Robotic surgical systems, surgical assistance robots, and robotic surgical methods

Abstract

To provide a robot surgery system capable of achieving appropriate gripping force while suppressing complication of a structure around an elongated element.SOLUTION: A robot surgery system 100 comprises: a surgical instrument 40 having a pair of jaw members 43a, 43b; an operation handle 11; and a patient side device 20 including a robot arm 21a to which the surgical instrument 40 is attached, and which includes drive units 212a, 212b for driving driven members 44c, 44d, and a controller 24 for driving the drive units 212a, 212b on the basis of a jaw command open angle with respect to an open angle θ of the pair of jaw members 43a, 43b associated with input to the operation handle 11. When it is determined that current values of the drive units 212a, 212b exceed a predetermined threshold during a closing operation of the pair of jaw members 43a, 43b, the controller 24 drives the drive units 212a, 212b in a restriction mode in which the magnitude of the jaw command open angle is restricted.SELECTED DRAWING: Figure 13

Description

Technical Field

[0001] The present invention relates to a robotic surgical system, a surgical support robot, and a robotic surgical method.

Background Art

[0002] Conventionally, robotic surgical systems including a surgical instrument having a pair of jaw members are known (see, for example, Patent Document 1).

[0003] The above Patent Document 1 discloses a surgical support robot system (robotic surgical system) including a robot control system capable of controlling the jaw angle and gripping force of a pair of jaws by using a surgical tool having a pair of jaws (jaw members), a position control unit and a gripping force control unit. In this surgical support robot system, a load cell or a torque sensor is provided on the cable for the gripping force control unit to acquire the tension of the cable for driving the jaws. Then, a desired gripping force is achieved by the gripping force control unit based on the cable tension measured by the load cell or torque sensor provided on the cable.

Prior Art Literature

Patent Literature

[0004]

Patent Document 1

Summary of Invention

Problem to be Solved by the Invention

[0005] However, in the surgical support robot system described in the above Patent Document 1, although a desired gripping force can be achieved, it is necessary to provide a load cell or a torque sensor on the cable for the gripping force control unit to acquire the cable tension of the surgical tool. In this case, there is a problem that the structure around the cable (elongated element) becomes complicated.

[0006] This invention was made to solve the above-mentioned problems, and one objective of this invention is to provide a robotic surgical system, a surgical support robot, and a robotic surgical method that can achieve appropriate gripping force while suppressing the complexity of the structure around elongated elements. [Means for solving the problem]

[0007] To achieve the above objective, a robotic surgical system according to the first aspect of this invention comprises: a surgical instrument having a pair of jaw members that open and close to grasp an object by driving an elongated element connected to a driven member; an input device to which commands for opening, closing and tightening the pair of jaw members are input; a robotic arm to which the surgical instrument is attached and which includes a current-driven drive unit that drives the driven member; and a control device that drives the drive unit based on jaw operation commands relating to the opening angle and tightening force of the pair of jaw members corresponding to the commands input to the input device, wherein the control device determines whether the current value of the drive unit exceeds a predetermined threshold during the closing operation of the pair of jaw members, and if it determines that the current value of the drive unit exceeds the predetermined threshold, it drives the drive unit in a restricted mode in which the magnitude of the jaw operation command is limited. In restricted mode, the minimum value of the jaw movement command is limited to a value greater than the initial value which is the minimum value of the jaw movement command when not in restricted mode. ru.

[0008] In the robotic surgical system according to the first aspect of this invention, as described above, control DeviceThe system is configured to determine whether the current value of the drive unit exceeds a predetermined threshold during the closing operation of a pair of jaw members. If it is determined that the current value of the drive unit exceeds the predetermined threshold, the drive unit is driven in a restricted mode in which the jaw command opening angle is limited. As a result, if it is determined that the current value of the drive unit exceeds a predetermined threshold during the closing operation of a pair of jaw members, the drive unit is driven in a restricted mode in which the jaw command opening angle is limited, thereby suppressing the generation of excessive gripping force. As a result, an appropriate gripping force can be achieved. Furthermore, since it is not necessary to provide load cells or torque sensors on elongated elements such as cables, wires, and rods in order to limit the jaw command opening angle, the complexity of the structure around the elongated elements can be suppressed compared to cases where load cells or torque sensors are provided on elongated elements. As a result, a robotic surgical system can be provided that can achieve an appropriate gripping force while suppressing the complexity of the structure around elongated elements.

[0009] A robotic surgical method according to the second aspect of this invention comprises a surgical instrument having a pair of jaw members that open and close to grasp an object by driving an elongated element connected to a driven member, and an input device into which commands to open, close and close and tighten the pair of jaw members are input. and a remote control device including a first control unit The robot arm includes a surgical instrument attachment and a current-driven drive unit that drives the driven component. and including a second control unit A robotic surgical method for a robotic surgical system comprising a surgical robot, wherein jaw operation commands relating to the opening angle and tightening force of a pair of jaw members corresponding to commands input to an input device. to the 1. Steps acquired by the control unit and , the The second control unit includes the step of driving a drive unit based on a jaw operation command, wherein the second control unit determines whether the current value of the drive unit exceeds a predetermined threshold during the closing operation of a pair of jaw members, and if it determines that the current value of the drive unit exceeds the predetermined threshold, the second control unit drives the drive unit in a restricted mode in which the magnitude of the jaw operation command is limited. In restricted mode, the minimum value of the jaw movement command is limited to a value greater than the initial value, which is the minimum value of the jaw movement command when not in restricted mode. .

[0010] In the robotic surgical method according to the second aspect of this invention, as described above, the step of driving the drive unit is configured to include a step of determining whether the current value of the drive unit exceeds a predetermined threshold during the closing operation of a pair of jaw members, and if it is determined that the current value of the drive unit exceeds the predetermined threshold, driving the drive unit in a restricted mode in which the size of the jaw command opening angle is limited. As a result, if it is determined that the current value of the drive unit exceeds a predetermined threshold during the closing operation of a pair of jaw members, the drive unit is driven in a restricted mode in which the size of the jaw command opening angle is limited, thereby suppressing the generation of excessive gripping force. As a result, an appropriate gripping force can be achieved. Furthermore, since it is not necessary to provide load cells or torque sensors on elongated elements such as cables, wires, and rods in order to limit the size of the jaw command opening angle, the complexity of the structure around the elongated elements can be suppressed compared to the case where load cells or torque sensors are provided around the elongated elements. As a result, a robotic surgical method can be provided that can achieve an appropriate gripping force while suppressing the complexity of the structure around the elongated elements.

[0011] A surgical assistance robot according to a third aspect of this invention comprises a surgical instrument having a pair of jaw members that open and close to grasp an object by driving an elongated element connected to a driven member; a robot arm to which the surgical instrument is attached and which includes a current-driven drive unit that drives the driven member; and a control unit that drives the drive unit based on jaw operation commands relating to the opening angle and closing force of the pair of jaw members, wherein the control unit determines whether the current value of the drive unit exceeds a predetermined threshold during the closing operation of the pair of jaw members, and if it determines that the current value of the drive unit exceeds the predetermined threshold, it drives the drive unit in a restricted mode in which the magnitude of the jaw operation command is limited. In restricted mode, the minimum value of the jaw movement command is limited to a value greater than the initial value which is the minimum value of the jaw movement command when not in restricted mode. ru.

[0012] In the surgical assistance robot according to the third aspect of this invention, as described above, the control unit is configured to determine whether the current value of the drive unit exceeds a predetermined threshold during the closing operation of a pair of jaw members, and if it is determined that the current value of the drive unit exceeds the predetermined threshold, it drives the drive unit in a restricted mode in which the size of the jaw command opening angle is limited. As a result, if it is determined that the current value of the drive unit exceeds a predetermined threshold during the closing operation of a pair of jaw members, the drive unit is driven in a restricted mode in which the size of the jaw command opening angle is limited, thereby suppressing the generation of excessive gripping force. As a result, an appropriate gripping force can be achieved. Furthermore, since it is not necessary to provide load cells or torque sensors on elongated elements such as cables, wires, and rods in order to limit the size of the jaw command opening angle, the complexity of the structure around the elongated elements can be suppressed compared to the case where load cells or torque sensors are provided on the elongated elements. As a result, it is possible to provide a surgical assistance robot that can achieve an appropriate gripping force while suppressing the complexity of the structure around the elongated elements. [Effects of the Invention]

[0013] According to the present invention, as described above, it is possible to achieve an appropriate gripping force while suppressing the complexity of the structure around the elongated element. [Brief explanation of the drawing]

