WO2025206297A1 - Surgical robot system and control method therefor - Google Patents

Abstract

A surgical robot system (10) is provided with: a plurality of robot arms (3) to each of which a surgical instrument (40) is mounted; an operation device (2) for receiving an operation input from an operator (S) for controlling the position and attitude of the surgical instrument (40); an arm control unit (28) for controlling the plurality of robot arms (3) on the basis of the operation input; a positioner (7) having an arm base (5) to which the plurality of robot arms (3) are mounted; and a positioner control unit (75) for controlling the positioner (7) to adjust the position and attitude of the arm base (5). The positioner control unit (75) adjusts at least one of the position and attitude of the arm base (5) during surgery. The arm control unit (28) controls the robot arm (3) without the movement of the surgical instrument (40) being affected by the adjustment of the position and/or attitude of the arm base (5) by the positioner control unit (75). The surgical robot system (10) can appropriately respond to changes in conditions during surgery.

Description

Surgical robot system and control method thereof

This disclosure relates to a surgical robot system and a control method thereof.

Instead of the conventional surgical method in which surgeons directly handle and operate surgical instruments, a surgical robot system has been disclosed that uses a robot to operate surgical instruments and perform surgical operations. Surgical robot systems are used, for example, in minimally invasive surgery, which can reduce the burden on patients undergoing surgery.

A surgical robot system generally comprises a surgical robot positioned next to the patient and an operating device that allows the surgeon to remotely operate the surgical robot. The operating device operated by the surgeon is, for example, located inside an operating room where a surgical bed on which the patient is placed is located. The surgical robot has a robotic arm, to which surgical instruments are detachably attached. The surgical instruments attached to the robotic arm are configured, for example, to be insertable into a port member provided on the patient. The port member is, for example, a trocar or cannula. Types of surgical instruments include forceps, electrocautery, staplers, endoscopes, etc., and are selected appropriately from among these depending on the surgical procedure, etc. When a surgical robot has multiple robotic arms, different types of surgical instruments may be attached to each robotic arm, or the same type of surgical instrument may be attached to two or more robotic arms. For example, an endoscope may be attached to one robotic arm and forceps to two or more other robotic arms.

By operating the operating device to operate the surgical robot, the surgeon (operator) can control the position and orientation of the surgical instrument attached to the robotic arm. If the surgical instrument itself has movable parts such as joints, such as forceps, the operating device can also be used to operate the movable parts of the surgical instrument. This allows the surgeon to control the position and orientation of the surgical instrument (and the movable parts, if any) using the operating device. For example, if the surgical instrument is configured with a pair of jaws at the tip of the shaft, the surgeon can control the position and orientation of the entire surgical instrument by operating the operating device, as well as control the opening and closing of the pair of jaws, or the rotation around the pitch axis and/or yaw axis. Furthermore, if the shaft itself is configured to be rotatable around its longitudinal axis, the surgeon can rotate the shaft of the surgical instrument (around the roll axis) by operating the operating device.

Some conventional surgical robot systems are equipped with a positioner having an arm base to which multiple robot arms are attached (see, for example, Patent Document 1). In these conventional surgical robot systems, the arm base is positioned by the positioner before the start of surgery, depending on, for example, the position of a port member (cannula, trocar, etc.) that penetrates the patient's body wall.

International Publication No. 2022/138495

In conventional surgical robot systems, once the arm base is positioned before the start of surgery, it is not generally assumed that the arm base will be changed during surgery, and there is room for further improvement in terms of responding to changing situations during surgery.

This disclosure has been made to solve the above-mentioned problems, and one purpose of this disclosure is to provide a surgical robot system and a control method thereof that can appropriately respond to changes in the situation during surgery.

(Aspect 1)
Aspect 1 of this disclosure is
a plurality of robotic arms, each of the plurality of robotic arms having a surgical instrument attached thereto;
an operating device that receives an operation input from an operator to control the position and posture of the surgical instrument;
an arm control unit that controls the plurality of robot arms based on the operation input;
a positioner having an arm base on which the plurality of robot arms are mounted;
a positioner control unit that controls the positioner to adjust the position and attitude of the arm base,
the positioner control unit adjusts at least one of the position and the attitude of the arm base during surgery;
The arm control unit is a surgical robot system that controls the multiple robot arms without the movement of the surgical instrument being affected by adjustment of at least one of the position and the attitude of the arm base by the positioner control unit.

(Aspect 2)
Aspect 2 of this disclosure is a surgical robot system described in aspect 1, wherein the positioner control unit adjusts at least one of the position and the posture of the arm base based on intraoperative conditions that change during surgery.

(Aspect 3)
Aspect 3 of this disclosure is a surgical robot system as described in Aspect 2, wherein the positioner control unit adjusts at least one of the position and the attitude of the arm base to adjust an instrument operating range, which is defined as the area in which the surgical instrument can operate within the surgical field, for a target robot arm that is at least one of the plurality of robot arms.

(Aspect 4)
Aspect 4 of this disclosure is a surgical robot system according to aspect 3, wherein the positioner control unit adjusts at least one of the position and the posture of the arm base based on the surgical field changing during surgery.

(Aspect 5)
Aspect 5 of the present disclosure is a surgical robot system according to aspect 4, wherein the surgical field is defined based on at least one of the position and orientation of an imaging device that images the surgical site during surgery.

(Aspect 6)
Aspect 6 of the present disclosure is a surgical robot system according to aspect 4 or 5, which has a surgical field designation means for designating the surgical field during surgery based on a command from the operator.

(Aspect 7)
Aspect 7 of the present disclosure is a surgical robot system according to any one of aspects 4 to 6, which includes a surgical field estimation means for automatically estimating the surgical field based on the inclination of the operating table.

(Aspect 8)
Aspect 8 of the present disclosure is a surgical robot system described in any one of aspects 3 to 7, which has a manual arm selection means for selecting the target robot arm based on a command from the operator.

(Aspect 9)
Aspect 9 of this disclosure is a surgical robot system described in any one of aspects 3 to 7, having an automatic arm selection means for selecting the robot arm being operated by the operation input from the operator as the target robot arm.

(Aspect 10)
Aspect 10 of this disclosure is a surgical robot system described in any one of aspects 1 to 9, in which the positioner control unit maintains a distance between the arm base and a virtual space preset around the arm base at a constant value or greater.

(Aspect 11)
Aspect 11 of this disclosure is a surgical robot system described in any one of Aspects 1 to 10, wherein the positioner control unit adjusts at least one of the position and the attitude of the arm base during surgery to avoid interference between one robot arm of the plurality of robot arms and another robot arm of the plurality of robot arms.

(Aspect 12)
Aspect 12 of this disclosure is
each of the plurality of robot arms has a plurality of drive axes, the number of the plurality of drive axes being greater than a minimum number of degrees of freedom required to control the position and orientation of the surgical instrument;
the arm control unit defines at least one of the plurality of drive shafts as a redundant drive shaft and controls the redundant drive shaft based on the operation input and constraint conditions;
12. A surgical robot system according to any one of aspects 1 to 11, wherein the constraint conditions are adjusted to maintain a proximity distance between the robot arm and an object present around the robot arm equal to or greater than a minimum allowable distance.

(Aspect 13)
Aspect 13 of this disclosure is
the surgical instrument has a longitudinal axis;
13. The surgical robot system of claim 12, wherein the redundant drive shaft rotates at least a portion of the surgical instrument about the longitudinal axis.

(Aspect 14)
Aspect 14 of this disclosure is a surgical robot system described in Aspect 13, wherein the arm control unit rotates at least a portion of the surgical instrument around the longitudinal axis in a direction that increases the proximity distance when the difference between the proximity distance and the minimum allowable distance becomes smaller than a predetermined threshold.

(Aspect 15)
Aspect 15 of the present disclosure is a surgical robot system described in any one of aspects 1 to 14, wherein the positioner includes a vertical articulated robot.

The surgical robot system and control method disclosed here can appropriately respond to changes in the situation during surgery.

