Patent Publication Number: US-2023138396-A1

Title: Automatic motion damping of teleoperated surgical system manipulators

Description:
CLAIM OF PRIORITY 
     This application claims the benefit of priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application Ser. No. 63/273,717, filed on Oct. 29, 2021, which is incorporated by reference herein in its entirety. 
    
    
     TECHNICAL FIELD 
     This document relates generally to medical devices, and more particularly to teleoperated surgical system manipulators. 
     BACKGROUND 
     Surgical systems, such as those employed for minimally invasive and orthopedic medical procedures, can include large and complex equipment to precisely control and drive relatively small instruments. Such systems are sometimes referred to as teleoperated systems or robotic surgical systems. One example of a teleoperated surgical system is the da Vinci® surgical system commercialized by Intuitive Surgical, Inc. 
     Teleoperated surgical systems can control and drive multiple instruments through one or more access ports in the body of the patient. Teleoperated surgical systems can include surgical instrument and user-controlled manipulator systems. The surgical instrument manipulator system can be operated as a follower to the user-controlled master manipulator system. Each of these manipulator systems can include electrically driven (powered) multiple degree-of-freedom (DOF) mechanisms that are configured to articulate in relatively complex motions in three dimensions. For example, a user operates via hands/fingers one or more user-input manipulators, the articulation of which causes articulation of one or more corresponding surgical instrument manipulators. 
     SUMMARY 
     Teleoperated surgical system manipulators include at least two links coupled to move with reference to each other at a joint (e.g., rotational, prismatic, spherical, and the like), and they are commonly driven by electric motors connected to actuate motion at joints or other portions of the manipulator mechanism. Such manipulator mechanisms can include low-friction joints, which in the event power is cut to the manipulator mechanism motor(s), may be unconstrained mechanically, electrically, or otherwise. When power is cut to the system, the unconstrained manipulators tend to move without restraint if the overall system/chassis to which they are coupled is moved or otherwise encounters external forces. In such cases, the manipulators or portions thereof can collide with one another or surrounding objects. The inventors have devised a system that short-circuits the manipulator motor when electrical power to the motor is cut, which in effect turns the motor into a generator and causes the motor to automatically dampen motion of the manipulator to which the motor is attached. 
     Although examples of automatically dampening motion of an electric motor actuated movable component are described in relation to teleoperated surgical systems, examples according to this disclosure could be applied to and employed in other types of systems. For example, automatically dampening motion of an electric motor actuated component by short-circuiting the motor when power to the motor is cut could be employed in a user input device for a video gaming system, e.g. a highly sensitive joy stick, as just one example. 
     A teleoperated surgical system in accordance with this disclosure includes a manipulator, an electric motor, and a power circuit. The motor is operatively connected to and configured to drive movement of at least a portion of the manipulator. The power circuit includes a plurality of wires and a switch. The wires connect a selectively activated power source to the motor. The switch is connected to the wires between the power source and the motor. On a first condition in which the power source changes from an activated state to a deactivated state, the switch short-circuits the motor to cause the unpowered motor to automatically dampen motion of the at least a portion of the manipulator. On a second condition in which the power source changes from the deactivated state to the activated state, the switch electrically connects the motor to the power source to supply operating power from the power source to the motor via the wires. 
     A system in accordance with this disclosure includes a movable component, an electric motor, and a power circuit. The electric motor is operatively connected to and configured to drive movement of the movable component. The power circuit includes a plurality of wires and a switch. The plurality of wires electrically connects a selectively activated power source to the motor. The switch is connected to the plurality of wires between the power source and the motor. On a first condition in which the power source changes from an activated state to a deactivated state to cause the motor to be unpowered, the switch short-circuits the motor to cause the unpowered motor to automatically dampen motion of the movable component. On a second condition in which the power source changes from the deactivated state to the activated state, the switch electrically connects the motor to the power source to supply operating power from the power source to the motor via the plurality of wires. 
     Each of these non-limiting examples can stand on its own or can be combined in various permutations or combinations with one or more of the other examples. 
     This Summary is intended to provide an overview of subject matter of the present patent application. It is not intended to provide an exclusive or exhaustive explanation of the invention. The detailed description is included to provide further information about various aspects of the inventive subject matter of the present patent application. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals having different letter suffixes may represent different instances of similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document. 
