Surgical robotic systems and methods for detecting and predicting cable breakage

Abstract

The invention relates to a surgical robotic system and method for detecting and predicting cable breakage, and specifically discloses a surgical robotic system including an instrument drive unit having a plurality of motors, with two motors being high side motors and two motors being low side motors. The instrument drive unit is coupled to an instrument having an end effector having a first jaw and a second jaw. The instrument also includes a plurality of cables, two of which are high-side cables actuatable by a high-side motor and two of which are low-side cables actuatable by a low-side motor. The high side cable is used to close the first and second jaw members, and the low side cable is used to open the first and second jaw members. The system also includes a controller to determine if one of the low-side cables is fractured based on a derivative of a jaw angle between the first and second jaws exceeding a jaw angle derivative threshold and a sum of motor torques of the high-side motors exceeding a combined high-side torque threshold.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of and priority to U.S. Provisional Patent Application Serial No. 63 / 518,902, filed on August 11, 2023, and U.S. Provisional Patent Application Serial No. 63 / 597,489, filed on November 9, 2023. The entire contents of the foregoing applications are incorporated herein by reference. Background Art

[0003] Surgical robotic systems are currently used for a variety of surgical procedures, including minimally invasive medical procedures. Some surgical robotic systems include a surgeon's console that controls a surgical robotic arm and a surgical instrument having an end effector (e.g., forceps or grasping instrument) coupled to and actuated by the robotic arm. In operation, the robotic arm moves to a position above the patient and then guides the surgical instrument into a small incision via a surgical port or natural orifice in the patient to position the end effector at a working site in the patient's body.

[0004] Surgical robotic instruments are actuated by one or more cables that may snap during use due to the high strain placed on them during actuation. Cable snapping results in uncontrolled movement of parts of the instrument (e.g., the end effector), which may damage other instruments or cameras. Summary of the invention

[0005] According to one embodiment of the present disclosure, a surgical robot system is disclosed. The system includes an instrument drive unit (IDU), which has: a first high-side motor, the first high-side motor having a first high-side torque sensor for measuring the torque of the first high-side motor and a first high-side position sensor for measuring the position of the first high-side motor. The IDU also includes a first low-side motor, the first low-side motor having a first low-side torque sensor for measuring the torque of the first low-side motor and a first low-side position sensor for measuring the position of the first low-side motor. The IDU further includes a second high-side motor, the second high-side motor having a second high-side torque sensor for measuring the torque of the second high-side motor and a second high-side position sensor for measuring the position of the second high-side motor. The IDU also includes a second low-side motor, the second low-side motor having a second low-side torque sensor for measuring the torque of the second low-side motor and a second low-side position sensor for measuring the position of the second low-side motor. The system also includes an instrument with an end effector, the end effector having a first jaw and a second jaw, each of which can be moved between an open position and a closed position. The apparatus also includes: a first high-side cable, which is coupled to the first jaw and can be actuated by the first high-side motor to move the first jaw toward a closed position; a first low-side cable, which is coupled to the first jaw and can be actuated by the first low-side motor to move the first jaw toward an open position; a second high-side cable, which is coupled to the second jaw and can be actuated by the second high-side motor to move the second jaw toward a closed position; and a second low-side cable, which is coupled to the second jaw and can be actuated by the second low-side motor to move the second jaw toward a closed position. The system also includes a controller for calculating an angle between the first jaw and the second jaw based on the position of one or more of the motors. The controller also calculates a combined torque of the first high-side motor and the second high-side motor. The controller also determines whether one of the first low-side cable or the second low-side cable is broken based on the angle and the combined torque between the first jaw and the second jaw. The controller also outputs an alarm based on determining that one of the first low-side cable or the second low-side cable is broken.

[0006] Implementations of the above embodiments may include one or more of the following features. According to one aspect of the above embodiments, the controller may further calculate a derivative of the angle between the first jaw and the second jaw. The controller may also calculate a first moving average of the derivative of the angle between the first jaw and the second jaw and a plurality of subsequent moving averages of the first moving average. The controller may additionally calculate a scaling value of each of the first moving average and the plurality of subsequent moving averages. Each of the plurality of subsequent moving averages may have a unique window size. The controller may also identify a minimum moving average of the derivative from the first moving average and each of the plurality of subsequent moving averages. The controller may further compare the minimum moving average of the derivative with a threshold derivative of the angle between the first jaw and the second jaw. The controller may also determine whether one of the first low-side cable or the second low-side cable is broken based on the angle between the first jaw and the second jaw exceeding an angle threshold and the minimum moving average of the derivative exceeding a threshold derivative of the angle between the first jaw and the second jaw.

[0007] According to another embodiment of the present disclosure, a surgical robot system is disclosed. The system includes an instrument drive unit (IDU) having a plurality of motors, the plurality of motors including a first pair of motors and a second pair of motors, wherein each of the plurality of motors includes a torque sensor for measuring motor torque and a position sensor for measuring angular position. The system also includes an instrument coupled to the IDU, the instrument including an end effector having a first jaw and a second jaw movable between an open position and a closed position. The instrument also includes a first pair of cables, each of which is actuated by one of the first pair of motors to move the first jaw and the second jaw toward the closed position, wherein one of the first pair of cables is coupled to the first jaw and the other of the first pair of cables is coupled to the second jaw. The instrument also includes a second pair of cables, each of which is actuated by one of the second pair of motors to move the first jaw and the second jaw toward the open position, wherein one of the second pair of cables is coupled to the first jaw and the other of the second pair of cables is coupled to the second jaw. The system further includes a controller for calculating an angle between the first jaw and the second jaw based on an angular position of one or more motors of the plurality of motors. The controller also calculates a combined torque of the first pair of motors and determines whether one or both cables of the second pair of cables are broken based on the angle between the first jaw and the second jaw and the combined torque. The controller also outputs an alarm based on determining that one or both cables of the second pair of cables are broken.