FIG. 1 is a perspective view showing a schematic configuration of a surgical robot system according to one embodiment. FIG. 1 is a plan view showing a schematic configuration of a surgical robot system according to one embodiment. FIG. 1 is a side view showing a schematic configuration of a surgical robot system according to one embodiment. FIG. 2 is another side view showing the schematic configuration of the surgical robot system according to the embodiment. FIG. 1 is a side view showing a surgical robot of a surgical robot system according to one embodiment. FIG. 1 is a perspective view showing a portion of a surgical robot of a surgical robot system according to one embodiment. FIG. 1 is a perspective view showing a schematic configuration of a surgical instrument attached to a robot arm of a surgical robot system according to one embodiment. FIG. 10 is a perspective view showing a schematic configuration of another surgical instrument attached to the robot arm of the surgical robot system according to one embodiment. FIG. 1 is a block diagram illustrating a system configuration of a control device of a surgical robot system according to an embodiment. FIG. 1 is a perspective view showing a schematic configuration of a robot arm and a surgical instrument of a surgical robot system according to one embodiment. FIG. 1 is a perspective view showing a schematic configuration of a distal end of a robot arm of a surgical robot system according to one embodiment and a surgical instrument attached to the distal end. FIG. 1 is a perspective view showing a schematic configuration of a distal end portion of a robot arm of a surgical robot system according to one embodiment. FIG. 1 is a diagram showing a schematic configuration of an arm base and a robot arm attached to the arm base of a surgical robot system according to one embodiment. FIG. 1 is a block diagram illustrating a schematic configuration of a drive control system of a surgical robot system according to one embodiment. FIG. 10 is a diagram showing an example of the operation of the surgical robot system according to one embodiment. FIG. 10 is another diagram showing an example of the operation of the surgical robot system according to the embodiment. FIG. 10 is yet another diagram showing an example of the operation of the surgical robot system according to one embodiment. 1 is a schematic diagram illustrating a virtual model of a robot arm and reference sites used in a control method for a surgical robot system according to one embodiment. FIG. 1 is a flowchart illustrating a control method for a surgical robot system according to one embodiment. FIG. 2 is a schematic diagram for explaining a control method of a surgical robot system according to one embodiment. FIG. 10 is another schematic diagram for explaining the control method of the surgical robot system according to one embodiment. FIG. 10 is yet another schematic diagram for explaining a control method of a surgical robot system according to one embodiment. FIG. 1 is a block diagram showing a schematic system of a surgical robot system according to one embodiment. 10A to 10C are diagrams illustrating an example of the operation of a surgical robot in a surgical robot system according to one embodiment. 10A and 10B are diagrams illustrating other examples of the operation of the surgical robot of the surgical robot system according to one embodiment. FIG. 10 is yet another diagram showing an example of the operation of the surgical robot of the surgical robot system according to one embodiment. 1A and 1B are diagrams for explaining the operation of a surgical robot in a surgical robot system according to one embodiment. 10A and 10B are other diagrams for explaining the operation of the surgical robot of the surgical robot system according to one embodiment. FIG. 10 is yet another diagram for explaining the operation of the surgical robot of the surgical robot system according to one embodiment. FIG. 10 is yet another diagram for explaining the operation of the surgical robot of the surgical robot system according to one embodiment. FIG. 2 is a schematic diagram for explaining a control method of a surgical robot system according to one embodiment. FIG. 10 is another schematic diagram for explaining the control method of the surgical robot system according to one embodiment. FIG. 10 is yet another schematic diagram for explaining a control method of a surgical robot system according to one embodiment.

The following describes embodiments that embody this disclosure.

The surgical robot system according to this embodiment is a robot system composed entirely of master-slave manipulators. The operating device that constitutes the master unit is equipped with a hand control that allows the operator (the surgeon who is performing the procedure) to manually manipulate its position and orientation. The coordinates of the hand control's position and orientation in a coordinate system set on the master side (master coordinates) are mapped to the coordinates of its position and orientation in a coordinate system set on the slave side (slave coordinates). Scaling can also be introduced in the mapping between the master coordinates and the slave coordinates. For example, a scaling coefficient can be set so that the amount of change in the slave coordinates is smaller than the amount of change in the master coordinates.

When the operator operates the hand control, the master coordinates change, and the slave coordinates change accordingly. The surgical robot system's control device calculates the axis values of each of the multiple drive axes of the robot arm of the surgical robot that makes up the slave unit from the slave coordinates (position and orientation). The control device controls the operation of the drive axes of the slave unit based on the axis values calculated.

In this specification, the drive shaft of a robot arm may be a joint of the robot arm, or it may be a drive shaft provided on the robot arm to drive a joint (driven shaft) included in a surgical instrument.

The robot arm of the surgical robot in the surgical robot system according to this embodiment has redundancy. That is, the degrees of freedom required for the task to be accomplished by the robot arm are fewer than the degrees of freedom (i.e., the number of drive axes) that the robot arm has. Conversely, the degrees of freedom of the robot arm are greater than the degrees of freedom required for the task. The degrees of freedom required for the task to be accomplished by the robot arm are typically the degrees of freedom required for (the task of) controlling the position and orientation of a surgical instrument detachably attached to the tip of the robot arm. Here, the number of drive axes that determines the degrees of freedom of the robot arm includes the number of drive axes for controlling the joints (joints of the movable parts of the surgical instrument) of the surgical instrument itself attached to the tip of the robot arm, and/or the number of drive axes for rotating the entire surgical instrument relative to the tip of the robot arm.

When the robot arm of the surgical robot that makes up the slave unit has redundancy like this, there is no unique solution (combination of multiple axis values) when calculating each axis value of the robot arm from the slave coordinates using inverse kinematics calculations; there are an infinite number of solutions. As a result, it is not possible to determine each axis value of the robot arm, and as it is, it is not possible to control the movement of the robot arm.

When a robot arm has redundancy, there will be extra axes that do not necessarily need to be operated from the perspective of completing a task. These extra axes can be called redundant axes. Because the robot arm as a whole has an extra number of axes, it is not necessarily the case that any particular axis among the multiple axes that make up the robot arm will be determined as a redundant axis. In other words, in inverse kinematics calculations for a robot arm with redundancy, which axis to treat as a redundant axis is not a given condition that is necessarily determined by the configuration of the robot arm, but rather is something that must be decided after the fact.

In the control method for the surgical robot system according to this embodiment, one drive axis is assigned to one redundant degree of freedom in the robot arm, and the drive axis to which this redundant degree of freedom is assigned is positioned as the redundant axis. For example, if the number of degrees of freedom required to control the position and orientation of a surgical instrument is n and the number of degrees of freedom (number of drive axes) of the robot arm is n+3, then the robot arm will have three redundant degrees of freedom. In this case, three drive axes are selected as redundant axes from the n+3 drive axes of the robot arm, and each of the selected three drive axes is assigned to one of the three redundant degrees of freedom. The degrees of freedom required to control the position and orientation of a surgical instrument are, for example, six degrees of freedom related to the movement of the end effector attached to the tip of the shaft of the surgical instrument in three-dimensional space (e.g., inside the patient's body).

Furthermore, when the shaft portion of the surgical instrument is inserted into a port member (trocar or cannula) placed on the surface of the patient's body, a center of rotation (pivot point) for the tilting movement of the shaft portion of the surgical instrument, which tilts together with the port member, may be set. In this case, the movement of the surgical instrument must be controlled so that the longitudinal axis of the shaft portion of the surgical instrument always passes through the center of rotation (pivot point) or its vicinity. As a result, the number of degrees of freedom n required to control the position and orientation of the surgical instrument increases by two, for a total of eight.

In this specification, the term "shaft portion of a surgical instrument" refers to a member or section that constitutes the entire or part of a surgical instrument, and is an elongated portion or member having a longitudinal axis. Shaft portions of surgical instruments include those that include joints and those that are flexible.

In the control method for the surgical robot system according to this embodiment, constraints are added for the number of redundant degrees of freedom possessed by the robot arm. The robot arm in this embodiment has multiple redundant degrees of freedom, and multiple constraints are set accordingly. Furthermore, in this embodiment, from the multiple drive axes of the robot arm, drive axes equal in number to the number of redundant degrees of freedom are selected as redundant axes, and one constraint is set for each redundant axis. Note that, while actual drive axes and redundant axes may correspond one-to-one, this is not necessarily the case. For example, the relationship between the axis values of two drive axes can also be treated as a redundant axis. As a specific example, if the axis value of one drive axis is θ1 and the axis value of the other drive axis is θ2, the θ defined by the constraint equation θ1 + θ2 = θ can be considered as the axis value of a new (virtual) redundant axis. A constraint, for example, constrains the operation of the redundant axis corresponding to that constraint in relation to the configuration of the robot arm, which is determined by the combination of the axis values of the multiple drive axes of the robot arm. In other words, constraints are imposed on the configuration of the robot arm, and the operation of the redundant axis corresponding to those constraints is controlled so that changes in the configuration of the robot arm remain within the range constrained by the constraints. This point will be described in more detail later, with reference to Figure 15, etc.

