JP2023033162A - Robot surgery system, surgery support robot, and robot surgery method - Google Patents

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

The present invention relates to a robotic surgery system, a surgical assistance robot, and a robotic surgery method.

2. Description of the Related Art Conventionally, there has been known a robotic surgery system that includes a surgical instrument having a pair of jaw members (see, for example, Patent Document 1).

In the patent document 1, a surgical tool having a pair of jaws (jaw members), a position control section and a gripping force control section are used to control the jaw angle and gripping force of the pair of jaws. A surgical assistance robotic system (robotic surgical system) provided with the system is disclosed. In this surgical assistance robot system, the cable is provided with a load cell or a torque sensor in order to obtain the tension of the cable for the gripping force control unit to drive the jaws. A gripping force controller then achieves the desired gripping force based on the cable tension measured by a cable load cell or torque sensor.

Japanese Patent Publication No. 2020-536685

However, in the surgical assist robot system described in Patent Document 1, while a desired gripping force can be achieved, the gripping force control section acquires the cable tension of the surgical tool by applying a load cell or torque to the cable. A sensor must be provided. In this case, there is a problem that the structure around the cable (elongated element) becomes complicated.

The present invention has been made to solve the above problems, and one object of the present invention is to achieve an appropriate gripping force while suppressing complication of the structure around the elongated element. To provide a robotic surgery system, a surgery support robot, and a robotic surgery method capable of

To achieve the above object, a robotic surgical system according to a first aspect of the present invention is 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 a command to open and close a pair of jaw members is input; a robot arm to which a surgical instrument is attached and which includes a drive section for driving the driven member; and a pair of jaw members associated with the input to the input device. a control unit for driving the driving unit based on the jaw command opening angle regarding the opening angle of the pair of jaw members, wherein the control unit keeps the current value of the driving unit at a predetermined level during the closing operation of the pair of jaw members. If it is determined that the current value of the drive unit exceeds the threshold value, the drive unit is driven in a limit mode in which the magnitude of the commanded jaw opening angle is limited. Let

In the robotic surgery system according to the first aspect of the present invention, as described above, the controller determines whether or not the current value of the drive unit exceeds the predetermined threshold value during the closing operation of the pair of jaw members. Then, when it is determined that the current value of the drive unit exceeds a predetermined threshold value, the drive unit is driven in a limit mode in which the magnitude of the commanded jaw opening angle is limited. Accordingly, when it is determined that the current value of the drive unit exceeds the predetermined threshold value during the closing operation of the pair of jaw members, the drive unit is driven in the limit mode in which the magnitude of the commanded jaw opening angle is limited. Therefore, generation of an excessive gripping force can be suppressed. As a result, an appropriate gripping force can be achieved. Also, since there is no need to provide load cells or torque sensors on elongated elements such as cables, wires and rods to limit the magnitude of the commanded jaw opening angle, compared to providing load cells or torque sensors on elongated elements, It is possible to suppress the complication of the structure around the elongated element. As a result, it is possible to provide a robotic surgical system capable of achieving an appropriate grasping force while suppressing complication of the structure around the elongated element.

A robotic surgery method according to a second aspect of the present invention includes 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, and opening and closing the pair of jaw members. A robotic surgical method for a robotic surgery system comprising an input device for inputting commands and a surgical robot having a robotic arm to which a surgical instrument is attached and including a drive unit for driving a driven member, wherein an input to the input device obtaining a commanded jaw opening angle related to the opening angle of a pair of jaw members associated with the pair of It is determined whether or not the current value of the drive unit exceeds a predetermined threshold value during the closing operation of the jaw members, and if it is determined that the current value of the drive unit exceeds the predetermined threshold value, a jaw command and driving the drive in a limited mode in which the magnitude of the opening angle is limited.

In the robotic surgery method according to the second aspect of the present invention, as described above, the step of driving the drive unit is performed by determining whether the current value of the drive unit exceeds the predetermined threshold value during the closing operation of the pair of jaw members. and if it is determined that the current value of the drive unit exceeds a predetermined threshold value, the drive unit is driven in a limit mode in which the magnitude of the commanded jaw opening angle is limited. Configure. Accordingly, when it is determined that the current value of the drive unit exceeds the predetermined threshold value during the closing operation of the pair of jaw members, the drive unit is driven in the limit mode in which the magnitude of the commanded jaw opening angle is limited. Therefore, generation of an excessive gripping force can be suppressed. As a result, an appropriate gripping force can be achieved. Also, since there is no need to provide load cells or torque sensors on the elongated elements such as cables, wires and rods to limit the magnitude of the commanded jaw opening angle, the load cells or torque sensors around the elongated elements are less demanding. Therefore, it is possible to suppress the complication of the structure around the elongated element. As a result, it is possible to provide a robotic surgery method capable of achieving an appropriate grasping force while suppressing complication of the structure around the elongated element.

A surgical assistance robot according to a third aspect of the present invention includes a surgical instrument having a pair of jaw members that are opened and closed to grip an object by driving an elongated element connected to a driven member; a robot arm including a driving section that drives the driving member; and a control section that drives the driving section based on a jaw command opening angle related to the opening angle of the pair of jaw members, wherein the control section controls closing of the pair of jaw members. During operation, it is determined whether or not the current value of the drive unit exceeds a predetermined threshold value, and when it is determined that the current value of the drive unit exceeds the predetermined threshold value, the commanded jaw opening angle drive the drive in a restricted mode with limited power;

In the surgical assistance robot according to the third aspect of the present invention, as described above, the control unit determines whether or not the current value of the driving unit exceeds the predetermined threshold value during the closing operation of the pair of jaw members. Then, when it is determined that the current value of the drive unit exceeds a predetermined threshold value, the drive unit is driven in a limit mode in which the magnitude of the commanded jaw opening angle is limited. Accordingly, when it is determined that the current value of the drive unit exceeds the predetermined threshold value during the closing operation of the pair of jaw members, the drive unit is driven in the limit mode in which the magnitude of the commanded jaw opening angle is limited. Therefore, generation of an excessive gripping force can be suppressed. As a result, an appropriate gripping force can be achieved. Also, since there is no need to provide load cells or torque sensors on elongated elements such as cables, wires and rods to limit the magnitude of the commanded jaw opening angle, compared to providing load cells or torque sensors on elongated elements, It is possible to suppress the complication of the structure around the elongated element. As a result, it is possible to provide a surgical assistance robot capable of achieving an appropriate grasping force while suppressing complication of the structure around the elongated element.

According to the present invention, as described above, an appropriate gripping force can be achieved while suppressing complication of the structure around the elongated element.

1 is a diagram showing the configuration of a robotic surgery system according to a first embodiment; FIG. 1 is a block diagram showing the control configuration of the robotic surgery system according to the first embodiment; FIG. 4A and 4B are diagrams showing a configuration of an operation handle according to the first embodiment; FIG. FIG. 4 is a perspective view showing a state in which a surgical instrument is attached to the robot arm according to the first embodiment via an adapter; FIG. 4 is an exploded perspective view showing a state in which a surgical instrument is attached to the robot arm according to the first embodiment via an adapter; It is the perspective view which looked at the surgical instrument by 1st Embodiment from the downward direction. Fig. 2 is a perspective view showing a state in which a cover is removed from the base of the surgical instrument according to the first embodiment; Fig. 2 is a plan view showing a state in which a cover is removed from the base of the surgical instrument according to the first embodiment; 1 is a perspective view showing an end effector of a surgical instrument according to a first embodiment; FIG. 4 is an exploded perspective view showing a pair of jaw members and pulleys according to the first embodiment; FIG. Fig. 3 shows a pair of jaw members, a drive and a controller according to the first embodiment; 7 is a graph showing the relationship between the grip opening angle and the commanded opening angle of the jaws when there is no restriction according to the first embodiment; 7 is a graph showing the relationship between the grip opening angle and the commanded opening angle of the jaws in the limit mode according to the first embodiment; FIG. 4 is a diagram for explaining gripping of an object by a pair of jaw members according to the first embodiment; FIG. 4 is a cross-sectional view of the elongated element, the pulley part and the anti-fallout part according to the first embodiment; 7 is a flow chart showing control processing for starting a restriction mode in a state where the input device is operated according to the first embodiment; 7 is a flowchart showing control processing for canceling the restriction mode when the input device is being operated according to the first embodiment; 7 is a flow chart showing control processing for starting a restriction mode when the input device is not operated according to the first embodiment; Figure 10 shows a pair of jaw members, a drive and a controller according to a second embodiment; 9 is a graph for explaining a restricted mode according to the second embodiment; FIG. 9 is a graph showing the relationship between the detected angle and the minimum value of the commanded opening angle of the jaws according to the second embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention that embody the present invention will be described based on the drawings.

