the controller  838  may wake the power supply (e.g., enable operation of one or more DC/DC voltage converters  856  of the power supply  854 ) if activation of the “on/off” input device by a user is detected. The controller  838  may therefore initiate a sequence for transitioning the generator  800  to a “power on” state. Conversely, the controller  838  may initiate a sequence for transitioning the generator  800  to the power off state if activation of the “on/off” input device is detected when the generator  800  is in the power on state. In certain forms, for example, the controller  838  may report activation of the “on/off” input device to the UI processor  836 , which in turn implements the necessary process sequence for transitioning the generator  800  to the power off state. In such forms, the controller  838  may have no independent ability for causing the removal of power from the generator  800  after its power on state has been established. 
     In certain forms, the controller  838  may cause the generator  800  to provide audible or other sensory feedback for alerting the user that a power on or power off sequence has been initiated. Such an alert may be provided at the beginning of a power on or power off sequence and prior to the commencement of other processes associated with the sequence. 
     In certain forms, the isolated stage  802  may comprise an instrument interface circuit  840  to, for example, provide a communication interface between a control circuit of a surgical instrument (e.g., a control circuit comprising handpiece switches) and components of the non-isolated stage  804 , such as, for example, the logic device  816 , the DSP processor  822 , and/or the UI processor  836 . The instrument interface circuit  840  may exchange information with components of the non-isolated stage  804  via a communication link that maintains a suitable degree of electrical isolation between the isolated and non-isolated stages  802 ,  804 , such as, for example, an IR-based communication link. Power may be supplied to the instrument interface circuit  840  using, for example, a low-dropout voltage regulator powered by an isolation transformer driven from the non-isolated stage  804 . 
     In one form, the instrument interface circuit  840  may comprise a logic circuit  842  (e.g., logic circuit, programmable logic circuit, PGA, FPGA, PLD) in communication with a signal conditioning circuit  844 . The signal conditioning circuit  844  may be configured to receive a periodic signal from the logic circuit  842  (e.g., a 2 kHz square wave) to generate a bipolar interrogation signal having an identical frequency. The interrogation signal may be generated, for example, using a bipolar current source fed by a differential amplifier. The interrogation signal may be communicated to a surgical instrument control circuit (e.g., by using a conductive pair in a cable that connects the generator  800  to the surgical instrument) and monitored to determine a state or configuration of the control circuit. The control circuit may comprise a number of switches, resistors, and/or diodes to modify one or more characteristics (e.g., amplitude, rectification) of the interrogation signal such that a state or configuration of the control circuit is uniquely discernable based on the one or more characteristics. In one form, for example, the signal conditioning circuit  844  may comprise an ADC circuit for generating samples of a voltage signal appearing across inputs of the control circuit resulting from passage of interrogation signal therethrough. The logic circuit  842  (or a component of the non-isolated stage  804 ) may then determine the state or configuration of the control circuit based on the ADC circuit samples. 
     In one form, the instrument interface circuit  840  may comprise a first data circuit interface  846  to enable information exchange between the logic circuit  842  (or other element of the instrument interface circuit  840 ) and a first data circuit disposed in or otherwise associated with a surgical instrument. In certain forms, for example, a first data circuit may be disposed in a cable integrally attached to a surgical instrument handpiece or in an adaptor for interfacing a specific surgical instrument type or model with the generator  800 . The first data circuit may be implemented in any suitable manner and may communicate with the generator according to any suitable protocol, including, for example, as described herein with respect to the first data circuit. In certain forms, the first data circuit may comprise a non-volatile storage device, such as an EEPROM device. In certain forms, the first data circuit interface  846  may be implemented separately from the logic circuit  842  and comprise suitable circuitry (e.g., discrete logic devices, a processor) to enable communication between the logic circuit  842  and the first data circuit. In other forms, the first data circuit interface  846  may be integral with the logic circuit  842 . 
     In certain forms, the first data circuit may store information pertaining to the particular surgical instrument with which it is associated. Such information may include, for example, a model number, a serial number, a number of operations in which the surgical instrument has been used, and/or any other type of information. This information may be read by the instrument interface circuit  840  (e.g., by the logic circuit  842 ), transferred to a component of the non-isolated stage  804  (e.g., to logic device  816 , DSP processor  822 , and/or UI processor  836 ) for presentation to a user via an output device and/or for controlling a function or operation of the generator  800 . Additionally, any type of information may be communicated to the first data circuit for storage therein via the first data circuit interface  846  (e.g., using the logic circuit  842 ). Such information may comprise, for example, an updated number of operations in which the surgical instrument has been used and/or dates and/or times of its usage. 
     As discussed previously, a surgical instrument may be detachable from a handpiece (e.g., the multifunction surgical instrument may be detachable from the handpiece) to promote instrument interchangeability and/or disposability. In such cases, conventional generators may be limited in their ability to recognize particular instrument configurations being used and to optimize control and diagnostic processes accordingly. The addition of readable data circuits to surgical instruments to address this issue is problematic from a compatibility standpoint, however. For example, designing a surgical instrument to remain backwardly compatible with generators that lack the requisite data reading functionality may be impractical due to, for example, differing signal schemes, design complexity, and cost. Forms of instruments discussed herein address these concerns by using data circuits that may be implemented in existing surgical instruments economically and with minimal design changes to preserve compatibility of the surgical instruments with current generator platforms. 
     Additionally, forms of the generator  800  may enable communication with instrument-based data circuits. For example, the generator  800  may be configured to communicate with a second data circuit contained in an instrument (e.g., the multifunction surgical instrument). In some forms, the second data circuit may be implemented in a many similar to that of the first data circuit described herein. The instrument interface circuit  840  may comprise a second data circuit interface  848  to enable this communication. In one form, the second data circuit interface  848  may comprise a tri-state digital interface, although other interfaces may also be used. In certain forms, the second data circuit may generally be any circuit for transmitting and/or receiving data. In one form, for example, the second data circuit may store information pertaining to the particular surgical instrument with which it is associated. Such information may include, for example, a model number, a serial number, a number of operations in which the surgical instrument has been used, and/or any other type of information. 
     In some forms, the second data circuit may store information about the electrical and/or ultrasonic properties of an associated ultrasonic transducer, end effector, or ultrasonic drive system. For example, the first data circuit may indicate a burn-in frequency slope, as described herein. Additionally or alternatively, any type of information may be communicated to second data circuit for storage therein via the second data circuit interface  848  (e.g., using the logic circuit  842 ). Such information may comprise, for example, an updated number of operations in which the instrument has been used and/or dates and/or times of its usage. In certain forms, the second data circuit may transmit data acquired by one or more sensors (e.g., an instrument-based temperature sensor). In certain forms, the second data circuit may receive data from the generator  800  and provide an indication to a user (e.g., a light emitting diode indication or other visible indication) based on the received data. 
     In certain forms, the second data circuit and the second data circuit interface  848  may be configured such that communication between the logic circuit  842  and the second data circuit can be effected without the need to provide additional conductors for this purpose (e.g., dedicated conductors of a cable connecting a handpiece to the generator  800 ). In one form, for example, information may be communicated to and from the second data circuit using a one-wire bus communication scheme implemented on existing cabling, such as one of the conductors used transmit interrogation signals from the signal conditioning circuit  844  to a control circuit in a handpiece. In this way, design changes or modifications to the surgical instrument that might otherwise be necessary are minimized or reduced. Moreover, because different types of communications implemented over a common physical channel can be frequency-band separated, the presence of a second data circuit may be “invisible” to generators that do not have the requisite data reading functionality, thus enabling backward compatibility of the surgical instrument. 
     In certain forms, the isolated stage  802  may comprise at least one blocking capacitor  850 - 1  connected to the drive signal output  810   b  to prevent passage of DC current to a patient. A single blocking capacitor may be required to comply with medical regulations or standards, for example. While failure in single-capacitor designs is relatively uncommon, such failure may nonetheless have negative consequences. In one form, a second blocking capacitor  850 - 2  may be provided in series with the blocking capacitor  850 - 1 , with current leakage from a point between the blocking capacitors  850 - 1 ,  850 - 2  being monitored by, for example, an ADC circuit  852  for sampling a voltage induced by leakage current. The samples may be received by the logic circuit  842 , for example. Based changes in the leakage current (as indicated by the voltage samples), the generator  800  may determine when at least one of the blocking capacitors  850 - 1 ,  850 - 2  has failed, thus providing a benefit over single-capacitor designs having a single point of failure. 
     In certain forms, the non-isolated stage  804  may comprise a power supply  854  for delivering DC power at a suitable voltage and current. The power supply may comprise, for example, a 400 W power supply for delivering a 48 VDC system voltage. The power supply  854  may further comprise one or more DC/DC voltage converters  856  for receiving the output of the power supply to generate DC outputs at the voltages and currents required by the various components of the generator  800 . As discussed above in connection with the controller  838 , one or more of the DC/DC voltage converters  856  may receive an input from the controller  838  when activation of the “on/off” input device by a user is detected by the controller  838  to enable operation of, or wake, the DC/DC voltage converters  856 . 
       FIG. 21  illustrates an example of a generator  900 , which is one form of the generator  800  ( FIG. 21 ). The generator  900  is configured to deliver multiple energy modalities to a surgical instrument. The generator  900  provides RF and ultrasonic signals for delivering energy to a surgical instrument either independently or simultaneously. The RF and ultrasonic signals may be provided alone or in combination and may be provided simultaneously. As noted above, at least one generator output can deliver multiple energy modalities (e.g., ultrasonic, bipolar or monopolar RF, irreversible and/or reversible electroporation, and/or microwave energy, among others) through a single port, and these signals can be delivered separately or simultaneously to the end effector to treat tissue. 
     The generator  900  comprises a processor  902  coupled to a waveform generator  904 . The processor  902  and waveform generator  904  are configured to generate a variety of signal waveforms based on information stored in a memory coupled to the processor  902 , not shown for clarity of disclosure. The digital information associated with a waveform is provided to the waveform generator  904  which includes one or more DAC circuits to convert the digital input into an analog output. The analog output is fed to an amplifier  1106  for signal conditioning and amplification. The conditioned and amplified output of the amplifier  906  is coupled to a power transformer  908 . The signals are coupled across the power transformer  908  to the secondary side, which is in the patient isolation side. A first signal of a first energy modality is provided to the surgical instrument between the terminals labeled ENERGY1 and RETURN. A second signal of a second energy modality is coupled across a capacitor  910  and is provided to the surgical instrument between the terminals labeled ENERGY2 and RETURN. It will be appreciated that more than two energy modalities may be output and thus the subscript “n” may be used to designate that up to n ENERGYn terminals may be provided, where n is a positive integer greater than 1. It also will be appreciated that up to “n” return paths RETURNn may be provided without departing from the scope of the present disclosure. 
     A first voltage sensing circuit  912  is coupled across the terminals labeled ENERGY1 and the RETURN path to measure the output voltage therebetween. A second voltage sensing circuit  924  is coupled across the terminals labeled ENERGY2 and the RETURN path to measure the output voltage therebetween. A current sensing circuit  914  is disposed in series with the RETURN leg of the secondary side of the power transformer  908  as shown to measure the output current for either energy modality. If different return paths are provided for each energy modality, then a separate current sensing circuit should be provided in each return leg. The outputs of the first and second voltage sensing circuits  912 ,  924  are provided to respective isolation transformers  916 ,  922  and the output of the current sensing circuit  914  is provided to another isolation transformer  918 . The outputs of the isolation transformers  916 ,  928 ,  922  in the on the primary side of the power transformer  908  (non-patient isolated side) are provided to a one or more ADC circuit  926 . The digitized output of the ADC circuit  926  is provided to the processor  902  for further processing and computation. The output voltages and output current feedback information can be employed to adjust the output voltage and current provided to the surgical instrument and to compute output impedance, among other parameters. Input/output communications between the processor  902  and patient isolated circuits is provided through an interface circuit  920 . Sensors also may be in electrical communication with the processor  902  by way of the interface circuit  920 . 
     In one aspect, the impedance may be determined by the processor  902  by dividing the output of either the first voltage sensing circuit  912  coupled across the terminals labeled ENERGY1/RETURN or the second voltage sensing circuit  924  coupled across the terminals labeled ENERGY2/RETURN by the output of the current sensing circuit  914  disposed in series with the RETURN leg of the secondary side of the power transformer  908 . The outputs of the first and second voltage sensing circuits  912 ,  924  are provided to separate isolations transformers  916 ,  922  and the output of the current sensing circuit  914  is provided to another isolation transformer  916 . The digitized voltage and current sensing measurements from the ADC circuit  926  are provided the processor  902  for computing impedance. As an example, the first energy modality ENERGY1 may be ultrasonic energy and the second energy modality ENERGY2 may be RF energy. Nevertheless, in addition to ultrasonic and bipolar or monopolar RF energy modalities, other energy modalities include irreversible and/or reversible electroporation and/or microwave energy, among others. Also, although the example illustrated in  FIG. 21  shows a single return path RETURN may be provided for two or more energy modalities, in other aspects, multiple return paths RETURNn may be provided for each energy modality ENERGYn. Thus, as described herein, the ultrasonic transducer impedance may be measured by dividing the output of the first voltage sensing circuit  912  by the current sensing circuit  914  and the tissue impedance may be measured by dividing the output of the second voltage sensing circuit  924  by the current sensing circuit  914 . 
     As shown in  FIG. 21 , the generator  900  comprising at least one output port can include a power transformer  908  with a single output and with multiple taps to provide power in the form of one or more energy modalities, such as ultrasonic, bipolar or monopolar RF, irreversible and/or reversible electroporation, and/or microwave energy, among others, for example, to the end effector depending on the type of treatment of tissue being performed. For example, the generator  900  can deliver energy with higher voltage and lower current to drive an ultrasonic transducer, with lower voltage and higher current to drive RF electrodes for sealing tissue, or with a coagulation waveform for spot coagulation using either monopolar or bipolar RF electrosurgical electrodes. The output waveform from the generator  900  can be steered, switched, or filtered to provide the frequency to the end effector of the surgical instrument. The connection of an ultrasonic transducer to the generator  900  output would be preferably located between the output labeled ENERGY1 and RETURN as shown in  FIG. 21 . In one example, a connection of RF bipolar electrodes to the generator  900  output would be preferably located between the output labeled ENERGY2 and RETURN. In the case of monopolar output, the preferred connections would be active electrode (e.g., pencil or other probe) to the ENERGY2 output and a suitable return pad connected to the RETURN output. 
     Additional details are disclosed in U.S. Patent Application Publication No. 2017/0086914, titled TECHNIQUES FOR OPERATING GENERATOR FOR DIGITALLY GENERATING ELECTRICAL SIGNAL WAVEFORMS AND SURGICAL INSTRUMENTS, which published on Mar. 30, 2017, which is herein incorporated by reference in its entirety. 
     Robotic surgical systems can be used in minimally invasive medical procedures. During such medical procedures, a patient can be placed on a platform adjacent to a robotic surgical system, and a surgeon can be positioned at a console that is remote from the platform and/or from the robot. For example, the surgeon can be positioned outside the sterile field that surrounds the surgical site. The surgeon provides input to a user interface via an input device at the console to manipulate a surgical tool coupled to an arm of the robotic system. The input device can be a mechanical input devices such as control handles or joysticks, for example, or contactless input devices such as optical gesture sensors, for example. 
     The robotic surgical system can include a robot tower supporting one or more robotic arms. At least one surgical tool (e.g. an end effector and/or endoscope) can be mounted to the robotic arm. The surgical tool(s) can be configured to articulate relative to the respective robotic arm via an articulating wrist assembly and/or to translate relative to the robotic arm via a linear slide mechanism, for example. During the surgical procedure, the surgical tool can be inserted into a small incision in a patient via a cannula or trocar, for example, or into a natural orifice of the patient to position the distal end of the surgical tool at the surgical site within the body of the patient. Additionally or alternatively, the robotic surgical system can be employed in an open surgical procedure in certain instances. 
     A schematic of a robotic surgical system  15000  is depicted in  FIG. 22 . The robotic surgical system  15000  includes a central control unit  15002 , a surgeon&#39;s console  15012 , a robot  15022  including one or more robotic arms  15024 , and a primary display  15040  operably coupled to the control unit  15002 . The surgeon&#39;s console  15012  includes a display  15014  and at least one manual input device  15016  (e.g., switches, buttons, touch screens, joysticks, gimbals, etc.) that allow the surgeon to telemanipulate the robotic arms  15024  of the robot  15022 . The reader will appreciate that additional and alternative input devices can be employed. 
     The central control unit  15002  includes a processor  15004  operably coupled to a memory  15006 . The processor  15004  includes a plurality of inputs and outputs for interfacing with the components of the robotic surgical system  15000 . The processor  15004  can be configured to receive input signals and/or generate output signals to control one or more of the various components (e.g., one or more motors, sensors, and/or displays) of the robotic surgical system  15000 . The output signals can include, and/or can be based upon, algorithmic instructions which may be pre-programmed and/or input by the surgeon or another clinician. The processor  15004  can be configured to accept a plurality of inputs from a user, such as the surgeon at the console  15012 , and/or may interface with a remote system. The memory  15006  can be directly and/or indirectly coupled to the processor  15004  to store instructions and/or databases. 
     The robot  15022  includes one or more robotic arms  15024 . Each robotic arm  15024  includes one or more motors  15026  and each motor  15026  is coupled to one or more motor drivers  15028 . For example, the motors  15026 , which can be assigned to different drivers and/or mechanisms, can be housed in a carriage assembly or housing. In certain instances, a transmission intermediate a motor  15026  and one or more drivers  15028  can permit coupling and decoupling of the motor  15026  to one or more drivers  15028 . The drivers  15028  can be configured to implement one or more surgical functions. For example, one or more drivers  15028  can be tasked with moving a robotic arm  15024  by rotating the robotic arm  15024  and/or a linkage and/or joint thereof. Additionally, one or more drivers  15028  can be coupled to a surgical tool  15030  and can implement articulating, rotating, clamping, sealing, stapling, energizing, firing, cutting, and/or opening, for example. In certain instances, the surgical tools  15030  can be interchangeable and/or replaceable. Examples of robotic surgical systems and surgical tools are further described herein. 
     The reader will readily appreciate that the computer-implemented interactive surgical system  100  ( FIG. 1 ) and the computer-implemented interactive surgical system  200  ( FIG. 9 ) can incorporate the robotic surgical system  15000 . Additionally or alternatively, the robotic surgical system  15000  can include various features and/or components of the computer-implemented interactive surgical systems  100  and  200 . 
     In one exemplification, the robotic surgical system  15000  can encompass the robotic system  110  ( FIG. 2 ), which includes the surgeon&#39;s console  118 , the surgical robot  120 , and the robotic hub  122 . Additionally or alternatively, the robotic surgical system  15000  can communicate with another hub, such as the surgical hub  106 , for example. In one instance, the robotic surgical system  15000  can be incorporated into a surgical system, such as the computer-implemented interactive surgical system  100  ( FIG. 1 ) or the computer-implemented interactive surgical system  200  ( FIG. 9 ), for example. In such instances, the robotic surgical system  15000  may interact with the cloud  104  or the cloud  204 , respectively, and the surgical hub  106  or the surgical hub  206 , respectively. In certain instances, a robotic hub or a surgical hub can include the central control unit  15002  and/or the central control unit  15002  can communicate with a cloud. In other instances, a surgical hub can embody a discrete unit that is separate from the central control unit  15002  and which can communicate with the central control unit  15002 . 
     The description now turns to robotic surgical systems that include algorithms for controlling a robotic tool driver. In one aspect, the algorithms control a distal portion of a robotic arm and maintain a motor housing for driving modular robotic surgical tools. In various aspects, the following robotic surgical tool driver control algorithms are generally directed to: (1) sensing and control algorithms for safely and cooperatively operating the robotic surgical system, (2) controlling close interaction between components of the robotic surgical system, and (3) local sensing of functional parameters by measuring more that one physical input. The various robotic surgical tool driver control algorithms described hereinbelow may be implemented in a robotic surgical platform such as the one described with reference to  FIGS. 1-22 . Accordingly, throughout this description, for the sake of conciseness and brevity, the operation of the robotic surgical system will be described with reference to  FIG. 22 , which illustrates a schematic of a robotic surgical system  15000  that includes a central control unit  15002  (i.e., a central control circuit), a surgeon&#39;s console  15012 , a robot  15022  that includes one or more robotic arms  15024 , and a primary display  15040  operably coupled to the central control circuit  15002 . It will be appreciated that the central control circuit  15002  may be implemented as a control circuit as defined herein. 
     Robotic Surgical System with Safety and Cooperative Sensing Control 
     In various aspects, the present disclosure provides robotic surgical systems incorporating safety and cooperative sensing/control algorithms. The algorithms control robotic tool driver motors based on sensing parameters within the motor and/or motor control circuit in addition to external forces exerted on the motor and/or motor control circuit. In one aspect, a robotic controlled surgical end-effector actuation motor may be controlled based on a parameter of a sensed externally applied force to the end-effector. In one aspect, the externally applied force can be sensed by the robotic arm relative to the end-effector. In another aspect, externally derived control forces can be sensed from within the surgical end-effector by resolving ground response forces compared to internally generated forces. In yet another aspect, the externally derived control forces can be measured as reaction forces within the robotic arm itself. These and other variations of algorithms for controlling robotic surgical tool driver motors based on sensing parameters within the motor and/or the motor control circuit in addition to forces exerted external to the motor and/or the motor control circuit are described hereinbelow and may be implemented on the robotic platform described with reference to  FIGS. 1-22  hereinabove. 
       FIG. 23  is a graphical illustration  6000  of an algorithm implemented in a robotic surgical system for controlling robotic surgical tools based on motor current (I) and externally sensed parameters according to at least one aspect of the present disclosure. In the illustrated aspects, the robotic surgical tool is an end-effector coupled to an articulatable arm. The end-effector includes a clamp to grasp tissue. In various aspects, the externally sensed parameters include robotic tool arm force F arm , robotic tool clamp arm torque T arm , or robotic tool clamp force F clamp , among other parameters. The graphical illustration  6000  includes three separate graphs  6002 ,  6004 ,  6006 . A first graph  6002  depicts robotic arm force F arm , or robotic clamp arm torque T arm , as a function of time t, a second graph  6004  depicts motor current (I) as a function of time t, and a third graph  6006  depicts robotic tool clamp arm force F clamp  as a function of time t. 
       FIG. 24  illustrates a distal portion of a motor driven powered robotic surgical tool  6010  grasping tissue  6012  under low lateral tension according to at least one aspect of the present disclosure. The state of the robotic surgical tool  6010  grasping tissue  6012  under low lateral tension is represented in solid lines in the three graphs  6002 ,  6004 ,  6006  depicted in  FIG. 23 . The robotic surgical tool  6010  includes an arm  6024 , an end-effector  6016 , and an articulatable joint  6014  therebetween. The end-effector  6016  includes two jaws  6018 ,  6020  for clamping tissue  6012  therebetween and applying a clamping force F clampA  to the tissue  6012  under the control of a motor and/or motor control circuit resulting in low macro tension. The direction of the lateral force F tissueA  applied to the tissue  6012  is indicated by arrow  6022 . A downward force F armA  applied to the arm  6024  in the direction indicated by arrow  6023  causes a torque T jawA  to be applied to the end-effector  6016  and the jaws  6018 ,  6020 . 
       FIG. 25  illustrates a distal portion of the motor driven powered robotic surgical tool  6010  grasping tissue  6026  under high downward tension according to at least one aspect of the present disclosure. The state of the robotic surgical tool  6010  grasping tissue  6026  under high downward tension is represented in dashed line in the three graphs  6002 ,  6004 ,  6006  depicted in  FIG. 23 . The clamping force F clampB  is applied to the tissue  6026  by a motor controlled by a motor control circuit. The clamping force F clampB  results in high macro tension. The direction of the downward force F tissueB  applied to the tissue  6026  is indicated by arrow  6028 . The downward force F armB  applied to the arm  6024  of the robotic surgical tool  6010  causes a torque T jawB  to be applied to the end-effector  6016  and the jaws  6018 ,  6020  in the direction indicated by arrow  6029 . 
     The forces F tissueA , F clampA  may be sensed by one or more than one strain gauge sensor located within the jaws  6018 ,  6020  of the end-effector  6016 . The arm force F armA  may be sensed by a strain gauge sensor located either on the articulation joint  6014  or the arm  6024 . The torque T jawA  may be sensed by a torque sensor located at the articulation joint  6014 . Likewise, the forces F tissueB , F clampB  may be sensed by one or more than one strain gauge sensor located within the jaws  6018 ,  6020  of the end-effector  6016  and the force F armB  may be sensed by a strain gauge sensor located either on the articulation joint  6014  or the arm  6024 . The torque T jawB  may be sensed by a torque sensor located at the articulation joint  6014 . The outputs of the force and torque sensors may be accomplished by one or more than one of the circuits illustrated in  FIGS. 9, 10, 12, and 16-22 . Various techniques for implementing sensors into the jaws  6018 ,  6020  of an end-effector  6016  are described with respect to  FIGS. 80-100  and associated description in the specification in commonly owned US Patent Publication No. 2017/0202591A1 filed Dec. 16, 2016, which is herein incorporated by reference in its entirety. 