[0008] Implementations of the above embodiments may include one or more of the following features. According to one aspect of the above embodiments, the controller may further calculate the derivative of the angle between the first jaw and the second jaw. The controller may also calculate a first moving average of the derivative of the angle between the first jaw and the second jaw and a plurality of subsequent moving averages of the first moving average. The controller may additionally calculate a scaling value of each of the first moving average and the plurality of subsequent moving averages. Each of the plurality of subsequent moving averages has a unique window size. The controller may also identify the minimum moving average of the derivative from the first moving average and each of the plurality of subsequent moving averages. The controller may additionally compare the minimum moving average of the derivative with a threshold derivative of the angle between the first jaw and the second jaw. The controller may further determine whether one or both of the cables in the second pair of cables are broken based on the combined torque of the first pair of motors exceeding the torque threshold and the minimum moving average of the derivative exceeding the threshold derivative of the angle between the first jaw and the second jaw.

[0009] According to another embodiment of the present disclosure, a method for controlling a surgical robot instrument is disclosed. The method includes moving a first jaw and a second jaw apart, wherein the first jaw is connected to a first low-side cable that can be actuated by a first low-side motor, and the second jaw is connected to a second low-side cable that can be actuated by a second low-side motor. The method also includes approaching the first jaw and the second jaw, wherein the first jaw is connected to a first high-side cable that can be actuated by a first high-side motor, and the second jaw is connected to a second high-side cable that can be actuated by a second high-side motor. The method further includes measuring the torque of each of the first high-side motor and the second high-side motor and the first low-side motor and the second low-side motor and measuring the angular position of each of the first high-side motor and the second high-side motor and the first low-side motor and the second low-side motor. The method additionally includes calculating the angle between the first jaw and the second jaw based on the angular position of one of the first high-side motor, the second high-side motor, the first low-side motor or the second low-side motor at the controller. The method also includes calculating the combined torque of the first high-side motor and the second high-side motor at the controller. The method further includes determining at a controller whether one of the first low side cable or the second low side cable is broken based on an angle and a combined torque between the first jaw and the second jaw. The method further includes outputting an alarm based on determining that one of the first low side cable or the second low side cable is broken.

[0010] Implementations of the above embodiments may include one or more of the following features. According to one aspect of the above embodiments, the method may include calculating a derivative of the angle between the first jaw and the second jaw at a controller and calculating a first moving average of the derivative of the angle between the first jaw and the second jaw at the controller and a plurality of subsequent moving averages of the first moving average. The method may also include identifying a minimum moving average of the derivative from each of the first moving average and the plurality of subsequent moving averages at the controller and comparing the minimum moving average of the derivative with a threshold derivative of the angle between the first jaw and the second jaw at the controller. Determine whether one of the first low-side cable or the second low-side cable is broken based on the combined torque exceeding the torque threshold and the minimum moving average of the derivative exceeding the threshold derivative of the angle between the first jaw and the second jaw. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Various embodiments of the present disclosure are described herein with reference to the accompanying drawings, in which:

[0012] Figure 1 is a schematic diagram of a surgical robotic system according to an embodiment of the present disclosure, the surgical robotic system comprising a control tower, a control console, and one or more surgical robotic arms each disposed on a movable cart;

[0013] Figure 2 According to the embodiments of the present disclosure Figure 1 A three-dimensional diagram of a surgical robot arm of a surgical robot system;

[0014] Figure 3 is a perspective view of a mobile cart having a mounting arm according to an embodiment of the present disclosure, the mounting arm having Figure 1 The surgical robot arm of the surgical robot system;

[0015] Figure 4 According to the embodiments of the present disclosure Figure 1 A schematic diagram of the computer architecture of a surgical robot system;

[0016] Figure 5 is positioned around an operating table according to aspects of the present disclosure Figure 1 A plan view of a movable cart;

[0017] Figure 6 is a perspective view of an instrument drive unit and a surgical instrument according to an embodiment of the present disclosure, wherein the components are separated;

[0018] Figure 7 According to an embodiment of the present disclosure, Figure 1 A top perspective view of an end effector in a surgical robot system;

[0019] Figure 8 shows an end effector in various configurations according to an embodiment of the present disclosure;

[0020] Fig. 9 is a flow chart of a method for detecting and predicting high side cable breaks according to an embodiment of the present disclosure; and

[0021] Fig.10 is a flow chart of a method for detecting and predicting low side cable breaks according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0022] Embodiments of the presently disclosed surgical robotic system are described in detail with reference to the drawings, wherein like reference numerals designate identical or corresponding elements in each of the several views.

[0023] As will be described in detail below, the present disclosure relates to a surgical robotic system comprising a surgeon's console, a control tower, and one or more movable carts having a surgical robotic arm coupled to a mounting arm. The surgeon's console receives user input via one or more interface devices. The input is processed by the control tower as movement commands for moving the surgical robotic arm and instruments and / or cameras coupled thereto. Thus, the surgeon's console enables remote operation of the surgical arm and attached instruments / cameras. The surgical robotic arm comprises a controller configured to process movement commands and generate torque commands for activating one or more actuators of the robotic arm, which in turn will move the robotic arm in response to the movement commands.

[0024] refer to Figure 1 , the surgical robotic system 10 includes a control tower 20 that is connected to all components of the surgical robotic system 10 (including a surgeon's console 30 and one or more mobile carts 60). Each mobile cart 60 includes a robotic arm 40 having a surgical instrument 50 coupled thereto. The robotic arm 40 is also coupled to the mobile cart 60. The robotic system 10 may include any number of mobile carts 60 and / or robotic arms 40.

[0025] The surgical instrument 50 is configured for use during minimally invasive surgical procedures. In an embodiment, the surgical instrument 50 can be configured for open surgical procedures. In other embodiments, the surgical instrument 50 can be an electrosurgical forceps configured to seal tissue by compressing the tissue between the jaw members and applying electrosurgical current thereto. In other embodiments, the surgical instrument 50 can be a surgical stapler including a pair of jaws configured to grasp and clamp tissue, simultaneously deploy multiple tissue fasteners (e.g., staples) and cut stapled tissue. In other embodiments, the surgical instrument 50 can be a surgical clip applicator including a pair of jaws configured to apply a surgical clip to the tissue.

[0026] One of the robotic arms 40 may include an endoscopic camera 51 configured to capture a video of the surgical site. The endoscopic camera 51 may be a stereoscopic endoscope configured to capture two side-by-side (i.e., left and right) images of the surgical site to produce a video stream of the surgical scene. The endoscopic camera 51 is coupled to a video processing device 56, which may be disposed within the control tower 20. The video processing device 56 may be any computing device as described below, which is configured to receive a video feed from the endoscopic camera 51 and output a processed video stream.