[First embodiment]
(Configuration of robotic surgery system)
The configuration of a robotic surgical system 100 according to one embodiment will be described with reference to FIGS. 1 and 2. FIG.

As shown in FIG. 1 , the robotic surgery system 100 includes a remote control device 10 and a patient-side device 20 . A remote control device 10 is provided to remotely control medical equipment provided in a patient-side device 20 . When an operation mode command to be executed by the patient-side device 20 is input to the remote control device 10 by an operator who is a surgeon, the remote control device 10 transmits the motion mode command to the patient side via the controller 24 . Send to device 20 . Then, the patient-side device 20, in response to the operation mode command transmitted from the remote control device 10, operates a surgical instrument 40 attached to the robot arm 21a and an endoscopic device attached to the robot arm 21b. A medical instrument such as a mirror 50 is operated. This allows minimally invasive surgery. The patient-side device 20 is an example of a surgical robot and a surgical assistance robot. Also, the controller 24 is an example of a control unit.

The patient-side device 20 configures an interface for performing an operation on the patient P. FIG. The patient-side device 20 is arranged beside an operating table 30 on which the patient P lies. The patient-side device 20 has a plurality of robot arms 21a and 21b, of which an endoscope 50 is attached to one robot arm 21b and a surgical instrument 40 is attached to the other robot arms 21a. Each robot arm 21a, 21b is commonly supported by an arm base 22. As shown in FIG. A plurality of robot arms 21a and 21b have a plurality of joints, and each joint is provided with a driving unit including a servomotor and a position detector such as an encoder. The robot arms 21a and 21b are configured such that driving signals given via the controller 24 control the medical instruments attached to the robot arms 21a and 21b to perform desired operations.

The arm base 22 is supported by a positioner 23 placed on the floor of the operating room. Positioner 23 includes a vertical articulated robot. The positioner 23 is configured to three-dimensionally move the position of the arm base 22 . The controller 24 is a control circuit having a computing unit such as a CPU and memories such as ROM and RAM.

A surgical instrument 40 as a medical instrument is detachably attached to the distal end of the robot arm 21a. The surgical instrument 40 includes a housing 41 (see FIG. 4) attached to the robot arm 21a, an elongated shaft 42 (see FIG. 4), and an end effector 43 provided at the tip (distal end) of the shaft 42. (See FIG. 4). Examples of the end effector 43 include, but are not limited to, grasping forceps, scissors, hooks, high-frequency knives, snare wires, clamps, staplers, clip appliers, electric scalpels, and needles. can be done. In surgery using the patient-side device 20, the robot arm 21a introduces the surgical instrument 40 into the body of the patient P via a cannula (trocar) indwelled on the patient's body surface. The end effector 43 of the surgical instrument 40 is placed near the surgical site.

An endoscope 50 as a medical instrument is detachably attached to the distal end of the robot arm 21b. The endoscope 50 captures an image of the inside of the body cavity of the patient P, and the captured image is output to the remote control device 10 . As the endoscope 50, a 3D endoscope or a 2D endoscope capable of taking three-dimensional images is used. In surgery using the patient-side device 20, the robot arm 21b introduces the endoscope 50 into the body of the patient P via a trocar indwelled on the body surface of the patient. An endoscope 50 is then placed near the surgical site.

A remote control device 10 constitutes an interface with an operator. The remote control device 10 is a device for an operator to operate a medical instrument attached to the robot arm 21a. That is, the remote control device 10 is configured to be able to transmit operation mode commands to be executed by the surgical instrument 40 and the endoscope 50 input by the operator to the patient-side device 20 via the controller 24 . The remote control device 10 is installed, for example, beside the operating table 30 so that the state of the patient P can be clearly seen while operating the master. It should be noted that the remote control device 10 can be configured to, for example, wirelessly transmit operation mode instructions and be installed in a separate room from the operating room in which the operating table 30 is installed.

The operational aspects to be performed by the surgical instrument 40 are the operational aspects of the surgical instrument 40 (sequence of positions and orientations) and the operational aspects achieved by the individual functions of the surgical instrument 40 . For example, when the surgical instrument 40 is a grasping forceps, the operation mode to be executed by the surgical instrument 40 is the roll rotation position and pitch rotation position of the wrist of the end effector 43 and the operation of opening and closing the jaws. . Also, if the surgical instrument 40 is a high-frequency knife, the operational mode to be performed by the surgical instrument 40 can be an oscillating movement of the high-frequency knife, specifically supplying an electric current to the high-frequency knife. Also, if the surgical instrument 40 is a snare wire, the action mode to be performed by the surgical instrument 40 may be a restraining action and a restraining release action. Also, it may be an operation of burning off a surgical target site by supplying a bipolar or monopolar current.

The operation mode to be executed by the endoscope 50 is, for example, setting the position and posture of the tip of the endoscope 50 or setting the zoom magnification.

The remote control device 10 includes an operating handle 11, an operating pedal section 12, a display section 13, and a control device 14, as shown in FIGS. Note that the operating handle 11 is an example of an input device.

The operating handle 11 is provided for remotely operating a medical instrument attached to the robot arm 21a. Specifically, the operation handle 11 receives an operator's operation for operating the medical instruments (the surgical instrument 40 and the endoscope 50). Two operating handles 11 are provided along the horizontal direction. That is, one operating handle 11 of the two operating handles 11 is operated by the operator's right hand, and the other operating handle 11 of the two operating handles 11 is operated by the operator's left hand.

Further, the operating handle 11 is arranged so as 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 direction, the horizontal direction, the front-rear direction, and by rotating.

As shown in FIG. 3, the operating handle 11 is a hand controller that is manually operated by an operator. The operating handle 11 includes a support member 11a, a pair of grip members 11b provided on both sides of the support member 11a with the support member 11a interposed therebetween, and a finger insertion portion 11c provided on each of the pair of grip members 11b. have. The operator operates the operation handle 11 by inserting fingers (thumb, middle finger, etc.) into the pair of finger insertion portions 11c. That is, the base ends of the pair of grip members 11b are rotatably connected to the support member 11a. The opening angle of the pair of jaw members 43a, 43b is changed. A command for opening and closing the pair of jaw members 43a and 43b is input to the operating handle 11. As shown in FIG. The opening angle of the pair of grip members 11b is detected by, for example, a sensor. For example, the operating handle 11 has a Hall sensor in the support member 11a and a magnet in 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 in one of the pair of grip members 11b and a magnet in the other of the pair of grip members 11b, thereby detecting the opening angle of the pair of grip members 11b. A signal relating to the detected 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 controller 141 or controller 24, which will be described later.

As shown in FIG. 1, the remote control device 10 and the patient-side device 20 constitute a master-slave system in controlling the movements of the robot arm 21a and the robot arm 21b. That is, the operating handle 11 constitutes a master-side operation section in a master-slave type system, and the robot arm 21a and the robot arm 21b to which medical instruments are attached constitute a slave-side operation section. When the operator operates the operating handle 11, the movement of the operating handle 11 is traced by the tip of the robot arm 21a (the end effector 43 of the surgical instrument 40) or the tip of the robot arm 21b (the endoscope 50). The motion of robot arm 21a or robot arm 21b is controlled to move.

Further, the patient-side device 20 is configured to control the motion of the robot arm 21a according to the set motion magnification. For example, when the operating magnification is set to 1/2, the end effector 43 of the surgical instrument 40 is controlled to move a distance of 1/2 of the movement distance of the operating handle 11 . This allows precise surgery to be performed.

The operating pedal section 12 includes a plurality of pedals for performing functions related to medical instruments. The multiple pedals include a coagulation pedal, a cutting pedal, a camera pedal, and a clutch pedal. Also, the plurality of pedals are operated by the operator's feet.

The coagulation pedal is operable to coagulate the surgical site with surgical instrument 40 . Specifically, the coagulation pedal is operated to apply a voltage for coagulation to the surgical instrument 40 to coagulate the surgical site. The cutting pedal is operable to cut the surgical site with the surgical instrument 40 . Specifically, when the cutting pedal is operated, a cutting voltage is applied to the surgical instrument 40 to cut the surgical site.

The camera pedal is used for manipulating the position and orientation of the endoscope 50 that images the inside of the body cavity. Specifically, the camera pedal enables operation by the operation handle 11 of the endoscope 50 . In other words, while the camera pedal is pressed, the position and orientation of the endoscope 50 can be manipulated 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 operation handles 11 around the middle point of the left and right operation handles 11 . In addition, the endoscope 50 advances further by pushing both the left and right operation handles 11 . Also, by pulling the left and right operation handles 11 together, the endoscope 50 returns to the front. Further, the endoscope 50 moves vertically and horizontally by moving both the left and right operation handles 11 vertically and horizontally.