         FIG.  1    schematically depicts an example manipulator, which can be a portion of a user control system or a manipulator system of a teleoperated surgical system. 
         FIG.  2 A  and  FIG.  2 B  schematically depict another example manipulator including a power circuit in accordance with examples of this disclosure. 
         FIG.  3 A  and  FIG.  3 B  schematically depict another example manipulator including another power circuit in accordance with examples of this disclosure. 
         FIG.  4 A  and  FIG.  4 B  schematically depict two additional example manipulators, respectively including example power circuits in accordance with examples of this disclosure. 
         FIG.  5 A  is a plan view depicting an example teleoperated surgical system in a surgical environment. 
         FIG.  5 B  depicts an example teleoperated manipulator system. 
         FIG.  5 C  depicts an example user control system. 
         FIG.  5 D  depicts an example instrument. 
     
    
    
     DETAILED DESCRIPTION 
     Example teleoperated surgical systems in which examples according to this disclosure may be employed can generally include a user control system and an instrument manipulator system, as well as other components/systems. The user control system of such teleoperated surgical systems can include one or more control input devices, which are contacted and manipulated by the user to control articulation of one or more portions of the instrument manipulator system. Generally speaking, the user can perform surgical tasks at a work site near to or remote from the instrument manipulator system during a surgical procedure by using the control input devices of the user control system to control the instrument manipulator system. 
     The teleoperated instrument manipulator system can include a plurality of manipulator arms, each coupled to an instrument assembly. An instrument assembly can include, for example, a surgical instrument, and the instrument can include a surgical end effector at its distal end, e.g., for treating tissue of a patient. 
     The instrument manipulator system can be positioned close to a patient for surgery, where it can remain stationary until a particular surgical procedure or stage of a procedure is completed. The user control system can be positioned in various locations relative to the instrument manipulator system, e.g., in a sterile surgical field close to instrument manipulator system and the work site, in the same room as the instrument manipulator system and work site, or remotely from the instrument manipulator system and work site, e.g., in a different room, building, or other geographic location. 
     The manipulator arms and instrument assemblies of the instrument manipulator system can be controlled to move and articulate the instruments in response to manipulation by the user of the control input devices of the user control system. For example, when using the user control system, the user can sit in a chair or other support in front of the user control system, position his or her eyes in front of a display unit displaying the surgical site, and grasp and manipulate the control input devices to control surgical instruments connected to manipulators of the manipulator system. 
     As noted, the instrument manipulator system of such teleoperated surgical systems can include a plurality of manipulators. Additionally, the control input devices manipulated by the user to control the manipulator system can include one or more manipulators. Each manipulator, whether part of a teleoperated surgical system manipulator system or user control system, can include electrically driven multiple DOF mechanisms that are configured to articulate in relatively complex motions in three dimensions. 
       FIG.  1    schematically depicts manipulator  100 , which can be a portion of a user control system or an instrument manipulator system of a teleoperated surgical system. In  FIG.  1   , manipulator  100  includes manipulator arm (a kinematic linkage)  102 , end effector  104 , motor  106 , joint  108 , motor driver  110 , power source  112 , and power circuit  114 . Manipulator arm  102  is connected to end effector  104 . Manipulator  100  is illustrative of manipulators described herein. 
     Broadly, end effector  104  represents the distal-most portion of manipulator arm  102 . In an instrument manipulator, end effector  104  may be an instrument or a portion of an instrument, or optionally it may be omitted. In a user control system manipulator, end effector  104  is the portion of the manipulator the user grasps so as to move the user control system manipulator. 
     The motion/articulation of manipulator arm  102  is driven by motor  106 , which is connected to manipulator arm  102  at joint  108 . In an instrument manipulator, motor  106  moves two or more kinematic links with reference to each other so as to move a surgical instrument coupled to the distal end of the instrument manipulator. In a user control system manipulator, motor  106  likewise moves two or more kinematic links with reference to each other so as to accomplish functions such as initial manipulator arm positioning in space, maintaining manipulator arm position in space against the force of gravity, or providing selected resistance to a user control motion to provide a haptic sensation to the user. 