[0014] [Figure 1] This figure shows the configuration of the robotic surgical system according to the first embodiment. [Figure 2] This is a block diagram showing the control configuration of a robotic surgical system according to the first embodiment. [Figure 3] This figure shows the configuration of the operating handle according to the first embodiment. [Figure 4] This is a perspective view showing a robot arm according to the first embodiment with surgical instruments attached via an adapter. [Figure 5] This is an exploded perspective view showing a state in which surgical instruments are attached to a robot arm according to the first embodiment via an adapter. [Figure 6] It is a perspective view of the surgical instrument according to the first embodiment as viewed from below. [Figure 7] It is a perspective view showing a state where a cover portion is removed from a base body of the surgical instrument according to the first embodiment. [Figure 8] It is a plan view showing a state where a cover portion is removed from a base body of the surgical instrument according to the first embodiment. [Figure 9] It is a perspective view showing an end effector of the surgical instrument according to the first embodiment. [Figure 10] It is an exploded perspective view showing a pair of jaw members and a pulley according to the first embodiment. [Figure 11] It is a diagram showing a pair of jaw members, a drive unit, and a controller according to the first embodiment. [Figure 12] It is a graph showing the relationship between a grip opening angle and a commanded jaw opening angle in the case where there is no restriction according to the first embodiment. [Figure 13] It is a graph showing the relationship between a grip opening angle and a commanded jaw opening angle in the restriction mode according to the first embodiment. [Figure 14] It is a diagram for explaining gripping of an object by the pair of jaw members according to the first embodiment. [Figure 15] It is a cross-sectional view showing an elongated element, a pulley portion, and a falling-off prevention portion according to the first embodiment. [Figure 16] It is a flowchart showing control processing for starting the restriction mode in a state where an input device according to the first embodiment is being operated. [Figure 17] It is a flowchart showing control processing for canceling the restriction mode in a state where an input device according to the first embodiment is being operated. [Figure 18] It is a flowchart showing control processing for starting the restriction mode in a state where an input device according to the first embodiment is not operated. [Figure 19] It is a diagram showing a pair of jaw members, a drive unit, and a controller according to the second embodiment. [Figure 20]This graph illustrates the restriction mode according to the second embodiment. [Figure 21] This graph shows the relationship between the detection angle and the minimum commanded jaw opening angle according to the second embodiment. [Modes for carrying out the invention]

[0015] Hereinafter, embodiments of the present invention will be described based on the drawings.

[0016] [First Embodiment] (Configuration of the robotic surgical system) Referring to Figures 1 and 2, the configuration of a robotic surgical system 100 according to one embodiment will be described.

[0017] As shown in Figure 1, the robotic surgical system 100 comprises a remote control device 10 and a patient-side device 20. The remote control device 10 is provided for remotely controlling medical equipment installed on the patient-side device 20. When an operation command to be performed by the patient-side device 20 is input to the remote control device 10 by the operator (surgeon), the remote control device 10 transmits the operation command to the patient-side device 20 via the controller 24. The patient-side device 20 then operates medical instruments such as the surgical instrument 40 attached to the robot arm 21a and the endoscope 50 attached to the robot arm 21b in response to the operation command transmitted from the remote control device 10. This enables minimally invasive surgery. The patient-side device 20 is an example of a surgical robot and surgical assistance robot. The controller 24 is an example of a control unit.

[0018] The patient-side device 20 constitutes an interface for performing surgery on patient P. The patient-side device 20 is positioned beside the operating table 30 on which patient P lies. The patient-side device 20 has multiple robotic arms 21a, 21b, one of which has an endoscope 50 attached, and the other robotic arms 21a have surgical instruments 40 attached. Each robotic arm 21a, 21b is commonly supported by an arm base 22. The multiple robotic arms 21a, 21b have multiple joints, and each joint is provided with a drive unit including a servo motor and a position detector such as an encoder. The robotic arms 21a, 21b are configured to be controlled by drive signals provided via a controller 24 so that the medical instruments attached to the robotic arms 21a, 21b perform desired movements.

[0019] The arm base 22 is supported by a positioner 23 placed on the floor of the operating room. The positioner 23 includes a vertical articulated robot. The positioner 23 is configured to move the position of the arm base 22 in three dimensions. The controller 24 is a control circuit having a processing unit such as a CPU and memory such as ROM and RAM.

[0020] A surgical instrument 40, which serves as a medical device, is detachably attached to the tip of the robotic arm 21a. The surgical instrument 40 comprises a housing 41 (see Figure 4) attached to the robotic arm 21a, an elongated shaft 42 (see Figure 4), and an end effector 43 (see Figure 4) provided at the tip (distal end) of the shaft 42. Examples of end effectors 43 include, but are not limited to, grasping forceps, scissors, hooks, high-frequency knives, snare wires, clamps, staplers, clip applicators, electrosurgical units, and needles; various treatment instruments can be applied. In surgery using the patient-side device 20, the robotic arm 21a introduces the surgical instrument 40 into the patient P's body via a cannula (trocker) placed on the patient P's body surface. The end effector 43 of the surgical instrument 40 is then positioned near the surgical site.

[0021] An endoscope 50, used as a medical instrument, is detachably attached to the tip of the robotic arm 21b. The endoscope 50 is used to photograph the inside of the patient P's body cavity, and the captured images are output to the remote control device 10. A 3D endoscope or a 2D endoscope capable of capturing three-dimensional images is used as the endoscope 50. In surgery using the patient-side device 20, the robotic arm 21b introduces the endoscope 50 into the patient P's body via a trocker placed on the patient P's body surface. The endoscope 50 is then positioned near the surgical site.

[0022] The remote control device 10 constitutes an interface with the operator. The remote control device 10 is a device for the operator to operate medical instruments attached to the robot arm 21a. Specifically, the remote control device 10 is configured to transmit operation commands to be performed by the surgical instruments 40 and endoscope 50, which are input by the operator, to the patient-side device 20 via the controller 24. The remote control device 10 is installed, for example, next to the operating table 30 so that the operator can clearly see the patient P while operating the master. It is also possible to install the remote control device 10 in a room separate from the operating room where the operating table 30 is installed, for example, by transmitting operation commands wirelessly.

[0023] The actions to be performed by the surgical instrument 40 are the actions (a series of positions and postures) of the surgical instrument 40 and the actions realized by the individual functions of the surgical instrument 40. For example, if the surgical instrument 40 is a grasping forceps, the actions to be performed by the surgical instrument 40 are the roll rotation position and pitch rotation position of the wrist of the end effector 43 and the opening and closing of the jaws. If the surgical instrument 40 is a high-frequency knife, the actions to be performed by the surgical instrument 40 may be the vibration action of the high-frequency knife, specifically the supply of current to the high-frequency knife. If the surgical instrument 40 is a snare wire, the actions to be performed by the surgical instrument 40 may be the binding action and the release action of the binding state. It may also be the action of burning the surgical site by supplying current to the bipolar or monopolar.

[0024] The actions to be performed by the endoscope 50 include, for example, setting the position and orientation of the tip of the endoscope 50, or the zoom magnification.

[0025] As shown in Figures 1 and 2, the remote control device 10 includes an operating handle 11, an operating pedal unit 12, a display unit 13, and a control device 14. The operating handle 11 is an example of an input device.

[0026] The operating handle 11 is provided for remotely operating medical instruments attached to the robotic arm 21a. Specifically, the operating handle 11 accepts input from an operator for controlling medical instruments (surgical instruments 40, endoscope 50). There are two operating handles 11, arranged horizontally. That is, one of the two operating handles 11 is operated by the operator's right hand, and the other operating handle 11 is operated by the operator's left hand.

[0027] Furthermore, the operating handle 11 is positioned to extend from the rear side of the remote control device 10 toward the front side. The operating handle 11 is configured to be movable within a predetermined three-dimensional operating area. That is, the operating handle 11 is configured to be movable in the vertical, horizontal, forward, backward, and rotational directions.

[0028] As shown in Figure 3, the operating handle 11 is a hand controller operated by the operator. The operating handle 11 has a support member 11a, a pair of grip members 11b provided on both sides of the support member 11a, and finger insertion parts 11c provided on each of the pair of grip members 11b. The operator operates the operating handle 11 by inserting their fingers (such as the thumb and middle finger) into the pair of finger insertion parts 11c. That is, the base ends of the pair of grip members 11b are rotatably connected to the support member 11a, and by increasing or decreasing the opening angle of the pair of grip members 11b, the opening angle of the pair of jaw members 43a, 43b, which will be described later, is changed. Commands to open and close the pair of jaw members 43a, 43b are input to the operating handle 11. The opening angle of the pair of grip members 11b is detected, for example, by a sensor. For example, the operating handle 11 has a Hall sensor on the support member 11a and magnets on one or both of the pair of grip members 11b, thereby detecting the opening angle of the pair of grip members 11b. Alternatively, the operating handle 11 has a Hall sensor on one of the pair of grip members 11b and a magnet on the other of the pair of grip members 11b, thereby detecting the opening angle of the pair of grip members 11b. The detected signal regarding the opening angle of the pair of grip members 11b is converted into a jaw command opening angle relating to the opening angle θ of the pair of jaw members 43a and 43b by the control unit 141 or controller 24, which will be described later.

[0029] As shown in Figure 1, the remote control device 10 and the patient-side device 20 constitute a master-slave system for controlling the movements of robot arms 21a and 21b. That is, the operating handle 11 constitutes the master-side operating unit in the master-slave system, and robot arms 21a and 21b, to which medical instruments are attached, constitute the slave-side operating unit. When the operator operates the operating handle 11, the movement of robot arm 21a or robot arm 21b is controlled so that the tip of robot arm 21a (end effector 43 of surgical instrument 40) or the tip of robot arm 21b (endoscope 50) traces the movement of the operating handle 11.

[0030] Furthermore, the patient-side device 20 is configured to control the movement of the robot arm 21a according to the set motion magnification. For example, when the motion magnification is set to 1 / 2x, the end effector 43 of the surgical instrument 40 is controlled to move a distance equal to half the movement distance of the operating handle 11. This allows for precise and detailed surgical procedures to be performed.