The clutch pedal is used to temporarily disconnect the operating connection between the robot arm 21a and the operating handle 11 to stop the operation of the surgical instrument 40. FIG. Specifically, while the clutch pedal is operated, even if the operation handle 11 is operated, the robot arm 21a of the patient-side device 20 does not operate. For example, when the operating handle 11 is moved to the vicinity of the end of the movable range by operation, the clutch pedal is operated to temporarily disconnect the operating connection and return the operating handle 11 to the vicinity of the central position. can. When the operation of the clutch pedal is stopped, the robot arm 21a and the operation handle 11 are connected again, and the operation of the operation handle 11 can be restarted near the center.

The display unit 13 can display an image captured by the endoscope 50 . The display section 13 is composed of a scope type display section or a non-scope type display section (the scope type display section is shown in FIG. 1). A scope-type display unit is, for example, a peek-type display unit. In addition, the non-scope type display unit is a concept including an open type display unit having a flat screen, which is not a peek-type display such as the display of an ordinary personal computer.

When the scope-type display unit is attached, a 3D image captured by the endoscope 50 attached to the robot arm 21b of the patient-side device 20 is displayed. A 3D image captured by the endoscope 50 provided in the patient-side device 20 is also displayed when the non-scope type display unit is attached. Note that when a non-scope type display unit is attached, a 2D image captured by the endoscope 50 provided in the patient-side device 20 may be displayed.

Further, the display unit 13 is provided 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. That is, the head sensor 13 a is configured to detect whether or not the operator is looking into the display section 13 and operating the operating handle 11 .

As shown in FIG. 2, the control device 14 includes, for example, a control section 141 having a computing unit such as a CPU, a storage section 142 having memories such as ROM and RAM, and an image control section 143 . The control device 14 may be composed of a single control device that performs centralized control, or may be composed of a plurality of control devices that cooperate with each other and perform distributed control. The control unit 141 converts the action mode command input by the operation handle 11 into a action mode command to be executed by the robot arm 21 a or by the endoscope 50 according to the switching state of the operation pedal unit 12 . It is determined whether it is an operation mode command to be executed. Then, when the controller 141 determines that the motion mode command input to the operating handle 11 is the motion mode command to be executed by the surgical instrument 40, it issues the motion mode command to the robot arm 21a via the controller 24. Send. Thereby, the robot arm 21a is driven by the controller 24, and the operation of the surgical instrument 40 attached to the robot arm 21a is controlled by this driving.

Further, when the control unit 141 determines that the motion mode command input to the operation handle 11 is the motion mode command to be executed by the endoscope 50, the control unit 141 outputs the motion mode command to the robot arm 21b via the controller 24. to send. This drives the robot arm 21b, and this drive controls the operation of the endoscope 50 attached to the robot arm 21b.

The storage unit 142 stores, for example, control programs corresponding to the type of the surgical instrument 40, and the control unit 141 reads out these control programs according to the type of the surgical instrument 40 attached, whereby remote operation can be performed. Operation commands of the operation handle 11 and/or the operation pedal portion 12 of the apparatus 10 can cause the individual surgical instruments 40 to operate appropriately.

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 modification processing as necessary.

(Composition of surgical instruments, adapters, drapes and robotic arms)
Next, configurations of the surgical instrument 40, the adapter 60, the drape 70 and the robot arm 21a will be described with reference to FIGS. 4 to 6. FIG.

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

As shown in FIGS. 4 and 5, surgical instrument 40 is removably attached to robotic arm 21 a of robotic surgical system 100 . Specifically, the surgical instrument 40 is detachably attached to the robot arm 21a via the adapter 60. As shown in FIG. The adapter 60 is a drape adapter for sandwiching a sterilized drape 70 for covering the robot arm 21a with the robot arm 21a.

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

The robot arm 21a is covered by a drape 70 for use in a clean area. Here, in the operating room, cleaning operations are performed in order to prevent the surgically incised portion and the medical equipment from being contaminated with pathogenic bacteria, foreign substances, and the like. In this cleaning operation, a clean area and a contaminated area, which is an area other than the clean area, are set. The surgical site is placed in a clean area. Members of the surgical team, including the operator, should ensure that only sterile objects are in the clean area during surgery, and that objects in the contaminated area should be should be sterilized. Similarly, when surgical team assistants, including the operator, place their hands in the contaminated area, they perform hand sterilization prior to direct contact with objects located in the clean area. Instruments used in the clean area are sterilized or covered with a sterile drape 70 .

As shown in FIG. 5, the drape 70 includes a body portion 71 that covers the robot arm 21a and an attachment portion 72 that is sandwiched between the robot arm 21a and the adapter 60. As shown in FIG. The body portion 71 is configured by 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 body portion 71 is provided with an opening so that the robot arm 21a and the adapter 60 can be engaged with each other. A 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 molded resin member is made of a resin material such as polyethylene terephthalate. The attachment portion 72 is formed harder (harder to bend) 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 be engaged with each other. The opening of the mounting portion 72 may be provided so as to correspond to the portion where the robot arm 21a and the adapter 60 are engaged. Further, a plurality of openings of the mounting portion 72 may be provided so as to correspond to a plurality of engaging portions of the robot arm 21 a and the adapter 60 .

As shown in FIGS. 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 provided in the housing 41 and are rotatable around a rotation axis extending in the Z direction. A plurality of driven members 44 a to 44 d are provided for operating (driving) the end effector 43 . The driven members 44 b - 44 d are connected to the end effector 43 by flexible elongated elements W consisting of wires or cables threaded through the shaft 42 . As a result, the elongated elements W are driven according to the rotation of the driven members 44b to 44d, and the end effector 43 is operated (driven) according to the driving of the elongated elements W. Further, the driven member 44a is connected to the shaft 42 via a gear 42a (see FIG. 7). As a result, the shaft 42 is rotated according to the rotation of the driven member 44a, and the end effector 43 is also rotated according to the rotation of the shaft 42. As shown in FIG.

Each of the plurality of driven members 44a-44d includes protrusions 441 and 442 that engage the drive transmission member 61 of the adapter 60 to transmit the driving force from the robot arm 21a to the end effector 43. The projections 441 and 442 protrude from the surfaces of the driven members 44a to 44d on the Z2 direction side toward the adapter 60 side (Z2 direction side). A plurality of projections 441 and 442 are arranged linearly. 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.

As shown in FIG. 5 , the adapter 60 has multiple (four) drive transmission members 61 . The drive transmission member 61 is configured to transmit the driving force from the robot arm 21a to the driven members 44a to 44d of the surgical instrument 40. As shown in FIG. That is, the drive transmission member 61 is provided so as to correspond to the driven members 44a to 44d of the surgical instrument 40. As shown in FIG. The drive transmission member 61 is provided rotatably around a rotation axis extending in the Z direction.

Each of the plurality of drive transmission members 61 includes engagement recesses 611 that engage projections 441 and 442 of the driven members 44 a - 44 d of the surgical instrument 40 . The engaging recess 611 is provided on the surgical instrument 40 side (Z1 direction side) of the drive transmission member 61, and extends from the surface of the drive transmission member 61 on the Z1 direction side opposite to the surgical instrument 40 side (Z2 direction side). ). Each of the plurality of drive transmission members 61 includes an engaging concave portion that engages with the engaging convex portion 213 of the robot arm 21a on the surface on the Z2 direction side.

The robot arm 21 a has a frame 211 , a plurality (four) of driving portions 212 and a plurality of engaging protrusions 213 . The plurality of drive portions 212 are provided to correspond to the plurality (four) of the driven members 44a to 44d of the surgical instrument 40 and the plurality (four) of the drive transmission members 61 of the adapter 60, respectively. The drive unit 212 includes an absolute encoder and a servomotor, and is configured to rotationally drive the engagement projection 213 around a rotation axis extending in the Z direction. The engagement projection 213 engages with the engagement recess on the surface of the drive transmission member 61 on the Z2 direction side. The engaging convex portion 213 protrudes from the surface of the robot arm 21a on the Z1 direction side toward the Z1 direction side (adapter 60 side). The drive portion 212 rotates the drive transmission member 61 of the adapter 60 engaged with the engagement projection 213 around the rotation axis extending in the Z direction, and drives the driven member of the surgical instrument 40 engaged with the drive transmission member 61 . 44a to 44d are configured to rotate around a rotation axis extending in the Z direction.

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

As shown in FIGS. 7 and 8, driven members 44b-44d of surgical instrument 40 have elongated elements W wrapped around them. That is, the elongated elements W are connected to the driven members 44b-44d.