     The three graphs  6002 ,  6004 ,  6006  depicted in  FIG. 23  will now be described in combination with the motor driven powered robotic surgical tool  6010  depicted in  FIGS. 24-25 . The first graph  6002  depicted in  FIG. 23  depicts arm forces  6003 ,  6005  (F arm ), or arm torque T arm , applied to the arm  6024  as a function of time t, according to at least one aspect of the present disclosure. The first arm force  6003  (F arm ) shown in solid line is the force applied to the arm  6024  when the powered robotic surgical tool  6010  grasps tissue  6012  under low lateral tension, as depicted in  FIG. 24 . The first arm force  6003  (F arm ) remains constant over the time period shown. The second arm force  6005  (F arm ) shown in dashed line is the force applied to the arm  6024  when the powered robotic surgical tool  6010  grasps tissue  6026  under high downward tension, as depicted in  FIG. 25 . The second arm force  6005  (F arm ) also remains constant over the time period shown. As shown, the low lateral tension arm force  6003  (F arm ) applied to the arm  6024  is lower than the high downward tension arm force  6005  (F arm ) applied to the arm  6024 . 
     The second graph  6004  depicted in  FIG. 23  depicts currents  6007 ,  6009  (I) drawn by the motor as a function of time (t) according to at least one aspect of the present disclosure. The two motor currents  6007 ,  6009  (I) represent the current (I) drawn by the motor of the robotic surgical tool  6010  for the two different states depicted in  FIGS. 24-25 , respectively. The first motor current  6007  (I) shown in solid line is the motor current drawn by the motor when the robotic surgical tool  6010  grasps tissue  6012  under low lateral tension, as depicted in  FIG. 24 , and second motor current  6009  (I) shown in dashed line is the current drawn by the motor when the robotic surgical tool  6010  grasps tissue  6026  under high downward tension, as depicted in  FIG. 25 . As shown, both motor currents  6007 ,  6009  (I) ramp up from zero over an initial period and then level off to a constant during the time period shown. The first current  6007  (I) is lower over the time period shown than the second motor current  6009 . 
     The third graph  6006  depicted in  FIG. 23  depicts two clamp forces F clamp  applied to the jaws  6018 ,  6020  of the end-effector  6016  as a function of time (t) according to at least one aspect of the present disclosure. The first clamp force  6011  (F clamp ) shown in solid line is the force applied to the tissue  6012  under low lateral tension. The second clamp force  6013  (F clamp ) shown in dashed line is the force applied to the tissue  6026  under high downward tension. For comparison purposes, the first and second clamp forces  6011 ,  6013  (F clamp ) are substantially equal over the time period shown. 
     With reference now to  FIGS. 23-25 , the first clamp force  6011  (F clampA ) and the second clamp force  6013  (F clamp  B) (or the different pressures applied to the tissue  6012 ,  6026 ) are based on the rotational orientation of the jaws  6018 ,  6020  relative to the end-effector  6016  torque T jawA , T jawB  and therefore the first and second clamp forces  6011  (F clampA ),  6013  (F clampB ) sensed by the powered robotic surgical tool  6010  exerted on the tissue  6012 ,  6026 . In one aspect, the first and second clamp forces  6011  (F clampA ),  6013  (F clampB ) sensed by the powered device  6010  may be compared and then compensating for the motor torques created by the actuation of the drive motors based on the comparison. The motor control circuit could then be impacted based on a combination of the first and second motor currents  6007 ,  6009  (I) sensed by the motor control circuit, the torque created by the motor to its ground, and the tissue forces  6011  (F clampA ),  6013  (F clampB ) exerted on the robotic surgical system. 
     Without limitation, the robotic surgical tool  6010  may be a motor driven surgical stapler, an ultrasonic device, an electrosurgical device, or a combination device that incorporates one or more features of the stapler, ultrasonic, and electrosurgical devices in a single combination device. In one example, the robotic surgical tool  6010  is a motor driven stapler comprising a linear actuator that includes a longitudinally reciprocateable firing bar to open and close the jaws  6018 ,  6020 , drive staples through tissue  6012 ,  6026 , and drive a knife through the stapled portion of the tissue  6012 ,  6026  clamped between the jaws  6018 ,  6020 . In a linear actuator, the linear firing rate of the actuator is controlled by a motor and thus the firing rate of the actuator can be controlled by controlling the speed of the motor. The firing rate of the actuator can be reduced when thick tissue  6012 ,  6026  is sensed between the jaws  6018 ,  6020  of the end-effector  6016  and the firing rate can be further limited as the macro tissue tension is sensed through the comparison of the differences in torques sensed by the robotic surgical tool  6010  caused by the advancement motor. A slower firing rate under higher macro tissue tensions states improves staple formation by allowing more time for the tissue to stabilize by creeping before stapling and cutting the tissue  6012 ,  6026  as the pressure wave moves longitudinally proximal to the distal end during firing. 
     In another example, the energy required to produce a suitable actuation force to clamp the jaws  6018 ,  6020  on the tissue  6012 ,  6026  can be limited based on the initial contact with the tissue  6012 ,  6026  and the rate of tissue compression. The energy may be further reduced based on externally applied macro tension exerted on the knife by the tissue  6012 ,  6026  due to the support forces sensed by lifting the tissue  6012 ,  6026  while clamping. By way of comparison, the differences in the torques sensed by the stapler instrument and the torques generated by the actuation motors. 
     The following section describes a robotic surgical system for monitoring a motor control circuit and adjusting the rate, current, or torque of an adjacent motor control circuit.  FIG. 26  is a graphical illustration  6030  of an algorithm implemented in a robotic surgical system for monitoring a parameter of a control circuit of one motor within a motor pack to influence the control of an adjacent motor control circuit within the motor pack according to at least one aspect of the present disclosure. The graphical illustration  6030  includes three separate graphs  6032 ,  6034 ,  6036 . A first graph  6032  depicts impedance  6035  (Z) of a generator  6070  ( FIG. 27 ) as a function of time (t), a second graph  6036  depicts jaw clamp force  6038  (F c ) applied by a clamp jaw motor  6040  ( FIG. 27 ) as a function of time (t), and the third graph  6036  depicts knife advancement force  6044  (F knife ) applied by a knife motor  6046  as a function of time (t). 
       FIG. 27  illustrates the motor driven powered robotic surgical tool  6050  positioned on a linear slide  6074  attached to a robotic arm  6052  according to at least one aspect of the present disclosure. The motor driven powered robotic surgical tool  6050  includes a clamp jaw motor  6040  to open and close the jaws  6056 ,  6058  of the end-effector  6060 . The motor driven powered robotic surgical tool  6050  also includes a knife motor  6046  to advance and retract a knife  6064 . The end-effector  6060  includes electrodes for delivering RF energy to the tissue clamped between the jaws  6056 ,  6058  and a knife  6064  for cutting tissue once it has been suitably sealed with RF energy. The motor driven powered robotic surgical tool  6050  also includes an arm  6066  and an articulatable joint  6068 . Power is delivered to the motor driven powered robotic surgical tool  6050  from a generator  6070  coupled to the motor driven powered robotic surgical tool  6050  through a cable  6072 . Electrical power to operate the motors  6040 ,  6046  also may be coupled through the cable  6072 . 
     With reference now to both  FIGS. 26-27 , the first graph  6032  shown in  FIG. 26  depicts generator  6070  impedance  6035  (Z) as a function of time (t) from to over a predetermined period. The impedance  6035  (Z) is initially a nonzero value that decreases as pressure is applied to the tissue by clamping the jaws  6056 ,  6058  on the tissue while applying RF energy, supplied by the generator  6070 , through the electrodes in the jaws  6056 ,  6058 . As the RF energy and clamping pressure reduce the liquid content of the tissue, the impedance  6034  (Z) decreases and flattens out for a period of time until the tissue starts to sufficiently heat up and dehydrate causing the impedance  6035  (Z) to increase. At time t 1 , the impedance  6035  (Z) reaches a predetermined maximum value  6037 , which can be used to trigger a number of functions. One function, for example, is cutting off the energy supplied by the generator  6070  to stop heating the tissue before cutting it. The impedance  6035  (Z) curve resembles a bathtub and may be referred to as a “bathtub curve.” 
     With reference still to both  FIGS. 26-27 , the second graph  6034  shown in  FIG. 26  depicts jaw clamp force  6038  (F c ) applied by the clamp jaw motor  6040  as a function of time (t). At time to, the clamp jaw force  6038  (F c ) is initially a first value F c1  above zero. Over the time period t 1 , as the tissue is heated, the clamp jaw force  6038  (F c ) decreases nonlinearly to a second value F c2 , below the first value F c1 , at time t 1 . This coincides with the maximum impedance (Z) value  6037  in the first graph  6032 . The ratio of F c1  to F c2  can be selected to be greater than a predetermined threshold as follows: 
                   F     c   ⁢   1         F     c   ⁢   2         &gt;     ⁢   Threshold         
such that as the impedance  6035  (Z) varies from t 0  to t 1 , the clamp jaw force  6038  (F c ) drops nonlinearly from F c1  to F c2 , at which point the energy from the generator  6070  is cut off and the knife motor  6046  is actuated as shown in the third graph  6042 .
 
     With reference still to both  FIGS. 26-27 , the third graph  6044  shown in  FIG. 26  depicts knife advancement force  6044  (F knife ) applied by the knife motor  6046  as a function of time (t). Between to and t 1 , prior to the impedance  6035  (Z) reaching the predetermined maximum value  6037 , the knife motor  6046  is off and thus the knife advancement force  6043  (F knife ) is zero. When the impedance  6035  (Z) reaches the predetermined maximum value  6037  and the ratio 
               F     c   ⁢           ⁢   1         F     c   ⁢           ⁢   2             
is greater than the predetermined Threshold, the RF energy supplied by the generator  6070  is cut off and the knife motor  6046  is actuated to advance the knife  6064  to cut tissue located between the jaws  6056 ,  6058  of the end-effector  6060 .
 
     With reference still to both  FIGS. 26-27 , the motor driven powered surgical robotic tool  6050  may be configured to limit the gripping force generated by the jaw clamp motor  6040  based on the actuation force, rate, or acceleration of the articulation motor being commanded to operate in parallel to the jaw clamp motor  6040 . 
     Furthermore, monitoring the clamping force required to maintain a fixed tissue compression can be used in addition to other electrical methods to inform knife motions (e.g., initiation time, speed, etc.). 
       FIGS. 28-29  illustrate a robotic surgical system and method for sensing forces applied by a robotic surgical tool rotation motor assembly or linear slide and controlling jaw-to-jaw forces based on externally applied torsion along with gripping force generated by the robotic surgical tool actuation motor according to at least one aspect of the present disclosure. As depicted in  FIGS. 28-29 , first and second forces or reactions are sensed to accurately measure cumulative applied forces.  FIG. 28  illustrates a first robotic arm  6080  in a first position A according to at least one aspect of the present disclosure. The robotic arm  6080  includes a rotation portion  6082  rotatably mounted to a base  6084 , an articulation portion  6086 , and a linear slide portion  6088 . A motor driven surgical robotic tool  6090  is attached to a linear slide  6091 . The motor driven surgical robotic tool  6090  device may be any one of the motor driven devices disclosed herein, including for example, the motor driven surgical robotic tools  6010 ,  6050  depicted in  FIGS. 24, 25 and 27 , without limitation. The motor driven surgical robotic tool  6090  includes a motor pack  6092 , a shaft  6094 , and an end-effector  6096  that includes a first and second jaw  6098 ,  6099 . The base  6084  of the robotic arm  6080  includes a force plate  6093  to measure the reactionary vector load torque T A  and the load force F 1  required to lift tissue grasped within the jaws  6098 ,  6099  of the end-effector  6096 . The jaws  6098 ,  6099  are positioned at a distance x 1 , y 1 , z 1  from the base  6084  of the robotic arm  6080 . 
       FIG. 29  illustrates a second robotic arm  6100  in a second position B according to at least one aspect of the present disclosure. The robotic arm  6100  includes a rotation portion  6102  rotatably mounted to a base  6104 , an articulation portion  6106 , and a linear slide portion  6108 . A motor driven surgical robotic tool  6110  is attached to the linear slide  6108 . The motor driven surgical robotic tool  6110  may be any one of the motor driven devices disclosed herein, including for example, the motor driven surgical robotic tools  6010 ,  6050  depicted in  FIGS. 24, 25, and 27 , without limitation. The motor driven surgical robotic tool  6110  includes a motor pack  6112 , a shaft  6114 , and an end-effector  6116  that includes a first and second jaw  6118 ,  6119 . The base  6104  of the robotic arm  6100  includes a force plate  6122  to measure the reactionary vector load torque T B  and load force F 2  required to lift tissue grasped within the jaws  6118 ,  6119  of the end-effector  6116 . The jaws  6118 ,  6119  are positioned at a distance x 2 , y 2 , z 2  from the robot base  6104  of the robotic arm  6100 . 
       FIG. 30  illustrates one aspect of the force plate  6093 ,  6122  located at the base of the robotic arm  6080 ,  6100  or operating room (OR) table to measure reactionary vector loads in x, y, z axis according to at least one aspect of the present disclosure. With reference to  FIGS. 28-30 , integrating or attaching a sensing array to the patient or OR table enables direct measurement of the forces the body is resisting with respect to a common reference location. This enables the robotic arm  6080 ,  6100  to determine not only the force applied by the motor driven robotic surgical tools  6090 ,  6110 , but to affect that measure by the resistance load entered by the body. This also enables the determination of overall macro tissue tension induced by the manipulation of an actuator such as the forces F 1  of the jaws  6098 ,  6099  and F 2  of the jaws  6118 ,  6119 . A comparison of the reactionary vector loads of the robot base  6084 ,  6104  versus x, y, z motor loads of the robotic arms  6080 ,  6100  is described below with reference to  FIG. 31 . 
       FIG. 31  is a graphical illustration  6130  of an algorithm implemented in a robotic surgical system for comparing reactionary vector loads of the robot base  6084 ,  6104  versus x, y, z axis motor loads of the robotic arms  6080 ,  6100  according to at least one aspect of the present disclosure. With reference now to  FIGS. 28-31 , the first graph  6132  depicted in  FIG. 31  illustrates a comparison of the reactionary vector load  6134  along the x axis  of the robot base  6084  and the robot motor load  6136  along the x axis  of the robot motor  6092  according to at least one aspect of the present disclosure. The second graph  6142  depicted in  FIG. 31  illustrates the comparison of the reactionary vector load  6138  along the y axis  of the robot base  6084  and the robotic motor load  6140  along the y axis  of the robot motor  6092  according to at least one aspect of the present disclosure. The third graph  6152  depicted in  FIG. 31  illustrates the comparison of the reactionary vector load  6142  along the z axis  of the robot base  6084  and the motor load  6144  along the z axis  of the robot motor  6092  according to at least one aspect of the present disclosure. As shown in the first graph  6132 , the vector load  6134  and the motor load  6136  along the x axis  of the robot base  6084  and the robot motor  6092  generally track each. Similarly, as shown in the third graph  6152 , the vector load  6142  and to motor load  6144  along the z axis  of the robot base  6154  and the robot motor  6156  also generally track each other. However, as shown in the second graph  6142 , there is an aberration  6141  between the reactionary vector load  6138  and the motor load  6140  along the y axis  of the robot base  6144  and the robot motor  6146  between time t 1  and t 2 . An encoder warning is issued when an aberration  6141  is sensed by the central control circuit  15002  ( FIG. 22 ). 
     An alternative to the secondary measure of force with respect to a common reference may include an optical measurement of tissue strain and the utilization of a predefined imaginary modulus based on the physiologic and anatomic tissue parameters. In this regard, a table of tissue properties can be utilized to create an effective modulus for the tissue based on the optically sensed tissue being manipulated. The strain can be used with the locally applied robotic surgical tools forces to determine the overall macro tissue tension being induced. 
     The process flow diagrams  6160 ,  6180 ,  6190  described hereinbelow with reference to  FIGS. 32-33  will be described with reference to  FIGS. 23-25  and the robotic platform described with reference to  FIGS. 1-22 . In particular,  FIG. 17  illustrates a schematic diagram of a robotic surgical instrument  700  configured to operate a surgical robotic surgical tool described herein according to one aspect of this disclosure. Further,  FIG. 22  illustrates a schematic of a robotic surgical system  15000  that includes a central control circuit  15002 , a surgeon&#39;s console  15012 , a robot  15022  that includes one or more robotic arms  15024 , and a primary display  15040  operably coupled to the central control circuit  15002 . The central control circuit  15002  comprise a processor  15004  coupled to a memory  15006 . It will be appreciated that the central control circuit  15002  may be implemented as a control circuit as defined herein. 
       FIG. 32  is a logic flow diagram  6160  of a process depicting a control program or a logic configuration for controlling a robotic end-effector actuation motor based on a parameter of a sensed externally applied force to the end-effector according to at least one aspect of the present disclosure. The process depicted by the flow diagram  6160  may be represented as a series of machine executable instructions stored in the memory  15006  and executed by the processor  15004  of the central control circuit  15002  of the robotic surgical system  15000  depicted in  FIG. 22 . With further reference to  FIGS. 22-25 and 32 , in accordance with the process depicted by the flow diagram  6610 , the central control circuit  15002  is configured to receive  6162  a sensed parameter from an external sensor located on a robotic surgical tool  15030  such as the powered surgical robotic tool  6010  depicted in  FIGS. 24-25  and graphically depicted in  FIG. 23 . The external sensor is configured to sense externally applied forces relative to the end-effector  6016 . The central control circuit  15002  is configured to receive  6164  a sensed motor current (I) from a motor  15026 . The central control circuit  15002  is further configured to control  6166  the motor drivers  15028  based on the received sensed parameter and the received motor current (I). In one aspect, external sensors may include a strain gauge to sense external forces applied to the end-effector  6016  such as lateral or downward tissue force F tissue , arm force F arm , or clamp force F clamp ; torque sensors to sense the torque applied to the end-effector  6016  such as T jaw . In one aspect, the control  6166  includes adjustment of end-effector  6016  clamp arm pressure P based on the rotational orientation of the jaws  6018 ,  6020  relative to the torque T and therefore the forces sensed on the robotic surgical tool or motor driven powered device  6010  exerted by the tissue  6012 ,  6026 , for example. The central control circuit  15002  is further configured to actuate  6168  the drive motors  15026 , compare  6170  the sensed external forces, and compensate  6172  for motor torque created by actuation of the drive motors  15026 . 
     Still with reference to  FIGS. 22 and 32 , the central control circuit  15002  is further configured to control the rate of the linear advancement motor  15026  when thick tissue is sensed being fired and further limit the rate of the linear advancement motor  15026  when macro tissue tension is sensed through the comparison of the differences in torques sensed by the powered surgical robotic surgical tool  6010  and caused by the advancement motor  15026 . The central control circuit  15002  is further configured to limit energy clamp arm actuation force based on initial contact with tissue and the rate of tissue compression. The central control circuit  15002  is further configured to further reduce energy clamp arm actuation force based on an externally applied macro tension sensed on the blade by the tissue and the central control circuit  15002  is further configured to compare the differences in the torques sensed by the powered surgical robotic surgical tool  6010  and the torques generated by the advancement motors  15026 . 
       FIG. 33  is a logic flow diagram  6180  of a process depicting a control program or a logic configuration for monitoring one motor pack control circuit to adjust the rate, current, or torque of an adjacent motor control circuit according to at least one aspect of the present disclosure. The process depicted by the flow diagram  6180  may be represented as a series of machine executable instructions stored in the memory  15006  and executed by the processor  15004  of the central control circuit  15002  of the robotic surgical system  15000  depicted in  FIG. 22 . With further reference to  FIGS. 22, 25-26, 33 , in accordance with the process depicted by the flow diagram  6680 , the central control circuit  15002  is configured to receive  6182  a sensed parameter from a first motor  15026  (m 1 ) control circuit located on a robotic surgical tool  15030  such as the motor driven powered surgical robotic surgical tool  6050  depicted in  FIG. 26  and graphically depicted in  FIG. 25  to adjust  6184  a parameter of a second motor  15026  (m 2 ) control circuit located on the robotic surgical tool  15030 . The first and second motors  15026  (m 1 , m 2 ) may be located within the same motor pack of the robotic surgical tool  15030 . The adjustment parameter of the second motor  15026  (m 2 ) may be the motor rate, motor current, or motor torque, for example. In one aspect, the central control circuit  15002  is further configured to limit  6186  the gripping force generated by a jaw actuation motor  15026  (m 2 ), e.g., gripping motor, based on the actuation force, rate, or acceleration of an articulation motor  15026  (m 1 ) being commanded to operate in parallel to the jaw actuation motor  15026  (m 2 ). In another aspect, the central control circuit  15002  is further configured to monitor  6188  the clamping force required to maintain a fixed compression by the jaw actuation motor  15026  (m 2 ) and inform  6189  knife motions (e.g., initiation time, speed, etc.) based on the monitored clamping force. 
       FIG. 34  is a logic flow diagram  6190  of a process depicting a control program or a logic configuration for sensing the forces applied by the robotic surgical tool rotation motor or linear slide and the control of jaw to jaw control forces based on that externally applied torsion along with the gripping force generated by the robotic surgical tool actuation motor. The process depicted by the flow diagram  6190  may be represented as a series of machine executable instructions stored in the memory  15006  and executed by the processor  15004  of the central control circuit  15002  of the robotic surgical system  15000  depicted in  FIG. 22 . With reference now to  FIGS. 22, 28-31, and 34  the central control circuit  15002  is configured to receive  6192  reactionary vector loads of the robot base  6084 ,  6104  and receive  6194  motor loads of the robotic arms  6080 ,  6100  as depicted in  FIGS. 28-30  and graphically depicted in  FIG. 31 . The central control circuit  15002  is further configured to compare  6196  the reactionary vector loads of the robot base  6084 ,  6104  and the motor loads of the robotic arms  6080 ,  6100  to determine  6198  the force applied by the robotic arms  6080 ,  6100 . The central control circuit  15002  is further configured to generate  6199  a warning when an aberration is sensed between the reactionary vector load of the robot base  6084 ,  6104  and the motor load of the robotic arm  6080 ,  6100 . 
     Robotic Surgical System for Controlling Close Operation of End-Effectors 
     In various aspects, the present disclosure provides robotic surgical systems for modifying control algorithms of robotic surgical tool drivers of a robotic arm based on its relation to another robotic arm employing distance, orientation or location of the one robotic arm position with respect to the distance, orientation or location of the other robotic arm position. In one aspect, the present disclosure provides robotic surgical systems and methods for balancing the operational kinematics of one robotic surgical tool with respect to another robotic surgical tool for operation by employing a parameter of the arm-to-arm relationship as a means to effect robotic tool driver function. In another aspect, the present disclosure provides robotic surgical systems and methods for adjusting the antagonistic relationship of one robotic arm with respect to another robotic arm based on the vertical orientation of the one robotic arm with respect to the other robotic arm. In another aspect, the present disclosure provides robotic surgical systems and methods for adjusting the torque limits or motor current limits of one robotic arm based on the orientation of another robotic arm that is adjacent to the one robotic arm and positioned at an angle with respect to the one robotic arm. 
     In various aspects, the present disclosure provides robotic surgical systems and methods of verifying jaw position or velocity based on a redundant calculation of a resulting movement from the application of motor control parameters. In one aspect, the verification may be implemented through redundant sensing arrays located within a robotic arm or robotic surgical tool. In another aspect, the verification may be implement by visual tracking and comparative analysis. 
     In various aspects, the present disclosure provides robotic surgical systems and methods of controlling at least one operational parameter of the robotic surgical tool driver for controlling a circular stapler robotic surgical tool based on another parameter measured within the robotic surgical tool driver for controlling the circular stapler. In one aspect, the operational parameter may be motor current, retraction dependent on the position, magnitude, and forces of the anvil shaft, its drivers, or cutting member. 
     In one aspect, the present disclosure provides a robotic surgical system and method with arm-to-arm correlation to provide close operation control of an end-effector. In another aspect, adjustment algorithms for one arm may be employed to compensate for arm position relative to a base position of another arm. In another aspect, kinematic control adjustment parameters may be employed to compensate for arm-to-arm variances. For example, a 3D camera can be employed to generate relative positions of the end-effectors (establishing coordinate systems for each robotic surgical tool and then positioning the robotic surgical tool relative to its perceived position). These positions can be employed to back-calculate a perceived position relative to the universal home. Differences in measurements from the arms and from the camera can be used to inform the motion algorithms for each robotic surgical tool. In another aspect, the comparative calculation of the end-effectors relative positions as determined on a 3D camera monitor may be employed to verify the robotic arm joint angles and arm attachment position. 
     In one aspect, the present disclosure provides robotic surgical systems and methods that include redundant communication connections or sensing means to verify the kinematics of the function of robotic surgical tools. In this regard, safety algorithms are employed to verify expected positioning and orientation. Various aspects of vision systems for tracking instruments and verifying robotic control motions of robotic surgical tools are illustrated in  FIGS. 35-39 . 