[0031] The operating pedal section 12 includes multiple pedals for performing functions related to the medical device. These multiple pedals include a coagulation pedal, a cutting pedal, a camera pedal, and a clutch pedal. The multiple pedals are operated by the operator's feet.

[0032] The coagulation pedal allows the surgical instrument 40 to coagulate the surgical site. Specifically, when the coagulation pedal is operated, a coagulation voltage is applied to the surgical instrument 40, causing the surgical site to coagulate. The cutting pedal allows the surgical instrument 40 to cut the surgical site. Specifically, when the cutting pedal is operated, a cutting voltage is applied to the surgical instrument 40, causing the surgical site to cut.

[0033] The camera pedal is used to control the position and orientation of the endoscope 50, which images the inside of the body cavity. Specifically, the camera pedal enables the operation of the endoscope 50 by the operating handle 11. In other words, while the camera pedal is pressed, the position and orientation of the endoscope 50 can be controlled by the operating handle 11. For example, the endoscope 50 is operated using both the left and right operating handles 11. Specifically, the endoscope 50 is rotated by rotating the left and right operating handles 11 around their midpoint. Also, by pushing both the left and right operating handles 11 inward, the endoscope 50 moves inward. Also, by pulling both the left and right operating handles 11 outward, the endoscope 50 moves forward. Also, by moving both the left and right operating handles 11 up, down, left, and right, the endoscope 50 moves up, down, left, and right.

[0034] The clutch pedal is used to temporarily disconnect the operating connection between the robot arm 21a and the operating handle 11, thereby stopping the operation of the surgical instrument 40. Specifically, while the clutch pedal is being operated, the robot arm 21a of the patient-side device 20 will not move even if the operating handle 11 is operated. For example, when the operating handle 11 moves to near the end of its movable range, operating the clutch pedal temporarily disconnects the operating connection and returns the operating handle 11 to near the center position. When the operation of the clutch pedal is stopped, the robot arm 21a and the operating handle 11 are reconnected, and operation of the operating handle 11 can be resumed near the center.

[0035] The display unit 13 is capable of displaying images captured by the endoscope 50. The display unit 13 consists of a scope-type display unit or a non-scope-type display unit (Figure 1 shows a scope-type display unit). A scope-type display unit is, for example, a display unit that you look into. A non-scope-type display unit is a concept that includes an open-type display unit with a flat screen that is not the type you look into, such as the display of a normal personal computer.

[0036] When a scope-type display unit is installed, a 3D image captured by the endoscope 50 attached to the robot arm 21b of the patient-side device 20 is displayed. Even when a non-scope-type display unit is installed, a 3D image captured by the endoscope 50 provided on the patient-side device 20 is displayed. In addition, when a non-scope-type display unit is installed, a 2D image captured by the endoscope 50 provided on the patient-side device 20 may be displayed.

[0037] Furthermore, the display unit 13 is equipped with a head sensor 13a for detecting whether or not the operating handle 11 is being operated by the operator. Specifically, the head sensor 13a is configured to detect the presence of the operator's head. In other words, the head sensor 13a is configured to detect whether or not the operator is looking into the display unit 13 and operating the operating handle 11.

[0038] As shown in Figure 2, the control device 14 includes, for example, a control unit 141 having an arithmetic unit such as a CPU, a storage unit 142 having memory such as ROM and RAM, and an image control unit 143. The control device 14 may be composed of a single control device that provides centralized control, or it may be composed of multiple control devices that cooperate with each other to provide distributed control. The control unit 141 determines, according to the switching state of the operating pedal unit 12, whether the operation mode command input by the operating handle 11 is an operation mode command that should be executed by the robot arm 21a or an operation mode command that should be executed by the endoscope 50. When the control unit 141 determines that the operation mode command input to the operating handle 11 is an operation mode command that should be executed by the surgical instrument 40, it transmits the operation mode command to the robot arm 21a via the controller 24. As a result, the controller 24 drives the robot arm 21a, and this drive controls the operation of the surgical instrument 40 attached to the robot arm 21a.

[0039] Furthermore, when the control unit 141 determines that the operation command input to the operating handle 11 is an operation command that should be executed by the endoscope 50, it transmits the operation command to the robot arm 21b via the controller 24. This drives the robot arm 21b, and this drive controls the operation of the endoscope 50 attached to the robot arm 21b.

[0040] For example, the memory unit 142 stores control programs corresponding to the type of surgical instrument 40, and the control unit 141 reads these control programs according to the type of surgical instrument 40 that is attached, thereby enabling the operation commands of the operating handle 11 and / or operating pedal unit 12 of the remote control device 10 to operate in a manner suitable for the individual surgical instrument 40.

[0041] The image control unit 143 transmits the image acquired by the endoscope 50 to the display unit 13. The image control unit 143 performs image processing and modification as needed.

[0042] (Configuration of surgical instruments, adapters, drapes, and robotic arms) Next, the configuration of the surgical instrument 40, adapter 60, drape 70, and robot arm 21a will be described with reference to Figures 4 to 6.

[0043] Here, the direction in which the surgical instrument 40 extends (the direction in which the shaft 42 extends) is defined as the Y direction, the direction toward the tip of the surgical instrument 40 (the direction toward the end effector 43) within the Y direction is defined as the Y1 direction, and the direction opposite to the Y1 direction is defined as the Y2 direction. The direction in which the surgical instrument 40 and the adapter 60 are adjacent is defined as the Z direction, the direction toward the surgical instrument 40 within the Z direction is defined as the Z1 direction, and the direction opposite to the Z1 direction is defined as the Z2 direction. Furthermore, the direction perpendicular to the Y and Z directions is defined as the X direction, one side of the X direction is defined as the X1 direction, and the other side of the X direction is defined as the X2 direction.

[0044] As shown in Figures 4 and 5, the surgical instrument 40 is detachably attached to the robotic arm 21a of the robotic surgical system 100. Specifically, the surgical instrument 40 is detachably attached to the robotic arm 21a via an adapter 60. The adapter 60 is a drape adapter for sandwiching a sterile drape 70, which covers the robotic arm 21a, between the robotic arm 21a and the adapter 60.

[0045] The surgical instrument 40 is attached to the Z1 side of the adapter 60. The adapter 60 is attached to the Z1 side of the robot arm 21a.

[0046] The robotic arm 21a is covered with a drape 70 because it is used in a sterile area. In the operating room, sterile procedures are performed to prevent contamination of the surgically incised area and medical instruments by pathogens or foreign objects. In these sterile procedures, a sterile area and a contaminated area (areas outside the sterile area) are established. The surgical site is located in the sterile area. During surgery, members of the surgical team, including the operator, ensure that only sterilized objects are located in the sterile area, and when moving objects located in the contaminated area to the sterile area, these objects are sterilized. Similarly, when an assistant of the surgical team, including the operator, places their hands in the contaminated area, they sterilize their hands before directly touching objects located in the sterile area. Instruments used in the sterile area are sterilized or covered with a sterilized drape 70.

[0047] As shown in Figure 5, the drape 70 comprises a main body portion 71 that covers the robot arm 21a and a mounting portion 72 that is sandwiched between the robot arm 21a and the adapter 60. The main body portion 71 is made of a flexible film member formed in a film shape. The flexible film member is made of a resin material such as thermoplastic polyurethane or polyethylene. The main body portion 71 is provided with an opening so that the robot arm 21a and the adapter 60 can engage with each other. The mounting portion 72 is provided in the opening of the main body portion 71. The mounting portion 72 is made of a resin molded member. The resin molded member is made of a resin material such as polyethylene terephthalate. The mounting portion 72 is formed to be harder (less flexible) than the main body portion 71. The mounting portion 72 is provided with an opening so that the robot arm 21a and the adapter 60 can engage with each other. The opening of the mounting portion 72 may be provided so as to correspond to the engagement portion between the robot arm 21a and the adapter 60. Furthermore, the openings in the mounting portion 72 may be provided in multiple locations to correspond to multiple engagement points between the robot arm 21a and the adapter 60.

[0048] As shown in Figures 5 and 6, the surgical instrument 40 has a plurality (four) of driven members 44a, 44b, 44c, and 44d. The driven members 44a to 44d are housed within the housing 41 and are rotatable about a rotation axis extending in the Z direction. The plurality of driven members 44a to 44d are provided to operate (drive) the end effector 43. The driven members 44b to 44d are connected to the end effector 43 by flexible, elongated elements W consisting of wires or cables inserted into the shaft 42. As a result, the elongated elements W are driven in accordance with the rotation of the driven members 44b to 44d, and the end effector 43 is operated (driven) in accordance with the driving of the elongated elements W. In addition, the driven member 44a is connected to the shaft 42 via a gear 42a (see Figure 7). As a result, the shaft 42 rotates in accordance with the rotation of the driven member 44a, and the end effector 43 also rotates in accordance with the rotation of the shaft 42.

[0049] Each of the multiple driven members 44a to 44d includes projections 441 and 442 that engage with the drive transmission member 61 of the adapter 60 in order to transmit the driving force from the robot arm 21a to the end effector 43. The projections 441 and 442 protrude from the Z2-direction side surface of the driven members 44a to 44d toward the adapter 60 side (Z2 direction side). In addition, the projections 441 and 442 are arranged in a straight line. Furthermore, the projections 441 provided on the driven members 44a and 44b and the projections 442 provided on the driven members 44c and 44d have different shapes from each other.

