# Patent

## Title
Methods, systems, and devices relating to force control surgical systems

## Abstract

The various embodiments herein relate to robotic surgical systems and devices that use force and/or torque sensors to measure forces applied at various components of the system or device. Certain implementations include robotic surgical devices having one or more force/torque sensors that detect or measure one or more forces applied at or on one or more arms. Other embodiments relate to systems having a robotic surgical device that has one or more sensors and an external controller that has one or more motors such that the sensors transmit information that is used at the controller to actuate the motors to provide haptic feedback to a user.

## Background
CROSS-REFERENCE TO RELATED APPLICATION(S)
This application claims priority to U.S. Provisional Application 61/781,594, filed on Mar. 14, 2013 and entitled “Methods, Systems, and Devices Relating to Force Control Surgical Systems,” which is hereby incorporated herein by reference in its entirety.


GOVERNMENT SUPPORT
This invention was made with government support under Grant No. DGE-10410000 awarded by the National Science Foundation; Grant Nos. NNX09AO71A and NNX10AJ26G awarded by the National Aeronautics and Space Administration; and Grant No. W81XWF-09-2-0185 awarded by U.S. Army Medical Research and Materiel Command within the Department of Defense. Accordingly, the government has certain rights in this invention.


FIELD OF THE INVENTION
The various embodiments disclosed herein relate to robotic surgical systems and devices that use force and/or torque sensors to measure forces applied at various components of the system or device. Some exemplary implementations relate to various robotic surgical devices having one or more force/torque sensors that detect or measure one or more forces applied at or on one or more arms. Other embodiments relate to various systems that have a robotic surgical device and a controller, wherein the device has one or more sensors and the controller has one or more motors such that the sensors transmit information that is used at the controller to actuate the motors to provide haptic feedback to a user.
BACKGROUND OF THE INVENTION
Robotic surgical systems have surgical robotic devices or components positioned within a target cavity of a patient such that one or more arms or other components of such a device are configured to perform a procedure within the cavity. In these systems, an external controller is operably coupled to the surgical device such that a user can control or manipulate the device within the patient's cavity via the external controller. One disadvantage of such systems is the lack of tactile feedback for the user during the procedure. That is, the surgeon cannot “feel” the amount of force being applied by or on the arms or components of the surgical device within the patient's cavity in the same way that a surgeon would get some tactile feedback using standard laparoscopic tools (involving long tools inserted through trocars that are positioned into the cavity through incisions).
There is a need in the art for improved robotic surgical systems that can detect and/or measure forces applied at or on robotic surgical devices positioned within a patient and/or provide haptic feedback to the user at the external controller.
BRIEF SUMMARY OF THE INVENTION
Discussed herein are various robotic surgical devices, each having one or more force or torque sensors to measure force or torque applied to certain portions of the device. Additionally, surgical systems are also disclosed, each having an external controller that works in conjunction with sensors on a robotic surgical device to provide haptic feedback to a user.
In Example 1, a robotic surgical device comprises a device body configured to be positioned through an incision into a cavity of a patient, a first shoulder component operably coupled to the device body, a first arm operably coupled to the first shoulder component, and a force sensor operably coupled with the first arm. The first arm is configured to be positioned entirely within the cavity of the patient. The force sensor is positioned to measure an amount of force applied by the first arm.
Example 2 relates to the robotic surgical device according to Example 1, wherein the force sensor is disposed between the device body and the first shoulder component.
Example 3 relates to the robotic surgical device according to Example 1, wherein the force sensor is disposed on the first arm.
Example 4 relates to the robotic surgical device according to Example 3, wherein the first arm comprises an upper arm component and a forearm component, wherein the force sensor is disposed on the forearm component.
Example 5 relates to the robotic surgical device according to Example 1, wherein the first arm comprises an upper arm component and a forearm component, wherein the forearm component is operably coupled to the upper arm component at an elbow joint, wherein the forearm component comprises a link operably coupled at a distal end to the force sensor and operably coupled at a proximal end to an elbow joint.
Example 6 relates to the robotic surgical device according to Example 5, further comprising an interface plate disposed between the force sensor and the link.
Example 7 relates to the robotic surgical device according to Example 1, wherein the force sensor is positioned to measure the amount of force applied at a distal-most point on the first arm.