[0027] The surgeon console 30 includes a first display 32 that displays a video feed of the surgical site provided by a camera 51 disposed on the robotic arm 40 and a second display 34 that displays a user interface for controlling the surgical robotic system 10. The first display 32 and the second display 34 may be touch screens that allow for the display of various graphical user inputs.

[0028] The surgeon console 30 also includes a plurality of user interface devices, such as a foot pedal 36, and a pair of handle controllers 38a and 38b used by a user to remotely control the robotic arm 40. The surgeon console further includes armrests 33 for supporting the clinician's arms while operating the handle controllers 38a and 38b.

[0029] The control tower 20 includes a display 23 (which may be a touch screen) and outputs on a graphical user interface (GUI). The control tower 20 also serves as an interface between the surgeon console 30 and one or more robotic arms 40. In particular, the control tower 20 is configured to control the robotic arms 40 based on a set of programmable instructions and / or input commands from the surgeon console 30 so as to move the robotic arms 40 and corresponding surgical instruments 50 in a manner such that the robotic arms 40 and surgical instruments 50 perform a desired sequence of movements in response to inputs from the foot pedals 36 and the handle controllers 38a and 38b. The foot pedals 36 may be used to enable and lock the hand controllers 38a and 38b, reposition camera movement, and electrosurgery enable / disable. In particular, the foot pedals 36 may be used to perform a clutch action on the hand controllers 38a and 38b. The clutch is activated by pressing one of the foot pedals 36, which disconnects the hand controllers 38a and / or 38b from the robotic arm 40 and the corresponding instrument 50 or camera 51 attached thereto (i.e., prevents movement input). This allows the user to reposition the hand controllers 38a and 38b without moving the robotic arm 40 and instrument 50 and / or camera 51. This is useful when reaching the control boundaries of the surgical space.

[0030] Each of the control tower 20, the surgeon's console 30, and the robotic arm 40 includes a corresponding computer 21, 31, 41. The computers 21, 31, 41 are interconnected with each other using any suitable communication network based on wired or wireless communication protocols. The term "network" as used herein, whether plural or singular, means a data network, including but not limited to the Internet, an intranet, a wide area network, or a local area network, and is not limited to the full scope of the definition of a communication network covered by the present disclosure. Suitable protocols include, but are not limited to, the Transmission Control Protocol / Internet Protocol (TCP / IP), the Datagram Protocol / Internet Protocol (UDP / IP), and / or the Datagram Congestion Control Protocol (DCCP). Wireless communication can be achieved via one or more wireless configurations, such as radio frequency, light, Wi-Fi, Bluetooth (an open wireless protocol for exchanging data from fixed and mobile devices over short distances using short-length radio waves to create a personal area network (PAN)), (Specification of a suite of advanced communications protocols using small, low-power digital radios based on the IEEE 122.15.4-1203 standard for Wireless Personal Area Networks (WPANs).

[0031] Computer 21,31,41 may include any suitable processor (not shown) operably connected to a memory (not shown), which may include one or more of volatile, nonvolatile, magnetic, optical or dielectric, such as read-only memory (ROM), random access memory (RAM), electrically erasable programmable ROM (EEPROM), nonvolatile RAM (NVRAM) or flash memory. The processor may be any suitable processor (e.g., control circuit) suitable for performing the operations, calculations and / or instruction sets described in the present disclosure, including but not limited to hardware processors, field programmable gate arrays (FPGAs), digital signal processors (DSPs), central processing units (CPUs), microprocessors and combinations thereof. Those skilled in the art will appreciate that the processor may be replaced by using any logical processor (e.g., control circuit) suitable for performing the algorithms, calculations and / or instruction sets described herein.

[0032] refer to Figure 2 Each robotic arm 40 may include a plurality of links 42a, 42b, 42c that are interconnected at joints 44a, 44b, 44c, respectively. Other configurations of links and joints may be used as known to those skilled in the art. Joint 44a is configured to secure the robotic arm 40 to the mobile cart 60 and defines a first longitudinal axis. Figure 3 , the movable cart 60 includes a lift 67 and a mounting arm 61, which provides a base for mounting the robotic arm 40. The lift 67 allows the mounting arm 61 to move vertically. The movable cart 60 also includes a display 69, which is used to display information about the robotic arm 40. In an embodiment, the robotic arm 40 can include any type and / or number of joints.

[0033] The installation arm 61 includes a first link 62a, a second link 62b and a third link 62c, which provide lateral maneuverability of the robot arm 40. The links 62a, 62b, 62c are interconnected at joints 63a and 63b, and each joint may include an actuator (not shown) for rotating the links 62b and 62b relative to each other and relative to the link 62c. In particular, the links 62a, 62b, 62c can move in their corresponding lateral planes parallel to each other, thereby allowing the robot arm 40 to extend relative to the patient (e.g., an operating table). In an embodiment, the robot arm 40 can be connected to an operating table (not shown). The installation arm 61 includes a control device 65, which is used to adjust the movement of the links 62a, 62b, 62c and the elevator 67. In an embodiment, the installation arm 61 can include any type and / or number of joints.

[0034] The third link 62c may include a rotatable base 64 having two degrees of freedom. In particular, the rotatable base 64 includes a first actuator 64a and a second actuator 64b. The first actuator 64a can rotate around a first fixed arm axis perpendicular to a plane defined by the third link 62c, while the second actuator 64b can rotate around a second fixed arm axis transverse to the first fixed arm axis. The first actuator 64a and the second actuator 64b allow the robot 40 to achieve full three-dimensional orientation.