By setting multiple constraints in the control of the robot arm in this way, in this embodiment, which is equipped with a robot arm with multiple redundant axes, a definite solution can be calculated when calculating the axis values (joint variable values) of the drive axes of the robot arm from the position and posture of the end effector of the surgical instrument. In other words, in this embodiment, once the position and posture of the end effector of the surgical instrument are determined, the axis values (joint variable values) of the redundant axes are uniquely determined by the constraints. For example, the constraints can be configured as mathematical expressions that uniquely determine the axis values of the redundant axes based on the position and posture of the end effector. Because the axis values of the redundant axes can be determined by the constraints in this way, the same inverse kinematics calculations as when there are no redundant axes can be applied to multiple drive axes other than the redundant axes. The axis values of the redundant axes can also be called joint positions or joint angles.

The constraint conditions for redundant axes are also related to which of the multiple drive axes (multiple joints) of a robot arm is treated as a redundant axis. In other words, the content of the constraint conditions for redundant axes can change depending on which of the multiple drive axes of a robot arm is selected as a redundant axis. Furthermore, the constraint conditions for redundant axes can be determined from the perspective of avoiding interference between arms. For example, the constraint conditions for redundant axes can be set so that the robot arm operates within a range of motion where interference between arms is unlikely to occur.

As mentioned above, the constraint conditions for redundant axes can be determined from the perspective of avoiding interference between arms, but the content of the constraint conditions once determined is not always optimal. For example, when performing a certain surgery, even if the arm interference avoidance effect can be properly achieved at one stage during the surgery, the arm interference avoidance effect originally intended may not necessarily be achieved at another stage during the surgery.

In this embodiment, the constraint conditions for redundant axes are not positioned as fixed conditions that are not changed once they are set, but can be dynamically changed according to the situation at any given time, even during surgery. In other words, in this embodiment, the constraint conditions for redundant axes that are set, for example, before the start of surgery (at the time of setup, etc.) can be dynamically changed according to the situation at any given time after the start of surgery, for example, during the following operation by the operator (surgeon).

When the constraint conditions for the redundant axes are changed, the axis values of the multiple drive axes (joints) of the robot arm change accordingly. In other words, the axis values of the multiple drive axes of the robot arm are determined by calculation based on command values for the position and orientation of the end effector generated based on operation input from the operating device, and this calculation includes content related to the constraint conditions of the redundant axes. Therefore, when the constraint conditions for the redundant axes are changed, the content of the calculation process used to determine the axis values of the multiple drive axes (joints) of the robot arm from the command values for the position and orientation of the end effector changes, and the axis values of the multiple drive axes obtained as a result of the calculation also change.

Here, the operation of the robot arm's drive axes related to the constraints of the redundant axes does not affect the movement of the end effector. Therefore, even if the axis values of the robot arm's multiple drive axes change due to a change in the constraints of the redundant axes, this does not affect the movement of the end effector. When the axis values of the robot arm's multiple drive axes change due to a change in the constraints of the redundant axes, the configuration of the robot arm changes accordingly. The configuration of a robot arm can be defined as the spatial region occupied by the robot arm in the absolute coordinate system (or world coordinate system). Therefore, by changing the constraints of the redundant axes, it is possible to change the spatial region occupied by the robot arm in the absolute coordinate system. Changing the spatial region occupied by the robot arm due to a change in the constraints of the redundant axes can be achieved without affecting the movement of the end effector. In other words, by changing the constraints of the redundant axes, it is possible to change the spatial region occupied by the robot arm without affecting the movement of the end effector.

As described above, the shape of the robot arm can be changed to change its occupied spatial area without affecting the movement of the end effector. Therefore, for example, if there is a possibility that the arms will come close to each other and interfere with each other while an operator (practitioner) is operating the control device to perform treatment (during a so-called following operation), the control device can dynamically change the constraint conditions of the redundant axis, preventing the arms from interfering with each other in advance, without interrupting the operator's treatment (i.e., without interrupting the following operation).

If interference between arms occurs and the surgical robot stops, it is necessary to release the surgical robot from its stopped state (locked state) while taking the patient's safety into consideration. For example, it may be necessary to pull the surgical instrument out of the port member, reconfigure the robot arm to the appropriate shape, and then reattach the surgical instrument to the robot arm before releasing the surgical robot from its stopped state. Once the surgical robot stops due to interference between arms in this way, it takes time and effort to release the arm, and the surgery is interrupted during that time. In contrast, this embodiment can prevent interference between arms in advance, thereby reliably preventing the surgery from being interrupted by the surgical robot stopping and the subsequent recovery work. In this way, this embodiment can reliably ensure the continuity of the surgery by the operator in surgery using a surgical robot system.

The surgical robot system and its control method according to this embodiment will be described below with reference to the drawings.

As shown in Figures 1 to 3, the surgical robot system 10 according to this embodiment comprises a surgical robot 1 constituting at least a part of the slave unit, and an operating device 2 constituting at least a part of the master unit. The operating device 2 is placed beside the operating table 111 in the operating room. The operating device 2 may be placed at a location further away from the operating table 111 in the operating room, or it may be placed outside the operating room. The operator (surgeon) S who performs surgery using the surgical robot system 10 is located on the operating device 2 side, not the surgical robot 1 side, during the procedure in order to operate the operating device 2. The patient P on whom the surgery is to be performed is placed on the operating table 111 placed beside the surgical robot 1.

The operator S inputs operation inputs to the operation device 2 to control the position and posture of the surgical instrument 40. The operation inputs input to the operation device 2 are transmitted to the arm control unit 28 of the surgical robot 1 via a wired or wireless connection. The arm control unit 28 generates operation commands for the surgical robot 1 based on the operation inputs input to the operation device 2. The surgical robot 1 is operated based on these operation commands. In this way, the operation device 2 forms an interface between the surgical robot system 10 and the operator S, and is a device (master unit) for remotely operating the surgical robot 1 (slave unit).

The surgical robot 1 is equipped with a control device 4, and the arm control unit 28 is included in the control device 4. In this embodiment, the control device 4 is configured to be included in the surgical robot 1, but the control device 4 does not necessarily have to be included in the surgical robot 1, and can be provided outside the surgical robot 1 as a component of the surgical robot system 10. Also, in this embodiment, the arm control unit 28 is configured to be included in the control device 4, but the arm control unit 28 does not necessarily have to be included in the control device 4, and can be provided outside the control device 4 as a component of the surgical robot system 10.

The operating device 2 includes left and right operating manipulators 20A, 20B, multiple operating pedals 22, a touch panel 23, and a monitor 24. The monitor 24 is supported by a support arm 25. The touch panel 23 is mounted on a support bar 26. The operating manipulators 20A, 20B are equipped with left and right hand controls 21A, 21B that the operator operates with their left and right hands to input operating commands. The operating manipulators 20A, 20B are operating tools that accept operating inputs to generate movement commands for the position and posture of the surgical instrument 40. The operating pedal 22 is an operating tool that accepts commands such as zooming the endoscopic camera, switching control modes, and switching the robot arms 3 (3A, 3B, 3C, 3D) associated with the left and right operating manipulators 20A, 20B.

The monitor 24 is a scope-type display device that displays images captured by an endoscope inserted into the body of the patient P. The monitor 24 may also be a 3D viewer that displays 3D images. The support arm 25 can support the monitor 24 so that its height is aligned with the face of the operator S. A sensor 27 that detects the head of the operator S is provided near the monitor 24. For example, the arm control unit 28 is configured so that remote operation of the surgical robot 1 by the operating device 2 is possible only when the head of the operator S is detected by the sensor 27, but that remote operation of the surgical robot 1 by the operating device 2 is not possible when the head of the operator S is not detected by the sensor 27. The operator S operates the hand controls 21A, 21B and operating pedals 22 of the operating manipulators 20A, 20B while visually checking the affected area of the patient P on the monitor 24.