[0050] As shown in Figure 5, the adapter 60 has a plurality (four) of drive transmission members 61. The drive transmission members 61 are configured to transmit the driving force from the robot arm 21a to the driven members 44a to 44d of the surgical instrument 40. In other words, the drive transmission members 61 are provided to correspond to the driven members 44a to 44d of the surgical instrument 40. The drive transmission members 61 are provided to be rotatable about a rotation axis extending in the Z direction.

[0051] Each of the multiple drive transmission members 61 includes an engagement recess 611 that engages with the projections 441 and 442 of the driven members 44a to 44d of the surgical instrument 40. The engagement recess 611 is provided on the surgical instrument 40 side (Z1 direction side) of the drive transmission member 61 and is recessed from the Z1 direction side surface of the drive transmission member 61 toward the opposite side from the surgical instrument 40 (Z2 direction side). Each of the multiple drive transmission members 61 includes an engagement recess on the Z2 direction side surface that engages with the engagement projection 213 of the robot arm 21a.

[0052] The robot arm 21a has a frame 211, a plurality (4) of drive units 212, and a plurality of engaging protrusions 213. The plurality of drive units 212 are provided to correspond to the plurality (4) of driven members 44a to 44d of the surgical instrument 40 and the plurality (4) of drive transmission members 61 of the adapter 60, respectively. The drive unit 212 includes an absolute encoder and a servo motor and is configured to rotationally drive the engaging protrusions 213 around a rotation axis extending in the Z direction. The engaging protrusions 213 engage with engaging recesses on the Z2 direction side surface of the drive transmission member 61. The engaging protrusions 213 project from the Z1 direction side surface of the robot arm 21a toward the Z1 direction side (adapter 60 side). The drive unit 212 is configured to rotate the drive transmission member 61 of the adapter 60, which is engaged with the engaging projection 213, around a rotation axis extending in the Z direction, and also to rotate the driven members 44a to 44d of the surgical instrument 40, which are engaged with the drive transmission member 61, around a rotation axis extending in the Z direction.

[0053] (Detailed configuration of surgical instruments) Next, with reference to Figures 7 to 9, the detailed configuration of the surgical instrument 40 will be described. Here, an example will be described in which the end effector 43 of the surgical instrument 40 is a gripping forceps having a pair of jaw members 43a and 43b.

[0054] As shown in Figures 7 and 8, the elongated elements W are wrapped around the driven members 44b to 44d of the surgical instrument 40. In other words, the elongated elements W are connected to the driven members 44b to 44d.

[0055] The elongated element W3 is wound around the driven member 44b. Specifically, the first portion W3a of the elongated element W3 is wound around the upper part of the driven member 44b in a clockwise direction, and the second portion W3b of the elongated element W3 is wound around the lower part of the driven member 44b in a counterclockwise direction.

[0056] Furthermore, the elongated element W1 is wound around the driven member 44c. Specifically, the first portion W1a of the elongated element W1 is wound around the upper part of the driven member 44c in a clockwise direction, and the second portion W1b of the elongated element W1 is wound around the lower part of the driven member 44c in a counterclockwise direction.

[0057] Furthermore, the elongated element W2 is wound around the driven member 44d. Specifically, the first portion W2a of the elongated element W2 is wound around the upper part of the driven member 44d in a clockwise direction, and the second portion W2b of the elongated element W2 is wound around the lower part of the driven member 44d in a counterclockwise direction.

[0058] The elongated element W is passed from each of the driven members 44b to 44d, through the shaft 42, onto the end effector 43, and then back through the shaft 42 to reach the driven members 44b to 44d. The elongated element W is also placed on the built-in pulley 45. The built-in pulley 45 is held by the pulley holder 451.

[0059] As shown in Figures 8 and 9, the driven member 44c rotates around the axis of rotation, thereby operating the jaw member 43a of the pair of jaw members 43a and 43b of the end effector 43. Specifically, the driven member 44c is rotated by the drive unit 212, thereby driving the elongated element W1. The elongated element W1 connects the jaw member 43a and the driven member 44c via the inside of the shaft 42. By rotating in the C1 direction (see Figure 8), the driven member 44c pulls the first part W1a of the elongated element W1 and extends the second part W1b, driving the jaw member 43a in the C1a direction (see Figure 9), which is the direction in which the jaw member 43a opens. Furthermore, the driven member 44c rotates in the C2 direction (see Figure 8), which is opposite to the C1 direction, thereby pulling the second portion W1b of the elongated element W1 and pushing out the first portion W1a, driving the jaw member 43a in the C2a direction (see Figure 9), which is the direction in which the jaw member 43a closes.

[0060] The driven member 44d rotates around the axis of rotation, thereby operating the jaw member 43b of the pair of jaw members 43a and 43b of the end effector 43. Specifically, the driven member 44d is rotated by the drive unit 212, thereby driving the elongated element W2. The elongated element W2 connects the jaw member 43b and the driven member 44d via the inside of the shaft 42. By rotating in the C3 direction (see Figure 8), the driven member 44d pulls the first part W2a of the elongated element W2 and extends the second part W2b, driving the jaw member 43b in the C3a direction (see Figure 9), which is the direction in which the jaw member 43b opens. Furthermore, the driven member 44d rotates in the C4 direction (see Figure 8), which is opposite to the C3 direction, pulling the second portion W2b of the elongated element W2 and extending the first portion W2a, thereby driving the jaw member 43b in the C4a direction (see Figure 9), which is the direction in which the jaw member 43b closes. The pair of jaw members 43a, 43b are opened and closed by the driving of the elongated elements W of the driven members 44b and 44c.

[0061] The driven member 44b operates the wrist portion 43c of the end effector 43 by rotating around the axis of rotation. Specifically, the driven member 44b is rotated by the drive unit 212, thereby driving the elongated element W3. The elongated element W3 connects the wrist portion 43c and the driven member 44b via the inside of the shaft 42. By rotating in the C5 direction (see Figure 8), the driven member 44b pulls the first portion W3a of the elongated element W3 and feeds out the second portion W3b, driving the wrist portion 43c in the C5a direction (see Figure 9). Also, by rotating in the C6 direction (see Figure 8), which is opposite to the C5 direction, the driven member 44b pulls the second portion W3b of the elongated element W3 and feeds out the first portion W3a, driving the wrist portion 43c in the C6a direction (see Figure 9), which is opposite to the C5a direction.

[0062] The driven member 44a, which has a gear 443, is rotated by the drive unit 212 around its axis of rotation while the gear 42a connected to the proximal end of the shaft 42 is engaged with the gear 443, thereby operating the shaft 42 and the end effector 43. Specifically, the driven member 44a rotates in the C7 direction (see Figure 8), driving the shaft 42 to rotate in the C7a direction (see Figure 9), and thus driving the end effector 43 to rotate in the C7a direction. Also, the driven member 44a rotates in the C8 direction (see Figure 8), driving the shaft 42 to rotate in the C8a direction (see Figure 9), which is the opposite direction to the C7a direction, and thus driving the end effector 43 to rotate in the C8a direction.

[0063] (Configuration for controlling the opening and closing of a pair of jaw members)

[0064] Next, the opening and closing control of the pair of jaw members 43a and 43b will be described with reference to Figures 11 to 14. In the following, the drive unit 212 of the robot arm 21a that drives jaw member 43a will be referred to as drive unit 212a, and the drive unit 212 of the robot arm 21a that drives jaw member 43b will be referred to as drive unit 212b.

[0065] As shown in Figures 11 and 12, the controller 24 of the patient-side device 20 is configured to rotate the motors of the drive units 212a and 212b based on the jaw command opening angle, which is the opening angle θ of a pair of jaw members 43a and 43b. The jaw command opening angle is the command value of the opening angle θ of the pair of jaw members 43a and 43b, and is associated with the input to the operating handle 11. The jaw command opening angle is converted into a command value (drive signal) of the amount of rotation that the controller 24 gives to the motors of the drive units 212a and 212b, such that the opening angle θ of the pair of jaw members 43a and 43b corresponds to the opening angle of the pair of grip members 11b of the operating handle 11.

[0066] Figure 12 is a graph showing the relationship between the opening angle of a pair of grip members 11b and the jaw command opening angle of a pair of jaw members 43a and 43b, when there are no restrictions described later. In the graphs shown in Figure 12 (and Figure 13), the horizontal axis is the opening angle of the pair of grip members 11b, and the vertical axis is the jaw command opening angle of the pair of jaw members 43a and 43b. The graph in Figure 12 shows that as the opening angle of the pair of grip members 11b decreases, the pair of jaw members 43a and 43b gradually close, and that after the pair of jaw members 43a and 43b are completely closed (i.e., after the opening angle θ becomes zero), the motors of the drive units 212a and 212b rotate to move the pair of jaw members 43a and 43b in the closing direction, thereby generating a tightening force on the pair of jaw members 43a and 43b.

[0067] Here, regardless of whether or not an object T (see Figure 14) is present between the pair of jaw members 43a and 43b, if it is possible to tighten the pair of jaw members 43a and 43b to the minimum jaw command opening angle shown in the graph of Figure 12, there is a risk of excessive gripping force being generated.