[0035] The actuator 48b of the joint 44b is connected to the joint 44c via the belt 45a, and the joint 44c is further connected to the joint 46b via the belt 45b. The joint 44c can include a transfer case connecting the belts 45a and 45b, so that the actuator 48b is configured to rotate each of the links 42b, 42c and the holder 46 relative to each other. More specifically, the links 42b, 42c and the holder 46 are passively connected to the actuator 48b, which is forced to rotate around the pivot point "P", which is located at the intersection of the first axis defined by the link 42a and the second axis defined by the holder 46. In other words, the pivot point "P" is the remote center of motion (RCM) of the robot 40. Thus, the actuator 48b controls the angle θ between the first axis and the second axis, thereby allowing the surgical instrument 50 to be oriented. Due to the interconnection of the links 42a, 42b, 42c and the retainer 46 via the straps 45a and 45b, the angle between the links 42a, 42b, 42c and the retainer 46 is also adjusted to achieve the desired angle θ. In an embodiment, some or all of the joints 44a, 44b, 44c may include actuators to eliminate the need for mechanical linkages.

[0036] The joints 44a and 44b include actuators 48a and 48b that are configured to drive the joints 44a, 44b, 44c relative to each other through a series of belts 45a and 45b or other mechanical linkages such as drive rods, cables or levers. In particular, the actuator 48a is configured to rotate the robotic arm 40 about the longitudinal axis defined by the link 42a.

[0037] refer to Figure 2 The holder 46 defines a second longitudinal axis and is configured to receive an instrument drive unit (IDU) 52 ( Figure 1). The IDU 52 is configured to be coupled to the actuation mechanisms of the surgical instrument 50 and the camera 51 and is configured to move (e.g., rotate) and actuate the instrument 50 and / or the camera 51. The IDU 52 transmits the actuation force from its actuator to the surgical instrument 50 to actuate components of the end effector 49 of the surgical instrument 50. The holder 46 includes a sliding mechanism 46a that is configured to move the IDU 52 along a second longitudinal axis defined by the holder 46. The holder 46 also includes a joint 46b that rotates the holder 46 relative to the link 42c. During endoscopic surgery, the instrument 50 can be inserted through the endoscope access port 55 ( Figure 3 ) is inserted. The holder 46 also includes a port lock 46c ( Figure 2 ).

[0038] The IDU 52 is attached to the holder 46, and then the sterile interface module (SIM) 43 is attached to the distal portion of the IDU 52. The SIM 43 is configured to secure a sterile drape (not shown) to the IDU 52. The instrument 50 is then attached to the SIM 43. The instrument 50 is then inserted through the access port 55 by moving the IDU 52 along the holder 46. The SIM 43 includes a plurality of drive shafts that are configured to transmit the rotation of the respective motors of the IDU 52 to the instrument 50, thereby actuating the instrument 50. In addition, the SIM 43 provides a sterile barrier between the instrument 50 and other components of the robotic arm 40 (including the IDU 52).

[0039] The robot arm 40 also includes a plurality of manual override buttons 53 ( Figure 1 ), these manual override buttons can be used in manual mode. The user can press one or more of these buttons 53 to move the component associated with the button 53.

[0040] refer to Figure 4, each of the computers 21, 31, 41 of the surgical robot system 10 may include multiple controllers, which may be implemented in hardware and / or software. The computer 21 of the control tower 20 includes a controller 21a and a safety observer 21b. The controller 21a receives data about the current position and / or orientation of the handle controllers 38a and 38b and the status of the foot pedal 36 and other buttons from the computer 31 of the surgeon's console 30. The controller 21a processes these input positions to determine the desired drive commands for each joint and / or IDU 52 of the robotic arm 40, and transmits these commands to the computer 41 of the robotic arm 40. The controller 21a also receives the actual joint angles measured by the encoders of the actuators 48a and 48b, and uses this information to determine force feedback commands, which are transmitted back to the computer 31 of the surgeon's console 30 to provide tactile feedback through the handle controllers 38a and 38b. The safety observer 21b performs validity checks on data entering and exiting the controller 21a and, if an error in data transmission is detected, notifies the system fault handler to place the computer 21 and / or surgical robot system 10 into a safe state.

[0041] The computer 41 includes a plurality of controllers, namely, a cart main controller 41a, a setting arm controller 41b, a robot arm controller 41c, and an instrument drive unit (IDU) controller 41d. The cart main controller 41a receives and processes joint commands from the controller 21a of the computer 21, and transmits them to the setting arm controller 41b, the robot arm controller 41c, and the IDU controller 41d. The cart main controller 41a also manages instrument exchange and the overall status of the movable cart 60, the robot arm 40, and the IDU 52. The cart main controller 41a also transmits the actual joint angles back to the controller 21a.

[0042] Each of the joints 63a and 63b and the rotatable base 64 of the installation arm 61 is a passive joint (i.e., there is no actuator therein) that allows manual adjustment by the user. The joints 63a and 63b and the rotatable base 64 include brakes that are disengaged by the user to construct the installation arm 61. When the brake is engaged, the installation arm controller 41b monitors the sliding of each of the joints 63a and 63b and the rotatable base 64 of the installation arm 61, or when the brake is disengaged, the installation arm controller can be freely moved by the operator without affecting the control of other joints. The robot arm controller 41c controls each joint 44a and 44b of the robot arm 40 and calculates the desired motor torque required for gravity compensation, friction compensation, and closed-loop position control of the robot arm 40. The robot arm controller 41c calculates a movement command based on the calculated torque. The calculated motor command is then transmitted to one or more of the actuators 48a and 48b in the robot arm 40. The actual joint positions are then transmitted by actuators 48a and 48b back to the robot controller 41c.

[0043] The IDU controller 41d receives the desired joint angles (such as wrist angle and jaw angle) of the surgical instrument 50 and calculates the desired current for the motors in the IDU 52. The IDU controller 41d calculates the actual angle based on the motor position and transmits the actual angle back to the cart main controller 41a.

[0044] The robotic arm 40 is controlled in response to the posture of the handle controller (e.g., handle controller 38a) controlling the robotic arm 40, which is transformed into the desired posture of the robotic arm 40 by the hand-eye transformation function performed by the controller 21a. The hand-eye function and other functions described herein are implemented in the software executable by the controller 21a or any other suitable controller described herein. The posture of one of the handle controllers 38a can be implemented as a coordinate position and roll-pitch-left-right (RPY) orientation relative to the coordinate reference system fixed to the surgeon's console 30. The desired posture of the instrument 50 is relative to the fixed system on the robotic arm 40. The posture of the handle controller 38a is then scaled by the zoom function performed by the controller 21a. In an embodiment, the coordinate position can be reduced and the orientation can be enlarged by the zoom function. In addition, the controller 21a can also perform a clutch function for disengaging the handle controller 38a from the robotic arm 40. In particular, if certain movement limits or other thresholds are exceeded, the controller 21a stops transmitting movement commands from the handle controller 38a to the robotic arm 40 and essentially acts like a virtual clutch mechanism, eg, limiting the mechanical input from affecting the mechanical output.