An elongated element W3 is wound around the driven member 44b. Specifically, a first portion W3a of the elongated element W3 is wound clockwise around the upper portion of the driven member 44b, and a second portion W3b of the elongated element W3 is wound counterclockwise around the lower portion of the driven member 44b. It is wrapped around.

An elongated element W1 is wound around the driven member 44c. Specifically, a first portion W1a of the elongated element W1 is wound clockwise around the upper portion of the driven member 44c, and a second portion W1b of the elongated element W1 is wound counterclockwise around the lower portion of the driven member 44c. It is wrapped around.

An elongated element W2 is wound around the driven member 44d. Specifically, a first portion W2a of the elongated element W2 is wound clockwise around the upper portion of the driven member 44d, and a second portion W2b of the elongated element W2 is wound counterclockwise around the lower portion of the driven member 44d. It is wrapped around.

The elongated element W passes from each of the driven members 44b-44d, passes through the shaft 42, is hung on the end effector 43, passes through the shaft 42 again, and reaches the driven members 44b-44d. The elongated element W is also hung on a built-in pulley 45 . The built-in pulley 45 is held by a pulley holding portion 451 .

As shown in FIGS. 8 and 9, the driven member 44c operates the jaw member 43a of the pair of jaw members 43a and 43b of the end effector 43 by rotating around the rotation axis. Specifically, the driven member 44c is rotated by the driving portion 212 to drive the elongated element W1. Elongated element W1 connects jaw member 43a and driven member 44c through the interior of shaft 42. As shown in FIG. The driven member 44c rotates in the C1 direction (see FIG. 8) to pull the first portion W1a of the elongated element W1 and feed out the second portion W1b to move the jaw member 43a in the C1a direction, which is the direction in which the jaw member 43a opens. (see FIG. 9). Further, the driven member 44c rotates in the direction C2 (see FIG. 8) opposite to the direction C1, thereby pulling the second portion W1b of the elongated element W1 and sending out the first portion W1a to move the jaw member 43a. The jaw member 43a is driven in the C2a direction (see FIG. 9), which is the closing direction.

The driven member 44d operates the jaw member 43b of the pair of jaw members 43a and 43b of the end effector 43 by rotating around the rotation axis. Specifically, the driven member 44d is rotated by the driving portion 212 to drive the elongated element W2. Elongated element W2 connects jaw member 43b and driven member 44d through the interior of shaft 42. As shown in FIG. The driven member 44d rotates in direction C3 (see FIG. 8) to pull the first portion W2a of the elongated element W2 and feed out the second portion W2b to move the jaw member 43b in the C3a direction, which is the direction in which the jaw member 43b opens. (see FIG. 9). Further, the driven member 44d rotates in the C4 direction (see FIG. 8) opposite to the C3 direction, thereby pulling the second portion W2b of the elongated element W2 and sending out the first portion W2a to move the jaw member 43b. The jaw member 43b is driven in the C4a direction (see FIG. 9), which is the closing direction. A pair of jaw members 43a, 43b are opened and closed by actuation of the elongated elements W of the driven members 44b, 44c.

The driven member 44b operates the wrist portion 43c of the end effector 43 by rotating around the rotation axis. Specifically, the driven member 44b is rotated by the driving portion 212 to drive the elongated element W3. The elongated element W3 connects the wrist portion 43c and the driven member 44b through the interior of the shaft 42. As shown in FIG. By rotating in the C5 direction (see FIG. 8), the driven member 44b pulls the first portion W3a of the elongated element W3 and sends out the second portion W3b to drive the wrist portion 43c in the C5a direction (see FIG. 9). . Further, the driven member 44b rotates in the C6 direction (see FIG. 8) opposite to the C5 direction, thereby pulling the second portion W3b of the elongated element W3 and sending out the first portion W3a to push the wrist portion 43c. It is driven in the C6a direction (see FIG. 9), which is the opposite direction to the C5a direction.

The driven member 44a having the gear 443 is rotated around the rotation axis by the drive unit 212 in a state where the gear 42a connected to the proximal end of the shaft 42 and the gear 443 are engaged, thereby rotating the shaft 42. Operate to operate the end effector 43 . Specifically, the driven member 44a rotates in the C7 direction (see FIG. 8) to rotate the shaft 42 in the C7a direction (see FIG. 9) and rotate the end effector 43 in the C7a direction. . Further, the driven member 44a rotates in the C8 direction (see FIG. 8) to rotate the shaft 42 in the C8a direction (see FIG. 9), which is the opposite direction to the C7a direction. direction.

(Structure of Opening/Closing Control of Pair of Jaw Members)

Next, the opening/closing control of the pair of jaw members 43a and 43b will be described with reference to FIGS. 11 to 14. FIG. In the following description, the drive section 212 of the robot arm 21a that drives the jaw member 43a is referred to as drive section 212a, and the drive section 212 of the robot arm 21a that drives the jaw member 43b is referred to as drive section 212b.

As shown in FIGS. 11 and 12, the controller 24 of the patient-side device 20 rotates the motors of the drive units 212a and 212b based on the commanded jaw opening angle related to the opening angle θ of the pair of jaw members 43a and 43b. is configured as The commanded jaw opening angle is a command value for the opening angle .theta. The commanded jaw opening angle is such that the opening angle θ of the pair of jaw members 43 a and 43 b corresponds to the opening angle of the pair of grip members 11 b of the operating handle 11 . is converted into a command value (driving signal) for the amount of rotation given to the

FIG. 12 is a graph showing the relationship between the opening angle of the pair of grip members 11b and the commanded jaw opening angle of the pair of jaw members 43a and 43b when there are no restrictions to be described later. In the graph shown in FIG. 12 (and FIG. 13), the horizontal axis is the opening angle of the pair of grip members 11b, and the vertical axis is the commanded jaw opening angle of the pair of jaw members 43a, 43b. In the graph shown in FIG. 12, as the opening angle of the pair of grip members 11b becomes smaller, the pair of jaw members 43a and 43b are gradually closed and the pair of jaw members 43a and 43b are completely closed. Later (that is, after the opening angle θ becomes zero), the pair of jaw members 43a, 43b are rotated to further move the pair of jaw members 43a, 43b in the closing direction. 43b is shown to generate the tightening force.

Here, regardless of whether or not the object T (see FIG. 14) exists between the pair of jaw members 43a and 43b, the pair of jaw members 43a and 43b are moved to the minimum value of the commanded jaw opening angle shown in the graph of FIG. If it is possible to tighten 43a, 43b, excessive gripping force may occur.

Therefore, in the first embodiment, as shown in FIGS. 13 and 14, the controller 24 controls the current value applied to the motors of the drive units 212a and 212b (hereinafter referred to as motor current value) is monitored, and when it is determined that the object T is gripped from the motor current value, the drive units 212a and 212b are driven in a limit mode in which the magnitude of the commanded jaw opening angle is limited. It is configured. That is, the controller 24 determines whether or not the motor current values of the drive units 212a and 212b exceed a predetermined threshold value during the closing operation of the pair of jaw members 43a and 43b, and determines whether the motor current values of the drive units 212a and 212b are When it is determined that the current value exceeds a predetermined threshold value, the drive units 212a and 212b are driven in a limit mode in which the magnitude of the commanded jaw opening angle is limited. As a result, when it is determined that the motor current value of the drive units 212a and 212b exceeds the predetermined threshold value during the closing operation of the pair of jaw members 43a and 43b, the commanded jaw opening angle is limited. Since the driving portions 212a and 212b are driven in the limit mode, it is possible to suppress the generation of excessive gripping force. As a result, an appropriate gripping force can be achieved. In addition, since there is no need to provide a load cell or torque sensor on the elongated element W to limit the magnitude of the commanded jaw opening angle, there is less space around the elongated element W compared to the case where the elongated element W is provided with a load cell or torque sensor. complication of the structure can be suppressed. As a result, an appropriate gripping force can be achieved while suppressing complication of the structure around the elongated element W.

Specifically, when the controller 24 determines that the motor current values of the drive units 212a and 212b have exceeded a predetermined threshold value during the closing operation of the pair of jaw members 43a and 43b, the motors of the drive units 212a and 212b are The minimum value V2 of the commanded jaw opening angle is limited so that the difference between the value V1 of the commanded jaw opening angle when the current value exceeds a predetermined threshold value and the minimum value V2 of the commanded jaw opening angle becomes a predetermined value V3. The drive units 212a and 212b are driven in a limit mode in which the value is limited to a value larger than the initial value V4, which is the minimum value of the commanded jaw opening angle in the non-mode. As a result, the driving units 212a and 212b are driven in the limit mode in which the minimum value of the commanded jaw opening angle is limited to a value larger than the initial value V4, which is the minimum value of the commanded jaw opening angle when not in the limit mode. It is possible to more easily suppress the occurrence of excessive gripping force. As a result, an appropriate gripping force can be achieved more easily.