       FIG. 35  illustrates a robotic surgical system  7000  and method for confirming end-effector  7002  kinematics with vision system  7004  tracking according to at least one aspect of the present disclosure. The system  7000  includes end-effectors  7002  with reflectors or reflective markers  7012 ,  7018 ,  7019  to verify robotic control motions. The end-effector  7002  is coupled to a first robotic arm. The system  7000  also includes a vision system  7004  that includes an optical scope  7006  with at least one fluctuating wavelength emitter  7008 . The vision system  7004  is coupled to a second robotic arm. The end-effector  7002  includes reflective markers  7012 ,  7108 ,  7019  on a surface that can be scanned by the vision system  7004 . The reflective markers  7012 ,  7018 ,  7019  may be formed on the surface of the end-effector  7002  or may be applied to the surface of the end-effector  7002 . In one aspect, a shaft  7010  of the end-effector  7002  includes a global reflective marker  7012  disposed thereon and the upper jaw  7014  of the end-effector  7002  includes local reflective markers  7018  disposed thereon and the lower jaw  7016  of the end-effector  7002  includes local reflective markers  7019  disposed thereon. The reflective markers  7012 ,  7018 ,  7019  are coated with a polymer to allow for the reflectivity of a predefined wavelength. The end-effectors  7002  instrumented with the global and local reflective markers  7012 ,  7018 ,  7019  define the position of the end-effector  7002  based on the position and orientation of the global and local reflective markers  7012 ,  7018 ,  7019 . The global and local reflective markers  7012 ,  7018 ,  7019  may be coated or encapsulated with a polymer material that allows for reflectivity of a pre-defined wavelength of light more that other wavelengths. In one aspect, the wavelength may be selected to be inside or outside the visual spectrum. Alternatively, if a wavelength is selected within the visual spectrum, a display algorithm may be employed to remove or eliminated the spotlight reflected from the global and local reflective markers  7012 ,  7018 ,  7019  from an image before it is displayed to the user. In one aspect, the reflective markers  7012 ,  7018 ,  7019  may be formed or printed directly on the surfaces of the end-effectors  7002  or may be applied in the form of sticker to the surfaces of the end-effectors  7002  or other portions of a robotic arm. 
     In one aspect, the optical scope  7006  using the fluctuating wavelength emitter  7008  could employ a portion of the rate response to look only for reflective markers  7012 ,  7018 ,  7019  within the field of view of the optical scope  7006 . The reflective marker  7012 ,  7018 ,  7019  within the field of view of the optical scope  7006  may be used to verify the expected distances, orientation, and motions of the end-effector  7002  as it is used during the surgery, completely without the user awareness. 
       FIG. 36  illustrates a robotic surgical system  7020  and method for confirming end-effector  7002 ,  7003  kinematics with vision system  7004  tracking according to at least one aspect of the present disclosure. The system  7020  includes two end-effectors  7002 ,  7003  that include global reflectors or reflective markers  7012 ,  7013  and local reflectors or reflective markers  7018 ,  7019 ,  7021 ,  7023 , respectively, to verify robotic control motions. The two end-effectors  7002 ,  7003  are coupled to a first and third robotic arm. The system  7020  also includes a vision system  7004  that includes an optical scope  7006  with at least one fluctuating wavelength emitter  7008  that reflects light off the reflective markers  7012 ,  7013 ,  7018 ,  7019 ,  7021 ,  7023 . The vision system  7004  is coupled to a second robotic arm. Each end-effector  7002 ,  7003  is characterized by a robot sensed position  7036 ,  7038  shown in dashed line and a visually verified position  7040 ,  7042  shown in solid line. Accordingly, a distance x 1  is determined between the robot sensed position  7036  of the first end-effector  7002  and the visually verified position  7042  of the second end-effector  7003  based on light reflected by the local reflective markers  7019 . Likewise, a distance x 2  is determined between the visually verified position  7040  of the first end-effector  7002  based on light reflected by the local reflective markers  7012  and the robot sensed position  7038  of the second end-effector  7003 . Distance d 1  to a critical structure  7044  is determined between the robot sensed position  7038  of the second end-effector  7003  and distance d 2  to the critical structure  7044  is determined between the visually verified position  7042  of the second end-effector  7003  to the critical structure  7044 . The determination of the distance between the first end-effector  7002  and the critical structure  7044  can be determined in a similar manner. The critical structure  7044  is located within a boundary  7046  that is considered to be a high risk zone  7048 . A low risk zone  7050  is located outside the boundary  7046 . 
     In one aspect, the fluctuating wavelength emitters  7008  imaging source may include a regular white light source. In this case, the reflective marker  7012 ,  7018  identifiers may be reflective and of a pre-defined color (i.e., white or green). In this case, the creation of the image for display to the user would include eliminating the bright reflection while still enabling the vision system  7004  to track and correlate the robotic arm and end-effector  7002  motions and to minimize the distraction of the user by the reflection. 
       FIG. 37  illustrates a robotic surgical system  7030  and method for detecting a location  7032  of the distal end  7060  of a fixed shaft  7062  and a straight-line travel path  7064  to an intended position  7034  according to at least one aspect of the present disclosure. Here, a robotic arm  7066  is attached to a trocar  7068 , which is shown inserted through the wall  7070  of a body cavity. The trocar  7068  can rotate about a remote center of motion  7072  (RCM). The distal end  7060  of the fixed shaft  7062  is initially positioned at a first location  7032  referenced by coordinates x 1 , y 1 , z 1  and the straight-line travel path  7064  of the distal end  7060  of the fixed shaft  7062  is positioned at a second location  7034  referenced by coordinates x 2 , y 2 , z 2  after the trocar  7068  is rotated by the robotic arm  7066  about the RCM  7072  by a predetermined angular rotation. 
       FIG. 38  illustrates tracking system  7080  for a robotic surgical system defining a plurality of travel paths  7081  of the distal end  7082  of an end-effector  7083  based on velocity as the distal end  7082  of the end-effector  7083  travels form a first location  7084  to a second location  7086  according to at least one aspect of the present disclosure. The end-effector is coupled to a robotic arm. The first location  7084  of the distal end  7082  of the end-effector  7083  is referenced by coordinates x 1 , y 1 , z 1  and the second location  7086  of the distal end  7082  of the end-effector  7083  is referenced by coordinates x 2 , y 2 , z 2 . The distal end  7082  of the end-effector  7083  can travel from the first location  7084  to the second location  7086  at full velocity along an optimal travel path  7088 , however, the distal end  7082  of the end-effector  7083  can travel from the first location  7084  to the second location  7086  along an acceptable travel path  7090  if it slows down from full velocity. If the distal end  7082  of the end-effector  7083  is detected along an unacceptable travel path  7092 , the distal end  7082  of the end-effector  7083  is stopped. 
       FIG. 39  is a graphical illustration  7100  of an algorithm for detecting an error in the tracking system  7080  depicted in  FIG. 38  and corresponding changes in velocity of the distal end  7082  of the end-effector  7083  according to at least one aspect of the present disclosure. The first graph  7102  depicts detected error E t  as a function of time and the second graph  7104  is the velocity V of the distal end  7082  of the end-effector  7083  as a function of time. The detected error E t  is given by:
 
 E   t =√{square root over ( x   2   +y   2   +z   2 )}.
 
The detected error E t , the degree of deviation from what is expected, in the tracking system  7080  could result in varied and escalating responses to correct the correlation or prohibit collateral damage. As shown in the first graph  7102 , when the detected error E t  is below a first error threshold  7106  the distal end  7082  of the end-effector  7083  is within the range of the optimal travel path  7088  and can move at full velocity  7108  as shown in the second graph  7104 . When the detected error E t  is between a first error threshold  7106  and a second error threshold  7110  the distal end  7082  of the end-effector  7083  is within the range of an acceptable travel path  7090  and can move at a slower velocity  7112  than full velocity  7108  as shown in the second graph  7104 . When the detected error E t  exceeds the second error threshold  7110  the distal end  7081  of the end-effector  7082  is in the unacceptable travel path  7092  and it is stopped  7114  as shown in the second graph  7104 .
 
     With reference now to  FIGS. 35-39 , correlation of end-effector  7002 ,  7003 ,  7083  action may be determined by verifying the motion the robot is indicating the end-effector  7002 ,  7003 ,  7083  to move through to the detected motion of the local reflective markers  7012 ,  7013 ,  7018 ,  7019 ,  7021 ,  7023  motion reflections on the end-effector  7002 ,  7003 ,  7083 . If the motions do not correlate directly, the robot may be incremented through a series of countermeasures including, for example, consecutive execution of countermeasure steps or escalating the response to circumvent the countermeasure steps based on the situational awareness of the system to procedural, surgeon, or device risks. Countermeasures may include, for example, slowing the actuation of advancement of the at-risk portion of the system; identification of the issue to the user; handing off primary control measurements from the primary means to the secondary visually measured means; or shutdown and re-calibration of the sub-system; among others. 
     A probability assessment may be employed by the robotic surgical system to determine the level of risk in process of operating with the variance detected. This risk probability may take into account aspects such as the magnitude of the variance, whether it is increasing or decreasing, proximity to critical anatomic structures or steps, risk of this particular sub-system resulting in a jammed or can not remove situation, among others. 
     The robotic surgical system may be configured to record these variances, track them over time, and supply the resulting information to a robot control tower and to an analytic cloud or remote system. Documentation and tracking of the variances may enable the update of the system control algorithms that could compensate, or update the response of the future system to similar issues. Detected variances also may be employed to re-calibrate certain elements of the control system on-the-fly to allow it to update minor detected correlation issues. 
     In various aspects, with reference back to  FIG. 22 , the present disclosure provides a robotic surgical system  15000  that includes a central control circuit  15002  configured to compare multiple sensing array outputs to allow the robotic surgical system  15000  to determine which component of the robotic surgical system  15000  is operating outside of an expected manner. In one aspect, the central control circuit  15002  is configured to compare primary motor  15026  (m1) control sensors with secondary sensors to verify motion of the primary motor  15026  (m1), for example. 
     With reference still to  FIG. 22 , in one aspect, a primary controller, such as the central control circuit  15002 , of virtual calculated positions is compared by the central control circuit  15002  against a secondary controller located on robotic surgical tool sensors to determine if an algorithm in the primary controller is operating outside of its normal operational range. The secondary control arrays may include the detection of loads or torques in the return or support structure of the robot or end-effector. The analysis may include comparing antagonistic support of one motor  15026  (m 1 ) based on the activation of certain functions of another motor  15026  (m 2 ). It may be indicated by local end-of-stroke switches or other discrete electronic indicators. 
     With reference still to  FIG. 22 , an array of piezoelectric crystals can be placed on known locations (e.g., end of robotic surgical tool, specific locations on an OR table, trocar, patch on patient, etc.) of the robotic surgical system  15000  to enable calculation of distance of objects from one another. This would create a local coordinate system that could either be fixed to a global coordinate system (e.g., the robot; X-Y-Z) or to a master arm/robotic surgical tool. In one aspect, with at least two piezoelectric crystals located on the same non-deformable object at a known separation distance and at least one on the distal tip, a calibration constant can be determined to account for changes in local impedance due to contamination. In one aspect, with at least two piezoelectric crystals on the same non-deformable object at a known separation distance, a vector can be established to determine the location of an end-effector without discrete end-effector crystals or sensors. 
     With reference still to  FIG. 22 , in one aspect, the robotic surgical system  15000  according to the present disclosure may include a completely autonomous safety measure system may be configured to run in parallel to the control array. If the autonomous system detects, through its autonomous sensors, a variance beyond a pre-defined amount, the autonomous system may limit or shut down the affected system until the variance is resolved. The safety system may include its own sensors or it could employ raw data from shared sensors to the primary control system that provides a secondary pathway for the shared sensors to transmit the relevant information. 
     With reference still to  FIG. 22 , in various aspects, the robotic surgical system  15000  includes local safety co-processing or processors for each interchangeable system as described with reference to  FIGS. 40-44 . Turning now to  FIG. 40 , there is illustrated a system  7120  for verifying the output of a local control circuit and transmitting a control signal according to at least one aspect of the present disclosure. The system  7120  includes a sterile housing  7122  and a motor pack  7124  that includes a plurality of motors  7125   a - 7125   d . In the illustrated aspect, the sterile housing  7122  includes apertures  7126   a - 7126   d  to receive the plurality of motors  7125   a - 7125   d . The sterile housing  7122  also includes a semi-autonomous motor control circuit  7128   a - 7128   d  (only  7128   a  and  7128   b  are shown), one for each of the motors  7125   a - 7125   d . Each of the control circuits  7128   a - 7128   d  includes, for each motor  7125   a - 7125   d , a primary control and feedback communication circuit  7130   a - 7130   d  (only  7130   a  and  7130   b  are shown) and a secondary independent verification communication circuit  7132   a - 7132   d  (only  7132   a  and  7132   b  are shown). The primary control and feedback communication circuits  7130   a - 7130   d  and the secondary independent verification communication circuits  7132   a - 7132   d  communicate with the motors  7125   a - 7125   d  via corresponding antennas  7140   a - 7140   d  (only  7140   a  and  7140   b  are shown. The primary control and feedback communication circuit  7130   a  transmits a wireless communication control signal  7134   a  to the motor pack  7124  and receives a wireless communication feedback signal  7136  from the motor pack  7124  via the antenna  7140   a . The secondary independent verification communication circuit  7132   b  transmits a secondary wireless control validation signal  7138   b  via the antenna  7140   b.    
     Still with reference to  FIG. 40 , a local current and voltage may be provided by a set of sensors located within each local control circuit as well as access to rotary encoder information and other sensors. Sensors include, for example, torque sensor, strain gages, accelerators, hall sensors, which outputs are all independently supplied to a secondary processor to verify the induced motions. The sensor outputs are correlated with the motions the requested primary control and feedback communication circuits  7130   a - 7130   d  believes to be correct. 
       FIG. 41  is a flow diagram  7150  of a process depicting a control program or a logic configuration of a wireless primary and secondary verification feedback system according to at least one aspect of the present disclosure. The process depicted by the flow diagram  7150  may be represented as a series of machine executable instructions stored in the memory  15006  and executed by the processor  15004  of the central control circuit  15002  of the robotic surgical system  15000  depicted in  FIG. 22 . With reference now to  FIGS. 22 and 41 , the user inputs  7152  a control motion into the robotic surgical system  15000  as depicted in  FIG. 22 . The main controller  7154  or central control circuit  15002  is configured to receive  7153  the user input signal and to send a notification  7156  to a safety processor  7158 . The main controller  7154  is configured to receive  7160  a notification from the safety processor  7158  and to issue  7162  an operation command to the motor  15026  via a slip connection, or alternatively, a wireless connection. The main controller  7154  is configured to issue  7164  a request  7166  for motor control to a semi-autonomous motor controller  7168  via a wireless, or slip connection. The semi-autonomous motor controller  7168  is configured to receive the request  7166  and to send a control signal  7170  to one or more than one sensor  7172  to control the power of the motor. The one or more than one sensor  7172  is configured to generate  7174  a response to the motor operation. The one or more than one sensor  7172  may include, for example, an encoder, force sensor, torque sensor, accelerometer, among others. The response  7174  is provided as a primary verification feedback signal to the semi-autonomous motor controller  7168  and to the safety processor  7158  as a secondary verification feedback signal  7176  via a wireless connection, or alternatively a wired connection. The safety processor  7158  provides the notification  7160  to the main controller  7154  based on the secondary verification feedback signal  7176 . 
       FIG. 42  is a graphical illustration  7180  of an algorithm for comparing motor control signals, safety verification signals, and motor current according to at least aspect of the present disclosure. A first graph  7181  depicts a primary motor control signal  7183  versus time. A second graph  7185  depicts a safety verification signal  7187  versus time. A third graph  7189  depicts motor current signal  7182  versus time. If there is a discrepancy between the measured signals and the control signals, a warning flag is supplied to the primary control system. If the discrepancy lasts longer than a predefined time or its magnitude exceeds a predefined threshold the controller&#39;s link to the motor is interrupted and the motor is shut down. Four separate conditions are now described below with reference to first, second, and third graphs  7181 ,  7185 ,  7189 . 
     In a first condition, at time t 3  there is a loss of the primary control signal  7183  as shown in section  7184  of the primary control signal  7183 , for example, where the primary control signal  7183  or feedback signal exhibits intermittent behavior. At time t 3 , however, there is no loss of the safety verification signal  7187  as shown in section  7186  of the safety verification signal  7187 . Accordingly, the motor command is not interrupted and the motor continues to operate as shown in section  7188  of the motor current signal  7182 . 
     In a second condition, at time t 6  there is no loss of the primary control signal  7183  as shown in section  7190  of the primary control signal  7183 . At time t 6 , however, there is a temporary loss of the safety verification signal  7187  for a period t&lt;x ms  threshold as shown in section  7192  of the safety verification signal  7187 . Accordingly, the motor command is not interrupted and the motor continues to operate as shown in section  7194  of the motor current signal  7182 . 
     In a third condition, at time t 7  there is a loss of the primary control signal  7183  as shown in section  7196  of the primary control signal  7183 . At time t 7 , however, there is no loss of the safety verification signal  7187  as shown in section  7198  of the safety verification signal  7187 . Accordingly, the motor command is not interrupted and the motor continues to operate as shown in section  7200  of the motor current signal  7182 . 
     In a fourth condition, at time t 10  there is a loss of the primary control signal  7183  as shown in section  7202  of the primary control signal  7183  and at time t 7 , there also is a loss of the safety verification signal  7187  as shown in section  7204  of the safety verification signal  7187 . Accordingly, the motor command is interrupted and the motor is stopped as shown in section  7206  of the motor current signal  7182 . 
       FIG. 43  is a flow diagram  7210  of a process depicting a control program or a logic configuration of a motor controller restart process due to motor controller shutdown due to communication loss according to at least one aspect of the present disclosure. The process depicted by the flow diagram  7210  may be represented as a series of machine executable instructions stored in the memory  15006  and executed by the processor  15004  of the central control circuit  15002  of the robotic surgical system  15000  depicted in  FIG. 22 . With reference now to  FIGS. 22 and 43 , in accordance with the process depicted by the flow diagram  7210 , the central control circuit  15002  is configured to detect  7212  that the motor controller shut-down due to a loss of communication signal. The central control circuit  15002  is configured to determine  7214  whether the communication signal is restored within a predefined time. When the communication signal is restored within a predefined time, the central control circuit  15002  is configured to continue along the YES branch and to restart  7216  the motor controller. When the communication signal is not restored within a predefined time, the central control circuit  15002  is configured to continue along the NO branch and to restart  7218  or to reset the communication signal. The central control circuit  15002  then is configured to determine  7220  whether the communication signals are restored. When the communication signals are restored, the central control circuit  15002  is configured to continue along the YES branch and restarts  7216  the motor controller. When the communication signals are not restored, the central control circuit  15002  is configured to continue along the NO branch and to report  7222  an error to the user and requires user intervention before restarting the motor controller. 
       FIG. 44  is a flow diagram  7230  of a process depicting a control program or a logic configuration for controlling a motor controller due to command or verification signal loss according to at least one aspect of the present disclosure. The process depicted by the flow diagram  7230  may be represented as a series of machine executable instructions stored in the memory  15006  and executed by the central control circuit  15002  of the robotic surgical system  15000  depicted in  FIG. 22 . With reference now to  FIGS. 22 and 44 , in accordance with the process depicted by the flow diagram  7230 , the central control circuit  15002  is configured to detect  7232  either a command signal loss or to detect  7234  a verification signal loss. When a loss of command signal is detected  7232  or loss of verification signal is detected  7234 , the central control circuit  15002  is configured to determine  7236  if there is a corresponding signal loss. When there is a corresponding signal loss, the central control circuit  15002  is configured to continue along the YES branch and to shut down  7238  the motor controller. When there is no corresponding signal loss the central control circuit  15002  is configured to continue along the NO branch and to continue  7240  semi-autonomous control of the motor controller. 
     In accordance with various aspects of the processes depicted by the flow diagrams  7210 ,  7230 , each sub-controller may include an individual safely processor or process overseeing the function of the systems as the system intended. This becomes much more important when the robot has removable and replaceable motor packs which have built in controllers. 
     In various aspects, the present disclosure provides a robotic surgical system and method that utilizes secondary confirmation of a controlled motor and robotic surgical tool motions to detect and compensate for differences in the system and aging of the system. In one aspect, the present disclosure provides a robotic surgical system and method for on-the-fly secondary source monitoring of mechanical outputs and adjustment of the control signals to compensate for detected differences. In one aspect, the same secondary measurements or motions, work, and output of sub-systems for confirmation of valid control functions of a safety processor may be employed through a secondary process to synchronize the primary control signal with the measured secondary measured signal. This would allow the sub-system to compensate for aging electronics and motors while providing the intended final output. The technique may be employed to compensate for the kinematic differences in mechanical sub-systems and tolerance differences and slop in systems. If the secondary measure is compared to the intended control signal and then the error terms are used to adjust the primary control signal to bring the comparison down below a predefined limit, it would allow the control signal to be adjusted individually for each sub-system and each motor pack. 
       FIG. 45  is a flowchart depicting a robotic surgical system utilizing a plurality of independent sensing systems according to at least one aspect of the present disclosure. Referring now to  FIG. 45 , a flow chart for a robotic surgical system is depicted. The flow chart can be utilized by a robotic surgical system, for example. In various instances, two independent sensing systems can be configured to detect the location and/or orientation of a surgical component, such as a portion of a robotic arm and/or a surgical robotic surgical tool. The first sensing system, or primary sensing system, can rely on the torque and/or load sensors on the motors and/or motor drivers of the robotic arm. The second sensing system, or secondary sensing system, can rely on magnetic and/or time-of-flight sensors on the robotic arm and/or surgical robotic surgical tool. The first and second sensing systems are configured to operate independently and in parallel. For example, at step  66502 , the first sensing system determines the location and orientation of a robotic component and, at step  66504 , communicates the detected location and orientation to a control unit. Concurrently, at step  66506 , the second sensing system determines the location and orientation of the robotic component and, at step  66508 , communicates the detected location and orientation to the control unit. 
     The independently-ascertained locations and orientations of the robotic component are communicated to a central control circuit at step  66510 , such as to a robotic control unit and/or a surgical hub. Upon comparing the locations and/or orientations, the control motions for the robotic component can be optimized at step  66512 . For example, discrepancies between the independently-determined positions can be used to improve the accuracy and precision of control motions. In certain instances, the control unit can calibrate the control motions based on the feedback from the secondary sensing system. The data from the primary and secondary sensing systems can be aggregated by a hub and/or data stored in a cloud to further optimize the control motions of the robotic surgical system. Reference may be made to U.S. patent application Ser. No. 15/940,711, the entire contents of which are incorporated herein by reference, for additional detailed discussion. 
     In various aspects, the present disclosure provides a robotic surgical system with a hierarchical control scheme to relate motions of independent arm or instrument operation. In one aspect, the one of the control arms may be defined as the master axes arm under which the other arms are verified against. Various techniques for detecting a primary control arm and verifying secondary robotic arms are described with reference to  FIGS. 45-46 . 
       FIG. 46  is a robotic surgical system  7250  for controlling a primary robotic arm and detecting and verifying secondary robotic arms according to at least one aspect of the present disclosure. The robotic surgical system  7250  includes a master coordinate tower  7252  with sensors  7253  to determine the position of the master coordinate tower  7252  relative to the location of other robotic arms  7254   a - 7254   d  to conform the position, motion, and orientation of the other robotic arms  7254   a - 7254   d . The master coordinate tower  7252  determines the footprint of the OR table  7256 , the position and orientation of other robotic arms  7254   a - 7254   d , the position and orientation of robotic end-effectors  7258   a ,  7258   b  shown as distance d 1 , and the position and orientation of adjacent robotic components  7259  shown as d 2 . In one aspect, a primary sensor  7257  may be positioned on the OR table  7256 . 
       FIG. 47  is a detailed view of the system  7250  depicted in  FIG. 46  according to at least one aspect of the present disclosure. As depicted in  FIG. 47 , an endoscope control robotic arm  7260  is selected as a master coordinate robotic arm to determine the position and orientation of a secondary robotic arm  7262 . The endoscope control robotic arm  7260  includes an endoscope arm  7264  to hold and guide a robotic surgical tool  7275  mounted on a linear slide  7284  equipped with an endoscope  7266 . The endoscope  7266  is configured to generate a stereoscopic cos array  7265  in the optical scope field of view  7268 . The endoscope control robotic arm  7260  also includes a magnetic field generator  7270  mounted on a fixed component  7272  of the endoscope control robotic arm  7260  to generate a magnetic field  7271 . The endoscope control robotic arm  7260  determines the gross orientation  7274  in the x, y, z coordinate system of the secondary robotic arm  7262  relative to the endoscope control robotic arm  7260 . The secondary robotic arm  7262  includes a robotic surgical tool  7277  mounted on a linear slide  7286  equipped with a motorized surgical stapler  7279  that includes an end-effector  7276 . 
     With reference now to  FIGS. 46-47 , in one aspect, the system  7250  may be implemented optically by using the endoscope control arm  7260  as the master control robotic arm. The system  7250  may include both the stereoscopic cos arrays  7265  for visualization as well as secondary sensors  7270 ,  7278  to determine proximity of adjacent robotic structures, such as the secondary robotic arm  7262 . Ultrasonic sensors may be positioned around the perimeter of the stereoscopic cos array  7265  generated by the endoscope  7266  to prevent cross-talk and allow the endoscope  7266  to simultaneously actively ping for distance, size, and orientation of adjacent robotic components  7259 , such as the secondary robotic arm  7262 . In one aspect, the system  7250  may include the integration of impedance sensors with magnetic field generators  7270  to generate a magnetic field  7271 . In one aspect, the system  7250  may include RFID  7278 , both active and/or passive RFID sensors, located on the master coordinate robotic arm  7260 , such as, for example, the endoscope control arm  7260 . 