The surgical robot 1 forms the interface between the surgical robot system 10 and the patient P. The surgical robot 1 is placed in the operating room beside the operating table 111 on which the patient P lies. The operating table 111 and its surrounding area in the operating room are sterilized to form a sterile field.

The surgical robot 1 comprises a positioner 7, an arm base 5 attached to the tip of the positioner 7, and multiple robot arms 3 (3A, 3B, 3C, 3D) detachably attached to the arm base 5.

As shown in Figure 4, in this embodiment, four robot arms 3A, 3B, 3C, and 3D are attached to the arm base 5. The number of installed robot arms 3 may be less than four or more than four. The tip 32 (see Figure 10) of each of the multiple robot arms 3 includes an instrument holder 36 to which a surgical instrument 40 is detachably attached (see also Figure 11). In other words, the instrument holder 36 constitutes at least a part of the tip 32 of the robot arm 3.

The positioner 7 of the surgical robot 1 according to this embodiment comprises an articulated robot. The positioner 7 is controlled by a positioner control unit 75 included in the control device 4. Note that the positioner control unit 75 does not necessarily have to be included in the control device 4, and may be provided outside the control device 4. A vertical articulated robot can be used as the articulated robot constituting the positioner 7, for example, a seven-axis vertical articulated robot. The positioner 7 includes a base 90 and a series of link units 91 whose base ends are connected to the base 90. The multiple link units 91 are connected to each other by joint units 92. The base 90 of the positioner 7 is attached to the top surface of the casing 71 of the movable carriage 70. An arm base 5 is provided at the tip of the positioner 7. By configuring the positioner 7 as a vertical articulated robot, for example a seven-axis vertical articulated robot, the position and orientation of the arm base 5 attached to the tip of the positioner 7 can be freely controlled in three-dimensional space. The position of the arm base 5 may be defined as the position of a reference point set on the arm base 5. For example, the reference point may be set at (the rotation axis of) the base end of the arm base 5 attached to the tip of the positioner 7.

As shown in FIG. 5, the multiple link portions 91 and multiple joint portions 92 of the positioner 7 are connected in the following order from the base end to the tip end: first joint portion 92A, first link portion 91A, second joint portion 92B, second link portion 91B, third joint portion 92C, third link portion 91C, fourth joint portion 92D, fourth link portion 91D, fifth joint portion 92E, fifth link portion 91E, sixth joint portion 92F, sixth link portion 91F, seventh joint portion 92G, seventh link portion 91G. The first joint portion 92A, fourth joint portion 92D, sixth joint portion 92F, and seventh joint portion 92G are configured as torsion joints. The second joint portion 92B, third joint portion 92C, and fifth joint portion 92E are configured as bending joints. With the above configuration, the positioner 7 can move the position of the arm base 5 three-dimensionally relative to the movable carriage 70 along the mutually perpendicular X-axis, Y-axis, and Z-axis directions, and can rotate the posture of the arm base 5 around the roll axis, pitch axis, and yaw axis.

The arm base 5 comprises an arm base main body 50, a positioner mounting section 51 provided on the back of the arm base main body 50 and to which the tip of the positioner 7 is attached, and a plurality of arm mounting sections 52 provided on the lower part of the arm base main body 50 and to which the base ends 80 of a plurality of robot arms 3 are attached. The arm base 5 is configured to be rotatable relative to the tip of the positioner 7. The arm base 5 is provided with an imaging section 53. The imaging section 53 is capable of capturing images of at least one of the operating table 111 and the patient P placed on the operating table 111.

In the surgical robot 1, the arm base 5 functions as a "hub" that serves as a base for multiple robot arms 3. Note that, although the positioner 7 in this embodiment is composed of a vertical articulated robot, the positioner 7 can also be composed of a manipulator other than a vertical articulated robot. For example, the positioner 7 may be a linear rail for supporting the arm base 5, an elevator device, or a bracket attached to the ceiling or wall. In this embodiment, the base 90 of the positioner 7 is attached to a movable cart 70, but instead, the base of the positioner 7 can be attached to a fixed object such as the wall or floor of the operating room, or a member fixed to these.

As shown in FIG. 6 , the cart 70 is provided with an operation unit 72 for setting and inputting the positions and postures (preparatory postures) of the positioner 7, arm base 5, and multiple robot arms 3 before surgery, etc. The operation unit 72 has a display unit 72a including, for example, a touch panel. The operation unit 72 has a joystick 72b for controlling the movement of the positioner 7. An enable switch 72c is provided near the joystick 72b to permit or prohibit manual movement of the positioner 7. When the enable switch 72c is pressed and movement of the positioner 7 is permitted, an operator such as a nurse or technician can operate the joystick 72b to move the positioner 7. In this way, the surgical robot system 10 has a manual mode in which the positioner 7 can be moved manually by the operator.

Furthermore, a handle 73 for controlling the movement of the cart 70 is provided near the operating unit 72 of the cart 70. The handle 73 has a throttle unit 73a that an operator such as a nurse or technician can grasp and rotate to control the movement of the cart 70. The handle 73 is also configured to be rotatable left and right (LR direction), and the direction of movement of the cart 70 changes as the handle 73 is rotated.

Furthermore, an enable switch 73b is provided near the handle 73 of the carriage 70 to permit or prohibit movement of the carriage 70. When the enable switch 73b is pressed down to permit movement of the carriage 70, the throttle section 73a of the handle 73 is operated, causing the carriage 70 to move forward, backward, left, and right by a traveling power section 74, which includes power from an electric motor or the like provided inside the carriage 70.

The positioner 7, arm base 5, and components from the base end 80 of the robot arm 3 to the instrument holder 36 of the robot arm 3 are covered with a sterile drape (not shown). These components, including the positioner 7, arm base 5, and components from the base end 80 of the robot arm 3 to the instrument holder 36, are shielded from the sterile field in the operating room.

Figure 7 shows a forceps assembly 40A as an example of a surgical instrument 40. The forceps assembly 40A includes a shaft portion 43, an end effector 44 including a pair of jaws provided at the tip of the shaft portion 43, and an instrument base 45 that holds the base end of the shaft portion 43 rotatably around the longitudinal axis of the shaft portion 43.

Figure 8 shows an endoscope assembly 40B, another example of a surgical instrument 40, which is an imaging device that is inserted into a patient's body to capture images of the condition of the surgical site. The endoscope assembly 40B includes an endoscope 12 and an endoscope holder 13. The endoscope holder 13 holds the endoscope 12 so that it can rotate around its longitudinal axis. A drive unit (not shown) is provided inside the endoscope holder 13 for rotating the endoscope 12 around its longitudinal axis. The front portion (camera side) of the endoscope 12 is formed as a shaft portion 43.

As mentioned above, the shaft portion 43 of the surgical instrument 40 may refer to an elongated member with the end effector 44 attached to its tip, or it may refer to the front portion (camera side portion) of the endoscope 12 formed as an elongated member.

The instrument base 45 of the forceps assembly 40A is provided with a locking portion (not shown) that releasably locks to the instrument holder 36 of the robot arm 3, and the instrument holder 36 is provided with a receiving portion (not shown) to which the locking portion locks. For example, the locking portion and receiving portion have complementary shapes, and a retractable portion that resiliently protrudes and retracts on one of the locking portion and receiving portion is releasably locked in a recessed portion on the other of the locking portion and receiving portion. For example, a surgical assistant can manually release the resiliently locked recessed portion, thereby removing the forceps assembly 40A from the instrument holder 36. The endoscope holder 13 also has a similar attachment/detachment mechanism, and can be attached to and detached from the instrument holder 36 by manual operation by a surgical assistant.

In the surgical robot 1 of this embodiment, an endoscope assembly 40B is removably held as a surgical instrument 40 in the instrument holder 36 of one of the multiple (four in this example) robot arms 3. A surgical instrument other than the endoscope assembly 40B, such as a forceps assembly 40A, is removably held as a surgical instrument 40 in the instrument holders 36 of the remaining (three in this example) robot arms 3. In the surgical robot 1 shown in Figure 4, the endoscope assembly 40B is attached to the second robot arm 3B, and surgical instruments other than the endoscope assembly 40B, such as a forceps assembly 40A, are attached to the first, third, and fourth robot arms 3A, 3C, and 3D.