In other words, when the controller 24 determines that the motor current values of the driving units 212a and 212b exceed the predetermined threshold value, the motor current values of the driving units 212a and 212b exceed the predetermined threshold value. The minimum value of the commanded jaw opening angle is set to a value (that is, V2) larger than the initial value V4 so that the closing angle of the pair of jaw members 43a and 43b after the determination becomes a predetermined value V3 (constant value). configured to reconfigure.

In the limit mode, when the value of the commanded jaw opening angle generated corresponding to the opening angle of the pair of grip members 11b of the operating handle 11 is less than the minimum value V2 of the commanded jaw opening angle after restriction, the controller 24 The actuators 212a and 212b are driven by the commanded jaw opening angle limited to the minimum value V2 of the commanded jaw opening angle after the limit. In the limit mode, the controller 24 ensures that the value of the commanded jaw opening angle generated corresponding to the opening angle of the pair of grip members 11b of the operating handle 11 is equal to or greater than the minimum value V2 of the commanded jaw opening angle after restriction. In this case, the actuators 212a and 212b are driven with the same commanded jaw opening angle as in the non-limiting mode (FIG. 12).

Further, in the first embodiment, the difference between the value V1 of the commanded jaw opening angle and the minimum value V2 of the commanded jaw opening angle when the motor current value of the drive units 212a and 212b exceeds a predetermined threshold value is a predetermined value. The value V3 is the same value as the difference V6 between the commanded jaw opening angle value V5 and the initial value V4 when the opening angle θ of the pair of jaw members 43a and 43b is zero. As a result, the difference between the value V1 of the commanded jaw opening angle and the minimum value V2 of the commanded jaw opening angle when the motor current values of the drive units 212a and 212b exceed the predetermined threshold value is determined by the pair of jaw members 43a and 43a. The minimum commanded jaw opening angle is set to the same value as the difference V6 between the value V5 of the commanded jaw opening angle when the opening angle θ of 43b is set to zero and the minimum value V4 of the commanded jaw opening angle in the case of the initial value. The drive units 212a and 212b can be driven in a limit mode in which values are limited. As a result, in the limit mode, a constant gripping force substantially corresponding to the maximum value of the gripping force when the pair of jaw members 43a and 43b does not grip the object T can be generated. can be more easily suppressed. As a result, an appropriate gripping force can be achieved more easily.

Further, in the first embodiment, the controller 24 controls the motor current values of the drive units 212a and 212b to exceed the predetermined threshold value and the value of the commanded jaw opening angle to the memory 25 of the patient-side device 20 (FIG. 1). reference), it is configured to switch to the limit mode when it is determined that the value is smaller than the immediately preceding (previous) value stored in the previous (previous) value. As a result, it is detected that the pair of jaw members 43a and 43b are gripping the object T from the motor current values of the drive units 212a and 212b, and the value of the commanded jaw opening angle becomes smaller than the previous value. When it is detected that the pair of jaw members 43a and 43b are closing due to the closed state, it is possible to switch to the limit mode. As a result, it is possible to switch to the limit mode at an appropriate timing when the grip force of the pair of jaw members 43a and 43b should be limited. Note that the memory 25 is an example of a storage unit.

Specifically, the controller 24 controls the motor current values of the drive units 212 a and 212 b to exceed a predetermined threshold value and the value of the commanded jaw opening angle to be higher than the value immediately before (previous) stored in the memory 25 . It is configured to switch to the limit mode when the determination that it is getting smaller is repeated a plurality of times (for example, twice). As a result, it is detected that the pair of jaw members 43a and 43b are gripping the object T from the motor current values of the drive units 212a and 212b, and the value of the commanded jaw opening angle becomes smaller than the previous value. Therefore, it is possible to switch to the restriction mode in a state in which it is reliably detected that the pair of jaw members 43a and 43b are closing. As a result, it is possible to switch to the restriction mode at a more appropriate timing.

More specifically, the controller 24 determines whether either the motor current value of the drive unit 212a or the motor current value of the drive unit 212b exceeds a predetermined threshold value and the value of the commanded jaw opening angle is stored in the memory 25. It is configured to switch to the limit mode when the determination that the value is smaller than the stored immediately preceding (previous) value is repeated multiple times.

Further, in the first embodiment, the controller 24 is configured to release the limit mode when the motor current values of the drive units 212a and 212b are equal to or less than a predetermined threshold value. As a result, when it is detected that the gripping of the object T by the pair of jaw members 43a and 43b has been released from the motor current values of the drive units 212a and 212b, the restriction mode can be released. As a result, the restriction mode can be released at an appropriate timing when the restriction mode should be released.

Specifically, when the surgical instrument 40 can be operated by the operation handle 11, the controller 24 controls the motor current values of the drive units 212a and 212b to be equal to or less than a predetermined threshold value and the jaw command to open. The value of the angle exceeds the value (that is, V1) at which the limit mode was started, or the value of the commanded jaw opening angle exceeds a value near the maximum value of the commanded jaw opening angle (eg, the maximum value -1 degree). is configured to exit Restricted Mode if As a result, when the surgical instrument 40 can be operated by the operating handle 11, the motor current values of the drive units 212a and 212b detect the releasing of the grip of the object T by the pair of jaw members 43a and 43b, and In addition, when it is detected that the pair of jaw members 43a and 43b are more open than when the limit mode is started because the value of the commanded jaw opening angle exceeds the value when the limit mode is started, the limit mode is entered. can be released. As a result, the restriction mode can be released at a more appropriate timing. Also, the release of the grip of 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 the value of the commanded jaw opening angle is near the maximum value of the commanded jaw opening angle. When it is detected that the pair of jaw members 43a and 43b are in the maximum open state, the limit mode can be released. As a result, even if the pair of jaw members 43a and 43b cannot open more than at the start of the limit mode because the pair of jaw members 43a and 43b were opened to the maximum at the start of the limit mode, Restricted mode can be canceled.

Note that the controller 24 detects the presence of the operator's head by the head sensor 13a (see FIG. 1), and when the operator performs a predetermined operation using the operating handle 11, the controller 24 operates the operating handle 11 to perform surgery. It is configured to detect that the instrument 40 is in an operable state (hereinafter also referred to as following). Further, when the head sensor 13a does not detect the presence of the operator's head, the controller 24 detects that the operating handle 11 cannot operate the surgical instrument 40 (hereinafter also referred to as "out of following"). It is configured.

Further, in the first embodiment, when the controller 24 detects that the motor current values of the drive units 212a and 212b have become equal to or less than a predetermined threshold value when the following is not performed, the commanded jaw opening angle is configured to exit restricted mode regardless of the value of As a result, considering that the commanded jaw opening angle does not change when outside following, the motor current values of the driving units 212a and 212b are used to release the gripping of the object by the pair of jaw members 43a and 43b. If detected, the limit mode can be canceled regardless of the value of the commanded jaw opening angle. As a result, the restricted mode can be released under conditions suitable for outside following. It should be noted that after starting the restricted mode during following, there is a case where the restricted mode is continued outside of following by switching to outside following. In this case, when the above conditions are satisfied, the restriction mode is canceled.

Further, in the first embodiment, the predetermined threshold value is set based on the frictional force of the motors of the drive units 212a and 212b. Accordingly, a predetermined threshold value for detecting gripping of the object T by the pair of jaw members 43a and 43b is set in consideration of the influence of the current value generated due to the frictional force of the driving portions 212a and 212b themselves. can do. As a result, gripping of the target object T by the pair of jaw members 43a and 43b by the predetermined threshold value is reduced compared to the case where the influence of the current value generated due to the frictional force of the drive units 212a and 212b themselves is not considered. can be detected accurately.

Specifically, the predetermined threshold is set by the following formula (1). As shown in equation (1) below, the predetermined threshold value is 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) with respect to the reference value, and , is set in consideration of the dynamic friction of the motor of the drive unit 212a (212b). In the following formula (1), since 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), the shaft speed of the drive unit 212a (212b) is It is considered as a value that varies with speed. Further, in the following formula (1), since the current value generated due to the dynamic friction of the driving portion 212a (212b) is constant regardless of the shaft speed of the driving portion 212a (212b), the driving portion 212a (212b) is considered as a constant value that does not change with the shaft speed.
α=α1+(a×As+b) (1)
here,
α: Predetermined threshold value α1: Reference value a: Constant b: Constant relating to viscous friction of the driving portion As: Variable of shaft speed (rotational speed) of the driving portion.