     Joint  108  can be a one or more mechanical DOF joint, which is configured to articulate manipulator arm  102  and end effector  104  in one or more dimensions in space. Joint  108  can include a low-friction joint, which in the event power is cut to motor  106 , may be unconstrained mechanically, electrically, or otherwise without the advent of examples according to this disclosure. When power is cut to such devices, such unconstrained manipulators can freely swing around if the overall system/chassis to which they are coupled is moved or otherwise encounters external forces. In such cases, a manipulator, or portions of a manipulator, can collide with another manipulator or surrounding objects. The inventors of the subject matter of the present disclosure have therefore devised a system that short-circuits motor  106  when power to the motor is cut, which in effect turns the motor into a generator and causes the motor to automatically dampen any motion of manipulator  102  to which it is attached. 
     Motor driver  110  is connected to and controls motor  106  via electrical wires  116 . Electrical power source  112  is coupled to motor driver  110  and motor  106 , and it provides operating power to motor  106 . In some examples, motor  106  may be connected to and controlled by a motor driver and/or a motor controller  110 . Motor  106  can be connected to one or both of a motor driver and motor controller. A motor driver may be employed to control delivery of the power to motor  106  required for motor operation according to one or more parameters and a motor controller may be employed to control speed, torque, direction (as examples) of the motor. 
     Power source  112  is an electric power node (e.g., a standard wall plug, a power supply output terminal, a battery, a battery terminal connection, etc.—any electric power node that can transition between powered and unpowered states) that receives generated or stored electrical power (e.g., electrical utility wall power, backup electrical generator power, rechargeable or disposable electrical battery power, etc.) used to run motor  106 . Electrical power circuit  114  is connected between motor  106  and power source  112 —in this example, between motor  106  and motor driver  110 . 
     In the event power from power source  112  to motor  106  is cut (e.g., changed from an activated state to a deactivated state), power circuit  114  functions to short-circuit motor  106 , which in effect turns motor  106  into a generator and causes motor  106  to automatically dampen any motion of manipulator  102 . For example, without the function of power circuit  114 , in the event power is cut to motor  106 , the weight of manipulator  102  would cause manipulator  102  and end effector  104  to fall under the force of gravity, as schematically depicted by the dashed-line position of manipulator  102  and end effector  104  in  FIG.  1   . In examples according to this disclosure, however, in the event power is cut to motor  106 , power circuit  114  functions to cause motor  102  to automatically dampen motion of manipulator  102 , which would cause manipulator  102  to maintain the solid-line position depicted in  FIG.  1    or to dampen motion of manipulator  102  in a trajectory between the solid and dashed-line positions depicted in  FIG.  1   . This example is illustrative, and power circuit  114  is configured to cause motor  106  to dampen any motion of manipulator  102 , including motion that would otherwise occur when the overall system/chassis to which manipulator  102  is coupled is moved or otherwise encounters external forces. 
       FIG.  2 A  and  FIG.  2 B  schematically depict another example manipulator  200  including power circuit  202  in accordance with this disclosure. In  FIGS.  2 A and  2 B , manipulator  200  includes electrical power circuit  202 , electric motor  204  to which one or more manipulator links are connected (not shown), electric motor driver  206 , electric power source  208 , and electrically conductive wires  210 . Power circuit  202  includes switch  212  and electrically conductive wires  214 . In the example of  FIGS.  2 A and  2 B , motor  204  is a brushed motor. 
     Motor driver  206  is connected to and controls motor  204  via electrical wires  210 . Power source  208  is coupled to motor driver  206  and motor  204 , and it provides operating power to motor  204 . Power source  208  is an electrical power node as described above. Power circuit  202  is connected between motor  204  and power source  208 —in this example, between motor  204  and motor driver  206 . 
     Power source  208  is configured to be toggled between an activated state, in which it provides operating power to motor  204  via motor driver  206  and wires  210 , and a deactivated state, in which power to motor  204  is cut off.  FIG.  2 A  depicts manipulator  200  in a first state (an activated state), in which power source  208  is supplying operating power to motor  204  via motor driver  206  and wires  210 . In this first state, switch  202  of power circuit  202  electrically connects motor  204  to motor driver  206 , which is configured to drive and control motor  204  to articulate a manipulator connected to the motor. 
       FIG.  2 B  depicts manipulator  200  in a second state (a deactivated state), in which power source  208  is deactivated and power to motor  204  is cut off. In this second state, switch  202  and wires  214  are configured to automatically short-circuit the electrical wires  210  to motor  204  to one another. Short-circuiting motor  204  in the manner depicted in  FIG.  2 B  causes motor  204  to effectively become an electrical generator. In this second state, any motion of the manipulator connected to motor  204  automatically causes motor  204  to generate an electromotive force in the opposite direction of the input motion of the manipulator, which functions to dampen motion of the manipulator. 