[0068] Therefore, in the first embodiment, as shown in Figures 13 and 14, the controller 24 monitors the current value applied to the motors of the drive units 212a and 212b (hereinafter also referred to as the motor current value) during the closing operation of the pair of jaw members 43a and 43b, and if it determines that the object T is being gripped based on the motor current value, it is configured to drive the drive units 212a and 212b in a restricted mode in which the size of the jaw command opening angle is limited. In other words, the controller 24 determines whether the motor current value of the drive units 212a and 212b exceeds a predetermined threshold during the closing operation of the pair of jaw members 43a and 43b, and if it determines that the motor current value of the drive units 212a and 212b exceeds a predetermined threshold, it is configured to drive the drive units 212a and 212b in a restricted mode in which the size of the jaw command opening angle is limited. As a result, if it is determined that the motor current value of the drive units 212a and 212b exceeds a predetermined threshold during the closing operation of the pair of jaw members 43a and 43b, the drive units 212a and 212b are driven in a limited mode in which the jaw command opening angle is restricted, thereby suppressing the generation of excessive gripping force. As a result, an appropriate gripping force can be achieved. Furthermore, since it is not necessary to provide a load cell or torque sensor on the elongated element W in order to limit the jaw command opening angle, the complexity of the structure around the elongated element W can be suppressed compared to the case where a load cell or torque sensor is provided on the elongated element W. As a result, an appropriate gripping force can be achieved while suppressing the complexity of the structure around the elongated element W.

[0069] Specifically, the controller 24 is configured to drive the drive units 212a and 212b in a restricted mode when it determines that the motor current value of the drive units 212a and 212b exceeds a predetermined threshold value during the closing operation of the pair of jaw members 43a and 43b. This restricted mode limits the minimum jaw command opening angle V2 to a value greater than the initial value V4, which is the minimum jaw command opening angle when the motor current value of the drive units 212a and 212b exceeds the predetermined threshold value, so that the difference between the jaw command opening angle value V1 and the minimum jaw command opening angle V2 becomes a predetermined value V3. As a result, the drive units 212a and 212b are driven in a restricted mode where the minimum jaw command opening angle is limited to a value greater than the initial value V4, which is the minimum jaw command opening angle when the restricted mode is not in effect, making it easier to suppress the generation of excessive gripping force. Consequently, an appropriate gripping force can be achieved more easily.

[0070] In other words, if the controller 24 determines that the motor current values ​​of the drive units 212a and 212b exceed a predetermined threshold, it is configured to reset the minimum value of the jaw command opening angle to a value greater than the initial value V4 (i.e., V2) so that the closing angle of the pair of jaw members 43a and 43b after determining that the motor current values ​​of the drive units 212a and 212b exceed the predetermined threshold becomes a predetermined value V3 (a constant value).

[0071] In the restricted mode, the controller 24 is configured to drive the drive units 212a and 212b with a jaw command opening angle that is restricted to the minimum restricted jaw command opening angle V2, if the value of the jaw command opening angle generated in accordance with the opening angle of the pair of grip members 11b of the operating handle 11 is less than the minimum restricted jaw command opening angle V2. In addition, in the restricted mode, the controller 24 is configured to drive the drive units 212a and 212b with the same jaw command opening angle as in the non-restricted mode (Figure 12), if the value of the jaw command opening angle generated in accordance with the opening angle of the pair of grip members 11b of the operating handle 11 is greater than or equal to the minimum restricted jaw command opening angle V2.

[0072] Furthermore, in the first embodiment, the predetermined value V3, which is the difference between the jaw command opening angle value V1 when the motor current value of the drive units 212a and 212b exceeds a predetermined threshold and the minimum jaw command opening angle V2, is the same value as the difference V6 between the jaw command opening angle value V5 when the opening angle θ of the pair of jaw members 43a and 43b is set to zero and the initial value V4. As a result, the drive units 212a and 212b can be driven in a restricted mode in which the minimum jaw command opening angle is limited, so that the difference between the jaw command opening angle value V1 when the motor current value of the drive units 212a and 212b exceeds a predetermined threshold and the minimum jaw command opening angle V2 is the same value as the difference V6 between the jaw command opening angle value V5 when the opening angle θ of the pair of jaw members 43a and 43b is set to zero and the minimum jaw command opening angle V4 in the initial value case. As a result, in the limiting mode, a constant gripping force can be generated that is approximately equivalent to the maximum gripping force when the pair of jaw members 43a and 43b are not gripping the object T. Therefore, it is possible to more easily suppress the generation of excessive gripping force. As a result, it is possible to more easily achieve an appropriate gripping force.

[0073] Furthermore, in the first embodiment, the controller 24 is configured to switch to limit mode when it determines that the motor current values ​​of the drive units 212a and 212b exceed a predetermined threshold, and that the jaw command opening angle value is smaller than the previous value stored in the memory 25 (see Figure 1) of the patient-side device 20. This allows the controller to switch to limit mode when it detects that the pair of jaw members 43a and 43b are gripping the object T based on the motor current values ​​of the drive units 212a and 212b, and when it detects that the pair of jaw members 43a and 43b are closing due to the jaw command opening angle value being smaller than the previous value. As a result, the controller can switch to limit mode at the appropriate timing when it is necessary to limit the gripping force of the pair of jaw members 43a and 43b. Note that the memory 25 is an example of a storage unit.

[0074] Specifically, the controller 24 is configured to switch to a limit mode if it repeatedly determines (for example, twice) that the motor current values ​​of the drive units 212a and 212b exceed a predetermined threshold, and the jaw command opening angle value is smaller than the previous value stored in the memory 25. This allows the controller to reliably detect that the pair of jaw members 43a and 43b are gripping the object T based on the motor current values ​​of the drive units 212a and 212b, and that the pair of jaw members 43a and 43b are closing due to the jaw command opening angle value being smaller than the previous value, before switching to the limit mode. As a result, the controller can switch to the limit mode at a more appropriate timing.

[0075] More specifically, the controller 24 is configured to switch to a limit mode if it repeatedly determines that either the motor current value of drive unit 212a or the motor current value of drive unit 212b exceeds a predetermined threshold, and the jaw command opening angle value is smaller than the value immediately before (previously) stored in memory 25.

[0076] Furthermore, in the first embodiment, the controller 24 is configured to release the restriction mode when the motor current values ​​of the drive units 212a and 212b fall below a predetermined threshold. This allows the restriction mode to be released when the release of the grip of the object T by the pair of jaw members 43a and 43b is detected based on the motor current values ​​of the drive units 212a and 212b. As a result, the restriction mode can be released at the appropriate timing when it should be released.

[0077] Specifically, the controller 24 is configured to release the restriction mode when the surgical instrument 40 is operable by the operating handle 11, the motor current values ​​of the drive units 212a and 212b fall below a predetermined threshold, and the jaw command opening angle value exceeds the value at which the restriction mode was started (i.e., V1), or exceeds a value near the maximum value of the jaw command opening angle (for example, the maximum value minus 1 degree). As a result, when the surgical instrument 40 is operable by the operating handle 11, the controller 24 can detect the release of the grip of the object T by the pair of jaw members 43a and 43b based on the motor current values ​​of the drive units 212a and 212b, and can release the restriction mode when it detects that the pair of jaw members 43a and 43b are more open than when the restriction mode was started because the jaw command opening angle value exceeds the value at which the restriction mode was started. As a result, the restriction mode can be released at a more appropriate timing. Furthermore, the limit mode can be released when the release of the grip on the object T by the pair of jaw members 43a and 43b is detected by the motor current values ​​of the drive units 212a and 212b, and when the value of the jaw command opening angle exceeds a value near the maximum value of the jaw command opening angle, indicating that the pair of jaw members 43a and 43b are in their maximum open state. As a result, the limit mode can also be released if the pair of jaw members 43a and 43b cannot open any further than they were at the start of the limit mode because they were already fully open at the start of the limit mode.

[0078] The controller 24 is configured to detect when the presence of the operator's head is detected by the head sensor 13a (see Figure 1) and when the operator performs a predetermined operation using the operating handle 11, it detects that the surgical instrument 40 is in a state where it can be operated by the operating handle 11 (hereinafter also referred to as "following"). The controller 24 is also configured to detect when the presence of the operator's head is not detected by the head sensor 13a, it detects that the surgical instrument 40 is in a state where it cannot be operated by the operating handle 11 (hereinafter also referred to as "outside of following").

[0079] Furthermore, in the first embodiment, the controller 24 is configured to release the restriction mode regardless of the jaw command opening angle value when it detects that the motor current values ​​of the drive units 212a and 212b have fallen below a predetermined threshold when the device is outside of following. This allows the restriction mode to be released regardless of the jaw command opening angle value when the device is outside of following, by detecting the release of the object grip by the pair of jaw members 43a and 43b based on the motor current values ​​of the drive units 212a and 212b, considering that the jaw command opening angle does not change. As a result, the restriction mode can be released under conditions suitable for when the device is outside of following. Note that there are cases where the restriction mode is started during following, then the device switches to outside of following, and the restriction mode continues outside of following. In this case, the restriction mode is released when the above conditions are met.

[0080] Furthermore, in the first embodiment, the predetermined threshold is set based on the frictional force of the motors of the drive units 212a and 212b. This allows the predetermined threshold for detecting the gripping of the object T by the pair of jaw members 43a and 43b to be set while taking into account the influence of the current value generated due to the frictional force of the drive units 212a and 212b themselves. As a result, the gripping of the object T by the pair of jaw members 43a and 43b can be accurately detected by the predetermined threshold, compared to when the influence of the current value generated due to the frictional force of the drive units 212a and 212b themselves is not considered.