α1 is a constant that serves as a reference for a predetermined threshold value. a is a constant related to viscous friction caused by grease or the like in the speed reducer of the drive unit 212a (212b). b is a constant related to dynamic friction generated due to the rotation of the speed reducer of the drive unit 212a (212b). α1, a and b are obtained in advance by experiments or the like. Although α1, a and b are not particularly limited, 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 of the driving section 212a (212b).

When determining whether or not to switch to the limit mode, the controller 24 uses the predetermined threshold value of the drive unit 212a obtained in real time by the above equation (1) and the motor of the drive unit 212a provided for the drive unit 212a. It is configured to compare with the motor current value of the drive unit 212a acquired in real time from the current detection unit 220a that detects the current value. Similarly, when determining whether or not to switch to the restriction mode, the controller 24 combines the predetermined threshold value of the drive unit 212b obtained in real time by the above equation (1) with the drive unit provided for the drive unit 212b. It is configured to compare the motor current value of the drive unit 212b acquired in real time from the current detection unit 220b that detects the motor current value of the drive unit 212b.

In the first embodiment, as shown in FIGS. 9 and 10, the end effector 43 includes a pulley 43d around which an elongated element W1 for driving the jaw member 43a is wound, and an elongated element W2 for driving the jaw member 43b. and a pulley 43e around which 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 has an engagement hole 43ea that engages with the engagement pin 43ba of the jaw member 43b. is provided. Also, the pair of jaw members 43a and 43b are configured to open and close on a shaft 43g different from the shaft 43f of the pulleys 43d and 43e by rotating the pulleys 43d and 43e. That is, the pair of jaw members 43a, 43b and the pulleys 43d, 43e form a link mechanism. Thereby, a large gripping force can be generated by the pair of jaw members 43a and 43b. Moreover, when using a pair of jaw members 43a and 43b having a large gripping force, the restriction mode can suppress generation of an excessive gripping force. The engagement hole 43da and the engagement hole 43ea are examples of a jaw driving engagement portion.

The elongated element W1 is wound around the pulley 43d, and is rotated by driving the elongated element W1. The elongated element W2 is wound around the pulley 43e, and is rotated by driving the elongated element W2. The pulleys 43d and 43e are rotatably supported on a common shaft 43f. Also, the pair of jaw members 43a and 43b are rotatably supported by a common shaft 43g. The axis 43g is an axis substantially parallel to the axis 43f. Further, the shaft 43g is arranged between the distal end side portion and the proximal end side portion of the pair of jaw members 43a and 43b. The shaft 43g is arranged between the distal end portions of the pair of jaw members 43a and 43b and the pulleys 43d and 43e. An engaging pin 43aa that is inserted into the engaging hole 43da of the pulley 43d is provided at the base end portion of the jaw member 43a. An engagement pin 43ba that is inserted into the engagement hole 43ea of the pulley 43e is provided at the base end portion of the jaw member 43b.

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 engaging pin 43aa engaged with the engaging 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 by a predetermined lever ratio and transmitted to the gripping portion of the object T on the distal end side of the jaw member 43a by the action of the link mechanism. 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 with 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 by a predetermined lever ratio and transmitted to the gripping portion of the object T on the distal end side of the jaw member 43b by the action of the link mechanism.

Here, when a relatively large object T (see FIG. 14) is gripped by a pair of jaw members 43a and 43b having a large gripping force as shown in FIG. 9, an excessive gripping force is likely to occur. Moreover, when an excessive gripping force is generated, the elongated elements W1 and W2 may fall off the built-in pulley 45 (see FIG. 8). That is, when an excessive gripping force is generated, for example, the one of the first portion W1a and the second portion W1b of the elongated element W1 that is sent out is excessively sent out, so that the built-in pulley 45 becomes loose. However, it may fall off the built-in pulley 45 . The same applies to the elongated element W2.

Therefore, in the first embodiment, as shown in FIG. 15, a fall-off prevention portion 46 is provided in the vicinity of the built-in pulley 45 to prevent the elongated elements W1 and W2 from falling off the built-in pulley 45. As shown in FIG. The anti-dropout portion 46 has recesses 461 for holding the elongated elements W1 and W2 with the grooves of the built-in pulley 45. As shown in FIG. The recess 461 covers the groove of the built-in pulley 45 from the side, thereby holding the elongated elements W1 and W2 arranged in the groove of the built-in pulley 45 in the space defined by the recess 461 and the groove of the built-in pulley 45. is provided as follows. In addition, the recess 461 corresponds to a total of four portions, two portions of the first portion W1a and the second portion W1b of the elongated element W1 and two portions of the first portion W2a and the second portion W2b of the elongated element W2. Four are provided so that it may carry out.

(Control processing for starting restricted mode)
Next, referring to FIG. 16, control processing for starting the limit mode during following by the controller 24 will be described based on a flowchart.

As shown in FIG. 16, first, in step S1, it is determined whether or not the motor current values of the driving units 212a and 212b have exceeded a predetermined threshold value. That is, in step S1, it is determined whether or not the pair of jaw members 43a and 43b have gripped the object T, thereby increasing the motor current values of the drive portions 212a and 212b.

Specifically, in step S1, the motor current value of the drive unit 212a exceeds the predetermined threshold value of the drive unit 212a according to the above formula (1), or the motor current value of the drive unit 212b exceeds the above formula (1). ), it is determined whether or not a predetermined threshold value of the drive unit 212b is exceeded. If both the motor current value of drive unit 212a and the motor current value of drive unit 212b do not exceed the predetermined threshold value, the process of step S1 is repeated. Further, when at least one of the motor current value of the drive unit 212a and the motor current value of the drive unit 212b exceeds the predetermined threshold value, the process proceeds to step S2.

Then, in step S2, it is determined whether or not the value of the commanded jaw opening angle generated corresponding to the opening angle of the pair of grip members 11b of the operating handle 11 is smaller than the value immediately before (previous time). If the value of the commanded jaw opening angle is not smaller than the previous value (previous time), the process proceeds to step S1. Also, if the value of the commanded jaw opening angle is smaller than the previous value (previous time), the process proceeds to step S3. For example, when proceeding from steps S1, S2, and S3 to step S1, the value of the commanded jaw opening angle is stored in the memory 25 as the previous (previous) value of the commanded jaw opening angle.

Then, in step S3, it is determined whether or not the conditions of steps S1 and S2 are satisfied two times in succession. If the conditions of steps S1 and S2 are not satisfied two times in a row, the process proceeds to step S1. Moreover, when the conditions of steps S1 and S2 are satisfied twice consecutively, the process proceeds to step S4.

Then, in step S4, switching to the limit mode is performed, and the value of the commanded jaw opening angle at the start of the limit mode is stored in the memory 25. FIG. In limit mode, the magnitude of the commanded jaw opening angle is limited, as described above. After that, the restricted mode is continued until the restricted mode is canceled.

(Control processing for canceling restriction mode)
Next, referring to FIG. 17, control processing for canceling the limit mode during following by the controller 24 will be described based on a flowchart.

As shown in FIG. 17, first, in step S11, it is determined whether or not the motor current values of the drive units 212a and 212b have become equal to or less than a predetermined threshold value. That is, in step S11, it is determined whether or not the motor current values of the drive units 212a and 212b have decreased because the pair of jaw members 43a and 43b no longer grip the object T.

Specifically, in step S11, the motor current value of the drive unit 212a becomes equal to or less than the predetermined threshold value of the drive unit 212a according to the above formula (1), and the motor current value of the drive unit 212b becomes equal to or below the above formula (1). It is determined whether or not the drive unit 212b is equal to or less than a predetermined threshold value. If both the motor current value of drive unit 212a and the motor current value of drive unit 212b are not equal to or less than the predetermined threshold value, the process of step S11 is repeated. Further, when both the motor current value of the drive unit 212a and the motor current value of the drive unit 212b are equal to or less than the predetermined threshold value, the process proceeds to step S12.

Then, in step S12, it is determined whether or not the value of the commanded jaw opening angle generated corresponding to the opening angle of the pair of grip members 11b of the operating handle 11 exceeds the value at the start of the limit mode. be. If the value of the commanded jaw opening angle exceeds the value at the start of the limit mode, the process proceeds to step S14. Then, in step S14, the restriction mode is canceled.

Also, in step S12, if the value of the commanded jaw opening angle does not exceed the value at the start of the limit mode, the process proceeds to step S13.