     In the example of  FIGS.  2 A and  2 B , motor  204  is a brushed motor. Additionally, in this example, power circuit  202  functions to short-circuit motor  204  and electrically disconnect motor driver  206 . However, additional examples according to this disclosure include power circuits that cause a brushed motor to automatically dampen motion of a manipulator connected to the motor and power circuits that short-circuit the motor and the motor driver to which they are connected. 
       FIG.  3 A  and  FIG.  3 B  schematically depict another example manipulator  300  including power circuit  302  in accordance with this disclosure. In  FIGS.  3 A and  3 B , manipulator  300  includes electrical power circuit  302 , electric motor  304  to which one or more manipulator arm links are connected (not shown), electric motor driver  306 , electrical power source  308 , and electrically conductive wires  310 . Power circuit  302  includes switch  312  and electrically conductive wires  314 . In the example of  FIGS.  3 A and  3 B , motor  304  is a brushless motor. 
     Motor driver  306  is connected to and controls motor  304  via electrical wires  310 . Power source  308  is coupled to motor driver  306  and motor  304 , and it provides operating power to motor  304 . Power source  308  is an electric power node as described above. Power circuit  302  is connected between motor  304  and power source  308 —in this example, between motor  304  and motor driver  306 . 
     Power source  308  is configured to be toggled between an activated state, in which it provides operating power to motor  304  via motor driver  306  and wires  310 , and a deactivated state, in which power to motor  304  is cut off.  FIG.  3 A  depicts manipulator  300  in a first state (an activated state), in which power source  308  is supplying operating power to motor  304  via motor driver  306  and wires  310 . In this first state, switch  302  of power circuit  302  electrically connects motor  304  to motor driver  306 , which is configured to drive and control motor  304  to articulate a manipulator connected to the motor. 
       FIG.  3 B  depicts manipulator  300  in a second state (a deactivated state), in which power source  308  is deactivated and power to motor  304  is cut off. In this second state, switch  312  and wires  314  are configured to automatically short-circuit the electrical wires  310  to motor  304  to one another. Short-circuiting motor  304  in the manner depicted in  FIG.  3 B  causes motor  304  to effectively become an electrical generator. In this second state, any motion of the manipulator connected to motor  304  automatically causes motor  304  to generate an electromotive force in the opposite direction of the input motion of the manipulator, which functions to dampen motion of the manipulator. Additionally, in the second state depicted in  FIG.  3 B , in which power source  308  is deactivated, power circuit  302  functions to disconnect motor driver  306  from motor  304 . 
       FIG.  4 A  and  FIG.  4 B  schematically depict two additional example manipulators  400  and  420  in accordance with this disclosure. Referring to  FIGS.  4 A and  4 B , manipulator  400  includes power circuit  402 , and manipulator  420  includes power circuit  422 . In a similar fashion as described above with reference to  FIGS.  2 A- 2 B and  3 A- 3 B , in the examples of  FIGS.  4 A and  4 B , power circuit  402  automatically dampens motion of a manipulator arm connected to brushed motor  404  upon power to motor  404  from power source  408  being cut. Likewise, power circuit  422  automatically dampens motion of a manipulator arm connected to brushless motor  424  upon power to motor  424  from power source  428  being cut. In the example of  FIG.  4 A , however, in the event power source  408  is deactivated, power circuit  402  also short-circuits motor driver  406 . Similarly, in the event power source  428  is deactivated, power circuit  422  also short-circuits motor driver  426 . 
     There are advantages to both example manipulators in which a power circuit short-circuits both the motor and motor driver without physically disconnecting the motor driver, and example manipulators in which a power circuit short-circuits the motor and physically disconnects the motor driver without short-circuiting the motor driver. For example, if the power circuit short-circuits both the motor and the motor driver, the overall manipulator may be more reliable because the electrical circuitry never physically disconnects the motor driver. In examples in which the power circuit short-circuits the motor and physically disconnects the motor driver, if electrical relay or other electrical contacts in the switch of the power circuit degrade to the point they can no longer establish an electrical connection, the motor driver may become disconnected regardless of the activation state of the power source. On the other hand, in examples in which the power circuit short-circuits both the motor and the motor driver, if the switch of the power circuit becomes de-energized while the motor is running, the short-circuited motor driver could damage the driver. 