     In one aspect, the system  7250  may include a passive method that includes an endoscope arm  7264  configured to generate an RF wake-up signal to be received by the communication array of the adjacent robotic end-effector  7276  or robotic arms  7262  and configured to respond with a measured signal strength and directional aspect to allow the endoscope arm  7264  to calculate the location of an adjacent device, such as the end-effector  7276  located on the secondary robotic arm  7262 . 
     In another aspect, as an alternative to the passive method, the system  7250  may include an active method where a magnetic field generator  7270  is used to generate a magnetic field  7271  to create power within an adjacent RF transmitter  7280  and allow it to transmit a signal back to the master endoscope control arm  7260  device, such as the endoscope  7265 . The master device, e.g., the endoscope  7265 , would then calculate the signal strength of the returned signal and read its identifier in order to determine what device was responding and where it was located. In the active method, the endoscope control arm  7260  could have both an RF transmitter  7280  for RF signals and a receiver  7282  to receive the bounced back signal. This would allow it to determine the size, location, and orientation of adjacent structures. 
     In various aspects, the present disclosure further provides a robotic surgical system and method for controlling and operating the control arms attached to the end-effectors end-effector to end-effector positioning and orientation as a control means for operating the control arms attached to the end-effectors.  FIGS. 48-50  illustrate end-effector to end-effector communication and sensing to control robotic arm motions according to various aspects of the present disclosure. 
       FIG. 48  illustrates a positioning and orientation system  7290  for a robotic surgical system that includes an end-effector  7318  to end-effector  7320  positioning and orientation according to at least one aspect of the present disclosure. In the illustrated example, the positioning and orientation system  7290  includes a first robotic arm  7292 , a second robotic arm  7294 , and a third robotic arm  7296 . It will be appreciated that the positioning and orientation system  7290  may include at least two robotic arms and more than three robotic arms, without limitation. The robotic arms  7292 ,  7294 ,  7296  includes linear robotic surgical tools  7298 ,  7300 ,  7302  mounted to linear slides  7304 ,  7306 ,  7308 . The first robotic arm  7292  includes a vision system, such as for example, a visual endoscope  7299 . The distal end of the endoscope  7299  includes optics for transmitting and receiving light in various wavelengths, including, for example, the cos array as previously discussed with respect to  FIGS. 35, 36, 47 . The second and third robotic arms  7294 ,  7296  each include robotic controlled robotic surgical tools  7300 ,  7302  that include end-effectors  7318 ,  7320  for surgical stapling and cutting, ultrasonic sealing and cutting, electrosurgical sealing and cutting, or a combination of stapling and cutting, ultrasonic sealing and cutting and electrosurgical sealing and cutting. The linear robotic surgical tools  7298 ,  7300 ,  7302  of each of the robotic arms  7292 ,  7294 ,  7296  is controlled by a driver  15028  which is controlled by the central control circuit  15002  as described with reference to  FIG. 22  to advance and retract the robotic surgical tools  7298 ,  7302 ,  7304 . The robotic arms  7292 ,  7294 ,  7296  are shown positioned within a body wall  7322  of a patient  7324  lying on an OR table  7326 . A spatial envelope  7328 , or guard band, is provided between the robotic arms  7292 ,  7294 ,  7296  and the body wall  7322  of the patient  7324 . The robotic arms  7292 ,  7294 ,  7296  are configured to determine gross positioning and orientation  7330 ,  7332 ,  7334  in x, y, z coordinate space of each robotic arm  7292 ,  7294 ,  7296  and the OR table  7326 . 
     The endoscope  7299  of the vision system is configured to determine positioning and orientation of the end-effectors  7318 ,  7320 , including the distance d 1  between the end-effectors  7318 ,  7320 . Certain portions of the second robotic arm  7294  are controlled with respect to the other first and third robotic arms  7292 ,  7296 . Similarly, certain portions of the third robotic arm  7296  are controlled with respect to the first and second robotic arms  7292 ,  7294 . 
       FIG. 49  is a perspective view of the end-effector to end-effector positioning and orientation system  7290  depicted in  FIG. 48  according to at least one aspect of the present disclosure. The perspective view shows the intracorporeal distances d 1  between the end-effectors  7318 ,  7320 . The perspective view also shows the extracorporeal distances d 2  between any of the robotic arms  7292 ,  7294 ,  7336 . 
       FIG. 50  illustrates one of the second robotic arm  7294  depicted in  FIGS. 48 and 49 , with global and local control of positioning and orientation according to at least one aspect of the present disclosure. The robotic arm  7294  depicted in  FIG. 50  is representative of the first robotic arm  7292  equipped with a visual endoscope  7299  as part of the vision system, for example, and also is representative of the third robotic arm  7296 . The robotic arm  7294  includes a linear robotic surgical tool  7300  driven and actuated by a linear robotic surgical tool driver  7310  that includes a motor pack and controls local movements. The robotic surgical tool  7300  includes and end-effector  7318 . The robotic arm  7294  includes first, second, and third pivotable arms  7340 ,  7342 ,  7344  that pivot to define angles θ, β, α as shown. The entire robotic arm  7294  rotates about axis defined by Z. The linear robotic surgical tool driver  7310  advances and retracts the shaft  7346  of the robotic surgical tool  7300  over Δ. The robotic arm  7294  controls global movements Z, θ, β, α. The linear robotic surgical tool driver  7310  controls local movement Δ, where the distal end  7348  of the shaft  7346  of the fixed robotic surgical tool  7300  is the dividing line  7348  between global control and local control. 
     With reference now to  FIGS. 48-50 , certain portions of the robotic control arm  7292 ,  7294 ,  7296  motions could be controlled based on the displacement of the end-effectors  7318 ,  7320  with respect to each other. Rather than actuating the linear robotic surgical tool driver  7310  a predefined distance A based on the user input, the relative closing of distance d 1  between any two end-effectors  7318 ,  7320  may be used by the central control circuit  15002  ( FIG. 22 ). 
     With reference still to  FIGS. 48-50 , the illustrated end-effector  7318  to end-end-effector  7320  positioning and orientation system  7290  may include a vision system endoscope  7299  to determine the distances d 1 , d 2  ( FIG. 49 ), velocities, and orientations of the end-effectors  7318 ,  7320  directly. The endoscope  7299  is configured to follow the user input motions and to adjust the motions of the robotic control arm  7292  motions as necessary and to move the end-effectors  7318 ,  7320  in relation to a local coordinate system. 
     As depicted in  FIG. 48 , the 3D spatial envelope  7328  is provided for the positioning and orientation system  7290  to reduce collisions between the robotic arms  7292 ,  7294 ,  7296  and the body wall  7322  of the patient  7324 . With a common coordinate system defined, the approved spatial envelope  7328  can be defined for each robotic arm  7292 ,  7294 ,  7296 . Each robotic arm  7292 ,  7294 ,  7296  is given a 3D spatial envelope  7328  in which it is allowed to operate. Any need to exit this spatial envelope  7328  is requested from either another robotic arm  7292 ,  7294 ,  7296 , the “master” control system central control circuit  15002  ( FIG. 22 ), or all participants in the communication system ( FIGS. 1-22 ). If the approving authority(s) agree, a new, adjusted envelope may be assigned to all robotic arms  7292 ,  7294 ,  7296 . Accordingly, every single movement does not have to be negotiated by the control system for the positioning and orientation system  7290 , only large-scale movements. This minimizes computational requirements and simplifies collision. 
     In various aspects, the present disclosure provides a robotic surgical system and method configured to adjust tissue tension based on robot shaft or robot arm measured macro shaft/end-effector torques. The robotic surgical system and method also provides an automation technique for operating an energy robotic surgical tool. The robotic surgical system and method also provides adjustment of control boundaries and warnings based on the determined temperature of the energy device end-effector. 
     In one aspect, the robotic surgical system and method provide hyper-spectral imaging measurement of blade/end-effector temperature.  FIG. 51  illustrates an electromechanical robotic surgical tool with a shaft  67503  having a distal end  67502  and an end-effector  67504  mounted to the shaft  67503  in the vicinity of patient tissue  67506  according to at least one aspect of the present disclosure. The end-effector  67504  includes jaws  67507 ,  67508 , with jaw  67507  being in the form of an ultrasonic blade. The shaft  67503  and the end-effector  67506  are part of a robotic surgical system and can be mounted on an electromechanical arm. The robotic surgical system can include an endoscope, such as binocular scope  67512 , having at least one visual sensor  67510 . The illustrated visual sensor  67510  is disposed at a distal end of a binocular scope  67512 . The illustrated visual sensor  67510  is an infrared sensor, but the visual sensor can be a CCD, a CMOS, or the like. The visual sensor  67510  can be configured to detect the temperature T b  of at least part of the end-effector  67504 , for example of the ultrasonic blade  67507  of the end-effector  67504 , and/or the temperature T t  of the tissue  67506  of the patient that is adjacent the end-effector  67504 . 
     In one aspect, a controller can be configured to compare the temperature T b  of the ultrasonic blade and the temperature T t  of the tissue of the patient and determine distance thresholds  67514 ,  67516  and  67518  for different temperatures of the end-effector  67504 . The distance thresholds  67514 ,  67516  and  67518  can represent a variety of safe and/or non-harmful distances for the tissue  67506  and/or the end-effector  67504 , such as the closest distance from the tissue  67506  of the patient that the heated end-effector  67504  can be positioned without causing damage to the tissue  67506 . For example, distance threshold  67514  can represent the closest position an end-effector  67504  having a temperature T 1  can be positioned with respect to the tissue  67506  of the patient; distance threshold  67516  can represent the closest position an end-effector  67504  having a temperature T 2  can be positioned with respect to the tissue  67506  of the patient; and distance threshold  67518  can represent the closest position an end-effector  67504  having a temperature T 3  can be positioned with respect to the tissue  67506  of the patient. 
     Temperature T 1  is less than temperature T 2  which is less than temperature T 3 . The temperatures T 1 , T 2 , T 3  can represent the temperature T b  of the ultrasonic blade  67507  directly or can represent the compared temperatures between the temperature T b  of the ultrasonic blade and the temperature T t  of the tissue. An infrared sensor, such as the Melexis MLX90621, can be integrated into the binocular scope  67512  and/or the end-effector  67504 , and can act to compare the end-effector temperature with an adjacent tissue temperature for an accurate indication of temperature. This process can occur before and/or during and/or after use of the end-effector to affect tissue. Force thresholds based on force limits can also be used in addition to or instead of distance thresholds. 
     While  FIG. 51  illustrates measuring threshold distances from the end-effector  67504 , distances can also be measured from surrounding tissue. For example,  FIG. 52  illustrates the end-effector  67504  in the vicinity of tissue  67506  according to at least one aspect of the present disclosure. However, threshold distances  67550 ,  67552 , and  67554  are measured relative to tissue  67506  instead of the end-effector  67504 , as is depicted in  FIG. 51 . A safe threshold distance of the end-effector  67504  from tissue  67506  can thus vary depending on the temperature of the end-effector  67504 . 
     As illustrated  FIG. 52 , the controller can be configured to facilitate movement of the end-effector  67504  toward the tissue  67506  of the patient at varying distances from the tissue based on temperature. When the temperature of the end-effector  67504  is at a highest point (illustrated on the far left of graph  67700  of  FIG. 52 ), the heated end-effector  67504  is disposed at a location farthest from tissue  67506  of the patient (illustrated on the far left of graph  67702  of  FIG. 53 ). Thus graph  67702  illustrates the T 2  distance threshold  67704 . The T 2  distance threshold  67704  is the closest distance that the heated end-effector  67504  having a temperature T 2  can get to the tissue  67506  of the patient without causing damage. As the temperature of the end-effector  67504  reduces over time, the end-effector  67504  can get closer to tissue  67506  without damaging the tissue  67506 . At  67706  the end-effector  67504  is at a low enough temperature to be able to touch the tissue  67506  without causing damage to the tissue  67506  (illustrated on the far right of graphs  67700 ,  67702 ). 
     With reference to graph  67702 , at time  67708  the robotic surgical system can be configured to stop the advance of the end-effector  67504  toward the tissue  67506  until the temperature of the end-effector  67504  has decreased further. For example, line  67710 , illustrated in the graph  67702 , represents the closest proximity of the end-effector  67504  with respect to the tissue  67506  of the patient when the temperature of the end-effector  67504  is below a temperature  67712 . When the temperature of the end-effector  67504  has a temperature T 1 , the robotic surgical system can be configured to stop the movement of the end-effector  67504  toward the tissue  67506  of the patient at the distance  67514 . The distance  67514  is represented by the line  67710  in graph  67702  of  FIG. 53 . At  67716 , the robotic surgical system can be configured to halt the movement of the end-effector  67504  toward the tissue  67506 . Dashed line  67714  of graph  67702  is an exemplary illustration of the velocity of end-effector  67504 . As the end-effector  67504  approaches tissue  67506 , the velocity of end-effector  67504  can be configured to be reduced to ensure the controller and the overall robotic system can stop the end-effector  67504  at selected distance thresholds. In some variations, an alert can be provided to the operator of the robotic surgical system that the heated end-effector  67504  has reached a threshold distance. Reference may be made to U.S. patent application Ser. No. 15/238,001, now U.S. Patent Application Publication No. 2018/0049792, the entire contents of which are incorporated herein by reference, for additional detailed discussion. 
     In one aspect, the present disclosure provides a robotic surgical system and method for measuring blade temperature using natural frequency shifting. In one aspect, an internal shaft temperature sensor is employed to sense heat flux from the end-effector. 
     In one aspect, the present disclosure provides a robotic surgical system and method that includes an integrated flexible circuit for with a thermal sensor to measure the component temperature of mechanisms and components of a robotic surgical tool.  FIG. 54  is a cross-sectional view of one aspect of a flexible circuit  67600  comprising RF electrodes and data sensors embedded therein according to at least one aspect of the present disclosure. The flexible circuit  67600  can be mounted to the right or left portion of an RF clamp arm  67602 , which is made of electrically conductive material such as metal. Below the RF clamp arm  67602 , down (vertical) force/pressure sensors  67606   a ,  67606   b  are embedded below a laminate layer  67604 . A transverse force/pressure sensor  67608  is located below the down (vertical) force/pressure sensor  67606   a ,  67606   b  layer and a temperature sensor  67610  is located below the transverse force/pressure sensor  67608 . An electrode  67612  is electrically coupled to the generator and configured to apply RF energy to the tissue  67614  located below the Turning now to  FIG. 55 , an end-effector  67800  comprises a jaw member  67802 , flexible circuits  67804   a ,  67804   b , and segmented electrodes  67806   a ,  67806   b  provided on each flexible circuit  67804   a ,  67804   b . Each segmented electrode  67806   a ,  67806   b  comprises several segments. As shown, a first segmented electrode  67806   a  comprises first and second segment electrode segments  67808   a ,  67808   b  and a second segmented electrode  67806   b  comprises first and second segment electrode segments  67810   a ,  67810   b . The jaw member  67802  is made of metal and conducts heat to maintain the jaw member  67802  cool. Each of the flexible circuits  67804   a ,  67804   b  comprises electrically conductive elements  67814   a ,  67814   b  made of metal or other electrical conductor materials and are electrically insulated from the metal jaw member  67802  by an electrically insulative laminate. The conductive elements  67814   a ,  67814   b  are coupled to electrical circuits located either in a shaft assembly, handle assembly, transducer assembly, or battery assembly. 
       FIG. 56  is a cross sectional view of an end-effector  67900  comprising a rotatable jaw member  67902 , a flexible circuit  67904 , and an ultrasonic blade  67906  positioned in a vertical orientation relative to the jaw member with tissue  67908  located between the jaw member  67902  and the ultrasonic blade  67906 . The ultrasonic blade  67906  comprises side lobe sections  67910   a ,  67910   b  to enhance tissue dissection and uniform sections  67912   a ,  67912   b  to enhance tissue sealing. In the vertical orientation depicted in  FIG. 56 , the ultrasonic blade  67908  is configured for tissue dissection. 
     The flexible circuit  67904  includes electrodes configured to deliver high-frequency (e.g., RF) current to the tissue  67908  grasped between the jaw member  67902  and the ultrasonic blade  67906 . In one aspect, the electrodes may be segmented electrodes as described herein in connection with  FIG. 55 . The flexible circuit  67904  is coupled to a high-frequency (e.g., RF) current drive circuit. In the illustrated example, the flexible circuit electrodes  67904  are coupled to the positive pole of the high-frequency (e.g., RF) current energy source and the ultrasonic blade  67906  is coupled to the negative (e.g., return) pole of the high-frequency (e.g., RF) current energy source. It will be appreciated that in some configurations, the positive and negative poles may be reversed such that the flexible circuit  67904  electrodes are coupled to the negative pole and the ultrasonic blade  67906  is coupled to the positive pole. The ultrasonic blade  67906  is acoustically coupled to an ultrasonic transducer. In operation, the high-frequency (e.g., RF) current is employed to seal the tissue  67908  and the ultrasonic blade  67906  is used to dissect tissue using ultrasonic vibrations. Reference may be made to U.S. patent application Ser. No. 15/382,238, now U.S. Patent Application Publication No. 2017/0202591, the entire contents of which are incorporated herein by reference, for additional detailed discussion. 
     In one aspect, the present disclosure provides a robotic surgical system and method for automatic adjustment of robotic drive shafts to control cut techniques.  FIGS. 57A and 57B  illustrate an embodiment of an end-effector  68400  of a robotic surgical system in accordance with the described techniques. As depicted in  FIG. 57A , the end-effector  68400  includes a lower jaw or ultrasonic blade  68410 , and an upper jaw or clamp member  68420  that are configured to clamp tissue therebetween. In this example, the end-effector  68400  is shown in operation, when tissue  68430  is clamped between the blade and clamp member  68410 ,  68420 . In the illustrated example, the tissue  68430  is in the form of a blood vessel. A person skilled in the art will appreciate, however, that the tissue can be any other type of tissue. 
     In operation, as depicted in  FIG. 57A , when the clamp member  68420  is brought in proximity to the blade  68410  and the tissue  68430  is clamped therebetween, ultrasound energy is applied to the tissue  68430 .  FIG. 57A  illustrates by way of example the end-effector  68400  engaged with the tissue  68430  when cauterization of the tissue  68430  is complete. The described techniques can be used to coagulate and cauterize tissue, and these processes are used interchangeably. Treating tissue with ultrasound energy involves destroying tissue by cauterization, which leads to coagulation of the tissue-denaturing protein in the tissue and tissue desiccation. To create an effective seal across the tissue  68430 , the tissue cauterized and coagulated in a controlled manner. Thus, creation of the tissue involves a precise control over a number of parameters during cauterization, such as a power level, pressure exerted on tissues by the jaws of an end-effector, lift velocity of an ultrasound blade, and other parameters. 
     As mentioned above,  FIG. 57A  illustrates the end-effector  68400  when cauterization of the tissue  68430  is completed. As depicted in  FIG. 57A , the blade and the clamp member  68410 ,  68420  are shown in contact with the tissue  68430 . When the robotic surgical system determines that the cauterization of the tissue  68430  is complete, the surgical system causes the end-effector  68400  to be lifted, such that the blade  68410  performs a (final) cut through the tissue.  FIG. 57B  illustrates that the end-effector  68400  (and thus the blade  68410 ) is lifted, as schematically shown by arrows one of which is labeled as  68414   a , and the tissue  68430  is cut, such that a portion of the tissue  68432  is disassociated from the end-effector  68400  (another portion of the cut tissue  68430  is not labeled). 
       FIG. 58  illustrates two examples of graphs of trajectory curves representing impedance values and corresponding curves representing lift velocities of end-effector&#39;s blades for different types of tissues. The impedance curves represent tissue impedance values measured when the end-effector, such as the end-effector  68400  in  FIGS. 57A  and  57 B, is used to apply ultrasonic energy to tissue when the end-effector is in contact with the tissue. The lift velocity curves (which can be, in some cases, linear) represent respective velocities with which the end-effector can be automatically lifted once cauterization of tissue having certain characteristics is determined to be complete. 
       FIG. 58  shows an impedance curve  68510  for one type of tissue, such as a larger (thicker) vessel or other type of tissue.  FIG. 58  also shows an impedance curve  68520  for another type of tissue, such as a smaller (thinner) vessel or other type of tissue. The curves  68510 ,  68520  can be constructed using tissue impedance values (z) as a function of time (t). As shown, both curves  68510 ,  68520  have a shape resembling a bathtub. In particular, regardless of their specific shapes and length, the curves  68510 ,  68520  follow a period of a decrease of the initial (relatively high) tissue impedance, which can be followed by a plateau, and then by an increase in electrical impedance of the tissue. The curves  68510 ,  68520  terminate at first and second time points t1, t2 at which certain threshold impedance values are reached. These indicate a completion of the tissue cauterization process upon which the surgical system can cause a lift of the end-effector. It should be appreciated that the time points t1, t2 are referred to herein as “first” and “second” for description purposes only, and not to indicate any order. Reference may be made to U.S. patent application Ser. No. 15/237,691, now U.S. Patent Application Publication No. 2018/0049798, the entire contents of which are incorporated herein by reference, for additional detailed discussion. 
     In various aspects, the present disclosure provides a robotic surgical system that includes energy control based on the sensed advancement rate and pressure of drawing an ultrasonic jaw over a tissue structure.  FIG. 59  illustrates an end-effector  69400  of a robotic surgical system according to at least one aspect of the present disclosure. The end-effector  69400  is configured to cut and seal tissue by applying one or more forms of energy (e.g., ultrasonic and/or RF) thereto. The end-effector  69400  includes an upper jaw or a clamp member  69410  and a lower jaw or blade  69420  that are configured to clamp tissue therebetween or contact tissue in other ways. The end-effector can also be moved over tissue with an outer surface of the blade  69420  positioned in contact with the tissue. The end-effector can be advanced, dragged, or otherwise moved along the tissue to create a cut therethrough or other feature. The end-effector also includes a strain gauge  69430 . 
     In some embodiments, the end-effector  69400  can be adapted to sense one or more parameters including, for example, a force F exerted against the end-effector  69400 .  FIG. 58  illustrates by way of example a position of the end-effector  69400  when it is moved (e.g., dragged) along a tissue  69440  in a direction of an arrow  69401 . In this example, as shown, the end-effector  69400  is moved in the direction  69401  as the tissue  69440  is being cut such that the cut is created. The strain gauge  69430  can be configured to measure the force F exerted against the end-effector  69400  (e.g., the blade  69420 ) by the tissue  69440 . Specifically, the strain gauge  69430  is subjected to a bend load that corresponds to the force F exerted against the end-effector  69400  (e.g., the blade  69420 ). In the illustrated example, the tissue  69440  is in the form of mesentery tissue. However, it should be appreciated that the tissue  69440  can be any other type of tissue without departing from the scope of the present disclosure. Reference may be made to U.S. patent application Ser. No. 15/237,700, now U.S. Patent Application Publication No. 2018/0049817, the entire contents of which are incorporated herein by reference, for additional detailed discussion. 
       FIG. 60  illustrates the sensor assembly  69000  coupled adjacent to an embodiment of an end-effector  69050  that includes a cutting robotic surgical tool  69060  (e.g., tissue boring robotic surgical tool) according to at least one aspect of the present disclosure. As depicted in  FIG. 60 , the sensor assembly  69000  is coupled to a part of a shaft  69040  with the end-effector  69050  at a distal end of the shaft  69040 . Forces applied to a distal end of the cutting robotic surgical tool  69060  are sensed in the shaft  69040  by the sensor assembly  69000 . The shaft  69040  and end-effector  69050  can be part of a robotic surgical tool assembly coupled to a robotic arm of a robotic surgical system, with the sensor assembly  69000  in communication with the control system. As such, the control system can control the movement of the robotic arm and thus the cutting robotic surgical tool  69060  to perform a cutting or boring of tissue using the cutting robotic surgical tool  69060 . As depicted in  FIG. 60 , the cutting robotic surgical tool  69060  (which can be an ultrasonic wave guide) has an elongated cylindrical body that is configured to bore into tissue, such as by jackhammering a distal end of the elongated cylindrical body against and through tissue to puncture or cut through the tissue. Although the cutting robotic surgical tool  69060  is depicted in  FIG. 60  as having an elongated cylindrical body, the cutting robotic surgical tool  69060  can have any number of various shapes and features for cutting, puncturing, or making an incision in tissue without departing from the scope of this disclosure. 
       FIGS. 61A-61C  illustrate an example of the cutting robotic surgical tool  69060  boring through tissue  69100 . As depicted in  FIG. 61A , the distal end of the cutting robotic surgical tool  69060  is not in contact with the tissue  69100  and therefore a force is not applied against the distal end of the cutting robotic surgical tool  69060  by the tissue  69100 . The control system can detect the absence of the applied force to commence or increase the advancement of the robotic arm in the direction of the tissue  69100  to assist with cutting into the tissue  69100 . As depicted in  FIG. 61B , the distal end of the cutting robotic surgical tool  69060  is in contact with the tissue  69100  and a force is applied against the distal end of the cutting robotic surgical tool  69060  by the tissue  69100 . A variety of forces can be applied to the distal end of the cutting robotic surgical tool  69060  as the cutting robotic surgical tool  69060  advances through the tissue, which can be monitored by the control system for determining appropriate velocities of movement of the robotic arm (e.g., jackhammering velocity, velocity of advancement of cutting robotic surgical tool, etc.). Control of the robotic arm by the control system can be based on such determined appropriate velocities to assist with effectively cutting the tissue  69100 . As depicted in  FIG. 61C , the distal end of the cutting robotic surgical tool  69060  is extending through the tissue  69100  and is no longer in contact with the tissue  69100 . As such, a force is not applied against the distal end of the cutting robotic surgical tool  69060  by the tissue  69100 . The control system can detect the absence of the applied force to decrease, including stop, the advancement or movement of the robotic arm, which can prevent unwanted cutting or boring of adjacent tissue. As such, the control system can determine appropriate velocities and directions of movement based on current and past sensed forces and velocities. 