[0081] Specifically, the predetermined threshold is set by the following equation (1). As shown in the following equation (1), the predetermined threshold is set considering the product of the viscous friction of the motor of the drive unit 212a (212b) and the shaft speed of the drive unit 212a (212b), and the dynamic friction of the motor of the drive unit 212a (212b), relative to the reference value. In the following equation (1), the current value generated due to the viscous friction of the drive unit 212a (212b) changes according to the shaft speed of the drive unit 212a (212b), and is therefore considered as a value that changes according to the shaft speed of the drive unit 212a (212b). Also, in the following equation (1), the current value generated due to the dynamic friction of the drive unit 212a (212b) is constant regardless of the shaft speed of the drive unit 212a (212b), and is therefore considered as a constant value that does not change according to the shaft speed of the drive unit 212a (212b). α = α1 + (a × As + b) ... (1) Here, α: predetermined threshold α1: Reference value a: Constant relating to viscous friction of the drive unit b: Constants related to the dynamic friction of the drive unit As: Variable for the shaft speed (rotational speed) of the drive unit. That is the case.

[0082] α1 is a constant that serves as the basis for a predetermined threshold. a is a constant relating to viscous friction caused by grease or the like in the reducer of the drive unit 212a (212b). b is a constant relating to kinetic friction caused by rotation in the reducer of the drive unit 212a (212b). α1, a, and b are determined in advance through experiments or other means. α1, a, and b are not particularly limited, but for example, α1 is 0.2 [Arms], a is 0.0006 [Arms / sec / deg], and b is 0.1194 [Arms]. As is a variable representing the shaft speed (rotational speed) of the drive unit 212a (212b). As can be obtained based on the output of a position detector such as an encoder in the drive unit 212a (212b).

[0083] The controller 24 is configured to compare a predetermined threshold value of the drive unit 212a, acquired in real time by formula (1) above, with the motor current value of the drive unit 212a, acquired in real time by a current detection unit 220a provided for the drive unit 212a and used to detect the motor current value of the drive unit 212a, when determining whether or not to switch to the limit mode. Similarly, the controller 24 is configured to compare a predetermined threshold value of the drive unit 212b, acquired in real time by formula (1) above, with the motor current value of the drive unit 212b, acquired in real time by a current detection unit 220b provided for the drive unit 212b and used to detect the motor current value of the drive unit 212b, when determining whether or not to switch to the limit mode.

[0084] Furthermore, in the first embodiment, as shown in Figures 9 and 10, the end effector 43 includes a pulley 43d around which a slender element W1 that drives the jaw member 43a is wound, and a pulley 43e around which a slender element W2 that drives the jaw member 43b is wound. The pulley 43d is provided with an engagement hole 43da that engages with the engagement pin 43aa of the jaw member 43a, and the pulley 43e is provided with an engagement hole 43ea that engages with the engagement pin 43ba of the jaw member 43b. The pair of jaw members 43a and 43b are configured to open and close on an axis 43g different from the axis 43f of the pulleys 43d and 43e by rotating the pulleys 43d and 43e. In other words, the pair of jaw members 43a and 43b and the pulleys 43d and 43e form a link mechanism. This allows the pair of jaw members 43a and 43b to generate a large gripping force. Furthermore, when using a pair of jaw members 43a and 43b with a large gripping force, the above limiting mode can suppress the generation of excessive gripping force. The engagement holes 43da and 43ea are examples of engagement parts for jaw driving.

[0085] Pulley 43d has an elongated element W1 wound around it and rotates by the drive of the elongated element W1. Pulley 43e has an elongated element W2 wound around it and rotates by the drive of the elongated element W2. Pulleys 43d and 43e are rotatably supported on a common shaft 43f. A pair of jaw members 43a and 43b are rotatably supported on a common shaft 43g. Shaft 43g is approximately parallel to shaft 43f. Shaft 43g is positioned between the tip and base portions of the pair of jaw members 43a and 43b. Shaft 43g is positioned between the tip portions of the pair of jaw members 43a and 43b and pulleys 43d and 43e. An engagement pin 43aa is provided on the base portion of jaw member 43a, which is inserted into the engagement hole 43da of pulley 43d. The base end portion of the jaw member 43b is provided with an engagement pin 43ba, which is inserted into the engagement hole 43ea of ​​the pulley 43e.

[0086] When the pulley 43d is rotated around the shaft 43f by the elongated element W1, rotational driving force is transmitted to the jaw member 43a via the engagement pin 43aa engaged in the engagement hole 43da. This causes the jaw member 43a to rotate around the shaft 43g. At this time, the rotational driving force of the pulley 43d is amplified and transmitted to the object gripping portion of the jaw member 43a at the tip end by the action of the link mechanism at a predetermined lever ratio. Similarly, when the pulley 43e is rotated around the shaft 43g by the elongated element W2, rotational driving force is transmitted to the jaw member 43b via the engagement pin 43ba engaged in the engagement hole 43ea. This causes the jaw member 43b to rotate around the shaft 43g. At this time, the rotational driving force of the pulley 43e is amplified and transmitted to the object gripping portion of the jaw member 43b at the tip end by the action of the link mechanism at a predetermined lever ratio.

[0087] Here, when a relatively large object T (see Figure 14) is gripped by a pair of jaw members 43a and 43b with a large gripping force as shown in Figure 9, excessive gripping force is likely to occur. Furthermore, when excessive gripping force occurs, the elongated elements W1 and W2 may fall off the built-in pulley 45 (see Figure 8). In other words, when excessive gripping force occurs, for example, the part of the elongated element W1 that is fed out, such as the first part W1a and the second part W1b, may be fed out excessively, causing loosening in the built-in pulley 45 and potentially causing it to fall off the built-in pulley 45. The same applies to the elongated element W2.

[0088] Therefore, in the first embodiment, as shown in Figure 15, a fall prevention portion 46 is provided near the built-in pulley 45 to prevent the elongated elements W1 and W2 from falling off the built-in pulley 45. The fall prevention portion 46 has a recess 461 for holding the elongated elements W1 and W2 between itself and the groove of the built-in pulley 45. The recess 461 is provided so as to cover the groove of the built-in pulley 45 from the side, thereby holding the elongated elements W1 and W2, which are placed in the groove of the built-in pulley 45, within the space partitioned by the recess 461 and the groove of the built-in pulley 45. Furthermore, there are four recesses 461, corresponding to a total of four parts: the two parts of the elongated element W1, the first part W1a and the second part W1b, and the two parts of the elongated element W2, the first part W2a and the second part W2b.

[0089] (Control process for initiating restricted mode) Next, referring to Figure 16, the control process for initiating the restriction mode during following by the controller 24 will be explained based on a flowchart.

[0090] As shown in Figure 16, first, in step S1, it is determined whether the motor current values ​​of the drive units 212a and 212b have exceeded a predetermined threshold. That is, in step S1, it is determined whether an increase in the motor current values ​​of the drive units 212a and 212b has occurred as a result of the pair of jaw members 43a and 43b gripping the object T.

[0091] Specifically, in step S1, it is determined whether the motor current value of drive unit 212a exceeds a predetermined threshold value for drive unit 212a according to equation (1) above, or whether the motor current value of drive unit 212b exceeds a predetermined threshold value for drive unit 212b according to equation (1) above. If neither the motor current value of drive unit 212a nor the motor current value of drive unit 212b exceeds the predetermined threshold value, the process in step S1 is repeated. If at least one of the motor current value of drive unit 212a or the motor current value of drive unit 212b exceeds the predetermined threshold value, the process proceeds to step S2.

[0092] Then, in step S2, it is determined whether the value of the jaw command opening angle, which is generated in accordance with the opening angle of the pair of grip members 11b of the operating handle 11, is smaller than the previous value. If the value of the jaw command opening angle is not smaller than the previous value, the process proceeds to step S1. If the value of the jaw command opening angle is smaller than the previous value, the process proceeds to step S3. For example, when proceeding from steps S1, S2, or S3 to step S1, the value of the jaw command opening angle is stored in memory 25 as the value of the previous jaw command opening angle.

[0093] Then, in step S3, it is determined whether the conditions of steps S1 and S2 were met two times in a row. If the conditions of steps S1 and S2 were not met two times in a row, the process proceeds to step S1. If the conditions of steps S1 and S2 were met two times in a row, the process proceeds to step S4.

[0094] Then, in step S4, the machine switches to restricted mode, and the value of the jaw command opening angle at the start of restricted mode is stored in memory 25. In restricted mode, the size of the jaw command opening angle is restricted as described above. The restricted mode continues thereafter until it is released.

[0095] (Control process for disabling restricted mode) Next, referring to Figure 17, the control process for releasing the restriction mode during following by the controller 24 will be explained based on a flowchart.

[0096] As shown in Figure 17, first, in step S11, it is determined whether the motor current values ​​of the drive units 212a and 212b have fallen below a predetermined threshold. That is, in step S11, it is determined whether the motor current values ​​of the drive units 212a and 212b have decreased because the pair of jaw members 43a and 43b have stopped gripping the object T.

[0097] Specifically, in step S11, it is determined whether the motor current value of drive unit 212a is less than or equal to a predetermined threshold value for drive unit 212a according to equation (1) above, and whether the motor current value of drive unit 212b is less than or equal to a predetermined threshold value for drive unit 212b according to equation (1) above. If both the motor current value of drive unit 212a and the motor current value of drive unit 212b are not less than or equal to the predetermined threshold value, the process in step S11 is repeated. If both the motor current value of drive unit 212a and the motor current value of drive unit 212b are less than or equal to the predetermined threshold value, the process proceeds to step S12.