In Example 8, a robotic surgical system comprises a robotic surgical device configured to be positioned into a cavity of a patient through an incision, a processor, and a user controller operably coupled to the processor. The robotic surgical device comprises a device body, at least one arm operably coupled to the body, and at least one sensor operably coupled to the device. The processor is operably coupled to the at least one sensor. The user controller comprises a base, an upper arm component operably coupled to the base at a shoulder joint, a forearm component operably coupled to the upper arm component at an elbow joint, and a grasper operably coupled to the forearm component at a wrist joint. The shoulder joint comprises a first actuator operably coupled to the processor. The elbow joint comprises a second actuator operably coupled to the processor. The wrist joint comprises a third actuator operably coupled to the processor. The at least one sensor is configured to sense force or torque at the robotic surgical device and transmit force or torque information to the processor. The processor is configured to calculate the force or torque being applied at the robotic surgical device and transmit instructions to actuate at least one of the first, second, or third actuator based on the force or torque, thereby providing haptic feedback at the controller.
Example 9 relates to the robotic surgical system according to Example 8, wherein the at least one sensor is a force sensor operably coupled to the at least one arm.
Example 10 relates to the robotic surgical system according to Example 8, wherein the at least one sensor is a torque sensor operably coupled to a joint of the at least one arm.
Example 11 relates to the robotic surgical system according to Example 8, wherein the at least one sensor is a force sensor positioned between the device body and the at least one arm.
Example 12 relates to the robotic surgical system according to Example 8, wherein the at least one sensor is a force sensor disposed within the device body.
In Example 8, a robotic surgical device comprises a device body configured to be positioned through an incision into a cavity of a patient, a first arm operably coupled to the device body, a force sensor, and an end effector operably coupled to the actuator. The first arm comprises an actuator disposed within the first arm. Further, the first arm is configured to be positioned entirely within the cavity of the patient. The force sensor is operably coupled to the actuator. The end effector is positioned at a distal end of the first arm.
Example 14 relates to the robotic surgical device according to Example 13, further comprising a push/pull rod comprising a distal portion and a proximal portion, wherein the push/pull rod is operably coupled to the actuator at the proximal portion and further wherein the push/pull rod is operably coupled to the end effector at the distal portion.
Example 15 relates to the robotic surgical device according to Example 14, wherein the force sensor is disposed proximal to the actuator and is operably coupled to the proximal portion of the push/pull rod.
Example 16 relates to the robotic surgical device according to Example 14, wherein the end effector is a grasper, wherein the grasper comprises an open configuration when the push/pull rod is urged to a distal position, and further wherein the grasper comprises a closed configuration when the push/pull rod is urged to a proximal position.
Example 17 relates to the robotic surgical device according to Example 14, wherein the force sensor is operably coupled to the push/pull rod such that the force sensor is positioned along the length of the push/pull rod.
Example 18 relates to the robotic surgical device according to Example 13, wherein the end effector is a grasper.
Example 19 relates to the robotic surgical device according to Example 13, further comprising a shaft operably coupled to the end effector and a first gear operably coupled to the shaft, wherein the actuator comprises a second gear operably coupled to the first gear.
Example 20 relates to the robotic surgical device according to Example 19, wherein actuation of the actuator causes the shaft to rotate, thereby causing the end effector to rotate.
While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. As will be realized, the invention is capable of modifications in various obvious aspects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a perspective view of a robotic surgical device with a force sensor, according to one embodiment.
FIG. 1B is an exploded perspective view of a portion of the robotic surgical device of FIG. 1A.
FIG. 2 is a perspective view of a robotic surgical device with a force sensor, according to another embodiment.
FIG. 3A is a side view of certain components of an arm of a robotic surgical device with a force sensor, according to one embodiment.
FIG. 3B is an exploded side view of certain components of the arm of FIG. 3A.
FIG. 3C is a side view of certain components of the arm of FIG. 3A.
FIG. 4 is a schematic depiction of an electronics package relating to the output of data from a sensor, according to one embodiment.
FIG. 5A is a perspective view of a controller, according to one embodiment.
FIG. 5B is an exploded perspective view of a portion of the controller of FIG. 5A.
FIG. 5C is a side view of the controller of FIG. 5A.
FIG. 6 is a schematic flow chart relating to a surgical system having an external controller and a robotic device, according to one embodiment.
FIG. 7 is a perspective view of an arm of a robotic surgical device with a force sensor, according to one embodiment.
FIG. 8 is a perspective view of an arm of a robotic surgical device with a force sensor, according to another embodiment.
FIG. 9 is a perspective view of an arm of a robotic surgical device with a force sensor, according to a further embodiment.
FIG. 10A is a perspective view of an end effector of a robotic surgical device with a force sensor, according to one embodiment.
FIG. 10B is a perspective view of an end effector of a robotic surgical device with a force sensor, according to another embodiment.