     As described with reference to the examples of  FIGS.  2 A- 4 B , example power circuits in accordance with this disclosure include a switch. The switch employed in example power circuits is configured to automatically toggle between two states corresponding to corresponding two states of a power source to which the switches are connected. In a first state, in which the power source is activated, the switch of a power circuit in accordance with this disclosure is configured to electrically connect a motor connected to a teleoperated surgical system manipulator to the power source to provide operating power to the motor to articulate the manipulator. In a second state, in which the power source is deactivated, the switch is configured to automatically short-circuit the motor upon deactivation of the power source. A variety of types of switches can be employed in example power circuits  202 ,  302 ,  402 ,  422 , and other power circuits in accordance with this disclosure, including a variety of electrically activated switches. For example, switches employed in example power circuits  202 ,  302 ,  402 ,  422 , and other power circuits in accordance with this disclosure can include electromechanical relays or solid-state relays or other switching devices including solid-state electronics, as some examples of the types of switching hardware that could be employed in example power circuits in accordance with this disclosure. 
     The location and packaging of example power circuits in accordance with this disclosure can vary from the particular examples described above with reference to  FIGS.  2 A- 4 B . For example, a power circuit that functions to short-circuit a manipulator motor automatically upon the main power (i.e., a main generated or stored electrical power source; in contrast to an auxiliary or backup generated or stored electrical power source) to the motor being deactivated could be incorporated and included in circuitry within a motor driver. As an example, a motor driver commonly includes circuits including field-effector transistors (FETs) that can be controlled rapidly to make and break electrical connections. Such FETs within a motor driver could be controlled to short-circuit the motor within the driver. However, the FETs inside the motor driver would generally be powered by the main power source to the driver and motor, and FET&#39;s default state in the absence of power is disconnected. Thus, in such examples, a battery power source could be included in the motor driver. The battery could be connected to FETs of the motor driver such that, upon the main power source to the driver and motor being deactivated, the battery power source is activated to power the FETs in the motor driver to short-circuit the motor. 
       FIG.  5 A  is a plan view depicting an example medical procedure environment that includes a multi-arm manipulator system  500  adjacent to a surgical table  502  that supports a patient  504 . In  FIG.  5 A , a second manipulator system  506  may also be situated at the surgical table  502 . The manipulator systems  500 ,  506  may be free-standing on a movable base, or they may be mounted to a table, floor, wall, or ceiling, or they may be supported on another piece of equipment in the clinical environment. 
     The manipulator system  500  or system  506  may be part of a larger system  508 , which may include other sub-systems, including, for example, fluoroscopy or other imaging equipment. One or both of the manipulator systems  500 ,  506  may be operatively coupled to a user control system  550 . The user control system  550  may include one or more user input devices (e.g., controls) that may be configured to receive inputs from a user (e.g., clinician). The user control system  550  may also include or one or more user feedback devices (e.g., viewing system, or tactile or auditory feedback system) that may be configured to provide information to the user regarding the movement or position of an end effector, or an image of a surgical area. Example power circuits in accordance with this disclosure, which function to cause a manipulator motor to automatically dampen motion of the manipulator connected to the motor upon power to the motor being cut can be employed in, for example, manipulator system  500 , manipulator system  506 , and/or user control system  550 . 
       FIG.  5 B  depicts example manipulator system  500 . The example manipulator system  500  includes a base  510 , a support tower  512 , and one or more manipulator arms  514 ,  516 ,  518 ,  520 , which may be mounted on the support tower  512 . An instrument  530  (shown in more detail in  FIG.  5 D ) is mounted to an instrument mount  522  on one of the manipulator arms  514 ,  516 ,  518 ,  520 . The instrument mount  522  includes, as an example, an instrument carriage  524 , which is mounted to a spar  526 , which may be a telescoping or non-telescoping spar. A cannula  528  may be mounted to a cannula mount  526 , and the instrument  530  may be inserted through a cannula seal in the cannula  528 , and into the patient  504  ( FIG.  5 A ) for use in a therapeutic or diagnostic surgical procedure. Through movement of the manipulator arms  514 ,  516 ,  518 ,  520 , the translation and orientation of the instrument  530  may be controlled in multiple mechanical degrees of freedom, e.g. lateral, horizontal, vertical, angular movements in one, two, or three planes. 