Then, in step S13, it is determined whether or not the value of the commanded jaw opening angle exceeds a value near the maximum value (maximum value -1 degree here). If the value of the commanded jaw opening angle does not exceed the maximum value -1 degree, the process proceeds to step S11. If the value of the commanded jaw opening angle exceeds the maximum value -1 degree, the process proceeds to step S14. Then, in step S14, the restriction mode is canceled.

(Control processing for canceling restriction mode)
Next, referring to FIG. 18, control processing for canceling the non-following restriction mode by the controller 24 will be described based on a flowchart.

As shown in FIG. 18, first, in step S21, it is determined whether or not the motor current values of the drive units 212a and 212b have become equal to or less than a predetermined threshold value. Note that the process of step S21 is the same as the process of step S11 shown in FIG. Therefore, when both the motor current value of the driving section 212a and the motor current value of the driving section 212b are not equal to or less than the predetermined threshold value, the process of step S21 is repeated. Further, when both the motor current value of the drive unit 212a and the motor current value of the drive unit 212b are equal to or less than the predetermined threshold value, the process proceeds to step S22. Then, in step S22, the restriction mode is canceled. In the control processing for canceling the limit mode outside following shown in FIG. 18, unlike the control processing for canceling the limit mode during following shown in FIG. has not been determined.

[Second embodiment]
Next, a second embodiment will be described with reference to FIGS. 19 to 21. FIG. In the second embodiment, unlike the first embodiment, an example of switching to a limit mode in which the minimum value of the commanded jaw opening angle is limited to zero or less will be described. In the drawings, the same components as in the first embodiment are indicated by the same reference numerals, and descriptions thereof are omitted.

(Configuration of robotic surgery system)
A robotic surgery system 300 according to the second embodiment, as shown in FIG. 19, includes a controller 324 in place of the controller 24 of the first embodiment. Note that the controller 324 is an example of a control unit.

FIG. 20 is a graph (graph shown in FIG. 12) showing the relationship between the opening angle of the pair of grip members 11b and the commanded jaw opening angle of the pair of jaw members 43a and 43b. It is a graph to which a graph (indicated by a dashed-dotted line) showing the relationship with values is added. In the graph shown in FIG. 20, the horizontal axis is the opening angle of the pair of grip members 11b, and the vertical axis is the commanded jaw 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 values of the drive portions 212a and 212b exceed a predetermined threshold value. For example, the detected angle takes into account the elongation of the elongated 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 values of the drive units 212a and 212b exceed a predetermined threshold value. can be estimated by

FIG. 21 is a graph showing the relationship between the detected angle and the minimum value of the commanded jaw opening angle. In the graph shown in FIG. 21, the horizontal axis is the detected angle, and the vertical axis is the minimum commanded jaw opening angle of the pair of jaw members 43a and 43b. Further, in the graph shown in FIG. 21, the graph showing the relationship between the detected angle and the minimum value of the commanded jaw opening angle when the control of the first embodiment is performed is shown by the solid line, and the control of the second embodiment is shown by the solid line. A graph showing the relationship between the detected angle and the minimum value of the commanded jaw opening angle is indicated by a dashed line.

Here, in the second embodiment, as shown in FIGS. 20 and 21, the controller 324 controls the motor current values of the drive units 212a and 212b to be equal to or lower than a predetermined threshold value during the closing operation of the pair of jaw members 43a and 43b. is exceeded, the minimum value V2 of the jaw command opening angle is a value larger than the initial value V4, and the drive units 212a and 212b are driven in a limit mode limited to zero or less. there is That is, in the limit mode of the second embodiment, not only the lower limit value of the minimum value of the jaw command opening angle, but also the upper limit value is limited. Here, for example, when 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 thinly. In the first embodiment, the minimum value of the commanded jaw opening angle of the pair of jaw members 43a and 43b may be greater than zero (see FIG. 21). There is a risk that the object T may fall off the jaw members 43a and 43b. On the other hand, in the second embodiment, even in the limit mode, the minimum value of the commanded jaw opening angle is set to always be zero or less. , 43b closes following changes in the thickness of the object T, so that the object T can be reliably gripped.

In the second embodiment, the upper limit value V11 of the minimum value V2 of the commanded jaw opening angle after the limit is set in the limit mode. The upper limit value V11 is a negative value smaller than zero by a predetermined amount. As a result, unlike the case where the upper limit V11 is zero, the pair of jaw members 43a and 43b can be completely displaced in the limit mode even if the backlash between the jaw member 43a (43b) and the pulley 43d (43e) is considered. It can be operated in such a way that it can be completely closed. The upper limit value V11 is set to a negative value smaller by a predetermined amount corresponding to the backlash between the jaw member 43a (43b) and the pulley 43d (43e). For example, if the backlash is 1.5 degrees, the upper limit value V11 is set to -1.5 degrees.

Further, in the second embodiment, when the controller 324 determines that the motor current values of the drive units 212a and 212b have exceeded a predetermined threshold during the closing operation of the pair of jaw members 43a and 43b, the motor current value is configured to detect the rotation angle of the motor when exceeds a predetermined threshold value, and to control switching to the limit mode based on the detected rotation angle of the motor. Specifically, when the controller 324 determines that the motor current values of the drive units 212a and 212b have exceeded a predetermined threshold value during the closing operation of the pair of jaw members 43a and 43b, the detected angle is set to the predetermined value V12. In the above cases, the mode is switched to the limit mode, and when the detected angle is less than the predetermined value V12, the mode is not switched to the limit mode. As a result, it is possible to prevent unnecessary switching to the limit mode in a region where the detection angle is small. When not switching to the limit mode, the minimum value of the commanded jaw opening angle is the initial value V4.

Further, when the controller 324 determines that the motor current value of the driving units 212a and 212b exceeds the predetermined threshold value during the closing operation of the pair of jaw members 43a and 43b, the detected angle is equal to or greater than the predetermined value V12. is configured to switch to restricted mode if Specifically, when the detected angle is equal to or greater than a predetermined value V12 and less than a predetermined value V13 (V13>V12), the controller 324 sets the minimum value V2 of the commanded jaw opening angle to a value greater than the initial value V4. and is configured to switch to a limit mode in which the voltage is limited to less than the upper limit value V11. In this case, the controller 324 is configured to limit the minimum value V2 of the commanded jaw opening angle so that the minimum value V2 of the commanded jaw opening angle gradually decreases as the detected angle decreases. For example, the controller 324 is configured to obtain the minimum value V2 of the commanded jaw opening angle according to Equation (2) below.
V2=V4×R+V4-c (2)
here,
V2: Minimum value of commanded jaw opening angle after limitation V4: Initial value (minimum value of commanded jaw opening angle before limitation)
R: Reduction ratio with respect to detection angle (variable that changes according to detection angle)
c: A predetermined constant.

Further, the controller 324 is configured to switch to a limit mode in which the minimum value V2 of the commanded jaw opening angle is limited to the upper limit value V11 when the detected angle is equal to or greater than the predetermined value V13. In this case, the controller 324 is configured to limit the minimum value V2 of the commanded jaw opening angle so that the minimum value V2 of the commanded jaw opening angle becomes the upper limit value V11 regardless of the detected angle.

[Modification]
It should be noted that the embodiments disclosed this time should be considered as examples and not restrictive in all respects. The scope of the present invention is indicated by the scope of the claims rather than the description of the above-described embodiments, and includes all modifications (modifications) within the meaning and scope equivalent to the scope of the claims.

For example, in the first and second embodiments, the pair of jaw members are driven by flexible elongated elements made of wires or cables, but the present invention is not limited to this. For example, a pair of jaw members may be driven by rigid elongated elements comprising rods.

Further, in the first and second embodiments, an example is shown in which the operation handle having a pair of grip members is provided as an input device for inputting a command to open and close the pair of jaw members. It is not limited to this. For example, an operating handle other than the operating handle having a pair of grip members may be provided as an input device for inputting commands for opening and closing the pair of jaw members. Also, an input device other than the operating handle may be provided as an input device for inputting a command to open and close the pair of jaw members.

Further, in the first embodiment, the predetermined value, which is the difference between the value of the commanded jaw opening angle when the motor current value of the driving unit exceeds the predetermined threshold value, and the minimum value of the commanded jaw opening angle is An example was shown in which the difference between the value of the commanded jaw opening angle when the opening angle of the jaw member is zero and the minimum value of the commanded jaw opening angle in the case of the initial value is the same value, but the present invention is based on this Not limited. For example, the predetermined value may be a value larger than the difference between the value of the commanded jaw opening angle when the opening angle of the pair of jaw members is zero and the minimum value of the commanded jaw opening angle when the opening angle is the initial value. and may be a small value.