[0045] The desired pose of the manipulator 40 is based on the pose of the handle controller 38a and then communicated through an inverse kinematics function executed by the controller 21a. The inverse kinematics function calculates the angles of the joints 44a, 44b, 44c of the manipulator 40 that achieve the scaled and adjusted pose input by the handle controller 38a. The calculated angles are then communicated to the manipulator controller 41c, which includes a joint axis controller with a proportional-derivative (PD) controller, a friction estimator module, a gravity compensator module, and a double-sided saturation block configured to limit the command torque of the motors of the joints 44a, 44b, 44c.

[0046] refer to Figure 5 , the surgical robotic system 10 is set up around an operating table 90. The system 10 includes movable carts 60a-d, which may be numbered "1" to "4". During set up, each of the carts 60a-d is positioned around the operating table 90. The position and orientation of the carts 60a-d depends on a number of factors, such as the placement of a plurality of access ports 55a-d, which in turn depends on the surgery being performed. Once the port placement is determined, the access ports 55a-d are inserted into the patient's body, and the carts 60a-d are positioned to insert the instruments 50 and the endoscopic camera 51 into the corresponding ports 55a-d.

[0047] During use, each of the mechanical arms 40a-d engages the latch 46c ( Figure 2 ) is attached to the entry port 55 ( Figure 3 ) is attached to one of the access ports 55a-d inserted into the patient's body. The IDU 52 is attached to the holder 46, and then the SIM 43 is attached to the distal portion of the IDU 52. Thereafter, the instrument 50 is attached to the SIM 43. The instrument 50 is then inserted through the access port 55 by moving the IDU 52 along the holder 46.

[0048] refer to Figure 6 , the IDU 52 is shown in greater detail and is configured to transmit power and actuation force from its motors 152a, 152b, 152c, 152d to the instrument 50 to drive movement of components of the instrument 50, such as articulation, rotation, pitch, yaw, clamping, cutting, etc. The IDU 52 may also be configured to activate or fire electrosurgical energy-based instruments, etc. (e.g., cable drives, pulleys, friction wheels, rack and pinion arrangements, etc.).

[0049] The IDU 52 includes a motor group 150 and a sterile barrier housing 130. The motor group 150 includes motors 152a, 152b, 152c, 152d for controlling various operations of the instrument 50. The instrument 50 is removably connected to the IDU 52. When the motors 152a, 152b, 152c, 152d of the motor group 150 are actuated, the rotation of the drive transmission shafts 154a, 154b, 154c, 154d of the motors 152a, 152b, 152c, 152d is respectively transmitted to the drive assembly of the instrument 50. The instrument 50 is configured to convert the rotational force / movement supplied by the IDU 52 (e.g., via the motors 152a, 152b, 152c, 152d of the motor group 150) into longitudinal movement or translation of the cable or drive shaft to achieve the end effector 200 ( Figure 7 )’s various functions.

[0050] Each of the motors 152a, 152b, 152c, 152d includes a current sensor 153, a torque sensor 155, and a position sensor 157. For simplicity, only the operation of the motor 152a is described below. The sensors 153, 155, 157 monitor the performance of the motor 152a. The current sensor 153 is configured to measure the current consumption of the motor 152a, and the torque sensor 155 is configured to measure the motor torque. The torque sensor 155 can be any force or strain sensor including one or more strain gauges, which are configured to convert mechanical force and / or strain into a sensor signal indicating the torque output by the motor 152a. The position sensor 157 can be any device that provides a sensor signal indicating the number of revolutions of the motor 152a, such as a mechanical encoder or an optical encoder. The parameters measured and / or determined by the position sensor 157 can include speed, distance, revolutions per minute, position, etc. The sensor signals from sensors 153, 155, 157 are transmitted to the IDU controller 41d, which then controls the motors 152a, 152b, 152c, 152d based on the sensor signals. In particular, the motors 152a, 152b, 152c, 152d are controlled by an actuator controller 159, which controls the output torque and angular velocity of the motors 152a, 152b, 152c, 152d. In an embodiment, additional position sensors may also be used, including but not limited to potentiometers, Hall effect sensors, accelerometers, and gyroscopes coupled to the movable component and configured to detect travel distance. In an embodiment, a single controller may perform the functions of the IDU controller 41d and the actuator controller 159.

[0051] refer to Figure 6, the instrument 50 includes an adapter 160 having a housing 162 at a proximal portion thereof and an elongated shaft 164 extending distally from the housing 162. The housing 162 of the instrument 50 is configured to be selectively coupled to the IDU 52 of the robot so that the motors 152a, 152b, 152c, 152d of the IDU 52 can operate the end effector 200 of the instrument 50. The housing 162 of the instrument 50 supports a drive assembly that mechanically and / or electrically cooperates with the motors 152a, 152b, 152c, 152d of the IDU 52. The drive assembly of the instrument 50 may include any suitable electrical and / or mechanical components to achieve drive force / movement.

[0052] The surgical instrument also includes an end effector 200 coupled to the elongated shaft 164. The end effector 200 may include any number of degrees of freedom that allow the end effector 200 to articulate, pivot, etc. relative to the elongated shaft 164. The end effector 200 may be any suitable surgical end effector configured to treat tissue, such as a dissector, grasper, sealer, stapler, etc.