[0098] Then, in step S12, it is determined whether the value of the jaw command opening angle, which is generated in accordance with the opening angle of the pair of grip members 11b of the operating handle 11, exceeds the value at which the limit mode was started. If the value of the jaw command opening angle exceeds the value at which the limit mode was started, the process proceeds to step S14. Then, in step S14, the limit mode is released.

[0099] Furthermore, if the value of the jaw command opening angle in step S12 does not exceed the value at the time the limit mode was started, the process proceeds to step S13.

[0100] Then, in step S13, it is determined whether the value of the jaw command opening angle exceeds a value near the maximum value (in this case, the maximum value minus 1 degree). If the value of the jaw command opening angle does not exceed the maximum value minus 1 degree, the process proceeds to step S11. If the value of the jaw command opening angle exceeds the maximum value minus 1 degree, the process proceeds to step S14. Then, in step S14, the restriction mode is released.

[0101] (Control process for disabling restricted mode) Next, referring to Figure 18, the control process by which the controller 24 releases the restriction mode outside of following will be explained based on a flowchart.

[0102] As shown in Figure 18, first, in step S21, it is determined whether the motor current values ​​of the drive units 212a and 212b have fallen below a predetermined threshold. The process in step S21 is the same as the process in step S11 shown in Figure 17. Therefore, if both the motor current values ​​of drive unit 212a and drive unit 212b are not below the predetermined threshold, the process in step S21 is repeated. If both the motor current values ​​of drive unit 212a and drive unit 212b fall below the predetermined threshold, the process proceeds to step S22. Then, in step S22, the restriction mode is released. In the control process for releasing the restriction mode outside of following shown in Figure 18, unlike the control process for releasing the restriction mode during following shown in Figure 17, the jaw command opening angle condition (conditions in steps S12 and S13) is not determined.

[0103] [Second Embodiment] Next, a second embodiment will be described with reference to Figures 19 to 21. In this second embodiment, unlike the first embodiment, an example will be described in which the minimum value of the jaw command opening angle is restricted to zero or less. Components identical to those in the first embodiment are shown in the figures with the same reference numerals, and their descriptions are omitted.

[0104] (Configuration of the robotic surgical system) The robotic surgical system 300 according to the second embodiment, as shown in Figure 19, is equipped with a controller 324 instead of the controller 24 of the first embodiment. Note that the controller 324 is an example of a control unit.

[0105] Figure 20 is a graph (shown in Figure 12) that shows the relationship between the opening angle of a pair of grip members 11b and the jaw command opening angle of a pair of jaw members 43a and 43b. The opening angle of the pair of grip members 11b and This graph includes a graph (shown by a dashed line) that shows the relationship with the minimum value of the jaw command opening angle. In the graph shown in Figure 20, the horizontal axis represents the opening angle of the pair of grip members 11b, and the vertical axis represents the jaw command opening angle of the pair of jaw members 43a and 43b. The detected angle is the opening angle θ of the pair of jaw members 43a and 43b when the motor current value of the drive units 212a and 212b exceeds a predetermined threshold. For example, the detected angle can be estimated by considering the elongation of the slender element W from the rotation angle of the motors of the drive units 212a and 212b detected by the controller 324 when the motor current value of the drive units 212a and 212b exceeds a predetermined threshold.

[0106] Figure 21 is a graph showing the relationship between the detection angle and the minimum jaw command opening angle. In the graph shown in Figure 21, the horizontal axis represents the detection angle, and the vertical axis represents the minimum jaw command opening angle of the pair of jaw members 43a and 43b. In the graph shown in Figure 21, the relationship between the detection angle and the minimum jaw command opening angle when the control of the first embodiment is performed is shown by a solid line, and the relationship between the detection angle and the minimum jaw command opening angle when the control of the second embodiment is performed is shown by a dashed line.

[0107] In the second embodiment, as shown in Figures 20 and 21, the controller 324 is configured to drive the drive units 212a and 212b in a restricted mode in which, if it determines that the motor current value of the drive units 212a and 212b exceeds a predetermined threshold value during the closing operation of the pair of jaw members 43a and 43b, the minimum value V2 of the jaw command opening angle is limited to a value greater than the initial value V4 and to zero or less. In other words, in the restricted mode of the second embodiment, not only the lower limit but also the upper limit of the minimum value of the jaw command opening angle is restricted. For example, if the object T is a tissue and the object T is pulled while being gripped by the pair of jaw members 43a and 43b, the thickness of the object T changes to a thinner shape. In the first embodiment described above, the minimum value of the jaw command opening angle of the pair of jaw members 43a and 43b may be greater than zero (see Figure 21), so depending on the change in the thickness of the object T, there is a risk that the object T may fall off the pair of jaw members 43a and 43b. On the other hand, in the second embodiment, even in the restricted mode, the minimum value of the jaw command opening angle is always set to be zero or less. Therefore, even if the thickness of the object T changes, the pair of jaw members 43a and 43b close in accordance with the change in the thickness of the object T, so that the object T can be gripped securely.

[0108] Furthermore, in the second embodiment, the limiting mode has an upper limit V11 set for the minimum value V2 of the jaw command opening angle after limiting. The upper limit V11 is a negative value that is a predetermined amount less than zero. This makes it possible to operate the pair of jaw members 43a and 43b to be completely closed in the limiting mode, even when considering the backlash between the jaw members 43a (43b) and the pulley 43d (43e), unlike when the upper limit V11 is zero. The upper limit V11 is set to a negative value that is a predetermined amount less than the backlash between the jaw members 43a (43b) and the pulley 43d (43e). For example, if the backlash is 1.5 degrees, the upper limit V11 is set to -1.5 degrees.

[0109] In the second embodiment, the controller 324 is configured to detect the rotation angle of the motor when the motor current value of the drive units 212a and 212b exceeds a predetermined threshold during the closing operation of the pair of jaw members 43a and 43b, and to control the switching to the limit mode based on the detected motor rotation angle. Specifically, the controller 324 is configured to switch to the limit mode if the detected angle is greater than or equal to a predetermined value V12 when it determines that the motor current value of the drive units 212a and 212b exceeds a predetermined threshold during the closing operation of the pair of jaw members 43a and 43b, and not switch to the limit mode if the detected angle is less than the predetermined value V12. This prevents unnecessary switching to the limit mode in the range where the detected angle is small. When the controller 324 does not switch to the limit mode, the minimum value of the jaw command opening angle is the initial value V4.

[0110] Furthermore, the controller 324 is configured to switch to a limit mode if it determines that the motor current value of the drive units 212a and 212b exceeds a predetermined threshold during the closing operation of the pair of jaw members 43a and 43b, and the detection angle is greater than or equal to a predetermined value V12. Specifically, the controller 324 is configured to switch to a limit mode if the detection angle is greater than or equal to a predetermined value V12 and less than a predetermined value V13 (V13 > V12), in which case the minimum value V2 of the jaw command opening angle is limited to a value greater than the initial value V4 and less than the upper limit value V11. In this case, the controller 324 is configured to limit the minimum value V2 of the jaw command opening angle such that the minimum value V2 of the jaw command opening angle gradually decreases as the detection angle decreases. For example, the controller 324 is configured to obtain the minimum value V2 of the jaw command opening angle using the following equation (2). V2 = V4 × R + V4 - c ... (2) Here, V2: Minimum jaw command opening angle after restriction V4: Initial value (minimum jaw command opening angle before limitations) R: Reduction ratio relative to detection angle (a variable that changes depending on the detection angle) c: A predetermined constant That is the case.

[0111] Furthermore, the controller 324 is configured to switch to a restriction mode in which the minimum value V2 of the jaw command opening angle is limited to the upper limit V11 when the detection angle is greater than or equal to a predetermined value V13. In this case, the controller 324 is configured to limit the minimum value V2 of the jaw command opening angle so that the minimum value V2 of the jaw command opening angle becomes the upper limit V11, regardless of the detection angle.

[0112] [Differentiation] It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than by the description of the embodiments above, and further includes all modifications (exceptions) within the meaning and scope equivalent to the claims.

[0113] For example, the first and second embodiments described above show an example in which a pair of jaw members are driven by a flexible, elongated element consisting of a wire or cable, but the present invention is not limited thereto. For example, a pair of jaw members may be driven by a rigid, elongated element consisting of a rod.

[0114] Furthermore, while the first and second embodiments described above show examples in which an operating handle having a pair of grip members is provided as an input device to which a command to open and close a pair of jaw members is input, the present invention is not limited thereto. For example, an operating handle other than an operating handle having a pair of grip members may be provided as an input device to which a command to open and close a pair of jaw members is input. Alternatively, something other than an operating handle may be provided as an input device to which a command to open and close a pair of jaw members is input.

[0115] Furthermore, in the first embodiment described above, an example was shown in which the predetermined value, which is the difference between the jaw command opening angle value when the motor current value of the drive unit exceeds a predetermined threshold and the minimum jaw command opening angle, is the same value as the difference between the jaw command opening angle value when the opening angle of the pair of jaw members is zero and the minimum jaw command opening angle in the initial value case. However, the present invention is not limited to this. For example, the predetermined value may be a value greater than or less than the difference between the jaw command opening angle value when the opening angle of the pair of jaw members is zero and the minimum jaw command opening angle in the initial value case.