In the above-described surgical robot 1, multiple components are connected in series, from the positioner 7 to the surgical instrument 40. In this specification, the end of the above-described series of components facing the positioner 7 (more specifically, the base 90 of the positioner 7) may be referred to as the "base end (of the series of components)," and the opposite end may be referred to as the "tip end (of the series of components)."

The arm control unit 28, which controls the operation of the surgical robot 1 based on operation input from the operation device 2, may be composed of a single controller for centralized control, or multiple controllers that cooperate with each other for distributed control. As shown in FIG. 9, the arm control unit 28 is composed of a computer 300 such as a microcontroller. The computer 300 has a processor 301 such as a CPU, memory 302 such as ROM and RAM, an I/O unit (input/output unit) 303, and an interface 304. The memory 302 stores control programs and various data used to control the operation of the surgical robot 1. The interface 304 is used for communication with the operation device 2 and various sensors (such as an encoder that detects the rotation angle of a servo motor, described below).

10 shows the schematic configuration of one robot arm 3 among the multiple robot arms 3 equipped in the surgical robot 1. A surgical instrument 40 is detachably attached to the tip 32 of the robot arm 3. In this embodiment, all of the multiple robot arms 3 equipped in the surgical robot 1 have the same or similar configurations, but at least one of the multiple robot arms 3 may have a different configuration from the other robot arms 3 (e.g., different degrees of freedom). As shown in FIG. 10, the robot arm 3 comprises an arm main body 30 and a translational movement mechanism 35 provided on the arm main body 30. The translational movement mechanism 35 has an instrument holder 36 movably provided on its main body. The translational movement mechanism 35 (including the instrument holder 36) constitutes at least a part of the tip 32 of the robot arm 3. As shown in FIGS. 10 and 11, an instrument base 45 of a surgical instrument 40 is detachably attached to the instrument holder 36 by an attachment/detachment mechanism (not shown). The tip 32 of the robot arm 3 is movable three-dimensionally relative to the base end 80 of the robot arm 3.

As shown in Figures 11 and 12, the instrument holder 36 of the translational movement mechanism 35 is equipped with an arm manual operation mechanism 39. The arm manual operation mechanism 39 has a command input unit 39A including buttons, joysticks, etc., and a manual controller 39B that drives the translational movement mechanism 35 in response to commands input from the command input unit 39A. Commands input from the command input unit 39A include, for example, commands related to a retraction operation to retract the surgical instrument 40 inserted into the port member 112 to a retracted position. A surgical assistant standing next to the surgical robot 1 may operate the command input unit 39A to control the retraction operation of the surgical instrument 40 using the manual controller 39B.

The arm main body 30 has a base end 80 that is detachably attached to the arm base 5, and multiple arm link sections that are connected in sequence from the base end 80 to the tip end. The arm main body 30 has multiple joint sections (multiple drive shafts) that are connected in sequence so that one arm link section rotates relative to another arm link section. The multiple arm link sections include a first link 81 to a sixth link 86. The multiple joint sections include a first joint J31 to a seventh joint J37. Note that, in this embodiment, the multiple joint sections (first joint J31 to seventh joint J37) of the arm main body 30 are configured as rotary joints equipped with rotary shafts, but at least some of the joint sections may be configured as linear joints.

More specifically, the base end of a first link 81 is connected to the tip side of the base end 80 of the robot arm 3 via a first joint J31 (base-end torsion joint), which is a torsion (roll) joint. The base end of a second link 82 is connected to the tip of the first link 81 via a second joint J32, which is a bending (pitch) joint. The base end of a third link 83 is connected to the tip of the second link 82 via a third joint J33, which is a torsion joint. The base end of a fourth link 84 is connected to the tip of the third link 83 via a fourth joint J34, which is a bending joint. The base end of a fifth link 85 is connected to the tip of the fourth link 84 via a fifth joint J35, which is a torsion joint. The base end of a sixth link 86 is connected to the tip of the fifth link 85 via a sixth joint J36, which is a bending joint. The base end of the translational movement mechanism 35 is connected to the tip of the sixth link 86 via the seventh joint J37 (tip side bending joint), which is a bending joint.

In this embodiment, the first link 81 has a bent shape between the adjacent joints J31 and J32. In other words, the first link 81 is configured so that the rotation axis of the first joint J31 and the rotation axis of the second joint J32 do not intersect. That is, the first link 81 has a first portion 81a and a second portion 81b. Of these, the first portion 81a extends from the first joint J31 on the base end side in a predetermined first direction (the direction of the rotation axis of the first joint J31). Furthermore, the second portion 81b extends from the tip of the first portion 81a in a second direction intersecting the extension direction of the first portion 81a (and perpendicular to the rotation axis of the second joint J32) and is connected to the second joint J32 on the tip side. The angle between the first direction and the second direction in the first link 81 is, for example, 120 degrees or more and 160 degrees or less (e.g., 140 degrees). The first portion 81a and the second portion 81b are smoothly connected. This makes it easier to pass wires such as electrical wiring through multiple arm link portions, even if some of the arm link portions have a bent shape.

Furthermore, the fourth link 84 has a bent shape between the adjacent joints J34 and J35, and this portion forms the elbow 11 of the arm main body 30. In other words, the fourth link 84 is configured so that the rotation axis of the fourth joint J34 and the rotation axis of the fifth joint J35 do not intersect. Furthermore, the rotation axis of the fifth joint J35 is offset from the rotation axis of the fourth joint J34 in a direction perpendicular to the rotation axis of the fourth joint J34 and the rotation axis of the fifth joint J35. That is, the fourth link 84 has a first portion 84a and a second portion 84b. Of these, the first portion 84a extends from the fourth joint J34 on the base end side in a predetermined first direction (a direction perpendicular to both the rotation axis of the fourth joint J34 and the rotation axis of the fifth joint J35). The second portion 84b extends from the tip of the first portion 84a in a second direction (the direction of the rotation axis of the fifth joint J35) that intersects with the extension direction of the first portion 84a and is connected to the fifth joint J35 on the tip side. The angle between the first direction and the second direction of the fourth link 84 is, for example, greater than or equal to 70 degrees and less than or equal to 110 degrees (e.g., 90 degrees). The first portion 84a and the second portion 84b are smoothly connected.

The other links 82, 83, 85, and 86 are formed in a straight line between adjacent joints. In other words, the other links 82, 83, 85, and 86 are configured so that the rotation axes of adjacent joints intersect.

Each arm link section is configured so that its cross-sectional area perpendicular to the longitudinal direction is smaller than that of the arm link section (or base end 80) connected to it closer to the base end. This causes the arm main body 30 to become gradually thinner from the base end 80 toward the tip end. Furthermore, each of the bending joints J32, J34, and J36 is configured so that the tip end of the base end side arm link section 81, 83, and 85 is located on one side of the rotational axis direction relative to the center of the joint section in the rotational axis direction. Also, the base end of the tip end side arm link section 82, 84, and 86 is configured to face the tip end of the base end side arm link section 81, 83, and 85 on the other side of the rotational axis direction relative to the center of the joint section in the rotational axis direction.

Furthermore, the width in the rotational axis direction of the joint, i.e., the distance between the outer ends in the rotational axis direction of the tip ends of the base-end-side arm link sections 81, 83, 85 and the outer ends in the rotational axis direction of the base ends of the tip-end-side arm link sections 82, 84, 86, is shorter than the diameter (maximum dimension) of the cross section perpendicular to the longitudinal direction of the portion located closer to the base end than the tip ends of the base-end-side arm link sections 81, 83, 85.

In this way, each joint and the arm link portion at its tip end are configured to be narrower than the arm link portion at its base end. This increases the range of movement of each arm body 30 (the range without interference with other arm bodies 30) in a workspace that becomes narrower the closer it is to the treatment area 110 of the patient P.

The outer shell of the arm body 30 is made of a material that is painted to be chemical-resistant. In addition, openings such as inspection holes on the arm body 30 are covered with resin covers. By making the covers out of a material such as resin, it is possible to reduce the weight of parts that do not contribute to the strength of the arm body 30. This makes it possible to reduce the impact even if the cover falls or the arm body 30 hits another arm body 30 or a treatment assistant. The outer shell of the arm body 30 itself may include parts made of resin materials.