[0053] like Figure 7 and Figure 8 As shown, the end effector 200 may include a pair of opposing jaws 120 and 122 that are movable relative to each other. In an embodiment, the end effector 200 may include a proximal portion 112 and a distal portion 114 having a first pin 113. Although the jaws 120 and 122 are shown as clamping jaws, it should be understood that the jaws may be any suitable type of jaws, such as scissors, etc. The end effector 200 may be actuated using a plurality of cables 201a-d that are routed through the proximal portion 112 and the distal portion 114 around their respective pulleys 112a, 112b, 114a, 114b that are integrally formed as arms of the proximal portion 112 and the distal portion 114. Each of the cables 201a-d is actuated by a respective motor 152a-d via a corresponding coupling disposed in the adapter 160. In an embodiment, the end effector 200 (i.e., the distal portion 114 and the jaws 120 and 122) can be articulated about an axis "AA" to control the left-right swing angle of the end effector relative to the longitudinal axis "XX". The distal portion 114 includes a second pin 115, to which a pair of jaws including a first jaw 120 and a second jaw 122 are pivotally coupled. The jaws 120 and 122 are configured to pivot about an axis "BB" defined by the second pin 115, thereby allowing control of the pitch angle of the jaws 120 and 122 and opening and closing the jaws 120 and 122. When the jaws 120 and 122 move between the open position and the closed position, by adjusting the Figure 8The tension and / or length and direction (e.g., proximal or distal) of the cables 201a-d shown are used to control the yaw, pitch, and jaw angle between the jaws. The end effector 200 also includes a cable displacement sensor 116 configured to measure the position of the cable 201. Thus, the end effector 200 can have three degrees of freedom: yaw, pitch, and jaw angle between the jaws 120 and 122.

[0054] The wrist end effector 200 utilizes drive cables 201a-d to articulate pitch, left and right swing and jaw degrees of freedom. The cables responsible for closing the jaws are referred to as high-side cables 201b and 201c, and the cables responsible for opening the jaws are referred to as low-side cables 201a and 201d. Therefore, the high-side cable 201c and the low-side cable 201a actuate the second jaw 122, and the high-side cable 201b and the low-side cable 201d actuate the first jaw 120. During closing, the high-side cables 201b and 201c are tensioned, and the minimum tension is applied to the low-side cables 201a and 201d. During opening, tension is applied to the cables in reverse, that is, a higher tension is applied to the low-side cables 201a and 201d, and the minimum tension is applied to the high-side cables 201b and 201c. Cables 201a-d are controlled by their respective motors 152a-d. Thus, motors 152b and 152c are high-side motors because they actuate high-side cables 201b and 201c, and motors 152a and 152d are low-side motors because they actuate low-side cables 201a and 201d.

[0055] The cables 201a-d are nominally under tension during teleoperation. At times, the cables 201a-d may fail, for example, due to wear. During certain movements of the end effector 200, such as during the closing of the jaws 120 and 122, when high tension is applied to the cables 201a-d, some of the cables 201a-d may break. With particular reference to the present design and arrangement of the cables 201a-d, the high side cables 201b, 201c may break during a high tension event. After breaking, there is uncontrolled movement of the end effector 200 due to the high tension in the intact high side cable 201b or 201c, for example, breaking to one side, which continues to actuate the corresponding motor 152b or 152c until the commanded position is reached. The present disclosure provides a system and method configured to use sensor signals from motors 152a-d to predict and / or detect when any of cables 201a-d, particularly high side cables 201b and 201c, will disconnect.

[0056] refer to Fig. 9, the method for predicting or detecting a break in the high side cables 201b and 201c is implemented as software instructions that can be executed by any suitable processor of the robotic system 10 (such as the IDU controller 41d, the main controller 21a, etc.). At step 300, the motor position and torque of each motor 152a-d are provided to the controller 41d. In particular, the torque sensor 155 provides torque measurement, and the position sensor 157 provides the angular rotational position of each of the motors 152a-d. The controller 41d then uses the angular position to determine the position of the cables 201a-d and the end effector 200. Steps 301-307 for gripper position or angle verification and steps 302-308 for torque verification can be performed in parallel. In particular, torque and gripper position are used to detect and / or predict cable breakage.

[0057] At step 301, the jaw position, such as the angle between the jaws 120 and 122, is calculated based on the angular position data provided by the position sensor 157 of the motor 152a-d. Then, at step 303, the calculated jaw angle is processed by taking the derivative of the calculated jaw angle, and then the derivative of the calculated jaw angle is filtered using a median filter at step 305. Then, at step 307, the resulting filtered derivative of the jaw angle is compared to a first torque threshold, and a true value is output if the processed jaw angle value is less than the threshold, otherwise the controller 41d outputs a false value.

[0058] The method also performs torque verification at steps 302-308. At step 302, the torques of the motors 152b and 152c controlling the high-side cables 201b and 201c are summed to obtain a combined torque value. Then, at step 304, the resulting sum of motor torques is processed by taking a derivative of the resulting sum of motor torques, and then the derivative of the resulting sum of motor torques is filtered using a median filter at step 306. Then, at step 308, the resulting filtered derivative of the summed motor torques is compared to a first torque threshold, and a true value is output if the processed torque sum value is greater than the threshold, otherwise the controller 41d outputs a false value.

[0059] At step 310, the controller receives as input the outputs of the torque and jaw position determinations from steps 307 and 308 and performs an AND operation on these inputs. Thus, if both values ​​are true, i.e., the torque value is above the torque threshold and the jaw angle value is below the angle threshold, the method proceeds to step 312. If the output of step 310 is no (i.e., one or both of the values ​​of steps 307 and 308 are false), the method still proceeds to step 312.

[0060] Step 313 provides another layer of detection, receiving input from alternative branch verification steps 313 and 314. At step 313, the controller 41d receives the unprocessed jaw angle from step 301 and compares the jaw angle to the second jaw angle threshold. If the jaw angle is less than the second jaw angle threshold, the controller 41d outputs a true value, otherwise the controller 41d will output a false value.

[0061] At step 314, the controller 41d receives the processed motor torque value (i.e., the filtered derivative of the summed torque) from step 306 and compares the torque value to a second torque threshold. If the torque value is greater than the second torque threshold, the controller 41d outputs a true value, otherwise the controller 41d outputs a false value.

[0062] Thus, at step 312, the controller 41d compares the three inputs from steps 310, 313, 314 and performs an OR operation on these inputs. Thus, if any of these inputs is true, a cable break is detected. At step 316, the controller 41d reports the detected cable break to the controller 21a, which outputs the cable break of one of the high-side cables 201b and 201c on the GUI of one or more of the displays 23, 32, 34. In addition, the controller 21a may also take corrective action to control the instrument 50, which may include adjusting the motor, for example, reducing torque output or speed, or shutting off and stopping the motor coupled to the broken cable, etc., overriding the user input in the event that the user input requested through the handle controllers 38a and 38b does not control the instrument, and / or automatically retracting the instrument 50 from the patient.