DETAILED DESCRIPTION
The various embodiments herein relate to a surgical device configured to detect and measure the amount of force applied by the arm of the device. In certain embodiments, the surgical device is a robotic device with a robotic arm and at least one force sensor configured to detect the amount of force. In one embodiment, the force that is measured is the amount of force applied to the distal end of the robotic arm (also referred to herein as the “endpoint”). The information relating to the amount of force is then transmitted from the sensor to an external controller.
FIGS. 1A and 1B depict one embodiment of a robotic surgical device 10 having a body 12 and two robotic arms 14, 16. The body 12 has two shoulders: a right shoulder 18 and a left shoulder 20. The right arm 14 is coupled to the right shoulder, and the left arm 16 is coupled to the left shoulder 20. In this implementation, the force sensor 22 is operably coupled to the body 12 between the body 12 and the left shoulder 20. As best shown in FIG. 1B, the distal portion of the body 12 in one embodiment has a recessed portion 8 defined therein as shown, and sensor 22 is positioned in the recessed portion 8 and coupled to the body 12 in that recessed portion 8.
Further, in certain implementations, the sensor 22 is coupled at its proximal end to a proximal connection component 24 and at its distal end to a distal connection component 26. In the embodiment depicted in FIG. 1B, the proximal connection component 24 is a proximal recessed component or proximal female connection component (also referred to herein as a “cup”) 24 that is configured to receive and couple to the proximal end of the sensor. Further, the distal connection component 26 is a distal plate 26 have at least one projection (or “pin”) 26A disposed on the proximal face of the plate 26 that is configured to mate with an appropriate opening (not shown) in the distal end of the sensor 22. In addition, the proximal connection component 24 has a projection 24A on its proximal face that is configured to mate with an appropriate opening (not shown) in the body 12. Plus, the distal plate 26 is configured to be received in a recessed portion or female connection 28 in the shoulder 20. In this embodiment, the proximal connection component 24 and distal connection component 26 can provide a substantially rigid coupling of the sensor 22 to the body 12 and shoulder 20. In alternative embodiments, the device 10 can have no shoulder components and the force sensor 22 can be positioned instead between the body 12 and the left arm 16 (rather than between the body 12 and the shoulder 20).
According to one implementation, this configuration results in the sensor 22 being positioned close to the incision in the patient when the device 10 is positioned correctly for purposes of a procedure. Given the position of the force sensor 22 proximal to the shoulder 20, it is understood that the sensor 22 will be subject to greater forces (due to the weight and length of the left arm 16) in comparison to a sensor positioned somewhere along or in a portion of the arm 16 itself. It is further understood that the position of the sensor 22 will also result in the sensor's 22 force detection being influenced by any forces applied anywhere along the length of the arm 16. The force sensor 22 is configured to detect and collect data relating to the amount of force being applied by the arm 16 during a procedure. In certain embodiments, the data is used to calculate the amount of force being applied at the most distal point on the arm 36 (the endpoint).
In one specific implementation, the force sensor 22 is a force torque sensor 22. Alternatively, the sensor 22 can be any known force or torque sensor as described in further detail elsewhere herein.
An alternative embodiment of a robotic device 30 with a force sensor 40 is depicted in FIG. 2. This device 30 also has a body 32 and right 34 and left 36 arms. This specific example is focused on the right arm 34, but it is understood that the description applies equally to the left arm 36 as well. In this particular implementation as shown, the sensor 40 is positioned near the distal end of the forearm 34B of the right arm 34. The proximity of the sensor 40 to the endpoint 42 (where the force is being measured) allows for the use of a smaller sensor 40 (due to the lesser forces being applied to the sensor 40 due to its position), thereby requiring less space in the forearm 34B and allowing for the possibility of a smaller forearm 34B. Further, according to one embodiment, the positioning of the force sensor 40 so close to the endpoint 42 eliminates the influence of any forces applied to the arm proximal to the sensor 40, thereby eliminating any irrelevant data created by such forces.
Alternatively, it is understood that the sensor 40 could be positioned anywhere on or within any of the components of either arm 34, 36 of this device 30 or any other device described or contemplated herein. For example, with respect to the right arm 34, a force sensor could be positioned within or on the right shoulder 38, the right upper arm 34A, or the right forearm 34B. Alternatively, the sensor could be positioned on or within any part of the left arm 36. Alternatively, the device 30 can have at least one sensor in each arm 34, 36. That is, in addition to the sensor 40 in the forearm 34B of the right arm 34, the device 30 can also have at least one sensor (not shown) on or in any component of the left arm 36. In a further alternative, each arm 34, 36 can have two or more sensors. In yet another implementation, the arms 34, 36 can each have multiple sensors such that the sensors detect and collect redundant data. The redundant data can then be filtered using known methods such as, but not limited to, Kalman filtering, to provide a more robust calculation of the forces being applied by the surgical device 30 to the tissue of the patient.
In one embodiment, the force sensor (such as force sensors 22 or 40) are force/torque sensors. According to another implementation, the force sensor is any sensor that can directly or indirectly measure the force at any point on the surgical device. Alternatively, any force sensor disclosed or contemplated herein can be any known sensor that can provide six degrees of force measurement. In another embodiment, the force sensor can be any known sensor that provides at least one dimension of force sensing. In a further alternative, the force sensor (including either of force sensors 22 or 40) can be a collection, group, arrangement, or set of two or more sensors that can provide six degrees of force measurement. In yet another alternative, the force information can be gathered by measuring the amount of torque at one or more of the joints of the arm of the device. For example, in one embodiment, the amount of torque can be measured at both the shoulder joint (between the shoulder 38 and the upper arm 34A) and the elbow joint (between the upper arm 34A and the forearm 34B) and that information can be used to calculate the amount of force being applied by the arm 34. In one implementation, the amount of torque is measured using any known torque sensor. Alternatively, the torque can be measured by measuring the motor current or be measuring the windup in the joint (or joints) by comparing absolute position sensor data to incremental position data. In a further alternative, the amount of joint torque can be measured using any other known method for measuring torque.
It is understood that any of the sensors disclosed or contemplated herein can be commercially available sensors or custom sensors. In accordance with one implementation, the force sensor is a known force/torque sensor called Nano17TM, which is commercially available from ATI Industrial Automation, located in Apex, N.C. Alternatively, the sensor is a known reaction torque sensor called TFF400TM, which is commercially available from Futek Advanced Sensor Technology, Inc., located in Irvine, Calif.