The translational movement mechanism 35 is a mechanism that translates the instrument holder 36, which is movably mounted on the main body of the translational movement mechanism 35, in the longitudinal axis direction Dt (Figure 10), thereby enabling the surgical instrument 40 attached to the instrument holder 36 to translate in the extension direction of the shaft portion 43.

The translational movement mechanism 35 is connected to the tip of the sixth link 86 of the arm main body 30 via a seventh joint J37, which is a bending joint. The seventh joint J37 extends in a direction perpendicular to the longitudinal axis direction Dt. A drive mechanism including a drive source for translationally moving the instrument holder 36 is provided inside the translational movement mechanism 35. The translational movement mechanism 35 can advance the surgical instrument 40 in the insertion direction and retract it in the withdrawal direction. The drive mechanism provided inside the translational movement mechanism 35 may be configured, for example, using a pulley and timing belt, or may be a mechanism including a gear train, or may be configured as a double-speed mechanism. In this way, the translational movement mechanism 35 forms an eighth joint J38, which is a linear joint that moves the instrument holder 36 linearly in the longitudinal axis direction Dt.

The instrument holder 36 removably holds the instrument base 45 of the surgical instrument 40. As shown in FIG. 12, the instrument holder 36 includes an instrument driver 38 having multiple (four in this example) drive shafts 37 that are rotationally driven to apply a driving force to the surgical instrument 40. One of the multiple drive shafts 37 of the instrument driver 38 generates a driving force that rotates the shaft portion 43 of the surgical instrument 40 about its longitudinal axis.

As shown in FIG. 7, a forceps assembly 40A, which is one of the surgical instruments 40, has an instrument base 45 provided at its proximal end, a shaft portion 43 whose proximal end is connected to the instrument base 45, and an end effector (treatment tool) 44 connected to the distal end of the shaft portion 43. Furthermore, the forceps assembly 40A is equipped with a drive force transmission portion (not shown) that is connected to the drive shaft 37 of the instrument drive unit 38 included in the instrument holder 36 by attaching the forceps assembly 40A to the instrument holder 36 and transmits the drive force of the drive shaft 37. The instrument drive unit 38 of the instrument holder 36 may have, for example, four drive shafts 37, and these drive shafts 37 are used, for example, to open and close the pair of jaws that form the end effector 44 of the forceps assembly 40A (FIG. 7), to pitch or yaw the end effector 44, and to roll the shaft portion 43 of the forceps assembly 40A around its longitudinal axis relative to the instrument base 45.

If the surgical instrument 40 attached to the instrument holder 36 is the endoscope assembly 40B shown in Figure 8, the drive shaft 37 of the instrument drive unit 38 of the instrument holder 36 drives a drive unit (not shown) provided inside the endoscope holder 13, thereby rotating the endoscope 12 around the longitudinal axis of its shaft portion 43.

The surgical instrument 40 has a defined longitudinal axis direction Dt (see FIG. 10), and the instrument base 45, shaft portion 43, and end effector 44 are arranged along the longitudinal axis direction Dt, in this order. The end effector of the surgical instrument 40 is not limited to the end effector 44 consisting of a pair of jaws shown in FIG. 7. In other words, the end effector of the surgical instrument 40 can be selected from a group including, for example, instruments with movable joints (e.g., forceps, scissors, graspers, needle holders, microdissectors, staple appliers, tackers, suction and irrigation tools, snare wires, clip appliers, etc.) and instruments without joints (e.g., cutting blades, cauterizing probes, irrigators, catheters, suction orifices, etc.).

The base end of the shaft 43 is connected to the instrument base 45 via a ninth joint J39 (tip-side torsion joint), which is a torsion (roll) joint. The rotation axis R9 of the ninth joint J39 has a rotation axis that is arranged coaxially with the central axis C of the shaft 43. The central axis C of the shaft 43 corresponds to the longitudinal axis of the surgical instrument 40. The rotation axis of the joint is the geometric (imaginary) axis of the rotating shaft.
As described above, in this embodiment, the instrument base 45 and the ninth joint J39 may be elements included in the robot arm 3 for positioning the shaft portion 43.

As mentioned above, the eighth joint J38, which is located between the seventh joint J37 and the ninth joint J39, is a linear joint, and therefore the orientation of the rotation axis R9 of the ninth joint J39 relative to the rotation axis R7 of the seventh joint J37 is fixed. The rotation axis R7 of the seventh joint J37 is perpendicular to a reference plane RP ( FIG. 10 ) that extends in the longitudinal direction Dt and includes the rotation axis R9 of the ninth joint J39. That is, in this embodiment, the seventh joint J37 constitutes a bending joint that defines the reference plane RP. The angle between the rotation axis R7 and the reference plane RP is not limited to a right angle; it is sufficient that the rotation axis R7 and the reference plane RP intersect. By rotating the seventh joint J37, the shaft portion 43 can be swung in an upright or downright direction.

As shown in Figure 13, in this embodiment, a plurality of (four in this example) arm attachment portions 52 are provided on the arm base 5 in accordance with a plurality of (four in this example) robot arms 3. The arm base 5 has an elongated shape with a longitudinal axis, and the plurality of arm attachment portions 52 are arranged side by side in the longitudinal direction of the arm base 5 (the direction indicated by D1 in Figure 13). By fixing the base ends 80 of the plurality of robot arms 3 to the plurality of arm attachment portions 52, respectively, the first link 81, which is the link on the side of the base ends 80 of the plurality of robot arms 3, is configured to be relatively rotatable around the rotation axis of the first joint J31.

Specifically, the multiple arm attachment portions 52 are arranged such that the base ends 80 of the multiple robot arms 3 are aligned in a row in a predetermined first direction D1. The first direction D1 is a direction set on (included in) a predetermined first plane P1. In this embodiment, the first plane P1 is a virtual plane parallel to the floor (horizontal plane) G when the arm base 5 is positioned in the preparation position (see Figure 3). The first direction D1 is, for example, the direction of the longitudinal axis of the elongated arm base 5, which is a horizontal direction, but is not limited to this. The first direction D1 is also a direction perpendicular to the rotation axis R1 of the first joint J31 of the robot arm 3, which will be described later. In other words, the multiple arm attachment portions 52 are aligned in a row in the first direction D1 (the depth direction of the paper in Figure 3) when viewed from above with the arm base 5 positioned in the preparation position, and face a second direction D2 perpendicular to the first direction D1. The arrangement of the arm attachment portions 52 is not limited to a single row, and they may be aligned in two rows. Additionally, some of the arm attachment portions 52 may be offset in the second direction D2. Additionally, some of the arm attachment portions 52 may be offset in the third direction D3. The third direction D3 is, for example, the vertical direction (the direction perpendicular to the paper surface in FIG. 13).

In the above, the instrument base 45 and the ninth joint J39 of the surgical instrument 40 have been described as components included in the surgical instrument 40, but these instrument base 45 and the ninth joint J39 can also be components included in the robot arm 3.

Figure 14 is a block diagram showing an example of the control system configuration of the surgical robot system 10. The arm body 30 of the robot arm 3 is provided with drive servomotors (denoted as SM in Figure 14) M31-M37 corresponding to each joint J31-J37 of the arm body 30, encoders (denoted as EN in Figure 14) E31-E37 that detect the rotation angles of the servomotors M31-M37, and reducers (not shown) that reduce the output of the servomotors M31-M37 to increase the torque.

Note that in Figure 14, of the joints J31 to J37, only the first joint J31 and the seventh joint J37 of the arm main body 30 are shown as representatives, and the control systems for the other joints J32 to J36 are omitted. Furthermore, the translational movement mechanism 35 is provided with a servo motor M38 (a servo motor that drives the interlocking mechanism) for translational movement of the eighth joint J38, a servo motor M39 for rotational movement of the ninth joint J39, encoders E38 and E39 that detect the rotation angles of the servo motors M38 and M39, and reducers (not shown) that reduce the speed of the output of the servo motors M38 and M39 to increase the torque.

Encoders E31 to E39 are provided as an example of a rotational position detection means for detecting the rotational position (rotation angle) of servo motors M31 to M39, and a rotational position detection means such as a resolver may be used instead of encoders E31 to E39.