     The translation and change in orientation of instrument  530  via manipulator arms  514 ,  516 ,  518 ,  520  may be driven by one or more electric motors, e.g. motors connected to and driving joints of the manipulator arms. In examples according to this disclosure, a power circuit may be connected between such manipulator motors and the power source powering the motors. Such power circuits, as described with reference to the examples of  FIGS.  1 - 4 B , can function to short-circuit the motor in the event power is cut thereto, which, causes the motor to automatically dampen motion of the manipulator. 
       FIG.  5 C  depicts example user control system  550 . The user control system  550  includes hand controls  555 ,  556  and foot pedal controls  560 ,  561 ,  562 . The hand controls  555 ,  556  and foot pedal controls  560 ,  561 ,  562  are used to control equipment at one or more of the manipulator systems  500 ,  506 . For example, an operator may manipulate portions of a distal end of an instrument  530  by using the instrument controls. The controls may include haptic feedback features so that a surgeon may interpret physical information at the instrument  530 , such as resistance or vibration, through the controls. The user control system  550  may also include a viewing system  565  that displays video or other images of a surgical site. 
     The control input devices of user control system  550 , e.g., hand controls  555 ,  556  can include one or more manipulators, which may be driven by an electric motor. In a similar fashion as described with reference to the manipulators of manipulator system  500 , manipulators of user control system  550  can include a power circuit connected between manipulator motor and a power source powering the motor. Such an example power circuit can function to short-circuit the motor in the event power is cut thereto, which causes the motor to automatically dampen motion of the manipulator of user control system  550 . 
       FIG.  5 D  depicts example instrument  530 . The instrument  530  includes a proximal portion  592 , which is configured to couple to an instrument mount on a manipulator arm. The instrument  530  also includes a distal portion  594  and an instrument shaft  596  between the proximal portion  592  and the distal portion  594 . The distal portion  594  shown is a stapler, and in other instruments it may be a cautery tool, cutter, camera, or other medically relevant end effector. The instrument  530  may be teleoperatively controlled via command signals received from a control computer, such as a user control system  550  to conduct a surgical procedure. Inputs may be received from a user (e.g., clinician), and the instrument  530  may be controlled based on the user inputs. 
     Persons of skill in the art will understand that any of the features described above may be combined with any of the other example features, as long as the features are not mutually exclusive. All possible combinations of features are contemplated, depending on clinical or other design requirements. In addition, if manipulator system units are combined into a single system (e.g., telesurgery system), each individual unit may have the same configuration of features, or, one patient-side unit may have one configuration of features and another patient-side unit may have a second, different configuration of features. 
     The examples (e.g., methods, systems, or devices) described herein may be applicable to surgical procedures, non-surgical medical procedures, diagnostic procedures, cosmetic procedures, and non-medical procedures or applications. The examples may be used for industrial applications, general robotic uses, manipulation of non-tissue work pieces, as part of an artificial intelligence system, or in a transportation system. 
     The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are also referred to herein as “examples.” Such examples may include elements in addition to those shown or described. But, the present inventors also contemplate examples in which only those elements shown or described are provided. Moreover, the present inventors also contemplate examples using any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein. 
     In the event of inconsistent usages between this document and any documents so incorporated by reference, the usage in this document controls. 
     In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of “at least one” or “one or more.” In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated. In this document, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open-ended, that is, a system, device, article, composition, formulation, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. 
     Geometric terms, such as “parallel”, “perpendicular”, “round”, or “square”, are not intended to require absolute mathematical precision, unless the context indicates otherwise. Instead, such geometric terms allow for variations due to manufacturing or equivalent functions. For example, if an element is described as “round” or “generally round”, a component that is not precisely circular (e.g., one that is slightly oblong or is a many-sided polygon) is still encompassed by this description. Coordinate systems or reference frames are provided for aiding explanation, and implantations may use other reference frames or coordinate systems other than those described herein. 
     The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with each other. Other embodiments may be used, such as by one of ordinary skill in the art upon reviewing the above description. The Abstract is provided to comply with 37 C.F.R. § 1.72(b) so as to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description as examples or embodiments, with each claim standing on its own as a separate embodiment, and it is contemplated that such embodiments may be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.