       FIG. 62  illustrates an end-effector being lifted or angled to cause the force applied by the tissue to increase against the ultrasonic blade  69140  thereby assisting with cutting the tissue  69145  as the end-effector  69200  is advanced in a direction that cuts the tissue  69145  according to at least one aspect of the present disclosure. Such lifting or angling can be caused by the control system collecting data from the sensors  69160  and determining that the tissue  69145  does not have a tension that is within the desired or optimal tension range. As such, the control system can either adjust the velocity of movement of the robotic arm (including stop movement) in the advancing direction (e.g., to cut tissue) or adjust the orientation of the end-effector  69200  relative to the tissue (e.g., angle, lift, and/or lower the end-effector  69200 ). For example, if the control system determines that the tension is too low, the control system can either reduce the velocity of movement of the robotic arm in the advancing direction or move the end-effector  69200  such that it is either lifted or angled to create more tension in the tissue  69145 . Based on the determined tissue tension, the control system can determine and control an appropriate energy density that is delivered to or received from the ultrasonic blade  69140 . For example, if tissue tension is determined to be below a threshold, the velocity of advancement of the robotic arm may be increased. In contrast, stopping or slowing advancement of the robotic arm may further reduce tension. As such, if the tissue tension is above the threshold, the velocity of the robotic arm can be reduced to prevent damage to the tissue. Furthermore, compression applied to the tissue (e.g., via jaw closure) can be increased when the tissue tension is above a threshold and/or additional power can be applied to the tissue to speed up cutting and thereby assist with decreasing tissue tension. 
       FIG. 63  illustrates an embodiment of a first end-effector  69210  of a first robotic surgical tool assembly  69220  coupled to a first robotic arm and a second end-effector  69230  of a second robotic surgical tool assembly  69240  coupled to a second robotic arm according to at least one aspect of the present disclosure. The first end-effector  69210  is coupled to a distal end of a first shaft  69215  of the first robotic surgical tool assembly  69220  and includes a pair of jaws  69217  that are movable between and open and closed configurations. In the closed or partially closed configuration, the pair of jaws  69217  secure a part of tissue  69250  therebetween, as depicted in  FIG. 63 . The pair of jaws  69217  is in communication with a first sensor  69260  that is configured to measure a tension in the tissue  69250  that is partially captured between the pair of jaws  69217 . The first sensor  69260  is in communication with a control system of the robotic surgical system and the control system can detect and monitor the measurements collected by the first sensor  69260 . Based on such measurements, the control system can determine and control one or more of a variety of movement parameters associated with either the first or second robotic arm to effectively and efficiently cut the tissue  69250 . The first sensor can include one or more of a variety of sensors, such as a strain gauge, and can be positioned in any number of locations along the first end-effector  69210  or first robotic surgical tool assembly  69220  for measuring tension in the tissue  69250 . For example, any of the tissue tension measuring features and mechanisms discussed above (such as with respects to  FIG. 62 ) can be implemented in this embodiment for measuring tension in the tissue  69250 . 
     As depicted in  FIG. 63 , the second end-effector  69230  is positioned at a distal end of a second shaft  69232  of a second robotic surgical tool assembly  69240 . The second end-effector  69230  includes a cutting robotic surgical tool or blade  69235  that can be advanced into the tissue  69250  for cutting the tissue. The cutting robotic surgical tool  69235  can include any number of features for assisting with cutting tissue, including any of the features discussed above for cutting tissue, such as the blade  69140  depicted in  FIG. 62 . The cutting robotic surgical tool  69235  is in communication with a second sensor  69270  that is configured to measure an amount of force applied on the cutting robotic surgical tool  69235 . The second sensor  69270  is in communication with the control system, which can detect and monitor the applied forces measured by the second sensor  69270 . Based on such measured forces, the control system can determine one or more of a variety of movement parameters associated with either the first or second robotic arm to effectively and efficiently cut the tissue  69250 . The second sensor  69270  can include one or more of a variety of sensors, such as a strain gauge, and can be positioned in any number of locations along the second end-effector  69230  or second robotic surgical tool assembly  69240  for measuring the applied forces along the cutting robotic surgical tool  69235 . For example, any of the force measuring features and mechanisms discussed above (such as with respects to  FIGS. 61A-61C and 62 ) can be implemented in this embodiment for measuring a force applied against the cutting robotic surgical tool  69235 . Reference may be made to U.S. patent application Ser. No. 15/237,753, now U.S. Patent Application Publication No. 2018/0049822, the entire contents of which are incorporated herein by reference, for additional detailed discussion. 
     In various aspects,  FIGS. 64-68  illustrate circular stapler control to allow functional operation by the surgeon while also controlling internal devices according to various aspects of the present disclosure.  FIG. 64  illustrates a patient  7400  lying on an OR table  7402  with a robot controlled circular stapler  7404  inserted in the rectal stump  7406  of the patient  7400  according to at least one aspect of the present disclosure. The circular stapler  7404  is controlled by a robotic arm  7408  and driven by a robotic surgical tool driver  7410 . The OR table  7402  includes multiple load cells  7410  to measure torque and loads in the x, y, z coordinate space. 
     The robotic arm  7408  is controlled to minimize the macro tension of the rectal stump  7406  relative to an inside the abdomen measure of stump position, extension, and orientation.  FIG. 65  illustrates a limiting robotic surgical tool  7404  induced tissue loading relative to a hard anatomic reference according to at least one aspect of the present disclosure. In the illustrated example, the robotic surgical tool  7404  is a circular stapler inserted in the rectal stump  7406  to a first depth D 1  abutting a pliable anatomical structure  7412 . The circular stapler robotic surgical tool  7404  is inserted into the rectal stump  7406  in the direction indicated by arrow  7414 . As the circular stapler robotic surgical tool  7404  is inserted into the rectal stump  7406  and contacts the pliable anatomical structure  7412  at the first depth D 1 , the pliable anatomical structure  7412  is under tension and can be measured as the torque T induced on the robotic surgical tool  7404 . When the robotic surgical tool  7404  reaches a maximum depth D Max , the pliable anatomical structure  7412  is under a maximum tension corresponding to a maximum torque T ZMax  induced on the robotic surgical tool  7404 . The torques T induced by the robotic surgical tool  7404  on the pliable anatomical structures  7412  could be measured by the reaction loads of the robotic surgical tool  7404  being compared to a relative ground based on the torques T measured on the patient  7400  or OR table  7402  by the load cells  7410 . 
     Having determined the relative torques between the robotic surgical tool  7404  and the hard anatomic references (in this case the pelvis and the skeletal system) limits could be pre-defined to prevent the robotic surgical tool  7404  or robotic surgical tool driver  7410  from exceeding during the manipulation or insertion of the powered circular stapler robotic surgical tool  7404 . As depicted in  FIG. 65 , when the torque induced on the robotic toll  7404  reaches a maximum torque T zMax , the robotic surgical tool  7404  retracts slightly to be in ideal tissue tension. 
       FIGS. 66 and 67  illustrate the insertion of the robotic surgical tool  7404  into the rectal stump  7406  according to various aspects of the present disclosure. As depicted in  FIG. 66 , the robotic surgical tool  7404  is shown improperly inserted at an angle to the proper direction of insertion indicated by arrow  7414 . This is improper and results in forces F 1  and F 2  inducing a torque T on the robotic surgical tool  7404  the can be measured. As depicted in  FIG. 67 , the robotic surgical tool  7404  is shown properly inserted in the direction indicated by arrow  7414 . When the robotic surgical tool  7404  is properly inserted, there is minimal torque T induced on the robotic surgical tool  7404 . 
       FIG. 68  is a graphical illustration  7420  of measured torque T on the OR table  7402  and robotic surgical tool  7404  positioning and orientation as a function of time t according to at least one aspect of the present disclosure. The three graphs will now be described in conjunction with  FIGS. 64-68 . The first graph  7422  depicts measured torque T x  in the x-axis and robotic surgical tool  7404  position and orientation angle relative to the x-axis as a function of time t. As shown, there is little fluctuation in torque T x  curve  7428  and x-axis angle  7430  over time about the 0-torque and 0°-angle reference line  7432 . Accordingly, there is no robotic surgical tool  7404  adjustment by the robotic arm  7408  and robotic surgical tool driver  7410 . 
     The second graph  7424  depicts measured torque T y  in the y-axis and robotic surgical tool  7404  position and orientation angle relative to the y-axis as a function of time t. As shown, when the torque T y  reaches a maximum torque T y Max limit  7434 , the central control circuit  15002  ( FIG. 22 ) adjusts the angle of the robotic surgical tool  7404  until the torque T y  drops below the maximum torque T y Max limit  7434  and the angle relative to the y-axis drops down to 0°. 
     The third graph  7426  depicts measured torque T z  in the z-axis and robotic surgical tool  7404  position and orientation angle relative to the z-axis, which corresponds to the depth of the robotic surgical tool  7404  inserted into the rectal stump  7406  (cm) as a function of time t. Here, as the depth into the rectal stump  7406 , the torque T z  remains within the ideal range as indicated by reference lines  7436  until the torque T z  reaches the upper limit  7438  at which point, the central control circuit  15002  ( FIG. 22 ) controls the robotic arm  7408  and driven by a robotic surgical tool driver  7410  to retract the robotic surgical tool  7404  to reduce tissue tension. 
       FIGS. 69A-69D  is a sequence depicting control of the shaft  7500  of a circular stapler robotic surgical tool  7404  as the location of the shaft  7504  of the anvil  7503  is approximated to the extended shaft  7500  of the circular stapler  7404 .  FIGS. 69A-69D  depict the combined multi-arm control motion thresholds for cooperative interactions of a grasper device  7508  located in the colon  7510  and the extended shaft  7500  of the circular stapler  7404  is located in the rectal stump  7406 . Accordingly, as the robotic arms advance the shaft  7500  of the circular stapler  7404  and the anvil shaft  7504 , the tissue tension F g  on the colon  7510  and the tissue tension F r  on the rectal stump  7406  are measured and the shaft  7500  of the circular stapler  7404  and the anvil shaft  7504  are adjusted to minimize each of the tissue tensions F g , F r . 
     With reference now to  FIGS. 64-70 ,  FIG. 70  is a graphical illustration  7520  of control of robotic arms of both internal colon grasper device  7508  and the shaft  7500  of the circular stapler  7404  to achieve acceptable tissue tension according to at least aspect of the present disclosure. With reference now also to  FIGS. 69A-69D , the first graph  7522  depicts tissue tension  7523  (F g ) on the colon  7510  as a function of time t and the second graph  7524  depicts tissue tension  7525  (F r ) on the rectal stump  7406 . The times t 1 -t 4  correspond to the state of the procedure depicted in  FIGS. 69A-69D . 
     With reference still to  FIGS. 64-70 , as depicted in  FIG. 69A , the grasper device  7508  is holding the anvil shaft  7502  and applies a first tissue tension F g1  on the colon  7510  according to at least one aspect of the present disclosure. The extended shaft  7500  of the circular stapler  7404  is located in the rectal stump  7406  and applies a first tissue tension F r1  on the rectal stump  7406 . As shown in the first and second graphs  7522 ,  7524  depicted in  FIG. 70 , at time t 1 , the tension F g1  is below the acceptable tissue tension threshold  7526  on the colon  7510  and the tension F r1  is below the acceptable tissue tension threshold  7528  on the rectal stump  7406 . 
     With reference still to  FIGS. 64-70 , as depicted in  FIG. 69B , the grasper device  7508  has extended the anvil shaft  7502  into the shaft  7506  of the circular stapler  7404 , which has been further extended into the colon  7510  and the rectal stump  7406  according to at least one aspect of the present disclosure. A second tissue tension F g2  is applied on the colon  7510  and a second tissue tension F r2  is applied on the rectal stump  7406 . In this situation, the second tissue tension F g2  applied on the colon  7510  is too high. Accordingly, the central control circuit  15002  ( FIG. 22 ) controls the robotic arm and linear drive to reduce the tissue tension F g2  on the colon  7510 . As shown in the first and second graphs  7522 ,  7524  depicted in  FIG. 70 , at time t 2 , the tension F g2  has increased above the acceptable tissue tension threshold  7526  on the colon  7510  and the tension F r2  remains below the acceptable tissue tension threshold  7528  on the rectal stump  7406 . 
     With reference still to  FIGS. 64-70 , as depicted in  FIG. 69C , the grasper device  7508  releases the anvil shaft  7502  and the tissue tension F g3  on the colon  7510  is reduced according to at least one aspect of the present disclosure. The tissue tension F r3  on the rectal stump  7406 , however, is now too high. Accordingly, the central control circuit  15002  ( FIG. 22 ) controls the robotic arm and linear drive to reduce the tissue tension F r3  on the rectal stump  7406 . As shown in the first and second graphs  7522 ,  7524  depicted in  FIG. 70 , at time t 3 , the tension F g3  has decreased below the acceptable tissue tension threshold  7526  on the colon  7510  and the tension F r3  has increased above the acceptable tissue tension threshold  7528  on the rectal stump  7406 . 
     With reference still to  FIGS. 64-70 , as depicted in  FIG. 69D , the grasper device  7508  has released the anvil shaft  7502  and the tissue tension F g4  on the colon  7510  is within an acceptable range according to at least one aspect of the present disclosure. The tissue tension F r4  on the rectal stump  7406  also is within an acceptable range and the procedure can be completed. As shown in the first and second graphs  7522 ,  7524  depicted in  FIG. 70 , at time t 4 , the tension F g4  has remains below the acceptable tissue tension threshold  7526  on the colon  7510  and the tension F r3  has decreased below the acceptable tissue tension threshold  7528  on the rectal stump  7406 . Accordingly, the central control circuit  15002  ( FIG. 22 ) determines that the circular stapler  7404  is read to fire. 
     With reference still to  FIGS. 64-70 , as illustrated in  FIGS. 69A-69D and 70 , the present disclosure provides a robotic surgical system and method for detecting the appropriate robotic surgical tool-to-robotic surgical tool coupling loads, such as tissue tension F g , F r , to determine if the anvil  7503  is properly seated on the circular stapler  7404 . The present disclosure also provides a method of controlling the macro tissue tension F g , F r  of both the internal robotic arm controlling the grasper device  7508  grasping the anvil shaft  7502  and the external robotic arm controlling the shaft  7506  of the circular stapler  7404  to prevent positional tissue loads F g , F r  from exceeding predefined thresholds  7526 ,  7528 . 
     With reference to  FIGS. 64-71 , in various aspects, the present disclosure provides a robotic surgical system and method for controlling the rate and load at which the anvil  7503  of the circular stapler  7404  is retracted.  FIG. 71  is a graphical illustration  7530  of anvil shaft  7502  rate and load control of a robotic circular stapler  7404  closing system according to at least one aspect of the present disclosure. The first graph  7532  depicts anvil  7503  gap  7540  as a function of time (t). The anvil  7503  gap is the greatest as time t 0 . The gap  7540  decreases sharply between t 0  and t 1  when the velocity  7544  of anvil  7503  retraction is the highest as shown in the third graph  7536 . Between time t 1  and t 2 , the gap  7541  decrease at a slower rate as the velocity  7544  of the anvil  7503  retraction is reduced. Between time t 2  and t 3 , the gap  7543  decrease at an even slower rate as the velocity  7544  of anvil  7503  retraction is reduced even further. 
     With reference still to  FIGS. 64-71 , the second graph  7534  depicts anvil  7503  compression force  7542  (lbs.) as a function of time t and the fourth graph  7538  depicts motor current  7546  (amps) as a function of time t. The motor current  7546  increases proportionally to the tissue compression force  7542 . Detection of the motor control current  7546  or tissue compression  7542  can be used to display initial compressive loading of the tissue and then to monitor the progression of the compression  7542 . In one aspect, the present disclosure provides a robotic surgical system with antagonistic control of the anvil  7503  retraction compression  7542  based on the advancement of the staple drivers or cutting blade. 
     With reference still to  FIGS. 64-71 , the third graph  7536  depicts velocity  7544  of the anvil  7503  retraction as a function of time t. Limiting the retraction of the robotic circular stapler  7404  trocar rate and force below a predefined first threshold prevents accidental unseating of the anvil  7503  from the trocar. The retraction rate of the anvil  7503  would move at a first approximation rate  7548  when the anvil is first seated to the first tissue compression  7550 , and then at a second rate  7552  slower than the first rate  7548  as the tissue compression  7554  progression occurs and the tissue compression exceeds a first threshold  7551 , and then at a third rate  7556  slower than the second rate  7552  if the tissue compression  7558  exceeds a predefined threshold  7557  or motor current  7546  exceeds a predefined threshold  7560 . And finally stopping if the current or tissue compression exceeds a maximum pre-defined threshold  7562 . 
     In various aspects, the present disclosure provides a robotic surgical system and method for controlling the rate of advancement of staple drivers based on another controlled parameter of a robotic surgical tool such as control rate and thresholds of the stapler drivers based on the anvil clamping system. In one aspect, the central control circuit  15002  ( FIG. 22 ) is configured to limit the rate of advancement of the staple driver based on the macro tissue tension T g , T r  measured by the robotic arm supporting the circular stapler  7404 . In one aspect, the central control circuit  15002  ( FIG. 22 ) is configured to limit the advancement rate of the drivers based on the motor current utilized to hold the anvil  7503  in position and resulting from tissue compression. 
     In various aspects, the present disclosure provides a robotic surgical system and method for controlling the rate or load limit of advancement of the cutting blade based on the reaction load measured through the motor current in the anvil clamping system.  FIGS. 72-76  illustrate antagonistic control of the anvil clamping control system and the tissue cutting member control system according to at least one aspect of the present disclosure. 
       FIG. 72  is a schematic diagram of an anvil clamping control system  7600  of a surgical stapler  7602  grasping tissue  7604  between an anvil  7606  and a staple cartridge  7608  and the force F anvil  on the anvil  7606  according to at least one aspect of the present disclosure. A knife  7610  is configured to advance distally to cut the tissue  7604 . The diagram  7600  also shows the force F anvil  on the anvil  7608  and the force F tissue  of the tissue  7604 . 
       FIG. 73  is a schematic diagram of a tissue cutting member control system  7620  of the surgical stapler  7602  depicted in  FIG. 72  grasping tissue  7604  between the anvil  7606  and the staple cartridge  7608  and the force F knife  on the knife  7610  while cutting the tissue  7604  according to at least one aspect of the present disclosure. 
       FIG. 74  is a schematic diagram  7630  of an anvil motor  7632  according to at least one aspect of the present disclosure. The anvil motor  7632  is an element of the anvil clamping control system  7600  depicted in  FIG. 72 . The anvil motor  7632  is configured to open and close the anvil  7606 . 
       FIG. 75  is a schematic diagram  7640  of a knife motor  7642  according to at least one aspect of the present disclosure. The knife motor  7642  is configured to advance and retract the knife  7610  depicted in  FIGS. 72-73 . 
       FIG. 76  is a graphical illustration  7650  of an algorithm for antagonistic or cooperative control of the anvil clamping control system  7600  and the tissue cutting member control system  7620  as illustrated in  FIGS. 72-75  according to at least one aspect of the present disclosure. The first graph  7652  depicts the anvil force F anvil  as a function of time t. A normal anvil force  7660  (F anvil ) is shown in dashed line and a loaded anvil force  7662  (F anvil ) in shown in solid line. The second graph  7654  depicts the knife force F knife  as a function of time t. A normal knife force  7664  (F knife ) is shown in dashed line and a loaded knife force  7666  (F knife ) in shown in solid line. The third graph  7656  depicts anvil motor velocity V anvil motor  as a function of time t. A normal anvil motor velocity  7668  (V anvil motor ) is shown in dashed line and a loaded anvil motor velocity  7670  (V anvil motor ) is shown in solid line. The fourth graph  7658  depicts knife motor velocity V knife  motor as a function of time t. A normal knife motor velocity  7672  (V knife  motor) is shown in dashed line and a loaded knife motor velocity  7674  (V knife  motor) is shown in solid line. As described herein antagonistic control is when the velocity V of the anvil motor  7632  and the knife motor  7634  are adjusted in an opposite direction and cooperative control is when the velocity V of the anvil motor  7632  and the knife motor  7642  are adjusted the same direction. 
     With reference now to  FIGS. 72-76 , at time interval T 1  the force  7676  on the anvil  7606  is too high. Accordingly, the loaded anvil motor velocity  7670  (V anvil motor ) is increased  7678  and the loaded knife motor velocity  7674  (V knife  motor) is decreased  7680  by the central control circuit  15002  ( FIG. 22 ) in an antagonistic manner to cooperate with the anvil clamping control system  7600 . 
     With reference still to  FIGS. 72-76 , at time interval T 2  the force  7682  on the knife  7610  is too high. Accordingly, the loaded anvil motor velocity  7670  (V anvil motor ) is increased  7684  and the loaded knife motor velocity  7674  (V knife  motor) also is increased  7686  by the central control circuit  15002  ( FIG. 22 ) in a cooperative manner to cooperate with the tissue cutting member control system  7620 . 
     With reference still to  FIGS. 72-76 , at time interval T 3  the force  7688  on the anvil  7606  is too low. Accordingly, the loaded anvil motor velocity  7670  (V anvil motor ) is decreased  7690  and the loaded knife motor velocity  7674  (V knife  motor) is decreased  7692  by the central control circuit  15002  ( FIG. 22 ) in a cooperative manner to cooperate with the anvil clamping control system  7600 . 
     With reference still to  FIGS. 72-76 , in various aspects, in several robotic surgical tool configurations (surgical stapler-utters, for example) more than one of the end-effector functions are coupled mechanically to one another during operation. In one aspect, the anvil motor  7632  and the knife motor  7642  systems of a surgical stapler-cutter are often coupled and operate simultaneously to close the anvil  7606  (closing) and advance the knife  7610  while driving staples from the staple cartridge  7608  (firing) during the firing operation. In this case it would be helpful to use one of the anvil motor  7632  and the knife motor  7642  of the two system as a measure of the operation of the other systems or in some circumstances to allow one system to compliment or resist the advance of the other system. 
     With reference still to  FIGS. 72-76 , in various aspects, the cooperative or antagonistic operation of two mechanically coupled systems such as the anvil motor  7632  and knife motor  7642  would enable one system to aid in the force distribution of the overall end-effector needs. As described in the  FIG. 76 , one system could also inhibit the free operation of the other system if the loads induced by the tissue are too low to resist the advancement of one system given an expected advancement and torque rate, improving sensitivity of control and holding. 
     With reference still to  FIGS. 72-76 , in various aspects, cooperative or antagonistic operation of two mechanically coupled systems such as the anvil motor  7632  and knife motor  7642  may be implemented with non-symmetric use of a complimentary and/or antagonistic system for advancement and then another variant for retraction. In this way, the mechanically coupled system could limit the speed of advancement in an antagonistic manner and then assure retraction by then reverting to a cooperative retraction manner where the two systems work together to insure proper retraction without system degradation. 
     In various aspects, with reference back to  FIG. 22 , the processes described hereinbelow with respect to  FIGS. 77-79  may be represented as a series of machine executable instructions stored in the memory  15006  and executed by the processor  15004  of the central control circuit  15002  of the robotic surgical system  15000  depicted in  FIG. 22 . 
       FIG. 77  is a flow diagram  7700  of a process depicting a control program or a logic configuration for controlling a first robotic arm relative to a second robotic arm according to at least one aspect of the present disclosure. The first robotic arm includes a first robotic surgical tool and a first robotic surgical tool driver. The second robotic arm includes a second robotic surgical tool and a second robotic surgical tool driver. The process depicted by the flow diagram  7700  may be represented as a series of machine executable instructions stored in the memory  15006  and executed by the central control circuit  15002  of the robotic surgical system  15000  depicted in  FIG. 22 . With reference now to  FIGS. 22 and 77 , in one aspect, the process depicted by the flow diagram  7700  may be executed by the central control circuit  15002 , where the central control circuit  15002  is configured to determine  7702  the position of a first robotic arm. The central control circuit  15002  is configured to determine  7704  the position of a second robotic arm. The central control circuit  15002  is configured to determine distance, orientation, location of the first robotic arm relative to the second robotic arm. The central control circuit  15002  is configured to modify  7706  a control algorithm for the first robotic arm based on the position of the first robotic arm position relative to the position of the second robotic arm. In one aspect, the central control circuit  15002  modifies  7706  a control algorithm of a first robotic surgical tool driver of the first robotic arm based on the position of the second robotic arm relative to the first robotic arm. In another aspect, the central control circuit  15002  is configured to modify  7706  a control algorithm of a robotic surgical tool driver of the first or second robotic arms based on the relative position of the first and second robotic arms. In another aspect, the central control circuit  15002  is configured to balance  7708  the operational kinematics of a first robotic surgical tool coupled to the first robotic arm relative to the second robotic arm based on a parameter of the first robotic arm relative to the second robotic arm to effect functions of the first or second robotic surgical tool driver. In another aspect, the central control circuit  15502  is configured to adjust  7710  the antagonistic relationship between the first robotic arm and the second robotic arm based on a vertical orientation of the first robotic arm relative to the second robotic arm. In another aspect, the central control circuit  15002  is configured to adjust  7712  the torque limits or motor current limits of the first robotic arm based on an orientation of the second robotic arm that is adjacent to the first robotic arm and is at an angle relative to the first robotic arm. 