The arm control unit 28 includes a control unit main body 29 that controls the movement of multiple robot arms 3 based on operation commands. Servo control units C31 to C39, indicated by SC in the figure, are electrically connected to the control unit main body 29, and multiple actuators related to servo motors M31 to M39 are electrically connected via amplifier circuits, etc.

In the above configuration, a position and orientation command for the tip 32 of the robot arm 3 is input to the control unit main body 29 based on operation input input to the operating device 2 during treatment. The control unit main body 29 generates and outputs a position command value based on the position and orientation command and the rotation angle detected by the encoders E31 to E39. The servo control units C31 to C39, which have acquired this position command value, generate and output a drive command value (torque command value) based on the rotation angle detected by the encoders E31 to E39 and the position command value. The amplifier circuit that has acquired this drive command value supplies a drive current corresponding to the drive command value to the servo motors M31 to M39. In this way, each servo motor M31 to M39 is servo-controlled so that the tip 32 of the robot arm 3 reaches a position and orientation corresponding to the position and orientation command.

The arm control unit 28 also has a memory unit 31 in the control unit main body 29 that can read data, and pre-stores surgical information input via the operation device 2. This surgical information includes the combination of multiple robot arms 3 used in the surgery.

In addition, the memory unit 31 stores information such as the length along the longitudinal axis direction Dt of the surgical instrument 40 held at the tip 32 of the robot arm 3. This enables the control unit main body 29 to grasp the position of the tip (end effector 44) of the surgical instrument 40 held at the tip 32 of the robot arm 3 based on the position and orientation command for the tip 32 of the robot arm 3. The position of the tip of the surgical instrument 40 is sometimes called the tool center point (TCP).

Furthermore, the memory unit 31 pre-stores predetermined preparation positions (for example, the respective positions and postures of the positioner 7, arm base 5, and robot arm 3 shown in FIG. 3) that are established before treatment for the arm base 5 and multiple robot arms 3. The memory unit 31 can store multiple preparation positions according to the type of treatment, the area to be treated, etc. The above-mentioned predetermined preparation positions are sometimes called setup positions.

Figures 15 to 17 are diagrams illustrating an example of the operation of the surgical robot system 10. In Figures 15 and 16, of the four robot arms 3, robot arm 3B and elements related to robot arm 3B are illustrated, with other elements being omitted as appropriate. Also, in Figure 17, of the four robot arms 3, robot arm 3A and elements related to robot arm 3A are illustrated, with other elements being omitted as appropriate.

As shown in Figures 1 to 3, in surgery using the surgical robot 1, the surgical assistant (or the operator S himself/herself) first uses the cart 70 to move the surgical robot 1 near the operating table 111. At this time, the positioner 7, arm base 5, and multiple robot arms 3 are located in predetermined storage positions set for the cart 70.

Port members 112, consisting of trocars or cannulas, are placed on the body surface of patient P, who is lying on the operating table 111, for example, lined up side by side in a straight line. In Figure 3, the port members 112 are arranged in a line in the depth direction of the page. However, the arrangement of multiple port members 112 is not limited to this arrangement.

Then, the positioner 7 is controlled to position the arm base main body 50 so that it is positioned above the patient P and the rotation axis R1 of the first joint J31 of the robot arm 3 attached to the arm attachment part 52 is oriented generally horizontally. The angle between the rotation axis R1 of the first joint J31 and the horizontal plane is, for example, within the range of -30 degrees to +30 degrees. The positioner 7 is also controlled to position the arm base main body 50 so that the second direction D2, which is the direction in which the arm attachment part 52 is oriented, is generally perpendicular to the direction in which the multiple port members 112 are arranged.

The surgical assistant then sets in the arm control unit 28 a remote center RC (predetermined center point) that is associated with each robot arm 3 in a one-to-one correspondence. In this task, the surgical assistant attaches, for example, a teaching surgical instrument 40 to the instrument holder 36 and moves the teaching surgical instrument 40 so that its tip is positioned in the center of the hole in the port member 112. The surgical assistant then inputs an instruction to set the remote center RC into the operation unit 72. As a result, the arm control unit 28 performs a forward transformation and calculates the position of the remote center RC based on the posture of the robot arm 3 at that time, the positional relationship of the tip of the shaft portion 43 of the teaching surgical instrument 40 relative to the instrument base 45, the position and posture of the base end portion 80, and information related to the parameters of each arm link portion.

In addition, the robot arms 3 and port members 112 are associated in a one-to-one correspondence so that the remote centers RC associated with each robot arm 3 are aligned in the order of the robot arms 3 in the first direction D1. That is, the robot arm 3A, which is the first from the right in the first direction D1, is associated with the port member 112, which is the first from the right in the first direction D1. Then, by calculating the remote center RC of this port member 112, the robot arm 3A is associated with the remote center RC, which is the first from the right in the first direction D1. The same applies to the other robot arms 3B, 3C, and 3D.

Then, the surgical assistant or operator S replaces the teaching surgical instrument 40 with a surgical instrument 40 such as a forceps assembly 40A or an endoscope assembly 40B. By performing this preliminary operation, the positioner 7, arm base 5, and multiple robotic arms 3 are positioned so that the port member 112 placed on the body surface of the patient P, which will be the treatment site 110, and the surgical instruments 40 attached to each robotic arm 3 have a predetermined initial positional relationship.

In this initial posture, the robot arm 3 has its base end 80 extending generally horizontally. The second link 82 and third link 83 connected to the bent first link 81 extend diagonally downward. More specifically, the second link 82 and third link 83 extend downward in the direction in which the rotation axis R1 of the first joint J31 extends (second direction D2), from the base end side of the base end 80 toward the tip end side (toward the toes of the patient P on the operating table 111). The fourth link 84, fifth link 85, and sixth link 86 fold back with the elbow 11 as their vertex and extend diagonally downward. More specifically, the fourth link 84, the fifth link 85, and the sixth link 86 extend downward in the direction in which the rotation axis R1 of the first joint J31 extends, from the tip side of the base end portion 80 toward the base end side (toward the head side of the patient P on the operating table 111).

In this embodiment, the arm control unit 28 does not accept operation from the operation device 2 while the surgical robot 1 (positioner 7, arm base 5, and multiple robot arms 3) moves from the storage position to the preparation position. Then, after the surgical robot 1 is positioned at the preparation position, the arm control unit 28 becomes able to accept operation from the operation device 2. During treatment after the surgical robot 1 is positioned at the preparation position, the arm control unit 28 generates operation commands based on operation input generated by the operator S operating the operation device 2. Then, in accordance with the operation commands generated based on the operation input from the operation device 2, the arm control unit 28 controls the operation of each robot arm 3 to appropriately change the position and posture of the surgical instrument 40. At this time, the arm control unit 28 controls the robot arm 3 by restricting the posture of the surgical instrument 40 so that the shaft portion 43 of the surgical instrument 40 inserted into the port member 112 passes through the remote center RC. This makes it possible to restrict in-plane movement of the port member 112 in the direction of the patient P's body surface.

During this treatment, the operation of moving the surgical instrument 40 to a target position and assume a target posture is achieved, for example, by an operation including the operation of joints including nine axes, joints J31 to J39. In this way, the robot arm 3 has more degrees of freedom than are necessary to control the position and posture of the surgical instrument 40. In other words, the robot arm 3 has redundancy. Therefore, the set of rotational positions (joint positions) of the multiple joints of the robot arm 3 corresponding to a certain target position and target posture of the shaft portion 43 of the surgical instrument 40 (or the configuration of the robot arm 3 determined by the set of these angular positions) is not uniquely determined. For example, the operation of rotating the shaft portion 43 in a circumferential direction about its central axis C can be achieved not only by rotating the ninth joint J39, which is arranged coaxially with the central axis C, but also by rotating the tip portion 32 of the arm main body 30 in a circumferential direction about the central axis C. Therefore, the arm control unit 28 combines the movement of the arm main body 30 and the movement of the ninth joint J39 to control the circumferential rotation of the shaft portion 43 around the central axis C. The arm control unit 28 then operates the arm main body 30 and the ninth joint J39 to satisfy the following constraints among the movements that can be made to rotate the shaft portion 43 around the central axis C or to maintain the shaft portion 43 in the same circumferential position without rotating it.