[0063] The present disclosure also provides a method for detecting a disconnection in the low side cables 201a and 201d. The IDU controller 41d executes a minimum torque algorithm that maintains tension in the cables 201a-d. Since there is no tension in one of the low side cables when one of the low side cables 201a and 201d is disconnected, the minimum torque algorithm keeps increasing the command torque to remove the slack in the broken cable. This results in unexpectedly high readings from the torque sensors 155 of the motors 152b and 152c that actuate the high side cables 201b and 201c.

[0064] As described above, the low side cables 201a and 201d are primarily used during the opening of the jaws 120 and 122. Therefore, when one of the low side cables 201a and 201d is disconnected, the opening of the jaws 120 and 122 may not occur. Therefore, even if the IDU controller 41d can indicate that the jaws 120 and 122 are fully open based on the position feedback from the corresponding position sensors 157 of the motors 152a-d, the jaws 120 and 122 remain fully closed. Therefore, when a new closing event is commanded, the IDU controller 41d applies an overtravel load to the fully closed blade. This results in an even higher torque sensor reading from the torque sensor 155 of the motors 152b and 152c that actuate the high side cables 201b and 201c. Therefore, the breakage of the low side cables 201a and 201d is detected by using the torque of the high side motors 152b and 152c during the subsequent closing event.

[0065] Therefore, the breakage of low side cables 201a and 201d is reflected in the torque sensor reading of the torque sensor 155 from the high side motors 152b and 152c that actuate high side cables 201b and 201c. The sum of the torque sensor readings of the motors 152b and 152c for actuating high side cables 201b and 201c shows an increase in amplitude after the opening event of the clamping jaws 120 and 122 and does not decrease to its expected range. Therefore, the breakage of low side cables 201a and 201d can be detected based on the unexpectedly high torque readings in the high side cables 201b and 201c. The torque sensor readings of the motors 152b and 152c for actuating high side cables 201b and 201c are usually below the preset torque threshold (which can be about 0.35Nm), except during the closing event and after each closing event until the interval in which the unsaturated clamping jaw position signal is stable.

[0066] refer to Fig.10 , the method for predicting or detecting the breakage of the low-side cables 201a and 201d is implemented as software instructions that can be executed by any suitable processor of the robot system 10 (such as the IDU controller 41d, the main controller 21a, etc.). At step 400, the motor position and torque of each motor 152a-d are provided to the controller 41d. In particular, the torque sensor 155 provides torque measurement, and the position sensor 157 provides the angular rotational position of each of the motors 152a-d. The controller 41d then uses the angular position to determine the position of the cables 201a-d and even the position of the end effector 200. Steps 401 and 402 for torque verification and steps 403-407 for jaw position or angle verification can be performed in parallel. In particular, torque and jaw position are used to detect and / or predict cable breakage.

[0067] The method performs torque verification at steps 401 and 402. At step 401, the torques of the motors 152b and 152c controlling the high-side cables 201b and 201c are summed to obtain a combined torque value. At step 402, the sum of the motor torques obtained is compared with a first combined torque threshold, and if the processed torque sum value exceeds the threshold, a true value is output, otherwise the controller 41d outputs a false value.

[0068] At step 403, the jaw position, such as the angle between the jaws 120 and 122, is calculated based on the angular position data provided by the position sensor 157 of the motor 152a-d. The calculated jaw angle is then processed by taking the derivative of the calculated jaw angle. The derivative of the expected jaw position is used in the low-side cable break detection algorithm to identify a closing event.

[0069] At step 404a, a first moving average filter is applied to the derivative of the jaw angle, i.e., position. At steps 404b-e, multiple different moving average filters are applied to the output of the first moving average filter from step 404a. Multiple moving average filters of the derivative of the desired jaw position with different (i.e., unique) window sizes are performed at steps 404b-e and used to process the interval after each closing event, in which a high torque sensor reading is expected. The calculated moving averages from steps 404a-e are scaled at steps 405a-e, respectively. At step 406, a minimum function is performed on the scaled moving averages from steps 405a-e to identify the minimum value from the group. The minimum moving average of the derivatives is then compared to the jaw position derivative threshold at step 407. If the minimum moving average of the derivative exceeds the threshold, the IDU controller 41d outputs a true value, otherwise the controller 41d outputs a false value.

[0070] At step 408, the IDU controller 41d determines whether the output from the comparison of steps 402 and 407 is true. If both are true, then at step 410, the IDU controller 41d reports the detected cable break to the controller 21a, which outputs the cable break of one of the low-side cables 201a and 201d on the GUI of one or more of the displays 23, 32, 34. In addition, the controller 21a may also take corrective action to control the instrument 50, which may include adjusting the motor, for example, reducing torque output or speed, or shutting off and stopping the motor coupled to the broken cable, etc., overriding the user input requested through the handle controllers 38a and 38b if the instrument is not controlled, and / or automatically retracting the instrument 50 from the patient. If one or both are false, the method returns to step 400 to continue monitoring the break of the low-side cables 201a and 201d.

[0071] It should be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be interpreted as limiting, but merely as an illustration of various embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the appended claims.

Claims

1. A surgical robot system, comprising: An instrument drive unit, the instrument drive unit comprising: a first high-side motor having a first high-side torque sensor for measuring a torque of the first high-side motor and a first high-side position sensor for measuring a position of the first high-side motor; a first low-side motor having a first low-side torque sensor for measuring a torque of the first low-side motor and a first low-side position sensor for measuring a position of the first low-side motor; a second high-side motor having a second high-side torque sensor for measuring torque of the second high-side motor and a second high-side position sensor for measuring a position of the second high-side motor; and a second low-side motor having a second low-side torque sensor for measuring torque of the second low-side motor and a second low-side position sensor for measuring a position of the second low-side motor; An instrument, the instrument being coupled to the instrument drive unit, the instrument comprising: an end effector having a first jaw and a second jaw each movable between an open position and a closed position; a first high-side cable coupled to the first jaw and actuatable by the first high-side motor to move the first jaw toward the closed position; a first low-side cable coupled to the first jaw and actuatable by the first low-side motor to move the first jaw toward the open position; a second high-side cable coupled to the second jaw and actuatable by the second high-side motor to move the second jaw toward the closed position; and a second low-side cable coupled to the second jaw and actuatable by the second low-side motor to move the second jaw toward the open position; and A controller, the controller: calculating an angle between the first jaw and the second jaw based on a position of at least one of the motors; calculating a combined torque of the first high-side motor and the second high-side motor; determining whether at least one of the first low-side cable or the second low-side cable is broken based on an angle between the first jaw and the second jaw and the combined torque; and An alarm is output based on determining that at least one of the first low side cable or the second low side cable is broken.