Further, in the first and second embodiments, the controller determines that the motor current value of the driving unit exceeds the predetermined threshold value and that the commanded jaw opening angle value is smaller than the previous value. case, the example of switching to the restriction mode has been shown, but the present invention is not limited to this. For example, when the controller detects that the motor current value of the drive exceeds a predetermined threshold, the controller may switch to limit mode regardless of the commanded jaw opening angle.

Further, in the first and second embodiments, the controller determines that the motor current value of the driving unit exceeds the predetermined threshold value and that the value of the commanded jaw opening angle is smaller than the previous value. Although an example of switching to the restriction mode when repeated multiple times has been shown, the present invention is not limited to this. For example, the controller determines only once that the motor current value of the driving unit exceeds a predetermined threshold value and the value of the commanded jaw opening angle is smaller than the previous value, and the limit mode is performed. You can switch to

Further, in the first and second embodiments, the controller controls the motor current value of the drive unit to be equal to or less than the predetermined threshold value and the value of the commanded jaw opening angle to the limit mode when following is in progress. or the value of the commanded jaw opening angle exceeds the value near the maximum value of the commanded jaw opening angle, the limit mode is canceled. Not limited. For example, when the controller determines that the motor current value of the drive unit has become equal to or less than a predetermined threshold during following, the controller may release the limit mode regardless of the commanded jaw opening angle.

Further, in the above-described first and second embodiments, an example in which the predetermined threshold value is set by the above formula (1) has been shown, but the present invention is not limited to this. For example, the predetermined threshold may be set by a formula other than formula (1) above.

Moreover, in the above-described first and second embodiments, an example in which the anti-falling portion is provided has been shown, but the present invention is not limited to this. For example, the drop-off preventing portion may not be provided.

Also, in the above-described first and second embodiments, the robotic surgery system is shown as a master-slave system, but the present invention is not limited to this. For example, a system including a semi-automated process in which a patient-side device automatically performs some steps without receiving instructions from a remote control device, or a fully-automated system in which a patient-side device performs alone may be used. In that case, the commanded jaw opening angle is generated by the control unit or the controller based on the control program including the limit mode.

Further, in the above-described second embodiment, an example in which the upper limit value of the minimum commanded jaw opening angle is set in the limit mode has been described, but the present invention is not limited to this. For example, it is not necessary to set the upper limit value of the minimum value of the commanded jaw opening angle in the limit mode.

Also, in the above-described second embodiment, an example in which the upper limit value is a negative value by a predetermined amount has been described, but the present invention is not limited to this. For example, the upper limit may be zero.

The functionality of the elements disclosed herein may be accomplished using general purpose processors, special purpose processors, integrated circuits, Application Specific Integrated Circuits (ASICs), conventional circuits, and/or those configured or programmed to perform the disclosed functions. can be implemented using a circuit or processing circuit that includes a combination of 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 or is programmed to perform the recited functions. The hardware may be the hardware disclosed herein, or other known hardware programmed or configured to perform the recited functions. A circuit, means or unit is a combination of hardware and software where the hardware is a processor which is considered a type of circuit, the software being used to configure the hardware and/or the processor.

20: Patient side device (surgical robot, surgery support robot), 11: Operation 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 (jaw driving engagement portion), 43f: shaft (shaft of pulley), 43g: shaft ( 44c, 44d: driven member; 100: robotic surgical system; 212a, 212b: drive unit; , V4: Initial value, V5: Jaw command opening angle value, V6: Difference, V11: Upper limit value, W1, W2: Elongated element, θ: Opening angle

Claims (15)

a surgical instrument having a pair of jaw members that open and close to grasp an object by actuation of an elongated element connected to a driven member;
an input device for inputting a command to open and close the pair of jaw members;
a robot arm to which the surgical instrument is attached and including a drive unit for driving the driven member; a surgical robot having a control unit that drives the unit,
The control section determines whether or not the current value of the driving section exceeds a predetermined threshold value during the closing operation of the pair of jaw members, and determines whether the current value of the driving section exceeds the predetermined threshold value. and driving the drive unit in a limit mode in which the magnitude of the commanded jaw opening angle is limited. When the controller determines that the current value of the drive unit exceeds the predetermined threshold value during the closing operation of the pair of jaw members, when the minimum value of the commanded jaw opening angle is not in the limit mode. 2. The robotic surgery system according to claim 1, wherein the drive unit is driven in the limited mode limited to a value larger than an initial value, which is the minimum value of the commanded jaw opening angle of . The difference between the value of the commanded jaw opening angle when the current value of the drive unit exceeds the predetermined threshold value and the minimum value of the commanded jaw opening angle in the limit mode is the opening of the pair of jaw members. 3. The robotic surgical system of claim 2, wherein the value is the same as the difference between the value of the commanded jaw opening angle when zeroing the angle and the initial value. further comprising a storage unit,
The control unit determines that the current value of the drive unit exceeds the predetermined threshold value and that the value of the commanded jaw opening angle is smaller than the previous value stored in the storage unit. 2. The robotic surgical system of claim 1, wherein the robotic surgical system switches to the restricted mode if a The control section determines that the current value of the drive section exceeds the predetermined threshold value and that the value of the commanded jaw opening angle is smaller than the previous value stored in the storage section. 5. The robotic surgical system of claim 4, wherein switching to said restricted mode after multiple iterations. 2. The robotic surgical system according to claim 1, wherein said control section cancels said limit mode when the current value of said driving section is equal to or less than said predetermined threshold value. When the surgical instrument is operable by the input device, the controller controls the current value of the drive unit to be equal to or less than the predetermined threshold value and the value of the commanded jaw opening angle to the above-described value. 7. The limit mode is released when the value exceeds the value when the limit mode is started or when the value of the commanded jaw opening angle exceeds a value near the maximum value of the command jaw opening angle. robotic surgery system. When the surgical instrument cannot be operated by the input device, the control section controls the operation of the operating device regardless of the value of the commanded jaw opening angle when the current value of the driving section becomes equal to or less than the predetermined threshold value. 7. The robotic surgical system of claim 6, wherein the restricted mode is canceled without first canceling the restricted mode. 2. The robotic surgical system according to claim 1, wherein said predetermined threshold value is set based on the frictional force of said drive unit. the surgical instrument further comprising a pulley around which the elongated element drives the jaw member;
The pulley is provided with a jaw drive engaging portion that engages with the jaw member,
2. The robotic surgical system of claim 1, wherein the pair of jaw members are opened and closed on an axis different from an axis of the pulley by rotating the pulley. When the control section determines that the current value of the drive section exceeds the predetermined threshold value during the closing operation of the pair of jaw members, the minimum value of the commanded jaw opening angle is higher than the initial value. 3. The robotic surgical system of claim 2, wherein the drive is driven in the limited mode with a large value and limited to zero or less. An upper limit value of a minimum value of the jaw command opening angle after limitation is set in the limitation mode,
12. The robotic surgical system of claim 11, wherein the upper limit is a negative value less than zero by a predetermined amount. The drive unit includes a motor,
When the controller determines that the current value of the motor exceeds the predetermined threshold value during the closing operation of the pair of jaw members, the controller determines that the current value of the motor exceeds the predetermined threshold value. 12. The robotic surgery system according to claim 11, wherein the rotation angle of said motor during operation is detected, and switching to said limit mode is controlled based on the detected rotation angle of said motor. A surgical instrument having a pair of jaw members that are opened and closed to grip an object by driving an elongated element connected to a driven member, an input device for inputting a command to open and close the pair of jaw members, and the surgical instrument. and a surgical robot having a robot arm including a drive unit for driving the driven member, wherein
obtaining a jaw command opening angle for the opening angle of the pair of jaw members associated with the input to the input device;
and driving the driving unit based on the commanded jaw opening angle;
The step of driving the drive section determines whether or not the current value of the drive section exceeds a predetermined threshold value during the closing operation of the pair of jaw members, and determines whether the current value of the drive section exceeds the predetermined threshold value. exceeding a threshold value of the commanded jaw opening angle, driving the drive unit in a limited mode in which the magnitude of the commanded jaw opening angle is limited. a surgical instrument having a pair of jaw members that open and close to grasp an object by actuation of an elongated element connected to a driven member;
a robotic arm to which the surgical instrument is attached and which includes a drive unit for driving the driven member;
a control unit that drives the driving unit based on a commanded jaw opening angle related to the opening angle of the pair of jaw members;
The control section determines whether or not the current value of the driving section exceeds a predetermined threshold value during the closing operation of the pair of jaw members, and the current value of the driving section exceeds the predetermined threshold value. A surgery support robot that drives the drive unit in a limit mode in which the magnitude of the commanded jaw opening angle is limited when it is determined that the commanded jaw opening angle is exceeded.

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