       FIG. 78  is a flow diagram  7800  of a process depicting a control program or a logic configuration for verifying a position or velocity of an end-effector jaw of a first surgical tool coupled to a first robotic arm based on a redundant calculation of a resulting movement of the end-effector from a motor application of control parameters of a second robotic arm coupled to a second surgical tool according to at least one aspect of the present disclosure. The first robotic arm includes a first robotic surgical tool, a first robotic surgical tool driver, and a first sensor to determine a position of the end-effector. The second robotic arm includes a second robotic surgical tool, a second robotic surgical tool driver, and a second sensor to determine the position of the end-effector independently of the first sensor. The process depicted by the flow diagram  7800  may be represented as a series of machine executable instructions stored in the memory  15006  and executed by the central control circuit  15002  of the robotic surgical system  15000  depicted in  FIG. 22 . With reference now to  FIGS. 22 and 78 , in one aspect, the process depicted by the flow diagram  7800  may be executed by the central control circuit  15002 , where the central control circuit  15002  is configured to determine  7802  the position of the end-effector based on the first sensor. The central control circuit  15002  is configured to determine  7804  the position of the end-effector based on the second sensor. The central control circuit  15002  is configured to verify  7806  the position of the end-effector based on the positions determined by the first and second sensors. In one aspect, the first sensor includes a first sensor array disposed on the first robotic arm and the second sensor includes a second sensor array disposed on the second robotic arm, where the second sensor array is redundant to the first sensor array. The central control circuit  15002  is configured to determine  7808  the position of the end-effector through the first sensor array and to verify  7810  the position of the end-effectors through the second, redundant, sensor array. In one aspect, the first sensor is an internal coordinate tracking system of the first robotic arm and the second sensor is an optical tracking system coupled to the second robotic arm. In this aspect, the central control circuit  15002  is configured to determine the position of the end-effector based on the internal coordinate tracking system of the first robotic arm, determine the position of the end-effector based on the optical tracking system of the second robotic arm, and compare the position of the end-effector determined by the internal coordinate tracking system and the optical tracking system to verify the position of the end-effector. In one aspect, the first sensor is disposed on a master coordinate tower proximal to the first and second robotic arms, where the master coordinate tower is in communication with the central control circuit  15002 , which is configured to determine the coordinates of the first and second robotic surgical tools. In one aspect, the first robotic surgical tool includes a first end-effector and the second robotic surgical tool includes a second end effector and the central control circuit  15002  is configured to determine the relative position between the first and second end-effectors. In one aspect, the central control circuit is configured to determine the position between the first and second robotic arms. 
       FIG. 79  is a flow diagram  7900  of a process depicting a control program or a logic configuration of controlling at least one operational parameter of a robotic surgical tool driver controlling a circular stapler robotic surgical tool based on another parameter measured within the robotic surgical tool driver controlling the circular stapler according to at least one aspect of the present disclosure. The robotic arm includes a circular stapler robotic surgical tool, a robotic surgical tool driver, and a sensor to measure a parameter within the surgical tool driver controlling the circular stapler. The process depicted by the flow diagram  7900  may be represented as a series of machine executable instructions stored in the memory  15006  and executed by the central control circuit  15002  of the robotic surgical system  15000  depicted in  FIG. 22 . With reference now to  FIGS. 22 and 79 , in one aspect, the process depicted by the flow diagram  7900  may be executed by the central control circuit  15002 , where the central control circuit  15002  is configured to determine  7902  a first operational parameter of the robotic surgical tool and determine a second parameter of the robotic surgical tool based on a measurement. In one aspect, the central control circuit  15002  is configured to measure  7904  a tissue load induced on the tissue by the robotic surgical tool. The central control circuit  15002  is configured to determine  7906  an anatomic reference. The central control circuit  15002  is configured to determine  7908  an operational parameter on the robotic surgical tool based on the measured load induced on the tissue by the robotic surgical tool. The central control circuit  15002  is configured to limit  7910  the load induced on the tissue relative to the anatomic reference. The central control circuit  15002  is configured to control  7912  a rate of retraction of the robotic surgical tool based on the load induced on the tissue relative to the anatomic reference. In one aspect, the central control circuit  15502  is configured to measure the torques induced by the surgical robotic tool on a pliable structure based on a reaction load of the robotic surgical tool compared to a relative ground based on torques measured on either the patient or an operating room table equipped with an array of load sensors. In one aspect, the operational parameter of the surgical robotic tool is the motor current and rate of the retraction of the robotic surgical tool is dependent on a position, magnitude, and force of the anvil shaft, the drivers, or cutting member of the circular stapler. 
     Robotic Surgical System with Local Sensing of Functional Parameters Based on Measurements of Multiple Physical Inputs 
     In various aspects, the present disclosure provides a robotic surgical system and method for monitoring the status of a robotic surgical tool in a redundant manner to verify the operation of the robotic surgical tool through measuring at least two separate sensors monitoring two different physical properties of the robotic surgical tool and robotic arm. In one aspect, one of the physical parameters is used to effect the measure of another physical parameter. In another aspect, at least one of the sensors is located on the robotic surgical tool and the other is located on the other side of a sterile barrier on the control arm. In another aspect, two different physical properties may be motor torque, motor current, strain in the mounting housing of the motor, strain on the sterile barrier mounting feature, reaction load of the arm to table, the reaction load of the patient with respect to the table, load distribution on the table, torque or resulting force within the robotic arm or any of its joints. 
     In various aspects, the present disclosure provides a robotic surgical system and method with dual modality of power transmission, motor control, and monitoring of a modular motor pack. The power transmission is capable of coupling electrically regardless of the orientation of the motor pack to the stationary wiring module about the primary rotation axis of the motor pack. At least one of the three (power transmission, motor control, data monitoring) includes a wired connection with the remaining couples being wireless. In another aspect, the wired connection includes a management feature within the housing to prevent binding or tangling. In another aspect, the power transmission is wireless power transmission between its fixed wire attachments on either or both sides. The wireless communication or power transmission may be coupled through at least two wire radial wire arrays with a pre-defined alignment between the arrays. The first array being positioned on a portion of the robotic surgical tool driver with the other coupled to the motor pack housed within the sterile barrier housing. In another aspect, the alignment is perpendicular to the axis defined by the tubular body of the sterile barrier clam shell. This configuration will enable more than a full rotation of the motor pack with respect to the robotic surgical tool driver while maintaining the alignment of the arrays. In another aspect, the coupled arrays capable of transmitting power or RF communication between the sterile portion of the robotic surgical tool and the non-sterile portion of the control arm while maintaining a constant signal strength or transmission strength throughout the entire rotation of the motor pack. In another aspect, the attached modular robotic surgical tool assembly capable of receiving high speed data communication and medium wattage power transfer through the sterile barrier. 
     In various aspects, the present disclosure provides a robotic surgical system and method for sensing a motor parameter or a response parameter to monitor or control the forces applied by a motor to a robotic surgical tool. For example, in one aspect, the central control circuit  15002  ( FIG. 22 ) ma be configured to sense motor torques and/or motor currents to determine loads applied to the motor and infer the loads applied to the robotic surgical tool. The motor forces may be sensed individually to isolate specific force couples, motor torque, and ground response, for example. The measurement of isolated force couples are employed to determine the overall applied forces. Each individual motor attachment location could be instrumented and used to determine the forces exerted on the robotic surgical tool or instrument by that individual motor. 
       FIG. 80  is a torque transducer having a body connecting a mounting flange and a motor flange according to at least one aspect of the present disclosure. The torque transducer is mounted on a motor. Referring now to  FIG. 80 , a torque transducer  60600  is disclosed. The torque transducer  60600  includes a mounting flange  60610 , a motor flange  60630  and a body  60620  interconnecting the mounting and motor flanges  60610 ,  60630 . The mounting flange  60610  is formed from a ring of radial protrusions  60613  that each define a fastener hole  60614  for receiving a fastener to secure the mounting flange  60610  to a fixed plate. The mounting flange  60610  defines recesses  60616  between each of the radial protrusions  60613 . The recesses  60616  may be used to route wiring to the strain gauge  60640  or between an instrument drive unit (IDU) and an adapter. Additionally or alternatively, the recesses  60616  may provide driver access to the fasteners of the motor flange  60630 . The mounting flange  60610  may include a locating feature or ring  60612  that extends distally to position or locate the torque transducer  60600  relative to a mounting plate. 
     The body  60620  is generally cylindrical and formed from a plurality of struts  60628  that extend between the mounting and motor flanges  60610 ,  60630  to define a channel  60622  through the body  60620 . The struts  60628  are configured to deflect or flex in response to torque applied about a transducer axis. The struts include a low stress regions  60624  adjacent each of the mounting and motor flanges  60610 ,  60630  and a high stress region  60626  between the low stress sections  60626 . The body  60620  includes a stress gauge  60640  disposed in the high stress region of at least one of the struts  60628 . Reference may be made to U.S. patent application Ser. No. 15/887,391, now U.S. Pat. No. 10,213,266, the entire contents of which are incorporated herein by reference, for additional detailed discussion. 
     If each motor has an individually isolated measure of axial, transverse, and radially applied forces then the operation of one system (i.e., firing) could be monitored and resolved by using the other motors within the robotic surgical tool, robotic surgical tool driver, and the robotic arm itself. This sum of the forces could be used as a secondary conformation measure of the primary measured motor response load. 
     If these loads do not confirm each other&#39;s motions an induced load could be made on the patient or the OR table. This could be detected by another measure of the resultant forces or the strain within the tissue may be monitored optically. 
     These overall induced forces as well as the coupled control forces may be used as a secondary safety measure on the control parameters of the operating motor. If the difference becomes more than a predefined threshold the motor control parameters could be limited (slowing, lowering torque, etc.) until the difference diminishes. If the difference continues to elevate the response of the system may be escalated unto and including stopping of reversing the action of the motor. 
     The individual motor torque may be compared to the motor controller measure of current to create a feedback loop that could verified applied torque.  FIG. 81  is a flowchart illustrating a method of controlling an instrument drive unit according to at least one aspect of the present disclosure. With reference to  FIG. 81 , a method  60200  of verifying torque measurements of a primary sensor or reaction torque transducer  60068  of an instrument drive unit with a sensor  60152  is disclosed. Initially, a controller  60126  receives an instruction signal to rotate a motor. In response to the instruction signal, the controller  60126  sends a control signal to the motor to rotate a drive shaft. 
     While the motor is rotating, the motor draws current from a motor energy source. This current is measured  60210  by sensor  60152 . The sensor  60152  generates  60212  a verification signal indicative of the measured current and transmits  60214  the verification signal to the controller  60126 . In addition, while the motor is rotating, a reaction torque transducer measures  60220  torque applied by the motor. The reaction torque transducer generates  60222  a torque signal indicative of the measured torque and transmits  60224  the torque signal to the controller  60126 . 
     The controller  60126  receives  60230  the verification signal and generates an acceptable range of torques which may be applied  60240  by the motor for the given verification signal. The controller  60126  then receives the torque signal from the reaction torque transducer and compares  60250  the torque signal to the acceptable range of torques. If the torque signal is within the acceptable range of torques, the controller  60126  continues  60255  to send a control signal to the motor to rotate the drive shaft. In contrast, if the torque signal is outside of the acceptable range of torques, the controller  60126  stops  60260  rotation of the motor by sending a control signal or ceasing to send a control signal. The controller  60126  then generates  60262  a fault signal indicative of the torque applied by the motor being outside of the acceptable range of torque values. The fault signal may be audible, visual, haptic, or any combination thereof to alert a clinician of the fault. Reference may be made to International Patent Application Serial No. PCT/US2016/037478, now International Patent Application Publication No. WO/2016/205266, the entire contents of which are incorporated herein by reference, for additional detailed discussion. 
     The torques measured by the sensing system coupled to the motor operation may not only be used to make sure they are within an acceptable range, but they also may be used in place of or in combination with the motor current and a means to change the parameter of the control circuit such as the central control circuit  15002  ( FIG. 22 ). The magnitude of the difference, the amount of time the difference has existed, the increase or decrease of the difference, and the magnitude of either the overall torque or overall motor current may be used to determine the error between the system and its response. This error then may be employed to speed up, slow down, increase the duty cycle, or even limit the control signals to the motor. 
     This closed loop control of the motor-to-motor controller may be employed in addition to the overall control of the robotic surgical tool and motor to insure more predictable responses, inhibit over-exertion, and improve safe control of the robotic surgical tool. This could potentially predict jams, collisions, etc., as they are occurring and limit the damage done by the system. 
     In various aspects, the present disclosure provides systems and methods fro sensing the resultant forces generated in the support frame of the motor as a proxy for applied motor forces. Sensing torques and moments applied through the motor mounting frame to determine the six degrees of freedom of forces applied by the motor pack. The forces exerted by the robotic surgical tool to both the robotic interface and the patient may be isolated. 
       FIG. 82  is a front perspective view of an instrument drive unit holder of a robotic surgical assembly with an instrument drive unit and a surgical instrument coupled thereto according to at least one aspect of the present disclosure.  FIG. 83A  is a side perspective view of a motor pack of the instrument drive unit of  FIG. 82  with an integrated circuit in a second configuration and separated from the motor assembly according to at least one aspect of the present disclosure.  FIG. 83B  is a side perspective view of the motor pack of the instrument drive unit of  FIG. 82  with the integrated circuit in a second configuration and separated from the motor assembly according to at least one aspect of the present disclosure. 
     With reference to  FIG. 82 , a robotic surgical system includes a surgical assembly, which includes an instrument drive unit holder (hereinafter, “IDU holder”)  61102  coupled with or to a robotic arm, an IDU  61100  is couplable to the IDU holder  61102 , and the surgical instrument  61010  is couplable to the IDU  61100 . IDU holder  61102  of surgical assembly holds IDU  61100  and surgical instrument  61010  and operably couples IDU  61100  to robotic arm. IDU holder  61102  includes an interface panel or carriage  61104  and an outer housing portion  61108  extending perpendicularly from an end of carriage  61104 . Carriage  61104  supports or houses a motor “M,” which receives controls and power from a control device. Carriage  61104  is slidably mounted onto a rail of robotic arm, and may be moved along rail via a motor driven chain or belt (not shown) or the like. IDU  61100  is non-rotatably couplable to carriage  61104  of IDU holder  61102 , and thus slides along rail of robotic arm concomitantly with carriage  61104 . 
     With reference to  FIGS. 82, 83A, and 83B , motor pack  61122  of IDU  61100  includes an exemplary motor assembly  61200  and an integrated circuit  61300 . It is envisioned that motor pack  61122  may include any number of motors  61150  supported in motor assembly  61200 . It is further envisioned that motors  61150  may be arranged in a rectangular formation such that respective drive shafts (not shown) thereof are all parallel to one another and all extending in a common direction. The drive shaft of each motor  61150  may operatively interface with a respective driven shaft of surgical instrument  61010  to independently actuate the driven shafts of surgical instrument  61010 . 
     In the exemplary embodiment illustrated herein, motor pack  61122  includes four motors  61150  supported in motor assembly  61200 . Motor assembly  61200  may include a distal mounting flange  61210  disposed at a distal end  61202  thereof, and a proximal mounting structure or frame  61220  disposed at a proximal end  61204  thereof. Proximal mounting structure  61220  includes four struts  61220   a - d  spanning between four posts  61204   a - d , wherein the proximal mounting structure  61220  defines proximal end  61204  of motor assembly  61200 . While four posts  61204   a - d  are shown and described herein, it is contemplated that any number of posts may be provided as needed. Also, while posts  61204   a - d  are arranged and illustrated herein in a rectangular configuration, it should be appreciated that any configuration is contemplated and within the scope of the present disclosure. 
     With reference to  FIG. 83B , another exemplary embodiment of motor assembly  61201  is illustrated which includes distal mounting flange  61210 , a proximal mounting cap  61250  and a constrainer  61260 . Proximal mounting cap  61250  is configured to sit and nest over integrated circuit  61300 , and includes four engagement regions  61252   a - d  configured to correspond with posts  61204   a - d , respectively. Constrainer  61260  is configured to sit and nest over proximal mounting cap  61250  and integrated circuit  61300 , where at least one clip feature  61262  selectively engages at least one wall  61254  of proximal mounting cap  61250 . In an embodiment, a screw  61204  passed through a respective screw hole  61266   a - d  of constrainer  61260  and a respective engagement region  61252   a - d , and threadably engages a respective post  61204   a - d , thus securing constrainer  61260  and proximal mounting cap  61250  to posts  61204   a - d.    
     Integrated circuit  61300  includes a plurality of walls or circuit boards  61320   a - d  and a nexus or hub  61330  ( FIG. 83A ), where each circuit board  61320   a - d  is coupled, either directly or indirectly, to nexus  61330 . Integrated circuit  61300  includes a third circuit board  61320   c  and a fourth circuit board  61320   d  that are coupled on opposing sides of second circuit board  61320   b . It should be appreciated that circuit boards  61320   a - d  and nexus  61330  of integrated circuit  61300  may be configured in any number of structural combinations, such as, for example, first, second, third, and fourth circuit boards  61320   a - d  being coupled, side-by-side, where one of first, second, third, or fourth circuit board  61320   a - d  is further coupled to one side of the first, second, third, or fourth side  61331   a - d  of nexus  61330 . In another exemplary embodiment, first and third circuit boards  61320   a ,  61320   c  may be coupled to first and third sides  61331   a ,  61331   c  of nexus  61330 , and second and fourth circuit boards  61320   b ,  61320   d  may be coupled to second and fourth sides  61331   b ,  61331   d  of nexus  61330 . Second circuit board  61320   b  has low electrical noise, whereas third and fourth circuit boards  61320   c ,  61320   d  have relatively high electrical noise. Reference may be made to International Patent Application Serial No. PCT/US2017/034394, now International Patent Application Publication No. WO/2017/205576, the entire contents of which are incorporated herein by reference, for additional detailed discussion. 
     In one aspect, the robotic surgical tool-to-robotic surgical tool driver modular attachment also may have limits on the load threshold that it is allow to sustain before the motors of the robotic arm or robotic surgical tool drivers are limited. The interface between the robotic surgical tool and the robotic surgical tool driver could have non-symmetric maximum restraining loads that correspond to the attachment direction of the coupling and therefore the thresholds before effecting the motor control parameters also may be asymmetric. The forces resisted by the modular joint may be separated into the different degrees-of-freedom (DOF) and each force monitored with respect to pre-defined limits. These limits could be at first optional and then compulsory as the loading increases above a first threshold and then a second threshold. Forces in certain directions may be higher or disregarded based on the DOF and the orientation with respect to the robotic surgical tool and its attachment, or the end-effector force direction. 
     In various aspects, the present disclosure provides a robotic surgical system and method for limiting the combined functional loading of the patient by determining the torques applied by the motors, their mechanical advantage based on the measured positional and orientation of the robotic surgical tool assembly and the comparison of that against the resultant loading as measured at the robotic surgical tool driver attachment location. If the combined functional loading exceeds a predefined threshold then limit the motors of the motor pack and the arm to stay underneath that threshold. 
       FIGS. 84-85  illustrate combined functional operating loading to limit robotic surgical tool control motions according to various aspects of the present disclosure.  FIG. 84  is a graphical illustration  8000  of limiting combined functional loading on the patient by determining the torques within robotic surgical tool driver and robotic arm/system according to at least one aspect of the present disclosure. The first graph  8002  depicts motor velocity  8004  as a function of time t. The second graph  8006  depicts estimated tissue force  8008  as a function of time. A first curve  8010 , shown in solid line, represents the estimated force applied to the on tissue by the robotic surgical tool driver and a second curve  8014 , shown in dashed line, represents the estimated force applied to the tissue by the robotic arm system. With reference now to the first and second graphs  8002 ,  8006 , the motor velocity  8004  is adjusted based on the estimated tissue forces  8008 . Between to and t 1 , when both of the estimated tissue force curves  8010 ,  8014  are below a first force threshold  8016  (F 1 ,) the motor velocity  8004  is set to a maximum velocity  8018  (V max ) by the central control circuit  15002  ( FIG. 22 ). If either one of the estimated tissue force curves  8010 ,  8014  rises above the first force threshold  8016  (F 1 ), as shown at t 1 , and remains below a second maximum force threshold  8020  (F max ), the motor velocity  8004  is set to a lower value  8022  (V 2 ) by the central control circuit  15002  and the control unit  15002  issues a warning signal to take action. If either one of the estimated tissue force curves  8010 ,  8014  continues to rise towards the second force threshold  8020  (F max ), as shown between t 2  and t 3 , the motor velocity  8004  is set to an even lower value  8024  (V 1 ) by the central control circuit  15002  and the central control circuit  15002  continues to issue a warning signal to take action. If either one of the estimated tissue force curves  8010 ,  8014  rises above the second force threshold  8020  (F max ), as shown at t 3 , the motor is shut down by setting the motor velocity  8004  to zero  8026  by the central control circuit  15002 . 
       FIG. 85  is a flow diagram  8100  of a system and method of limiting combined functional loading on the patient by determining the torques within robotic surgical tool driver and robotic arm/system according to at least one aspect of the present disclosure. The left side  8101  of the flow diagram  8100  depicts robotic surgical tool driver measurements  8102  and the right side  8103  of the flow diagram  8100  depicts robotic arm/system measurements  8104 . Turning to the robotic surgical tool driver measurements  8102 , the central control circuit  15002  ( FIG. 22 ) measures  8106  to maintain position. The central control circuit  15002  knows  8108  the geometry and, therefore, the mechanical advantage of the robotic system. The central control circuit  15002  employs the measurement  8106  and the knowledge  8108  to calculate  8110  actual tissue loads. Turning now to the robotic arm/system measurements  8104 , the central control circuit  15002  measures  8112  motor torque to maintain position. The central control circuit  15002  knows  8114  the geometry and, therefore, the mechanical advantage of the robotic system. The central control circuit  15002  employs the measurement  8112  and the knowledge  8114  to calculate  8116  actual robot system loads. The central control circuit  15002  then compares  8118  the calculated  8110  actual tissue loads to the calculated  8116  actual robot system loads and determines an estimated force on the tissue. Accordingly, the combined functional loading on the patient is thus limited by determining the torques within the robotic surgical tool driver and the robotic arm/system. The detection system doubles as an active restraining means to reduce overstrain conditions. 
     In various aspects, the present disclosure provides a robotic surgical system and method for sensing and adjustably restraining a support from further strain. In one aspect, the sensing system also behaves as an active restrainer to reduce overstrain conditions. In its initial operational mode, the sensing system is in an active restraint mode where electrical potential changes as the sensing system is strained. The sensing system may be arranged in an array. However, the array also is capable of receiving a signal and from the signal creating a restraining force to limit further deformation of the sensing array. One example of such sensing system is known as an electroactive polymer (EAP). An EAP changes shape (elongating or contracting) based on an applied electrical potential. This same effect, as manifested in the physical straining of the EAP, causes a measurable electrical parameter change. The sensing system could first be used in passive mode to measure deformation of a motor support frame. Then when a predefined level of strain is reached, an electrical potential is applied to the polymer causing it to either further contract or expand to create a secondary force couple that inhibits any further strain on the sensing system and thus the motor support frame. In a passive restraint mode, a conductive polymer may be utilized such that if resultant forces on the motor support frame exceed a certain limit, the conductive polymer will deform sufficiently to reduce/limit conduction and stop the motor. 
     In various aspects, the present disclosure provides a robotic surgical system and method for monitoring external parameters associated with the operation of a motor. A flexible circuit or thermocouple may be attached to the exterior of the motor or attached in the center of a group of four motors to monitor the operational temperature of the motor pack.  FIGS. 86-87  illustrate how motor control parameters may be adjusted based on the temperature of the motor pack according to various aspects of the present disclosure. 
       FIG. 86  illustrates a motor pack  8200  according to at least one aspect of the present disclosure. The motor pack  8200  includes a plurality of motors  8202  contained in a motor housing  8204 . A flexible circuit  8206  with temperature measurement electronics may be attached to each motor  8202  or may be located inside the motor housing  8204  to measure the heat output by the motors  8202  or the motor pack  8200  as a unit. In one aspect, a thermocouple may be attached to the motors  8202  or located inside the housing  8204  to measure the heat output by the motors  8202  or the motor pack  8200 . 