The force data collected by the force sensor(s) (or torque data collected by the torque sensor(s)) can be transmitted to a processor present in the robotic device (such as device 10 or 30) or in the external controller (not shown) and used to calculate the force being applied at the endpoint of the arm (or torque at the joint(s)). This will be described in further detail below. Known information relating to the dimensions of the robotic components and the kinematic arrangement of those components (such as the arm components) is incorporated into the calculation to determine the force at the endpoint (or torque at the joint(s)). Given that the calculation utilizes the dimensions of the components, the sensor(s) can be positioned anywhere along the robotic arm or even in the device body (as in FIG. 1) so long as the position is taken into account in the calculation.
FIGS. 3A, 3B, and 3C depict various aspects of a forearm 50 having a force sensor 52, according to another implementation. The forearm 50 has a motor housing 54, a front plate (also referred to herein as a “faceplate”) 56, two motors 58, 60, and an end effector 62 which is a grasper tool 62. The motor housing 54 has the two motors 58, 60 at least partially disposed therein and is coupled at its distal end to the front plate 56. The forearm 50 also has a base link 64 that is configured to operably couple the sensor 52 to the elbow of the arm (not shown) as will be described in further detail below. The sensor 52 is positioned in the distal-most position in the forearm 50.
As best shown in FIGS. 3A and 3B, the base link 64 has a body 64A made up of two rod-like pieces 64A1, 64A2 (as best shown in FIG. 3A), an interface plate 64B at the distal end of the link 64, and an end plate 64C at the proximal end having a coupling component 64D. The interface plate 64B is configured to couple to the sensor 52. In one implementation, the plate 64B is rigidly coupled to the sensor 52. The body 64A has space between and adjacent to the rod-like pieces 64A1, 64A2 that can be configured to receive or provide space for on-board electronic components and wiring (not shown). The electronic components can include, but are not limited to, local motor driving boards, absolute positioning sensor boards, biometric sensor boards, and measurement boards to access the sensor data collected by the sensor 52. The coupling component 64D is configured to couple to the elbow joint (not shown) and/or the upper arm (not shown) of the device. In one embodiment, the coupling component 64D as shown is a projection 64D that defines a circular hole configured to receive and couple to an articulate shaft (not shown) of the upper arm (not shown). Alternatively, the coupling component 64D can be any known mechanism, component, or apparatus for coupling a forearm to an upper arm or elbow of a medical device.
In one implementation, the base link 64 is physically separate from and not rigidly coupled to the motor housing 54. This separation of the two components allows forces applied to the grasper 62 to be transferred through the front plate 56 and into the sensor 52 and reduces the diffusion of such forces. According to certain embodiments, the base link 64 is a cantilevered link 64 that allows the sensor 52 to measure the force applied on the arm 50, and in some cases, the distal endpoint of the end effector 62. Alternatively, the link 64 need not be a cantilevered link 64, but instead can have one or more components that apply a known amount of force thereon. Regardless, the base link 64 allows the sensor 52 to accurately measure the force of interest.
As best shown in FIG. 3C, the motor configuration made up of the two motors 58, 60 is similar to a grasper end effector motor configuration as disclosed in U.S. Provisional Application 61/663,194, filed on Jun. 22, 2012, which is hereby incorporated herein by reference in its entirety. In this particular embodiment, the motor 60 is an open/close motor 60 that is rotationally fixed to motor gear 66, which is threadably coupled to driven gear 68, which is supported by two bearings 70A, 70B. In one embodiment, the bearings 70A, 70B are constrained by the motor housing 54. The driven gear 68 defines a lumen (not shown) having internal threads (not shown). An externally-threaded drive rod 72 is positioned in the lumen of the driven gear 68 such that the driven gear 68 is operably coupled to the rod 72. Due to the coupling of the internal threads of the driven gear 68 with the external threads of the rod 72, rotation of the driven gear 68 causes the drive rod 72 to move laterally back and forth along the longitudinal axis of the drive rod 72. The drive rod 72 is operably coupled to the grasper arms 62A, 62B at the pivot point 74 on the grasper yoke 76 such that the lateral movement of the drive rod 72 causes the grasper arms 62A, 62B to open and close.
The motor 58 is a rotational motor 58 that is rotationally fixed to motor gear 78, which is threadably coupled to driven gear 80, which is supported by two bearings 82A, 82B. In one embodiment, the bearings 82A, 82B are constrained by the motor housing 54. The driven gear 80 is rotationally fixed to the grasper yoke 76, which is rotationally fixed to the grasper arms 62A, 62B such that rotation of the rotational motor 58 causes rotation of the grasper tool 62.
In one embodiment, the motors 58, 60 are both 6 mm motors. Alternatively, the motors 58, 60 are known brushed or brushless motors. The motors 58, 60 can be any motors ranging in size from about 2 mm to about 15 mm in diameter, so long as the motors 58, 60 provide sufficient force and speed profiles to achieve desired results. In accordance with one implementation, the motors 58, 60 are coreless brushed motors called 0615 (6 mm) or 0816 (8 mm), which are commercially available from Micromo, located in Clearwater, Fla. Alternatively, the motors 58, 60 are brushless motors called EC 6 mm and EC 10 mm, which are commercially available from Maxon Motor, located in Fall River, Mass. In a further alternative, the motors 58, 60 can be any known motors used in medical devices.
As mentioned above, in use, any force sensor disclosed or contemplated herein (including, for example, any one or more of the force sensors 22, 40, 52 discussed and depicted above, or one or more torque sensors as also discussed above) is configured to detect and collect the amount of force (or torque) applied by the arm or arms of a surgical device.
As mentioned above, the information collected by the one or more sensors can then be outputted to a processor of some kind, such as a microprocessor in an external controller in communication with the surgical device. In one implementation, the data output occurs via an electronics package 80 as shown schematically in FIG. 4. In this embodiment, the representative single sensor 82 outputs (or transmits) analog or digital signals that are proportional to the amount of force detected by the sensor 82. The electronics package 80 can interpret and/or transmit these signals. The electronics package 80, according to one implementation, has a conditioning unit 84, a signal converting unit 86, and a transmission unit 88. It is understood that the sensor 82, the conditioning unit 84, the signal converting unit 86, the transmission unit 88, and computer 90 are all coupled to each other via at least one communication line. The communication line can be any line that can be used to carry signals from one component to another.
The conditioning unit 84 is configured to provide more robust or easier-to-detect signals. According to one embodiment, the conditioning unit 84 can be figured to filter, shift, amplify, or provide any other conditioning procedure to signals. The signal converting unit 86 is configured to convert analog signals to digital signals so that they can be used in a digital processor or computer. According to one embodiment, the signal converting unit 86 is an analog-to-digital converter (“ADC”). The transmission unit 88 is configured to transmit the signals from the electronics package 80 to the computer 90.