[0116] Furthermore, while the first and second embodiments described above show examples where the controller switches to limit mode when it determines that the motor current value of the drive unit exceeds a predetermined threshold and the jaw command opening angle value is smaller than the previous value, the present invention is not limited thereto. For example, the controller may switch to limit mode regardless of the jaw command opening angle when it detects that the motor current value of the drive unit exceeds a predetermined threshold.

[0117] Furthermore, while the first and second embodiments described above show examples where the controller switches to a limit mode when it repeatedly determines that the motor current value of the drive unit exceeds a predetermined threshold and the jaw command opening angle value is smaller than the previous value, the present invention is not limited to this. For example, the controller may switch to a limit mode after determining only once that the motor current value of the drive unit exceeds a predetermined threshold and the jaw command opening angle value is smaller than the previous value.

[0118] Furthermore, in the first and second embodiments described above, the controller was shown to release the restriction mode when, while following, the motor current value of the drive unit falls below a predetermined threshold, and the jaw command opening angle exceeds the value at which the restriction mode was started, or the jaw command opening angle exceeds a value near the maximum value of the jaw command opening angle. However, the present invention is not limited thereto. For example, when following, if the controller determines that the motor current value of the drive unit has fallen below a predetermined threshold, it may release the restriction mode regardless of the jaw command opening angle.

[0119] Furthermore, while the first and second embodiments described above show examples where a predetermined threshold is set by formula (1), the present invention is not limited thereto. For example, the predetermined threshold may be set by a formula other than formula (1).

[0120] Furthermore, although the first and second embodiments described above show examples in which a fall prevention mechanism is provided, the present invention is not limited thereto. For example, a fall prevention mechanism may not be provided.

[0121] Furthermore, while the robotic surgical system was shown as a master-slave type system in the first and second embodiments described above, the present invention is not limited thereto. For example, the system may include a semi-automated process in which the patient-side device automatically performs some steps without receiving instructions from a remote control device, or a fully automated system in which the patient-side device performs the steps independently. In that case, the jaw command opening angle is generated by the control unit or controller based on a control program that includes a limiting mode.

[0122] Furthermore, while the second embodiment described above shows an example where an upper limit is set for the minimum jaw opening angle in the limiting mode, the present invention is not limited thereto. For example, it is not necessary to set an upper limit for the minimum jaw opening angle in the limiting mode.

[0123] Furthermore, although the second embodiment described above shows an example where the upper limit is a negative value by a predetermined amount, the present invention is not limited thereto. For example, the upper limit may be zero.

[0124] The functions of the elements disclosed herein can be performed using circuits or processing circuits, including general-purpose processors, dedicated processors, integrated circuits, ASICs (Application Specific Integrated Circuits), conventional circuits, and / or combinations thereof, configured or programmed to perform the disclosed functions. A processor is considered a processing circuit or circuit because it includes transistors and other circuits. In this disclosure, a circuit, unit, or means is hardware that performs the enumerated functions, or hardware programmed to perform the enumerated functions. The hardware may be hardware disclosed herein, or other known hardware that is programmed or configured to perform the enumerated functions. If the hardware is a processor, which is considered a type of circuit, then the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and / or the processor. [Explanation of Symbols]

[0125] 20: Patient-side device (surgical robot, surgical assistance robot), 11: Operating handle (input device), 21a: Robot arm, 24, 324: Controller (control unit), 25: Memory (storage unit), 40: Surgical instrument, 43: End effector, 43a, 43b: Pair of jaw members, 43d, 43e: Pulley, 43da, 43ea: Engagement hole (engagement part for jaw drive), 43f: Shaft (shaft of pulley), 43g: Shaft (shaft of jaw member), 44c, 44d: Driven member, 100: Robot surgical system, 212a, 212b: Drive unit, T: Object, V1: Value of jaw command opening angle, V2: Minimum value of jaw command opening angle, V4: Initial value, V5: Value of jaw command opening angle, V6: Difference, V11: Upper limit value, W1, W2: Slender element, θ: Opening angle

Claims

1. A surgical instrument having a pair of jaw members that open and close to grip an object by driving an elongated element connected to a driven member, An input device to which commands are input to open, close and tighten the pair of jaw members, A surgical robot comprising: a robot arm to which the surgical instruments are attached and which includes a current-driven drive unit for driving the driven member; and a control device that drives the drive unit based on jaw operation commands relating to the opening angle and clamping force of the pair of jaw members corresponding to the commands input to the input device, The control device determines whether the current value of the drive unit exceeds a predetermined threshold during the closing operation of the pair of jaw members, and if it determines that the current value of the drive unit exceeds the predetermined threshold, it drives the drive unit in a restricted mode in which the magnitude of the jaw operation command is limited. A robotic surgical system in which, in the restriction mode, the minimum value of the jaw movement command is restricted to a value greater than the initial value which is the minimum value of the jaw movement command when not in the restriction mode.

2. The robotic surgical system according to claim 1, wherein the difference between the value of the jaw operation command when the current value of the drive unit exceeds the predetermined threshold and the minimum value of the jaw operation command in the limit mode is the same value as the difference between the value of the jaw operation command when the opening angle of the pair of jaw members is set to zero and the initial value.

3. The system further comprises a storage unit that sequentially stores the values ​​of the jaw operation commands, The robotic surgical system according to claim 1, wherein the control device switches to the limit mode when it determines that the current value of the drive unit exceeds a predetermined threshold and the value of the jaw operation command is smaller than the value previously stored in the storage unit.

4. The robotic surgical system according to claim 3, wherein the control device switches to the limit mode when it repeatedly determines that the current value of the drive unit exceeds a predetermined threshold and the value of the jaw operation command is smaller than the value previously stored in the storage unit.

5. The robotic surgical system according to claim 1, wherein the control device releases the limit mode when the current value of the drive unit falls below a predetermined threshold.

6. The robotic surgical system according to claim 5, wherein the control device releases the restriction mode when the surgical instrument is operable by the input device, the current value of the drive unit becomes less than or equal to the predetermined threshold, and the value of the jaw movement command exceeds the value at which the restriction mode was started or exceeds a value near the maximum value of the jaw movement command.

7. The robotic surgical system according to claim 5, wherein the control device, when the surgical instrument cannot be operated by the input device, releases the restriction mode regardless of the value of the jaw operation command when the current value of the drive unit falls below a predetermined threshold.

8. The robotic surgical system according to claim 1, wherein the predetermined threshold is set based on the frictional force of the drive unit.

9. The surgical instrument further comprises a pulley around which the elongated element that drives the jaw member is wound, The pulley is provided with a jaw-driving engagement portion that engages with the jaw member, The robotic surgical system according to claim 1, wherein the pair of jaw members open and close on an axis different from the axis of the pulley by rotating the pulley.

10. The robotic surgical system according to claim 1, wherein the control device determines that the current value of the drive unit exceeds a predetermined threshold during the closing operation of the pair of jaw members, and drives the drive unit in the restricted mode in which the minimum value of the jaw operation command is limited to a value greater than the initial value and to zero or less.

11. The aforementioned restriction mode has an upper limit set for the minimum value of the jaw operation command after restriction. The robotic surgical system according to claim 10, wherein the upper limit is a negative value less than zero by a predetermined amount.

12. The aforementioned drive unit includes a motor, The robotic surgical system according to claim 10, wherein the control device determines that the current value of the motor exceeds a predetermined threshold during the closing operation of the pair of jaw members, detects the rotation angle of the motor at the time the current value of the motor exceeds the predetermined threshold, and controls switching to the limiting mode based on the detected rotation angle of the motor.

13. A robotic surgical method for a robotic surgical system comprising: a surgical instrument having a pair of jaw members that open and close to grip an object by driving an elongated element connected to a driven member; a remote control device including an input device and a first control unit to which commands for opening, closing and tightening the pair of jaw members are input; and a surgical robot to which the surgical instrument is attached and which includes a robot arm including a current-driven drive unit for driving the driven member and a second control unit, wherein the surgical instrument is attached The first control unit acquires a jaw operation command relating to the opening angle and tightening force of the pair of jaw members corresponding to the command input to the input device, The second control unit includes the step of driving the drive unit based on the jaw operation command, The step of driving the drive unit includes the second control unit determining whether the current value of the drive unit exceeds a predetermined threshold during the closing operation of the pair of jaw members, and if it is determined that the current value of the drive unit exceeds the predetermined threshold, the second control unit drives the drive unit in a restricted mode in which the magnitude of the jaw operation command is limited. A robotic surgical method in which, in the restriction mode, the minimum value of the jaw movement command is restricted to a value greater than the initial value which is the minimum value of the jaw movement command when not in the restriction mode.

14. A surgical instrument having a pair of jaw members that open and close to grip an object by driving an elongated element connected to a driven member, A robotic arm to which the surgical instrument is attached and which includes a current-driven drive unit for driving the driven member, The system includes a control unit that drives the drive unit based on jaw operation commands relating to the opening angle and tightening force of the pair of jaw members, The control unit determines whether the current value of the drive unit exceeds a predetermined threshold during the closing operation of the pair of jaw members, and if it determines that the current value of the drive unit exceeds a predetermined threshold, it drives the drive unit in a restricted mode in which the magnitude of the jaw operation command is limited. In the aforementioned restriction mode, the minimum value of the jaw movement command is restricted to a value greater than the initial value which is the minimum value of the jaw movement command when not in the aforementioned restriction mode.

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