       FIG. 87  is a graphical illustration  8210  of a temperature control algorithm for monitoring external parameters associated with the operation of a motor according to at least one aspect of the present disclosure. A first graph  8212  depicts motor temperature  8214  as a function of time t as the velocity of the motor  8202  changes over time. A first temperature threshold  8213  (T 1 ) is set to provide a temperature warning and to take precautionary steps. A second temperature threshold  8219  (T 2 ) is set to shut down the motor  8202  if exceeded. A second graph  8216  depicts motor velocity  8218  as a function of time t. With reference to the first and second graphs  8212 ,  8216 , from time t 0  to t 1 , the motor velocity  8218  is set to maximum velocity  8220 . This phase of operation may coincide with advancement of a knife prior to contacting tissue and firing staples. During this period, the motor temperature  8214  rises until it crosses  8215  the first temperature threshold  8213  (T 1 ) at time t 1 . When the motor temperature  8214  crosses the first temperature threshold  8213  (T 1 ), the central control circuit  15002  ( FIG. 22 ) issues a temperature warning to take precautionary steps. Between time t 1  and t 2  the stapler is fired and the motor velocity  8218  is lowered to “limp mode” velocity  8222  where the motor  8202  is slowed or its functions are limited. During this period, the motor temperature continues to rise until it reaches the second temperature threshold  8219  (T 2 ) at time t 2 . At time t 2 , the motor  8202  is temporarily paused and the motor velocity  8218  is set to zero velocity  8224  until the motor temperature  8214  drops below the second threshold  8219  (T 2 ) and begins trending downward until time t 3  when the motor velocity  8218  resumes “limp mode” velocity  8226 . At time t 4 , the motor temperature  8214  crosses  8217  the first temperature threshold  8213  (T 1 ) in a downward trend and the motor velocity  8218  is once again set to maximum velocity  8228 . 
     With reference still to  FIGS. 86-87 , in one aspect, if the motor pack  8200  or the attached control electronics exceeds the first predefined threshold  8213  (T 1 ), the central control circuit  15002  ( FIG. 22 ) of the robotic surgical system  15000  ( FIG. 22 ) may adjust its controls and ventilation in order to limit further heat buildup within the motor pack  8200 . If the motor pack  8200  exceeds the second higher temperature threshold  8219  (T 2 ), the central control circuit may begin to limit the motor currents and operational loads of the motor pack  8200  to prevent further heat buildup. Finally if the temperature exceeds a third threshold T 3  (not shown) the central control circuit  15002  may completely shut down the motor pack  8200  require that the motor pack  8200  cool below a predetermined temperature before restarting. 
     In an alternative temperature control algorithm, the central control circuit  15002  ( FIG. 22 ) may pause the motor  8202  between operations or limiting the duty cycle of the motor  8202  instead of lowering the operational loads exerted by the robotic surgical system. The central control circuit  15002  ( FIG. 22 ) monitors the temperature of the motor pack  8200  and provides warnings to the user in advance of the motors  8202  crossing a predetermined temperature threshold T 1 , T 2 , T 3  . . . T n  to mitigate against a complete shut-down of the motor  8202  during a surgical procedure or a particular step of a surgical procedure. In one aspect, during a surgical procedure or a particular step of a surgical procedure, which could be informed by situational awareness, the user would be informed of actions being taken by the robotic surgical tool (e.g., stapler firing, etc.) based on a risk assessment performed to determine the best route to allow the device to proceed: shut down, go into a limp-mode that slows or limits functions, allow only the current step to be completed, etc. 
       FIG. 88  is a graphical illustration  8300  of magnetic field strength  8302  (B) of a motor  8202  as a function of time t according to at least one aspect of the present disclosure.  FIG. 89  is a graphical illustration  8304  of motor temperature  8306  as a function of time t according to at least one aspect of the present disclosure.  FIG. 90  is a graphical illustration  8308  of magnetic field strength (B) as a function motor temperature (T) according to at least one aspect of the present disclosure. The curve  8310  represents ΔB/ΔT, the rate of change of magnetic field strength to the change in motor temperature, where T 1  is the motor temperature at startup (cold), T 2  is the motor temperature with a cooling fan running during calibration/operation, and T 3  is the motor temperature without a cooling fan running during calibration/operation. Measuring magnetic field strength (B) and temperature (T) enables the calculation of dB/dT which may be a better indicator of magnet (motor) health vector. 
     With reference now to  FIGS. 22 and 86-90 , in one aspect, the central control circuit  15002  ( FIG. 22 ) modulates active cooling (e.g., turns a cooling fan on or off) during motor calibration and detects temperature change as a way to assess the health of the motor magnet. The central control circuit  15002  learns not just the absolute temperature of the motor  8202  but learns the thermal response of the motor  8202 . For example, the function of a motor  8202  can be affected by the deterioration of the magnetic field strength (B) of the rotor. Measurement of both magnetic field strength (B) and temperature T can result in guidelines for assessing the health of the motor  8202  based on absolute values or ranges; however, measuring the response of the magnetic field strength (B) as a function of temperature T, the resulting 
                 d   ⁢   B       d   ⁢   T       ,         
also provides an improved way to assess the health of the magnet even when the magnetic field strength (B) or temperature T are within normal operating ranges by determining or predicting how or if the motor  8202  is trending towards abnormal operating ranges.
 
     With reference still  FIGS. 22 and 86-90 , in one aspect, electronic circuits located within the motor pack  8200  are configured to monitor an electromagnetic field. If the magnetic field strength (B) exceeds a predefined threshold that could interfere with communication, control, or sensing of a motor operation, the central control circuit  15002  ( FIG. 22 ) may shut down the electrical power to the motor pack  8200 . In one aspect, a motor control algorithm may be modified based on an externally applied and monitored magnetic field strength (B). In one aspect, an integrated Hall effect sensor or an inductive sensor may be located within the motor pack  8200  to detect magnetic fields. The controlled activation of the motor  8202  could be based on detecting a predefined magnetic field fingerprint or a functional interaction detected by the Hall effect or inductive sensor and then detecting an external magnetic field and modifying the control algorithm to eliminate the effect of the internal or external magnetic field from the measurement. The resulting magnetic field may be compared against pre-defined thresholds to determine the reaction based on the intensity of the externally applied magnetic fields. 
     With reference still  FIGS. 22 and 86-90 , in one aspect, the reactions to the magnetic field measurements may include the central control circuit  15002  ( FIG. 22 ) slowing or stopping the motors  8202 . It also may include reliance on secondary non-magnetic measurements of motor operation, or it may result in notation to the user of the issue. In addition to determining if any external magnetic fields are unduly influencing sensing or operation of the motor  8202 , additional secondary passive measures also may be monitored and employed by the central control circuit  15002  to control functional aspects of the motor  8202  to prevent interference. In other aspects, the external portion of the motor  8202  may be coupled to a piezoelectric sensor to monitor acoustics of the motor  8202  operation. In other aspects, the external portion of the motor  8202  may be coupled to the piezoelectric sensor to measure vibration of the housing  8204  to monitor motor  8202  operation. 
     In various aspects, the present disclosure provides a robotic surgical system and method for detecting ground faults in the robotic surgical system  15000  ( FIG. 22 ). If the central control circuit  15002  ( FIG. 22 ) senses a floating ground, leakage current, or other electrical circuit contamination in which the robot, robotic surgical tool, or robotic surgical tool driver, which is now part of the robotic surgical system  15000 , the central control circuit  15002  will shut down that robotic arm. Monitoring of the ground condition of the robot, robotic surgical tool, or toll driver may be useful in preventing inadvertent cautery damage. In one aspect, a ground condition may occur from shorting a monopolar instrument onto the ground path of the robotic arm or robotic surgical tool or through capacitive coupling with a monopolar device. Responses to a ground condition may include, for example, preventing the application of RF energy, moving the robotic arms apart to remove interface, preventing further robotic arm or robotic surgical tool motion, or adjusting electrical circuits to eliminate or cause an electrical short circuit. 
     In one aspect, the robotic surgical system  15000  ( FIG. 22 ) of the present disclosure provides a sensor for detecting both the angle of rotation of the robotic surgical tool with respect to the robotic surgical tool driver and the number of times it has been rotated. Such continuous monitoring of the number of robotic surgical tool rotations may be employed by the central control circuit  15002  to prevent over-exertion of the robotic surgical tool. In one aspect, a resistive element having a multiple loop winding and a contact arm may be configured to move both radially and longitudinally causing the resistance to change as the device is rotated. This resistance continue to drop as the robotic surgical tool is rotated all the way around up to several times. In various aspects, the robotic surgical system  15000  ( FIG. 22 ) of the present disclosure further provides a system and method for calibration loading the robotic surgical tool. 
     With reference back to  FIG. 22 , in various aspects, the present disclosure provides a robotic surgical system  15000  and method for rotating the robotic surgical tool  15030 . In one aspect, the present disclosure provides an apparatus and method for managing the electrical connections between a rotatable modular robotic surgical tool  15030  and a fixed radial position of the robotic surgical tool driver  15028 . Implementation of such robotic surgical tool  15030  rotation capabilities requires the transmission of power and communication signals from the central control circuit  15002  to the robotic surgical tool driver  15028  and the robotic surgical tool  15030 . 
     One example of a hardwired system with coiled length to allow robotic surgical tool rotation is now discussed with respect to  FIGS. 91-92 . With reference to  FIGS. 91-92 , a flex spool assembly  62200  includes a first printed circuit board  62212 , a second printed circuit board  62214 , and a third printed circuit board  62216  according to at least one aspect of the present disclosure. First, second, and third printed circuit boards  62212 ,  62214 ,  62216  are rigid circuit boards rather than flex circuits. In some embodiments, first, second, and third printed circuit boards  62212 ,  62214 ,  62216  may be flex circuits and/or may be monolithically formed with first flex circuit  62210 . First printed circuit board  62212  is connected to a printed circuit board of an instrument drive unit (IDU) holder such that first printed circuit board  62212  is fixed relative to IDU. First printed circuit board  62212  is connected to first end portion  62210   a  of first flex circuit  62210  to transfer power and data to first flex circuit  62210 . First printed circuit board  62212  is connected to first end portion  62210   a  of first flex circuit  62210  to transfer power and data to first flex circuit  62210 . First printed circuit board  62212  has an electrical connector, for example, a female connector  62212   a , configured to be coupled to a corresponding male electrical connector (not explicitly shown) of printed circuit board of IDU holder. In some embodiments, a wire may be used in place of female connector  62212   a . It is contemplated that any of the disclosed electrical connectors may be zero insertion force (“ZIF”) connectors. 
     Second and third printed circuit boards  62214 ,  62216  of flex spool assembly  62200  are each disposed within intermediate portion  62210   c  of first flex circuit  62210  and are each connected to second end portion  62210   b  of first flex circuit  62210 . Second printed circuit board  62214  is configured to transfer power from first printed circuit board  62212  to a motor assembly of IDU. Second printed circuit board  62214  has an electrical connector, for example, a female connector  62214   a , configured to be coupled to first male electrical connector  62128  of integrated circuit  62120 . Third printed circuit board  62216  is disposed adjacent second printed circuit board  62214  and is configured to transfer data from first printed circuit board  62212  to various components of IDU and/or a surgical instrument. Third printed circuit board  62216  has an electrical connector, for example, a female connector  62216   a , configured to be coupled to second male electrical connector of integrated circuit  62120 . Female and male connectors  62214   a ,  62216   a  may be pin/position connectors, such as, for example, 40-pin connectors. 
     With continued reference to  FIGS. 91-92 , second flex circuit  62220  of flex spool assembly  62200  has a first end portion  62220   a  connected to a first end portion of first printed circuit board  62212 , and a second end portion  62220   b  disposed adjacent a second end portion of first printed circuit board  62212  to define a U-shaped intermediate portion  62220   c  that surrounds first flex circuit  62210 . First and second ends  62220   a ,  62220   b  of second flex circuit  62220  are fixed to a platform  62116  of IDU. Reference may be made to International Patent Application Serial No. PCT/US2017/035607, now International Patent Application Publication No. WO/2017/210516, the entire contents of which are incorporated herein by reference, for additional detailed discussion. 
     In one aspect, the wire management system may be employed to control the winding of the wire and control of it in the unwound state. In one aspect, a spring biased wrapping system may be employed for wire control of rotating motor units. In one aspect, a spring element may be provided that rewinds the wiring harness as the device is counter rotated back to its hot position. The spring bias on the spindle keeps the tension of the wiring harness as it rolls up to manage the wire. The wire management system could have a spring bias into the coiled state enabling the system to easily re-coil when counter rotated. In another aspect, the housings may include wire control passages that only allow the wire to move from one controlled orientation to another controlled orientation on a second spool without being bunched or tangled in-between. The flex circuit wire may contain structural elements within the flex-wire itself to prevent kinking, twisting, or unintended coiling. 
     In various aspects, the present disclosure provides an internal receiver cavity to enable the wiring harness to unwind in a controlled manner in order to allow it to fold up rather than twist and bind up.  FIGS. 93-94  illustrate an internal receiver  8300  with multiple cavities  8304 ,  8306  wire control features to maintain orientation and order of the wiring harness  8308  during rotation according to at least one aspect of the present disclosure. The wiring control housing  8302  may include a first cavity  8304  and a second cavity  8306  that are used to store the wiring harness  8308  in its fully retracted state and as the wiring harness  8308  is unrolled, it is contained within the second cavity  8306  to prevent tangling and unintended interactions with itself. The first, internal, receiver cavity  8304  includes a spring biased rotating spool  8312  to allow the wiring harness  8308  to unwind in a controlled manner in order to allow it to fold up rather than twist and bind up. 
       FIG. 94  illustrates a wiring harness  8308  according to at least one aspect of the present disclosure. The wiring harness  8308  includes a four rotation flex circuit  8310  and as spring biased rotating spool  8312  with electrical contacts  8314 . The electrical contacts  8314  connect stationary wiring  8316  to a circuit panel connector  8318 , which is used to connect to a circuit panel. 
       FIGS. 95-98  illustrate a semiautonomous motor controller  8400  local to a motor pack  8402  with a safety circuit according to at least one aspect of the present disclosure. The semiautonomous motor controller  8400  provides infinite rotation power transfer and communication with elements located on a control circuit and semiautonomous continuous motor control local to the motor pack  8402 . 
       FIG. 95  illustrates a semiautonomous motor controller  8400  local to a motor pack  8402  according to at least aspect of the present disclosure. In one aspect, the motor pack  8402  is a modular rotatable motor pack  8402 . The semiautonomous motor controller  8400  is located in a sterile field  8406  and communicates wirelessly to a non-sterile field  8408  safety processor  8410  via wireless communication circuits  8412 ,  8414 . A sterile barrier  8405  separates the sterile field  8406  from the non-sterile field  8408 . In the illustrated example, a motor housing  8416  of the motor pack  8402  contains up to four motors  8418 . A slip ring connector system  8419  includes a plurality of slip ring electrical traces  8420  are disposed on an exterior portion of the motor housing  8416 . A plurality of spring loaded plungers  8422  make electrical contact with the corresponding slip ring electrical traces  8420 . This configuration provides &gt;360° rotation of the motor housing  8416  within a sterile clam shell housing  8424 . Located within the sterile clam shell housing  8424  is a non-rotating contact interface connector  8426  to the robotic surgical tool driver  15028  ( FIG. 22 ) cartridge. In various aspects, the slip ring connector system  8419  provides a rotary interface between the motor pack  8402  and the sterile barrier  8405  through the spring loaded contacts  8422  and electrical wires  8427  coupled to the connector  8426 . In one aspect, the slip ring connector system  8419  includes a series of rotatable electrical traces  8420  and spring loaded contacts  8422  that allow for the motor pack  8402  to be rotated while still maintaining electrical contacts. 
       FIG. 96  is a detailed view of the spring loaded plunger  8422  depicted in  FIG. 95  according to at least one aspect of the present disclosure. The spring loaded plunger  8422  included a threaded housing  8428  and an internal spring  8430  to bias an electrical contact  8432  into electrical communication with the slip ring electrical contacts  8421  disposed on the exterior portion of the motor housing  8416 . A hook  8434  located at a tip of the electrical contact  8432  prevents the electrical contact  8432  from receding into the threaded housing  8428  and a flange  8435  located at a base of the electrical contact  8432  prevents the electrical contact  8432  from being ejected through the distal end  8436  of the threaded housing  8428 . The electrical contacts  8432  connect the slip ring electrical traces  8420  to the connector  8426  through the electrical wires  8427 . 
       FIG. 97  illustrates a wireless power system  8500  for transmission of electrical power between a surgical robot and a motor pack  8504  comprising a plurality of motors  8502  according to at least one aspect of the present disclosure. A magnetic shield  8506  made of suitable materials such as AL—Mn—Fe or Fe—Si—DL, among others, provides magnetic shielding to prevent magnetic field interference outside a sterile housing  8508  of the motor pack  8504 . Wireless power transfer coil arrangement includes a power transmitter coil  8510  and a power receiver coil  8512  to transfer electrical power between the surgical robot and the motor pack  8504 . A first set of coils includes a power transmitter coil  8510  and power receiver coil  8512  positioned within the robotic surgical tool driver carriage and a second set of coils including a power transmitter coil and a power receiver coil positioned adjacent the first set within the motor pack  8504  when seated in the robotic surgical tool driver  15028  ( FIG. 22 ), and the sterile barrier  8405  ( FIG. 95 ) positioned therebetween. The power transmitter coil  8510  and the receiver coil  8512  may be have a concentric configuration on the same axis about which the motor  8505  is allowed to rotate. This would allow full 360°+ rotation and any number of rotations without forcing the system to be counter-rotated back to a start position. In this configuration the power transmitter and receiver coils  8510 ,  8512  are mechanically limited to maintain a pre-established alignment. The Qi standard for medium power allows for 5 W-15 W power transfer in an envelope that is smaller than a 2-inch diameter which would allow the power transmitter and receiver coils  8510 ,  8512  system to be positioned over top of a four motor  8505  motor pack  8504  set without requiring additional space. 
       FIG. 98  is a diagram  8600  of the wireless power system  8500  for transmission of electrical power between a robot  8502  and a motor pack  8504  depicted in  FIG. 97  according to at least one aspect of the present disclosure. With reference now to both  FIGS. 97-98 , a first wireless power transfer coil  8510  transmits power to a wireless power receiver coil  8512  to supply electrical power to the motor pack  8504 . An accelerator  8602  is coupled to the wireless power receiver coil  8512 . The power accelerator  8602  is electrically coupled to a boost controller  8604 , which is electrically coupled to the wireless power receiver coil  8512  and to motor control circuits  8606 . The motor control circuits  8606  are electrically coupled to the motors  8505 . Both the motor control circuits  8606  and the motors  8505  are electrically coupled to the wireless power receiver coil  8512 . 
     With reference now to  FIGS. 95-98 , a rechargeable intermediate accumulator may be provided to improve the pair relationship between the capacity of wireless power transfer and its ability to provide high current draw multi-motor simultaneous operation. The accumulator may be located within the motor pack  8504  to prevent interruption of power, voltage sags, and to handle high current draw operations. 
     With reference to  FIG. 99 , a block diagram of an information transfer system according to at least one aspect of the present disclosure. The system  62040  includes a transmit unit  62050  and an intrabody instrument or robotic arm  62060 . The transmit unit  62050  may be in operable communication with an energy source  62052  and a storage unit  62054 . The robotic arm  62060  may include a receive unit  62062 , an energy storage unit  62064 , an instrument control electronics unit  62066 , a storage unit  62068 , and an LED indicating unit  62070 . The transmit unit  62050  may communicate with the receive unit  62062  of the robotic arm  62060  via a communications link  62042 . 
     Of course, several different types of connection components or communications links may be used to connect the transmit unit  62050  to the receive unit  62062 . As used herein, “connection component” may be intended to refer to a wired or wireless connection between at least two components of system  62040  that provide for the transmission and/or exchange of information and/or power between components. A connection component may operably couple consoles/displays (not shown) and robotic instruments to allow for communication between, for example, power components of robotic instruments and a visual display on, for example, a console. Reference may be made to U.S. patent application Ser. No. 13/024,503, now U.S. Pat. No. 9,107,684, the entire contents of which are incorporated herein by reference, for additional detailed discussion. 
       FIG. 100  generally depicts system  62100  for providing electrical power to a medical device  62102  according to at least one aspect of the present disclosure. It is contemplated that medical device  62102  could comprise virtually any type of powered medical device, including but not limited to, a cutting/cauterizing robotic surgical tool, an irrigation/aspiration robotic surgical tool, a visualization robotic surgical tool, a recording and/or printing device and the like. Medical device  62102  is provided with electronic circuit  62104  and resonant receiver  62106 . Electronic circuit  62104  may comprise any electronic/electrical circuit(s) used to operate medical device  62102 . Electronic circuit  62104  is electrically coupled to resonant receiver  62106 . 
     Also depicted in  FIG. 100  is power transmitting unit  62108  that includes resonant transmitter  62110 . It is contemplated that resonant transmitter  62110  generates a resonant magnetic field  62112  (depicted by the concentric lines) that transmits from power transmitting unit  62108 . Resonant receiver  62106  is “tuned” to the same frequency as resonant magnetic field  62112  such that, when resonant receiver  62106  is moved to a location within resonant magnetic field  62112 , a strong resonant coupling occurs between resonant receiver  62106  and resonant transmitter  62110 . The resonant coupling in one advantageous embodiment, comprises evanescent stationary near-field. While the transmitter/receiver may comprise virtually any type of resonant structure, it is contemplated that in an advantageous embodiment, the electromagnetic resonant system may comprise dielectric disks and capacitively-loaded conducting-wire loops. This arrangement provides the advantages of a strong coupling for relatively large and efficient power transfer as well as relatively weak interaction with other off-resonant environmental objects in the vicinity. Reference may be made to U.S. patent application Ser. No. 12/425,869, now U.S. Pat. No. 9,526,407, the entire contents of which are incorporated herein by reference, for additional detailed discussion. 
     Referring now to  FIG. 101 , a surgical instrument  63010  is provided according to at least one aspect of the present disclosure. The surgical instrument  63010  includes a handle  63020 , an adaptor  63030 , and a disposable loading unit  63040 . The adaptor  63030  includes a handle connector  63032  at a proximal end thereof and the handle  63020  defines an adaptor receiver  63026  for receiving the handle connector  63032  to releasably couple the adaptor  63030  to the handle  63020 . The disposable loading unit  63040  includes a loading unit connector  63042  at a proximal end thereof and the adaptor  63030  defines a loading unit receiver  63036  adjacent a distal end thereof to releasably couple the disposable loading unit  63040  to the adaptor  63030 . The disposable loading unit  63040  includes an end-effector assembly  63140  that includes a first and a second jaw member  63142 ,  63144 , each of which is moveable relative to one another and are configured to act on tissue. 
     An electrical interface  63050  is disposed within the adaptor receiver  63026  and the handle connector  63032 . The electrical interface  63050  is a non-contact electrical interface that transmits energy from the handle  63020  to the adaptor  63030  and transmits data signals from the adaptor  63030  and/or the disposable loading unit  63040  to the handle  63020 , between the adaptor receiver  63026  and the handle connector  63032 . It is contemplated that control signals are transmitted by the electrical interface  63050  from the handle  63020  to the adaptor  63030 . The handle  63020  may include a display  63025  configured to display information from the data signals from the adaptor  63030  and/or the disposable loading unit  63040  to a user of the surgical instrument  63010 . 
     Referring now to  FIG. 102 , the electrical interface  63050  may include a control circuit  63060  for transmitting the control signals according to at least one aspect of the present disclosure. The control circuit  63060  includes a proximal control coil  63062  and a distal control coil  63064  which form a control transformer  63068  when the handle connector  63032  of the adaptor  63030  is received within the adaptor receiver  63026  of the handle  63020 . The proximal control coil  63062  is disposed within a protrusion of the handle  63020  adjacent to but electrically shielded from the proximal coil  63052 . The distal control coil  63064  is positioned adjacent to a recess of the adaptor  63030  and to the distal coil  63054  but is electrically shielded from the distal coil  63054 . It will be appreciated that the control transformer  63068  is electrically shielded or isolated from the data transformer  63058  such that the data signals do not interfere with the control signals. 
     The control signals from the processor  63022  of the handle  63020  are transmitted to a control signal processor  63067  thereof. The control signal processor  63067  is substantially similar to the data signal processor  63057  and converts the control signals from the processor  63022  to high frequency control signals for transmission across the control transformer  63068 . The high frequency control signals are transmitted from the control signal processor  63067  to the proximal control coil  63062 . The proximal control coil  63062  receives energy from the energy source  63024  of the handle  63020 . It is also contemplated that the proximal control coil  63062  receives energy from a separate and distinct energy source (not shown). The energy received by the proximal control coil  63062  is inductively transferred across the control transformer  63068  to the distal control coil  63064 . Reference may be made to U.S. patent application Ser. No. 14/522,873, now U.S. Pat. No. 10,164,466, the entire contents of which are incorporated herein by reference, for additional detailed discussion. 
       FIG. 103  schematically illustrates an electrosurgical system (shown generally as  63400 ) that includes an electric-field capacitive coupler module  63420  coupled between a microwave generator assembly  63486  and a microwave energy delivery device  63410  according to at least one aspect of the present disclosure. 
     Microwave generator assembly  63486  includes a power generation circuit  63402  that generates and provides DC power from a DC power supply  63404  and a microwave frequency signal from a signal generator  63406 . Microwave generator assembly  63486  includes an amplifier unit  63408 , and may include a processing unit  63482  communicatively coupled to the amplifier unit  63408  and configured to control the amplifier unit  63408  to amplify the microwave frequency signal generated by the signal generator  63406  to a desired power level. DC power from the DC power supply  63404  and the microwave frequency signal from the signal generator  63406  are supplied to the amplifier unit  63408 . Amplifier unit  63408  may include one or more microwave signal amplifiers configured to amplify the microwave frequency signal, e.g., based on one or more signals received from the processing unit  63482 , from a first power level to at least one second power level. 