In one implementation, if the output signals from the sensor 82 are digital signals, they can be transmitted or outputted to the conditioning unit 84 (where they are amplified or otherwise conditioned) and then transmitted directly to the transmission unit 88, which transmits the signals to the computer 90. Alternatively, in those embodiments in which the output signals are analog, the signals can be conditioned via the conditioning unit 84 and also converted into digital signals via the signal converting unit 86 before being transmitted by the transmission unit 88 to the computer 90.
For purposes of this application, it is understood that the term “computer” is intended to mean any device that can be programmed to carry out arithmetic or logical operations. As such, “computer” encompasses any microprocessor, digital signal processor, or any other computer platform. This obviously would include any microprocessor, processor, or other type of computer incorporated into any external controller or user interface that is operably coupled to the surgical device.
According to one embodiment, the electronics package 80 is positioned on or in the surgical device (such as either of devices 10 or 30 as discussed above) and the computer 90 is positioned at a location that is external to the surgical device and the patient. Alternatively, both the electronics package 80 and the computer 90 are positioned on or in the robot. In yet another alternative, both the electronics package 80 and the computer 90 are positioned at some location external to the surgical device.
The computer 90 is configured to utilize the data for many end-user applications, including, for example, haptics, data collection for surgeon performance analytics, or for training purposes where the data is recorded and played back to trainees. In certain embodiments, the computer 90 uses the data to calculate the amount of force applied at the endpoint of one of the arms on the surgical device. Alternatively, the computer 90 can calculate the amount of force at any point on either of the arms.
In a further embodiment, the data can also be used for implementing methods of controlling the surgical device. That is, the information relating to the amount of force being applied by an arm of a device can be used to control that arm. In one example, if the arm contacts a cavity wall or an organ in the cavity, the force sensor 82 will sense the force applied to the arm as a result of this contact and the computer 90 can utilize that information to actuate the arm to perform some action to remedy the problem. For example, the computer 90 can actuate the arm to stop moving, shut down, reposition itself away from the point of contract, or take any other action to correct the problem. Various control methods that can be used by the computer 90 include force control, hybrid (force and position) control, admittance control, impedance control, or any combination of these or other known methods. In some embodiments, these methods can be used in conjunction with any combination of the existing position, velocity, acceleration, or current (torque control) control methods.
According to another implementation, the computer 90 can be configured to transmit the data to one or more other computers that can utilize the data for any of the applications described above or other applications.
Other embodiments of a surgical system relate to external controller embodiments having one or more force sensors (or other related types of sensors, such as torque sensors) that can be used to control a surgical device. FIGS. 5A, 5B, and 5C depict an external controller 100 having a known configuration similar to various commercial embodiments. This particular controller 100 has a controller arm 102 made up of an upper arm (also referred to as a first or upper link, rod, or tube) 102A and a forearm (also referred to as a second or lower link, rod, or tube) 102B. The upper arm 102A is rotatably coupled to a base 104 at a shoulder joint (also referred to as a first joint) 106 and the lower arm 102B is rotatably coupled to the upper arm 102A at an elbow joint (also referred to as a second joint) 108. A grasper 110 is rotatably coupled to the lower arm 102B at a wrist joint 112 and is configured to be grasped by a user (such as a surgeon).
As best shown in FIG. 5A, according to one implementation, the shoulder joint 106 is actually made up of two different joints: a rotating yaw joint 106A and a rotating pitch joint 106B. The rotating yaw joint 106A has a fixed joint component 106A1 coupled to the base 104 and a rotatable joint component 106A2 that is rotatably coupled to the fixed joint component 106A1 and rotates around an axis parallel to the longitudinal axis of the rotatable joint component 106A2 (and perpendicular to the plane of the base 104). The rotating pitch joint 106B has a fixed joint component 106B1 coupled to the rotatable joint component 106A2 and a rotatable joint component 10682 that is rotatably coupled to the fixed joint component 106B1 and rotates around an axis parallel to the plane of the base 104.
Continuing with FIG. 5A, the wrist joint 112 is actually made up of three joints 112A, 112B, 112C. The first wrist joint 112A is a rotatable coupling at the lower arm 102B such that the wrist link 112D rotates around an axis parallel to the longitudinal axis of the lower arm 102B. The second wrist joint 1128 is a rotatable coupling of the wrist link 112E to the wrist link 112D such that the wrist link 112E rotates around an axis that is perpendicular to the plane of the wrist link 112D. The third wrist joint 112C is a rotatable coupling of the grasper 110 to the wrist link 112E such that the grasper 110 rotates around an axis perpendicular to the plane of the wrist link 112E. These three joints 112A, 112B, 112C provide three axes of rotation. According to one implementation, the three axes of rotation of the three joints 112A, 112B, 112C all pass through a specific point.
In this embodiment, the grasper 110 has a pinch mechanism 116 made up of two finger loops 116A, 116B. In one implementation, the grasper 110 has a configuration that is substantially similar to the grasper used in the Da Vinci® system.
The controller 100 in this implementation also has motors that operate to provide haptic feedback. More specifically, the shoulder joint 106 has at least one motor positioned within the joint 106 (or otherwise operably coupled thereto). In one example, the motor 111 is coupled to or positioned within the joint 106 and operably coupled to the joint 106 such that the motor 111 can actuate the movement of the rotating yaw joint 106A. In another example, the motor 113 is coupled to the joint 106 and operably coupled thereto such that the motor 113 can actuate the movement of the rotating pitch joint 106B. Similarly, the elbow joint 108 also has at least one motor positioned within the joint 108 (or otherwise operably coupled thereto). In one example, the motor 109 is coupled to the joint 108 as shown. Alternatively, the motor 107 is disposed within the forearm 102B and operably coupled to the joint 108. Further, the wrist joint 112 can also have one or more motors operably coupled to one or more of the wrist joints 112A, 112B, 112C. For example, a motor 105 can be disposed within the forearm 102B that is operably coupled to the wrist link 112D such that the motor 105 can actuate the movement of the wrist link 112D. Alternatively, a motor 103 can be operably coupled to the wrist joint 1128 to actuate the movement of the wrist link 112E. In a further alternative, a motor 101 can be operably coupled to the wrist joint 112C to actuate the movement of the grasper 110. In operation, it is understood that the motors are used to provide haptic feedback to the user or surgeon during a procedure. That is, the one or more force sensors (or torque sensors), such as any of the sensors discussed above, operably coupled to the surgical device sense force applied to at least one arm of the device (or torque at one or more joints) and that information is transmitted back to a processor as discussed above. The processor can use that information to calculate the force or torque being applied and transmit instructions based on that information to the motors in the controller 100 to actuate those motors to generate similar force or torque in the controller 100 that can be felt by the user or surgeon at the grasper 110, thereby giving the user or surgeon feedback in the form of force (resistance) similar to the feedback the surgeon or user would receive if she or he was holding the actual surgical device component experiencing the force.