2. The surgical robot system according to claim 1, wherein: The controller further calculates a derivative of an angle between the first jaw and the second jaw.

3. The surgical robot system according to claim 2, wherein: The controller further calculates a first moving average of a derivative of an angle between the first jaw and the second jaw and a plurality of subsequent moving averages of the first moving average.

4. The surgical robot system according to claim 3, wherein: The controller further calculates a scaling value for the first moving average and each of the plurality of subsequent moving averages.

5. The surgical robot system according to claim 3, wherein: Each moving average of the plurality of subsequent moving averages has a unique window size.

6. The surgical robot system according to claim 3, wherein: The controller identifies a minimum moving average of the derivatives from the first moving average and each of the plurality of subsequent moving averages.

7. The surgical robot system according to claim 6, wherein: The controller compares a minimum moving average of the derivatives to a threshold derivative of an angle between the first jaw and the second jaw.

8. The surgical robot system according to claim 7, wherein: The controller determines whether at least one of the first low side cable or the second low side cable is broken based on the angle between the first jaw and the second jaw exceeding an angle threshold and a minimum moving average of the derivative exceeding a threshold derivative of the angle between the first jaw and the second jaw.

9. A surgical robot system, comprising: an instrument drive unit, the instrument drive unit comprising a plurality of motors, the plurality of motors comprising a first pair of motors and a second pair of motors, wherein each motor of the plurality of motors comprises a torque sensor for measuring motor torque and a position sensor for measuring angular position; An instrument, the instrument being coupled to the instrument drive unit, the instrument comprising: an end effector having a first jaw and a second jaw each movable between an open position and a closed position; a first pair of cables, each of the first pair of cables being actuated by one of the first pair of motors to move the first jaw and the second jaw toward the closed position, wherein one of the first pair of cables is coupled to the first jaw and the other of the first pair of cables is coupled to the second jaw; and a second pair of cables, each of the second pair of cables being actuated by one of the second pair of motors to move the first jaw and the second jaw toward the open position, wherein one of the second pair of cables is coupled to the first jaw and the other of the second pair of cables is coupled to the second jaw; and A controller, the controller: calculating an angle between the first jaw and the second jaw based on an angular position of at least one motor of the plurality of motors; calculating a combined torque of the first pair of motors; determining whether at least one cable of the second pair of cables is broken based on the angle between the first jaw and the second jaw and the combined torque; and An alarm is output based on determining that at least one of the second pair of cables is broken.

10. The surgical robot system according to claim 9, wherein: The controller further calculates a derivative of an angle between the first jaw and the second jaw.

11. The surgical robot system according to claim 10, wherein: The controller further calculates a first moving average of a derivative of an angle between the first jaw and the second jaw and a plurality of subsequent moving averages of the first moving average.

12. The surgical robot system according to claim 11, wherein: The controller further calculates a scaling value for the first moving average and each of the plurality of subsequent moving averages.

13. The surgical robot system according to claim 11, wherein: Each moving average of the plurality of subsequent moving averages has a unique window size.

14. The surgical robot system according to claim 11, wherein: The controller identifies a minimum moving average of the derivatives from the first moving average and each of the plurality of subsequent moving averages.

15. The surgical robot system according to claim 14, wherein: The controller compares a minimum moving average of the derivatives to a threshold derivative of an angle between the first jaw and the second jaw.

16. The surgical robot system according to claim 15, wherein: The controller determines whether at least one of the second pair of cables is broken based on a combined torque of the first pair of motors exceeding a torque threshold and a minimum moving average of the derivative exceeding a threshold derivative of an angle between the first jaw and the second jaw.

17. A method for controlling a surgical robotic instrument, the method comprising: moving a first jaw and a second jaw apart, wherein the first jaw is coupled to a first low-side cable actuatable by a first low-side motor and the second jaw is coupled to a second low-side cable actuatable by a second low-side motor; approximating the first jaw and the second jaw, wherein the first jaw is coupled to a first high-side cable actuatable by a first high-side motor and the second jaw is coupled to a second high-side cable actuatable by a second high-side motor; measuring a torque of each of the first and second high-side motors and the first and second low-side motors; measuring an angular position of each of the first and second high-side motors and the first and second low-side motors; calculating, at a controller, an angle between the first jaw and the second jaw based on an angular position of at least one of the first high-side motor, the second high-side motor, the first low-side motor, or the second low-side motor; calculating, at the controller, a combined torque of the first high-side motor and the second high-side motor; determining, at the controller, whether at least one of the first low-side cable or the second low-side cable is broken based on an angle between the first jaw and the second jaw and the combined torque; and An alarm is output based on determining that at least one of the first low side cable or the second low side cable is broken.

18. The method according to claim 17, further comprising: calculating, at the controller, a derivative of an angle between the first jaw and the second jaw; as well as A first moving average of a derivative of an angle between the first jaw and the second jaw and a plurality of subsequent moving averages of the first moving average are calculated at the controller.

19. The method according to claim 18, further comprising: identifying, at the controller, a minimum moving average of the derivatives from the first moving average and each of the plurality of subsequent moving averages; as well as A minimum moving average of the derivatives is compared at the controller to a threshold derivative of an angle between the first jaw and the second jaw.

20. The method according to claim 19, wherein: Determining whether at least one of the first low side cable or the second low side cable is broken is based on the combined torque exceeding a torque threshold and a minimum moving average of the derivative exceeding a threshold derivative of an angle between the first jaw and the second jaw.

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