     The microwave frequency signal outputted from the microwave amplifier unit  63408  is supplied to a first end of the transmission line  63411  connected to the generator connector  63409 . In some embodiments, the second end of the transmission line  63411  connects to the delivery device connector  63412  of the microwave energy delivery device  63410 . A suitable flexible, semi-rigid or rigid transmission line, e.g., cable assembly  63019 , may additionally, or alternatively, be provided to electrically-couple the microwave energy delivery device  63410  to an electric-field capacitive coupler module and/or the generator connector  63409 . The microwave frequency signal is passed through the device transmission line  63414  to the antenna  63416  at the distal end of the microwave energy delivery device  63410 . Reference may be made to U.S. patent application Ser. No. 14/022,535, now U.S. Pat. No. 9,106,270, the entire contents of which are incorporated herein by reference, for additional detailed discussion. 
     In various aspects, the present disclosure provides communication on a different return path than electrical power connections. Wired power transfer may be achieved with optical dual direction communication paths for control and sensed data return configured as a hybrid electrical and optical data, power, and control paths. 
     In one aspect, a high speed alternative to wireless communication may include an optical transfer system between the motor pack and the robotic surgical tool driver. This may be implemented by creating a roughly circular LED laser ring on the rotatable side of the assembly. That would allow a receiver to be a stationary element on the robotic surgical tool driver side that would always have aligned access to a portion of the light ring and therefore capable of receiving high speed high resolution data from the rotary component. 
     In one aspect, two sets of light rings and receivers may be coupled between the two systems enabling high speed dual direction communication in a non-contact manner. This would allow for the transmission and receiving of data in a sealed manner in-between any modular aspects of the system minimizing the possibility of shorting out or losing the signal due to contaminates or saturation of the joint within a fluid media. 
     In various aspects, the present disclosure provides a combination of wired and wireless RF communication systems to enable dual data return paths in combination with a single control path. In one aspect, the present disclosure provides a hybrid dual path sensor path may be implemented with a single control path. In another aspect, the present disclosure provides a hybrid direct connection power circuit and a wireless interface for communication and returned sensor data. In this regard, power transmission may be accomplished via a wired or wireless pair coil system as described herein and the communication to and from the modular robotic surgical tool may be accomplished wirelessly. 
     In one aspect, an antenna receiver of the wireless array may be positioned on an exposed portion of the motor pack at some distance away from the induction coils minimizing the amount interference from the power transmission. The antenna array is position on a portion of the motor pack which is outside of the surgical site, and is flex circuit connected to the sterile barrier and then in turn to the robotic surgical tool module by contacts in thru the sterile barrier 
     The electronic circuits, wire paths and connections are isolated and sealed. The electrical contacts may include a circumferential lip of insulating plastic to insure minimal cross-talk or signal loss even if the system where immersed in conductive fluid. This hybrid arrangement may be configured to provide a closed loop control circuit at all times that is in control of the motor assembly. The dual path return of sensor data would allow the system to verify the integrity of the processed data and allow it to use a safety algorithm to monitor the intended operation and the resulting motions of the drive systems. 
     In various aspects, the present disclosure provides a robotic surgical tool rotation mechanism. In one aspect, the robotic surgical tool rotation mechanism employs the robotic surgical tool driver linear drive axles to couple raise and lower and rotate. 
     With reference to  FIG. 104 , elongate link or slide rail  64040  includes a multidirectional movement mechanism  64100  configured to axially move a surgical instrument along a longitudinal axis of elongate link or slide rail  64040  and to rotate the surgical instrument about its longitudinal axis according to at least one aspect of the present disclosure. Multi-directional movement mechanism  64100  of a robotic arm generally includes a left-handed lead screw  64102 , a right-handed lead screw  64104 , and a slider  64110  axially movable along lead screws  64102 ,  64104 , but prevented from rotating relative to lead screws  64102 ,  64104 . Left-handed lead screw has a left-handed screw thread, and right-handed lead screw has a right-handed screw thread such that the screw threads for lead screws  64102 ,  64104  twist in opposite directions. Lead screws  64102 ,  64104  are disposed in parallel relation to one another within a cavity  64042  defined in elongate link or slide rail  64040 . Lead screws  64102 ,  64104  are rotatable within elongate link or slide rail  64040  while also being axially restrained within elongate link or slide rail  64040 . 
     Lead screws  64102 ,  64104  each include a respective first end  64102   a ,  64104   a  rotatably connected to a first end of elongate link or slide rail  64040 , and a respective second end  64102   b ,  64104   b . Second ends  64102   b ,  64104   b  of lead screws  64102 ,  64104  have or are coupled to motors, for example, a first canister motor “M1,” and a second canister motor “M2.” In some embodiments, gears, universal shafts, flexible shafts, brakes, and/or encoders may be associated with motors “M1,” “M2.” Motors “M1,” “M2” drive a rotation of lead screws  64102 ,  64104  and are electrically connected to a control device, via cables or a wireless connection, which is configured to independently control the actuation of motors “M1,” “M2.” 
     Slider  64110  of multi-directional movement mechanism  64100  is slidably disposed within cavity  64042  of elongate link or slide rail  64040  and operably coupled to lead screws  64102 ,  64104 . Slider  64110  has a generally rectangular shape, but it is contemplated that slider  64110  may assume any suitable shape. Slider  64110  defines a first passageway  64112  therethrough that has left-handed lead screw  64102  extending therethrough, and a second passageway  64114  therethrough that has right-handed lead screw  64104  extending therethrough. Slider  64110  further defines an opening  64116  in a side thereof. Slider  64110  is configured to be coupled to surgical instrument  64200  such that axial movement of slider  64110  relative to and along lead screws  64102 ,  64104  results in a corresponding axial movement of surgical instrument  64200 . 
     With reference to  FIGS. 105A and 105B , to cause a cogwheel  64140 , and the attached surgical instrument, to rotate in a clockwise direction as indicated by arrow “C” depicted in  FIG. 105B , first and second motors “M1,” “M2” of multi-directional movement mechanism  64100  are actuated to rotate both left-handed lead screw  64102  and right-handed lead screw  64104  in a counter-clockwise direction according to at least one aspect of the present disclosure. When left-handed lead screw  64102  is rotated in the counterclockwise direction, first nut  64120  tends to move in the upward or proximal direction indicated by arrow “D” depicted in  FIG. 105A , while when right-handed lead screw  64104  is rotated in the counterclockwise direction, second nut  64130  tends to move in the downward or distal direction indicated by arrow “E” depicted in  FIG. 105A . Since first and second nuts  64120 ,  64130  are being driven in opposite longitudinal directions, no movement of slider  64110  results, and first and second nuts  64120 ,  64130  begin to rotate counter-clockwise integrally with lead screws  64102 ,  64104  rather than relative to lead screws  64102 ,  64104 . The rotation of first and second nuts  64120 ,  64130  in the counter-clockwise direction drives a rotation of cogwheel  64140  in the clockwise direction. When the surgical instrument is non-rotatably received within cogwheel  64140 , the clockwise rotation of cogwheel  64140  causes surgical instrument  64200  to rotate therewith. Reference may be made to International Patent Application Serial No. PCT/US2017/019241, now International Patent Application Publication No. WO/2017/147353, the entire contents of which are incorporated herein by reference, for additional detailed discussion. 
     In various aspects, the present disclosure provides supported bearing rotation of a robotic surgical tool about the sterile barrier connection to the robotic surgical tool driver. Turning now to  FIG. 106 , the robotic surgical assembly  66100  is connectable to an interface panel or carriage  66042  which is slidably mounted onto the rail  66040  according to at least one aspect of the present disclosure. The carriage  66042  supports or houses a motor  66044  that receives controls and power from a control device. The carriage  66042  may be moved along the rail  66040  via a motor driven chain or belt or the like. Alternatively, the carriage  66042  may be moved along the rail  66040  via a threaded rod/nut arrangement. For example, the carriage  66042  may support a threaded nut or collar which receives a threaded rod therethrough. In use, as the threaded rod is rotated, the threaded collar, and in turn, the carriage  66042  are caused to be translated along the rail  66040 . A coupling  66046 , or the like, is connected to a drive shaft of motor  66044 , and may be rotated clockwise or counter clockwise upon an actuation of the motor  66044 . While a chain/belt or threaded rod and collar arrangement are described, it is contemplated that any other systems capable of achieving the intended function may be used (e.g., cable drives, pulleys, friction wheels, rack and pinion arrangements, etc.). 
     The carriage  66042  may rotatably support motor axis gear or pulley  66118  (e.g., a spur gear) and a tension gear or pulley  66120  within a coupling flange. A drive belt  66122  or the like extends around a pulley, a motor axis pulley and the tension pulley  66120 . The motor axis pulley is connectable to the coupling  66046  of the motor  66044 , and is driven by the motor  66044  upon an actuation thereof. Accordingly, in use, as the motor  66044  is actuated, the motor  66044  drives the coupling  66046 , which drives the motor axis pulley, to in turn drive the belt  66122 , and in turn, rotate the pulley. Reference may be made to International Patent Application Serial No. PCT/US2017/033899, now International Patent Application Publication No. WO/2017/205308, the entire contents of which are incorporated herein by reference, for additional detailed discussion. 
     Turning now to  FIGS. 107 and 108 , surgical instrument holder  65102  of surgical assembly  65100  functions both to actuate a rotation of a body  65114  of instrument drive unit  65110  and to support a housing  65202  of surgical instrument  65200  according to at least one aspect of the present disclosure. Surgical instrument holder  65102  includes a back member or carriage  65104 , and an outer member  65106  extending perpendicularly from an end of carriage  65104 . In some embodiments, outer member  65106  may extend at various angles relative to carriage  65104  and from various portions of carriage  65104 . Carriage  65104  has a first side and a second side  65108   b , opposite first side. First side of carriage  65104  is detachably connectable to rail  65040  of a robotic arm. Surgical assembly  65100  is configured such that surgical instrument holder  65102  may slide or translate along rail  65040  of robotic arm. Second side  65108   b  of carriage  65104  is configured to connect to instrument drive unit  65110 . In some embodiments, second side  65108   b  of carriage  65104  may define a longitudinal track (not shown) configured for slidable receipt of instrument drive unit  65110 . 
     Carriage  65104  of surgical instrument holder  65102  supports or houses a motor, such as, for example, canister motor “M” therein. Motor “M” receives controls and power from a control device to selectively rotate an inner housing or body  65114  of instrument drive unit  65110 . Motor “M” has a motor shaft  65109  extending longitudinally through carriage  65104  that is drivingly connected to gear of instrument drive unit  65110 . Specifically, motor shaft  65109  includes a gear  65109   a  for selective connection to gear of instrument drive unit  65110  to effect a rotation of body  65114  of instrument drive unit  65110  about its longitudinal axis “X.” 
     With reference to  FIG. 108 , instrument drive unit  65110  includes a plate or flange  65116  disposed at proximal end  65114   a  of body  65114  of instrument drive unit  65110  and which is fixed within outer housing  65112  of instrument drive unit  65110 . Plate  65116  has a first portion  65116   a  and a second portion  65116   b  extending laterally from first portion  65116   a . First portion  65116   a  of plate  65116  defines an annular cavity  65118  through a thickness thereof. Proximal end  65114   a  of body  65114  extends through annular cavity  65118  of plate  65116  and is rotatable therein. Second portion  65116   b  of plate  65116  extends radially beyond a periphery of proximal end  65114   a  of body  65114  of instrument drive unit  65110 . 
     Instrument drive unit  65110  further includes a driven coupler  65120 , a first gear  65130 , and a second gear  65140  disposed between driven coupler  65120  and first gear  65130  to transfer rotational motion of driven coupler  65120  to first gear  65130 . Each of driven coupler  65120 , first gear  65130 , and second gear  65140  is rotatably supported on or disposed with plate  65116 . In particular, driven coupler  65120  and second gear  65140  are rotatably supported within second portion  65116   b  of plate  65116 , and first gear  65130  is rotatably disposed on first portion  65116   a  of plate  65116 . As such, driven coupler  65120  and second gear  65140  are each laterally offset from longitudinal axis “X” of body  65114 , and first gear  65130  is coaxial with longitudinal axis “X” of body  65114 . Driven coupler  65120  has a first end  65120   a  extending proximally from a top surface  65117   a  of plate  65116 , and a second end  65120   b  extending distally from a bottom surface  65117   b  of plate  65116 . First end  65120   a  of driven coupler  65120  is in the form of a gear (e.g., a spur gear) having a toothed outer surface  65122  that is in meshing engagement with second gear  65140 . Second end  65120   b  of driven coupler  65120  is in the form of a gear (e.g., a crown gear) having downward projecting teeth configured to be non-rotatably inter-engaged with gear teeth of gear  65109   a  ( FIG. 104 ) of motor shaft  65109  of surgical instrument holder  65102 . 
     In operation, prior to or during a surgical procedure, instrument drive unit  65110  may be coupled to surgical instrument  65200  and surgical instrument holder  65102 . In particular, a proximal end of housing  65202  of surgical instrument  65200  is non-rotatably connected to distal end  65114   b  of body  65114  of instrument drive unit  65110 . Instrument drive unit  65110 , with surgical instrument  65200  attached thereto, is positioned relative to surgical instrument holder  65102  to operably couple second end or gear  65120   b  of driven coupler  65120  of instrument drive unit  65110  with gear  65109   a  of motor shaft  65109  of surgical instrument holder  65102 . With instrument drive unit  65110  operably coupled to surgical instrument holder  65102 , motor “M” of surgical instrument holder  65102  may be actuated to ultimately effect rotation of surgical instrument  65200  within outer member  65106  of surgical instrument holder  65102 . 
     As depicted in  FIG. 109 , an instrument drive unit is provided according to at least one aspect of the present disclosure. Instrument drive unit  65410  includes an outer housing (not shown), a body  65414 , a plate  65416 , a first gear  65430 , and a driven coupler  65420 , each being similar to the corresponding components of instrument drive unit  65110  described above. Rather than having a gear-to-gear connection between driven coupler  65420  and first gear  65430 , as is the case with instrument drive unit  65110 , body  65414  of instrument drive unit  65410  includes a belt or strap  65419  disposed about driven coupler  65420  and first gear  65430  to rotatably interconnect driven coupler  65420  with first gear  65430 . Belt  65419  has an outer surface  65419   a , and an inner surface  65419   b  defining a plurality of gear teeth. The gear teeth of belt  65419  are in meshing engagement with a toothed outer surface  65420   a  of driven coupler  65420  and teeth of first gear  65430  such that rotation of driven coupler  65420  rotates belt  65419 , which results in rotation of first gear  65430  to effect rotation of body  65414  about its longitudinal axis. Reference may be made to International Patent Application Serial No. PCT/US2017/034206, now International Patent Application Publication No. WO/2017/205481, the entire contents of which are incorporated herein by reference, for additional detailed discussion. 
     In various aspects, with reference back to  FIG. 22 , the processes described hereinbelow with respect to  FIG. 110  may be represented as a series of machine executable instructions stored in the memory  15006  and executed by the processor  15004  of the central control circuit  15002  of the robotic surgical system  15000  depicted in  FIG. 22 . 
       FIG. 110  is a flow diagram  8700  of a process depicting a control program or a logic configuration for controlling a robotic arm according to at least one aspect of the present disclosure. The robotic arm includes a robotic surgical tool, a robotic surgical tool driver, and at least two sensors disposed on the robotic arm to redundantly monitor a status of the robotic arm and to verify the operation of the surgical robotic tool. The at least two separate sensors monitor two different physical properties of the robotic arm to verify the operation of the robotic surgical tool. With reference now to  FIGS. 22 and 110 , in one aspect, the process depicted by the flow diagram  8700  may be executed by the central control circuit  15002 , where the central control circuit  15002  is configured to measure  8702  a first physical property of the robotic arm based on readings from a first sensor. The central control circuit  15002  is configured to measure  8704  a second physical property of the robotic arm based on readings from a second sensor. The central control circuit  15002  is configured to determine  8706  a status of the robotic arm based on the first and second measurements of the first and second physical properties of the robotic arm. The central control circuit  15002  is configured to determine  8708  the operation of the robotic surgical tool and to verify  8710  the operation of the robotic surgical tool based on the measured first and second physical properties of the robotic arm. In one aspect, the first physical parameter is employed by the central control circuit  15002  to effect measurement of the second physical property. In one aspect, the first sensor is disposed on the robotic surgical tool in a sterile field side of a sterile barrier and the second sensor is located on a portion of the robotic arm located on a non-sterile side of the sterile barrier. In one aspect, the two different physical properties may include motor torque, motor current, strain in the mounting housing of the motor, strain on the sterile barrier mounting feature, reaction load of the robotic arm to the operating table, reaction load of the patient with respect to the operating table, load distribution on the operating table, and/or torque or resulting force within the robotic arm or any of its joints. 
     While several forms have been illustrated and described, it is not the intention of the applicant to restrict or limit the scope of the appended claims to such detail. Numerous modifications, variations, changes, substitutions, combinations, and equivalents to those forms may be implemented and will occur to those skilled in the art without departing from the scope of the present disclosure. Moreover, the structure of each element associated with the described forms can be alternatively described as a means for providing the function performed by the element. Also, where materials are disclosed for certain components, other materials may be used. It is therefore to be understood that the foregoing description and the appended claims are intended to cover all such modifications, combinations, and variations as falling within the scope of the disclosed forms. The appended claims are intended to cover all such modifications, variations, changes, substitutions, modifications, and equivalents. 
     The foregoing detailed description has set forth various forms of the devices and/or processes via the use of block diagrams, flowcharts, and/or examples. Insofar as such block diagrams, flowcharts, and/or examples contain one or more functions and/or operations, it will be understood by those within the art that each function and/or operation within such block diagrams, flowcharts, and/or examples can be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. Those skilled in the art will recognize that some aspects of the forms disclosed herein, in whole or in part, can be equivalently implemented in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and/or writing the code for the software and or firmware would be well within the skill of one of skill in the art in light of this disclosure. In addition, those skilled in the art will appreciate that the mechanisms of the subject matter described herein are capable of being distributed as one or more program products in a variety of forms, and that an illustrative form of the subject matter described herein applies regardless of the particular type of signal bearing medium used to actually carry out the distribution. 
     Instructions used to program logic to perform various disclosed aspects can be stored within a memory in the system, such as dynamic random access memory (DRAM), cache, flash memory, or other storage. Furthermore, the instructions can be distributed via a network or by way of other computer readable media. Thus a machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer), but is not limited to, floppy diskettes, optical disks, compact disc, read-only memory (CD-ROMs), and magneto-optical disks, read-only memory (ROMs), random access memory (RAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic or optical cards, flash memory, or a tangible, machine-readable storage used in the transmission of information over the Internet via electrical, optical, acoustical or other forms of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.). Accordingly, the non-transitory computer-readable medium includes any type of tangible machine-readable medium suitable for storing or transmitting electronic instructions or information in a form readable by a machine (e.g., a computer). 
     As used in any aspect herein, the term “control circuit” may refer to, for example, hardwired circuitry, programmable circuitry (e.g., a computer processor comprising one or more individual instruction processing cores, processing unit, processor, microcontroller, microcontroller unit, controller, digital signal processor (DSP), programmable logic device (PLD), programmable logic array (PLA), or field programmable gate array (FPGA)), state machine circuitry, firmware that stores instructions executed by programmable circuitry, and any combination thereof. The control circuit may, collectively or individually, be embodied as circuitry that forms part of a larger system, for example, an integrated circuit (IC), an application-specific integrated circuit (ASIC), a system on-chip (SoC), desktop computers, laptop computers, tablet computers, servers, smart phones, etc. Accordingly, as used herein “control circuit” includes, but is not limited to, electrical circuitry having at least one discrete electrical circuit, electrical circuitry having at least one integrated circuit, electrical circuitry having at least one application specific integrated circuit, electrical circuitry forming a general purpose computing device configured by a computer program (e.g., a general purpose computer configured by a computer program which at least partially carries out processes and/or devices described herein, or a microprocessor configured by a computer program which at least partially carries out processes and/or devices described herein), electrical circuitry forming a memory device (e.g., forms of random access memory), and/or electrical circuitry forming a communications device (e.g., a modem, communications switch, or optical-electrical equipment). Those having skill in the art will recognize that the subject matter described herein may be implemented in an analog or digital fashion or some combination thereof. 
     As used in any aspect herein, the term “logic” may refer to an app, software, firmware and/or circuitry configured to perform any of the aforementioned operations. Software may be embodied as a software package, code, instructions, instruction sets and/or data recorded on non-transitory computer readable storage medium. Firmware may be embodied as code, instructions or instruction sets and/or data that are hard-coded (e.g., nonvolatile) in memory devices. 
     As used in any aspect herein, the terms “component,” “system,” “module” and the like can refer to a computer-related entity, either hardware, a combination of hardware and software, software, or software in execution. 
     As used in any aspect herein, an “algorithm” refers to a self-consistent sequence of steps leading to a desired result, where a “step” refers to a manipulation of physical quantities and/or logic states which may, though need not necessarily, take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It is common usage to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. These and similar terms may be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities and/or states. 
     A network may include a packet switched network. The communication devices may be capable of communicating with each other using a selected packet switched network communications protocol. One example communications protocol may include an Ethernet communications protocol which may be capable permitting communication using a Transmission Control Protocol/Internet Protocol (TCP/IP). The Ethernet protocol may comply or be compatible with the Ethernet standard published by the Institute of Electrical and Electronics Engineers (IEEE) titled “IEEE 802.3 Standard”, published in December, 2008 and/or later versions of this standard. Alternatively or additionally, the communication devices may be capable of communicating with each other using an X.25 communications protocol. The X.25 communications protocol may comply or be compatible with a standard promulgated by the International Telecommunication Union-Telecommunication Standardization Sector (ITU-T). Alternatively or additionally, the communication devices may be capable of communicating with each other using a frame relay communications protocol. The frame relay communications protocol may comply or be compatible with a standard promulgated by Consultative Committee for International Telegraph and Telephone (CCITT) and/or the American National Standards Institute (ANSI). Alternatively or additionally, the transceivers may be capable of communicating with each other using an Asynchronous Transfer Mode (ATM) communications protocol. The ATM communications protocol may comply or be compatible with an ATM standard published by the ATM Forum titled “ATM-MPLS Network Interworking 2.0” published August 2001, and/or later versions of this standard. Of course, different and/or after-developed connection-oriented network communication protocols are equally contemplated herein. 
     Unless specifically stated otherwise as apparent from the foregoing disclosure, it is appreciated that, throughout the foregoing disclosure, discussions using terms such as “processing,” “computing,” “calculating,” “determining,” “displaying,” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system&#39;s registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices. 
     One or more components may be referred to herein as “configured to,” “configurable to,” “operable/operative to,” “adapted/adaptable,” “able to,” “conformable/conformed to,” etc. Those skilled in the art will recognize that “configured to” can generally encompass active-state components and/or inactive-state components and/or standby-state components, unless context requires otherwise. 
     The terms “proximal” and “distal” are used herein with reference to a clinician manipulating the handle portion of the surgical instrument. The term “proximal” refers to the portion closest to the clinician and the term “distal” refers to the portion located away from the clinician. It will be further appreciated that, for convenience and clarity, spatial terms such as “vertical”, “horizontal”, “up”, and “down” may be used herein with respect to the drawings. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and/or absolute. 
     Those skilled in the art will recognize that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to claims containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. 
     In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that typically a disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms unless context dictates otherwise. For example, the phrase “A or B” will be typically understood to include the possibilities of “A” or “B” or “A and B.” 
     With respect to the appended claims, those skilled in the art will appreciate that recited operations therein may generally be performed in any order. Also, although various operational flow diagrams are presented in a sequence(s), it should be understood that the various operations may be performed in other orders than those which are illustrated, or may be performed concurrently. Examples of such alternate orderings may include overlapping, interleaved, interrupted, reordered, incremental, preparatory, supplemental, simultaneous, reverse, or other variant orderings, unless context dictates otherwise. Furthermore, terms like “responsive to,” “related to,” or other past-tense adjectives are generally not intended to exclude such variants, unless context dictates otherwise. 
     It is worthy to note that any reference to “one aspect,” “an aspect,” “an exemplification,” “one exemplification,” and the like means that a particular feature, structure, or characteristic described in connection with the aspect is included in at least one aspect. Thus, appearances of the phrases “in one aspect,” “in an aspect,” “in an exemplification,” and “in one exemplification” in various places throughout the specification are not necessarily all referring to the same aspect. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more aspects. 
     Any patent application, patent, non-patent publication, or other disclosure material referred to in this specification and/or listed in any Application Data Sheet is incorporated by reference herein, to the extent that the incorporated materials is not inconsistent herewith. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material. 
     In summary, numerous benefits have been described which result from employing the concepts described herein. The foregoing description of the one or more forms has been presented for purposes of illustration and description. It is not intended to be exhaustive or limiting to the precise form disclosed. Modifications or variations are possible in light of the above teachings. The one or more forms were chosen and described in order to illustrate principles and practical application to thereby enable one of ordinary skill in the art to utilize the various forms and with various modifications as are suited to the particular use contemplated. It is intended that the claims submitted herewith define the overall scope.