In one embodiment, the motors in the controller 100 are known brushed or brushless motors. The motors can be any motors ranging in size from about 4 mm to about 30 mm in diameter, so long as the motors provide sufficient force and speed profiles to achieve desired results. In accordance with one implementation, the motors are any motors within that size range that are commercially available from Micromo, located in Clearwater, Fla. or from Maxon Motor, located in Fall River, Mass. In a further alternative, the motors can be any known motors of appropriate size used in medical devices or related controller components.
According to one implementation as best shown in FIG. 5B, the controller 100 has a force sensor 120 associated with the shoulder joint 106. More specifically, in one embodiment, the sensor 120 has a first component 120A coupled to the base 104 and a second component 120B coupled to the fixed joint component 106A1. In use, the sensor 120 detects any force applied to either the fixed joint component 106A1 or the base 104. The sensor 120 also has a connection component 120C that extends from the sensor 120 to a computer or other type of processor. Alternatively, one or more sensors can be positioned anywhere on or within the controller 100 at any location between the base 104 and the finger loops 116A, 116B. In accordance with another aspect, a single six-axis force sensor is positioned within or coupled to the yaw joint 106A (like sensor 120) and a separate sensor (not shown) is positioned on the grasper 110. Using analytical or iterative methods, force data from the sensor 120 at the yaw joint 106A and known information about the structural parameters of the controller 100 can be used by a processor to determine internal and external forces while the separate sensor on the grasper 110 can be used to determine grasping pressures or other relevant information. In a further implementation, separate sensors can be positioned at every joint 106, 108, 112 and provide feedback. In yet another embodiment, a single sensor is positioned somewhere on or operably coupled to the grasper 110.
In operation, it is understood that the one or more force sensors on the controller 100 are configured to sense force applied to the controller 100 by the user or surgeon, and that information is transmitted back to a processor as discussed above. The processor can use that information to calculate the force or torque being applied at the controller 100 and take that information into account for purposes of creating appropriate haptic feedback to the user at the controller 100 using the one or more motors described above that are operably coupled to the controller 100, thereby helping to ensure that the appropriate amount of force is being applied to the user's hand during use of the controller 100.
It is understood that the one or more sensors used with a controller (such as the controller 10) can be any of the force or torque sensors discussed above in relation to the surgical device embodiments. It is further understood that one or more sensors can be operably coupled in a similar fashion in similar configurations with any known controller having any known configuration that is capable of at least one directional force.
FIG. 6 depicts a schematic representation of a surgical system 130 having an external controller 132 that is operably coupled to a surgical device 142. The external controller 132 can be any known controller (including, for example, the controller 100 discussed above) having at least one force sensor 134, along with at least one set of actuators or motors chosen from at least one of the following: motor drivers 136, motor brakes 138, and/or some other known type of actuators 140. The surgical device 142 can be any known surgical device (including, for example, either of the devices 10, 30 discussed above) having a control system 144 (typically in the form of a microprocessor or other type of computer) and at least one force sensor 146. As a result, this system 130 allows a surgeon 162 (or other user) to use the controller 132 to operate the surgical device 142 while the force sensors 134, 148 provide the system with force information that allows the system to provide haptic feedback to the surgeon 162 through the controller 132.
In use, the surgeon manipulates the controller 132 to control the surgical device 142. As a result of that manipulation, the controller 132 transmit information to the control system 144 in the surgical device 142. In one embodiment, the information transmitted by the controller 132 constitutes measurements relating to the physical position of the arm (or arms) of the controller 132. The information is used by the control system 144 to actuate the arm (or arms) of the surgical device 142 to move as desired by the surgeon 162. The force sensor 146 operates as discussed above with respect to sensors 22, 40, 52 by sensing the force applied to the device 142. In this implementation, the sensor 146 outputs that information to a haptic control process or application 158 running on a processor or computer 148 (which can be the same as the computer 90 discussed above or a similar processor, microprocessor, or computer) to determine the desired haptic forces (the amount of feedback force desired to be provided to the surgeon 162) via known methods such as, for example, proportional or exponential force feedback, impedance control, admittance control, or hybrid control.
According to one embodiment, the workspace limitations of the surgical device 142 can also be taken into account in this system 130. That is, the workspace limitation information can be saved in the device control system 144 (and provided to the haptic control algorithms 158) or it can be stored in the processor 148. In one embodiment, the information is modeled as an inward force that simulates a wall. Regardless, the information is used to transmit information to the controller that actuates one or more of the actuators 136, 138, 140 to generate forces at the controller 132 that help to prevent the surgeon 162 from exceeding the workspace of the surgical device 142. In one embodiment, the information actuates the actuator(s) 136, 138, 140 to provide direct force or vibration at the controller 132. Alternatively, the system can provide visual cues to the surgeon 162.
In one implementation, the computer 148 can also be configured to compensate for the outside forces in the system caused by gravity, friction, and inertia. That is, the force sensor 134 associated with the controller 132 detects and collects information about all forces being applied to the controller 132, not just the forces applied by the surgeon 162. This force information is provided to the computer 148 in one lump sum that includes all such forces. In this embodiment, the system 130 can take one or more of the outside forces into account and compensate for or “cancel out” those outside forces.
For example, one implementation of the system 130 allows for compensation for gravity. That is, the processor 148 can use structural and positional information about the controller 132 to calculate the effect of gravity on the controller 132 and effectively “subtract” that amount of force or otherwise “cancel out” that amount of force from the force detected by the sensor 134. As a result, in an ideal embodiment of the system 130, when the surgeon removes her hands from the controller 132, the controller 132 should not fall but instead should appear weightless as a result of the compensation for gravity.
Another implementation allows for dynamic compensation. That is, the processor 148 can use structural and positional information about the controller 132 to calculate the effect of inertia and other dynamic forces on the controller 132 during use and effectively “subtract” or otherwise “cancel out” that amount of force from the force detected by the sensor 134. As a result, rapid movements by the surgeon 162 would not create reaction forces provided as haptic feedback to the surgeon 162 and the effect would be that the mass of the controller 132 would not impose any forces on the system 130.
In a further embodiment, the system 130 can allow for friction compensation. That is, the processor 148 can use one or more force sensors in the controller 132 to detect any unexpected forces experienced by the controller 132 when force is applied to the handles of the controller 132 by the surgeon 162. Those unexpected forces can then be effectively “subtracted” from the force detected by the sensor 134. The result is a frictionless system that exhibits little resistance to movement.
In one embodiment, the system 130 can have only one form of compensation, such as, for example, gravity compensation. Alternatively, the system 130 can have two forms of compensation. In a further alternative, the system 130 can compensate for all three types of external forces: gravity, dynamic forces, and friction.
Once the computer has added up the total amount of the outside/unwanted forces to be compensated for, that amount is subtracted from the total amount of force information provided by the force sensor 134. The result of the calculation is the “error” between the amount of force actually applied to the controller 132 by the surgeon 162 and the amount of force that was desired. Information about this “error” amount is provided to a haptic control system or application 160 that actuates one or more of the actuators (the motor drivers 136, the motor brakes 138, and/or the other actuators) in the controller 132 to add or subtract that amount of force needed based on the error, thereby providing the haptic feedback to the surgeon 162. Hence, the haptic control system 160 determines the appropriate amount of haptic forces to generate in the controller 132.
Another force-sensing grasper 180 embodiment is depicted in FIG. 7. In this implementation, the force being measured is the force applied along the drivetrain of the end effector. That is, the force sensor is integrated into the actuation component(s) or motor(s) of the end effector to measure directly the force applied by that component/motor (those components/motors) to the end effector. The end effector 180 is configured to transmit force feedback information to the surgical system, wherein the force feedback information is any information relating to the force which the end effector 180 is applying during use of the end effector 180. In certain implementations, this information can be used to adjust the amount of force being applied when it is determined that the force is too great or insufficient for the action being performed.
In this specific embodiment as shown, as mentioned above, the end effector 180 is a grasper end effector 180 having a grasper tool 182. The actuation system provided for this grasper end effector 180 in the embodiment as shown is merely an exemplary, known system and constitutes only one of many types and configurations of actuation systems that can be used for actuating a grasper tool 182, including the various systems discussed in the embodiments above. As shown, the grasper end effector 180 is configured to have two degrees of freedom. That is, the grasper tool 182 rotates about its long axis and moves between an open configuration and a closed configuration. To achieve movement of the grasper tool 182 between the open and closed configurations, the grasper end effector 180 has a shaft 184 that contains a threaded inner push/pull rod (not shown) that is coupled to the actuator or motor 186 (shown in FIG. 7 as a motor and gearhead) via the gears 188. The shaft 184 has an internal lumen (not shown) defined within the shaft 184, and the lumen has internal threads that match up with the external threads on the push/pull rod (not shown). In use, the motor 186 actuates the rotation of the gears 188, which causes the inner push/pull rod (not shown) to rotate. In contrast, the shaft 184 is restrained such that it cannot rotate. In one embodiment, the shaft 184 is fixed rotationally via a clamp 190. Thus, the meshing of the threads of the rod with the internal threads of the shaft 184 means that the rotation of the rod within the restrained shaft 184 causes the rod to translate laterally, thereby causing the grasper tool 182 to move between its open and closed positions.
In one embodiment, the force-sensing grasper 180 operates to sense the amount of force being applied by the grasper tool 182 by measuring the amount of axial force being transmitted through the push/pull rod (not shown) in the shaft 184. More specifically, the device has a sensor 192 that is positioned such that it can measure the force generated through the coupling of the gears 188 and the push/pull rod (not shown) coupled to the shaft 184. That is, the sensor 192 is positioned in FIG. 7 such that it is operably coupled to a proximal portion of the push/pull rod. In one embodiment, the sensor 192 measures tension and compression. According to one exemplary implementation, the sensor 192 is a force sensor 192 that measures axial loading. For example, the sensor 192 can be one of the ELFS Series of load cells available from Entran Sensors & Electronics in Fairfield, N.J. Alternatively, the sensor 192 can be any known type of force sensor.
FIG. 8 depicts another embodiment of a force-sensing end effector 200. In this embodiment, the sensor 202 is positioned on the push/pull rod (not shown) proximal to the clamp 190. In one embodiment, the sensor 202 is positioned on or in operable coupling with the push/pull rod (not shown) within the shaft 184. Alternatively, the sensor 202 is positioned on or externally to the shaft 184, but still operably coupled to the push/pull rod. The sensor 202 is configured to measure the force applied to the push/pull rod (not shown).
FIG. 9 depicts yet another implementation of a force-sensing end effector 210. In this embodiment, the sensor 212 is operably coupled to the motor 186 such that the sensor 212 measures the current consumed by the motor 186. The information relating to the current can be used to determine the amount of force being applied by the grasper tool 182.
FIGS. 10A and 10B depict two additional embodiments of force-sensing end effectors 220, 222 that measure contact force at the graspers (rather than measuring directly the force applied by the actuator(s)/motor(s)). In the embodiment shown in FIG. 10A, a sensor 224 is positioned on the grasper tool 182 itself. More specifically, the sensor 224 is positioned on the internal face of one of the two jaws of the tool 182 such that the sensor 224 measures the contact force on the internal face of the jaw. Alternatively, as shown in FIG. 10B, a sensor 226 can be positioned on an external face of a jaw of the grasper tool 182 near the pivot axis of the tool 182 such that the sensor 226 measures the deflection of the grasper. Using the deflection information, the force applied to the tool 182 can be determined.
Although the present invention has been described with reference to preferred embodiments, persons skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.

## Claims

1. A robotic surgical system comprising:
(a) a robotic surgical device configured to be positioned into a cavity of a patient through an incision, the device comprising:
(i) a device body;
(ii) at least one arm operably coupled to the body, wherein the at least one arm is configured to be positioned entirely within the cavity of the patient; and
(iii) at least one sensor operably coupled to the device;

(b) a processor operably coupled to the at least one sensor; and
(c) a user controller operably coupled to the processor, the user controller comprising:
(i) a base;
(ii) an upper arm component operably coupled to the base at a shoulder joint, wherein the shoulder joint comprises a first actuator operably coupled to the processor;
(iii) a forearm component operably coupled to the upper arm component at an elbow joint, wherein the elbow joint comprises a second actuator operably coupled to the processor; and
(iv) a grasper operably coupled to the forearm component at a wrist joint, wherein the wrist joint comprises a third actuator operably coupled to the processor,

wherein the at least one sensor is configured to sense force or torque at the robotic surgical device and transmit force or torque information to the processor,
wherein the processor is configured to calculate the force or torque being applied at the robotic surgical device and transmit instructions to actuate at least one of the first, second, or third actuator based on the force or torque, thereby providing haptic feedback at the controller.

2. The robotic surgical system of claim 1, wherein the at least one sensor is a force sensor operably coupled to the at least one arm.

3. The robotic surgical system of claim 1, wherein the at least one sensor is a torque sensor operably coupled to a joint of the at least one arm.

4. The robotic surgical system of claim 1, wherein the at least one sensor is a force sensor positioned between the device body and the at least one arm.

5. The robotic surgical system of claim 1, wherein the at least one sensor is a force sensor disposed within the device body.

6. A robotic surgical system comprising:
(a) a robotic surgical device comprising:
(i) a device body configured to be positioned through an incision into a cavity of a patient;
(ii) a first shoulder component operably coupled to the device body;
(iii) a first arm operably coupled to the first shoulder component, wherein the first arm is configured to be positioned entirely within the cavity of the patient; and
(iv) a sensor operably coupled to the device,
wherein the device body is configured to be disposed in the incision when the first arm is positioned within the cavity;

(b) a processor operably coupled to the sensor; and
(c) a user controller operably coupled to the processor, the user controller comprising:
(i) a base;
(ii) a controller upper arm component operably coupled to the base at a shoulder joint, wherein the shoulder joint comprises a first actuator operably coupled to the processor;
(iii) a controller forearm component operably coupled to the controller upper arm component at an elbow joint, wherein the elbow joint comprises a second actuator operably coupled to the processor; and
(iv) a grasper operably coupled to the controller forearm component at a wrist joint, wherein the wrist joint comprises a third actuator operably coupled to the processor,

wherein the sensor is configured to sense force or torque at the robotic surgical device and transmit force or torque information to the processor, and
wherein the processor is configured to calculate the force or torque being applied at the robotic surgical device and transmit instructions to actuate at least one of the first, second, or third actuator based on the force or torque, thereby providing haptic feedback at the controller.

7. The robotic surgical system of claim 6, wherein the sensor is disposed between the device body and the first shoulder component.

8. The robotic surgical system of claim 6, wherein the sensor is disposed on the first arm.

9. The robotic surgical system of claim 8, wherein the first arm comprises a first arm upper arm component and a first arm forearm component, wherein the sensor is disposed on the first arm forearm component.

10. The robotic surgical system of claim 6, wherein the first arm comprises a first arm upper arm component and a first arm forearm component, wherein the first arm forearm component is operably coupled to the first arm upper arm component at an elbow joint, wherein the first arm forearm component comprises a link operably coupled at a distal end to the force sensor and operably coupled at a proximal end to the elbow joint.

11. The robotic surgical system of claim 10, further comprising an interface plate disposed between the force sensor and the link.

12. The robotic surgical system of claim 6, wherein the sensor is positioned to measure the amount of force applied at a distal-most point on the first arm.

13. A robotic surgical system comprising:
(a) a robotic surgical device comprising:
(i) a device body configured to be positioned through an incision into a cavity of a patient;
(ii) a first arm operably coupled to the device body, the first arm comprising an arm actuator disposed within the first arm, wherein the first arm is configured to be positioned entirely within the cavity of the patient;
(iii) a sensor operably coupled to the arm actuator; and
(iv) an end effector operably coupled to the arm actuator, the end effector positioned at a distal end of the first arm;

(b) a processor operably coupled to the sensor; and
(c) a user controller operably coupled to the processor, the user controller comprising:
(i) a base;
(ii) a controller upper arm component operably coupled to the base at a shoulder joint, wherein the shoulder joint comprises a first actuator operably coupled to the processor;
(iii) a controller forearm component operably coupled to the forearm upper arm component at an elbow joint, wherein the elbow joint comprises a second actuator operably coupled to the processor; and
(iv) a controller grasper operably coupled to the controller forearm component at a wrist joint, wherein the wrist joint comprises a third actuator operably coupled to the processor,

wherein the sensor is configured to sense force or torque at the robotic surgical device and transmit force or torque information to the processor,
wherein the processor is configured to calculate the force or torque being applied at the robotic surgical device and transmit instructions to actuate at least one of the first, second, or third actuator based on the force or torque, thereby providing haptic feedback at the controller.

14. The robotic surgical system of claim 13, further comprising a push/pull rod comprising a distal portion and a proximal portion, wherein the push/pull rod is operably coupled to the arm actuator at the proximal portion and further wherein the push/pull rod is operably coupled to the end effector at the distal portion.

15. The robotic surgical system of claim 14, wherein the sensor is disposed proximal to the arm actuator and is operably coupled to the proximal portion of the push/pull rod.

16. The robotic surgical system of claim 14, wherein the end effector is a device grasper, wherein the device grasper comprises an open configuration when the push/pull rod is urged to a distal position, and further wherein the device grasper comprises a closed configuration when the push/pull rod is urged to a proximal position.

17. The robotic surgical system of claim 14, wherein the sensor is operably coupled to the push/pull rod such that the sensor is positioned along the length of the push/pull rod.

18. The robotic surgical system of claim 13, wherein the end effector is a device grasper.

19. The robotic surgical system of claim 13, further comprising a shaft operably coupled to the end effector and a first gear operably coupled to the shaft, wherein the arm actuator comprises a second gear operably coupled to the first gear.

20. The robotic surgical system of claim 19, wherein actuation of the arm actuator causes the shaft to rotate, thereby causing the end effector to rotate.