In setting the constraint conditions, as shown in FIG. 15, the arm control unit 28 first sets a reference point RD for each robot arm 3. As shown in FIG. 13, the reference point RDB of robot arm 3B is located on a reference line RLB, which is an extension of the rotation axis R1 of the first joint J31 of robot arm 3B. The reference point RDA of robot arm 3A is located on a reference line RLA, which is offset to one side (positive direction) of the first direction D1 (direction perpendicular to the rotation axis R1) with respect to the rotation axis R1 of the first joint J31 of robot arm 3A (see also FIG. 17). In this operation example, the first direction D1 is also the horizontal direction. The first direction D1 is parallel to the longitudinal direction of the arm base 5. The reference point RDC of robot arm 3C is located on a reference line RLC, which is offset to the other side (negative direction) of the first direction D1 with respect to the rotation axis R1 of the first joint J31 of robot arm 3C. Furthermore, the reference point RDD of the robot arm 3D is located on a reference line RLD that is offset to the other side (negative direction) of the first direction D1 with respect to the rotation axis R1 of the first joint J31 of the arm 3D. The offset distance of the reference line RL of each robot arm 3 is set to an individual value. This makes it possible to appropriately prevent interference with other equipment in the surgical robot system 10, such as an adjacent robot arm 3, and with the surrounding environment, such as assistants.

Next, as shown in FIG. 16, the arm control unit 28 determines whether the length L of the perpendicular line vh from the reference point RD to the central axis C of the shaft unit 43, which assumes the target posture at the target position, is shorter than a predetermined lower limit length Lmin. If the arm control unit 28 determines that the length of the perpendicular line vh is shorter than the lower limit length Lmin, it moves the position of the reference point RD on the reference line RL in a direction away from the central axis C of the shaft unit 43 so that the length of the perpendicular line vh becomes longer than the predetermined length Lmin. Note that if the arm control unit 28 determines that the length of the perpendicular line vh is longer than the lower limit length Lmin, it does not execute this process. Note that the arm control unit 28 may determine the position of the reference point RD on the reference line RL based on a continuous function that defines the relationship between the length L of the perpendicular line vh and the position of the reference point RD on the reference line RL, without making the above determination.

Next, as shown in FIG. 15, the arm control unit 28 positions the joints J31 to J39 so that the reference plane RP passes through the reference point RD. As described above, the reference plane RP is a plane that includes the rotation axis R9 of the ninth joint J39 extending in the longitudinal direction Dt and intersects with the rotation axis R7 of the seventh joint J37.

This constrains the translational movement mechanism 35 and instrument base 45 to swing around the axis Rv connecting the reference point RD and the remote center RC. Therefore, when rotating the shaft portion 43 in a circumferential direction around its central axis C, the proportion of the movement of rotating the tip portion 32 of the robot arm 3 in a circumferential direction around the central axis C can be reduced. Furthermore, the proportion of the movement of rotating the shaft portion 43 by rotating the ninth joint J39 can be increased. This allows the translational movement mechanism 35, which is connected perpendicularly to the seventh joint J37, to assume a position facing outward from the reference point RD. This prevents the translational movement mechanism 35 and instrument base 45 from assuming a position that protrudes to the side of the robot arm 3 (in the first direction D1). As a result, interference with other devices in the surgical robot system 10, such as an adjacent robot arm 3, and the surrounding environment can be prevented. Furthermore, because the robot arm 3 can be oriented such that the sixth link 86 of the arm main body 30 faces from the seventh joint J37 toward the center of the robot arm 3, the link length of the arm main body 30 can be used effectively, widening the range of motion. Furthermore, because multiple robot arms 3 are oriented so that they spread out in a fan shape from the arm base main body 50, interference between adjacent robot arms can be reduced.

Furthermore, as shown in FIG. 16 , for example, when the shaft portion 43 swings around the remote center RC and approaches the reference point RD, the radius of rotation of the tip 32 of the robot arm 3 around the central axis C during the operation of rotating the shaft portion 43 around the central axis C becomes smaller. As a result, the operation of the robot arm 3 becomes sensitive, and large vibrations and reduced tracking ability may occur in the translational movement mechanism 35 and the instrument base 45 due to sudden movement of the robot arm 3. In this regard, when the arm control unit 28 determines that the length L of the perpendicular line vh is shorter than the lower limit length Lmin, it moves the position of the reference point RD on the reference line RL so that the length of the perpendicular line vh is longer than the predetermined length Lmin. Therefore, it is possible to prevent the radius of rotation of the operation of moving the tip 32 of the robot arm 3 around the central axis C from becoming smaller when the shaft portion 43 approaches the reference point RD, thereby suppressing sensitive operation of the robot arm 3. Furthermore, if the arm control unit 28 determines the position of the reference point RD on the reference line RL based on a continuous function that defines the relationship between the length L of the perpendicular line vh and the position of the reference point RD on the reference line RL, it is possible to avoid the occurrence of overly sensitive movements.

In this way, the arm control unit 28 controls the robot arm 3 so that the shaft portion 43 of the surgical instrument 40 assumes the target posture at the target position. Once a new target position and target posture are set, the arm control unit 28 again determines whether the length L of the perpendicular line vh is shorter than the predetermined lower limit length Lmin, and then executes subsequent processing.

In addition to the control method described above, the surgical robot system 10 according to this embodiment can also implement the control method described below to more reliably avoid interference between the robot arm 3 and surrounding objects (e.g., an adjacent robot arm 3).

In this embodiment, at least a portion of each of the multiple robot arms 3 is modeled. For example, as shown in FIG. 18, the robot arm 3 may be modeled so that at least a portion of it is surrounded by a capsule-shaped virtual model. The target portion of the robot arm 3 to be modeled may include at least a portion of the translational movement mechanism 35. At least a portion of the virtual model of the robot arm 3 is set as the reference portion. In FIG. 18, the reference portion is represented by a capsule indicated by a solid line. The reference portion may be a portion that is assumed to be most likely to come close to adjacent robot arms 3 during treatment. For example, a portion of the translational movement mechanism 35 may be selected as the reference portion.

As shown in FIG. 19, the arm control unit 28 determines the proximity distance between the reference portions of the virtual models of, for example, adjacent robot arms 3 (step S1). For example, it determines the proximity distance between the reference portion of the virtual model of the first robot arm 3A and the reference portion of the virtual model of the second robot arm 3B.

Next, the arm control unit 28 determines whether the difference between the proximity distance determined in step S1 and the minimum allowable distance is equal to or greater than a predetermined threshold (step S2). Figure 20 shows a situation in which the difference between the minimum allowable distance and the proximity distance d12 between the reference portion of the first robot arm 3A and the reference portion of the second robot arm 3B is smaller than the predetermined threshold, and the difference between the minimum allowable distance and the proximity distance d23 between the reference portion of the second robot arm 3B and the reference portion of the third robot arm 3C is greater than the predetermined threshold.

If the arm control unit 28 determines that the difference between the proximity distance between the arms and the minimum allowable distance is smaller than a predetermined threshold, it selects the robot arm 3 to be adjusted (step S3). As the robot arm 3 to be adjusted, for example, from the pair of robot arms 3 whose proximity distances have been determined, the robot arm that is operating by operation (following operation) based on operation input from the operation device 2 is selected.

By making the robot arm 3 in operation the adjustment target, the operating range of the robot arm 3 in operation can be expanded. In other words, if adjustment is not performed, the robot arm 3 in operation will need to stop its operation, for example, to prevent interference with other robot arms when the proximity distance to other robot arms becomes smaller than the minimum allowable distance. In contrast, by making the robot arm 3 in operation the adjustment target, it is possible to continue operation to control the position and orientation of the surgical instrument 40 while avoiding interference with other robot arms.

Furthermore, for example, if a first robot arm 3A in operation approaches a second robot arm 3B that is stationary and the proximity distance between the arms becomes smaller than the minimum allowable distance, attempting to increase the proximity distance between the stationary second robot arm 3B and the first robot arm 3A by adjusting the configuration of the second robot arm 3B may result in a shorter proximity distance between the second robot arm 3B being adjusted and the adjacent third robot arm 3C. In this case, it may become necessary to adjust the configuration of the third robot arm 3C as an additional adjustment target. It is desirable to avoid this chain reaction of increasing the number of robot arms to be adjusted, in order to prevent the control from becoming more complicated, for example. In this regard, by adjusting the operating first robot arm 3A rather than the stationary second robot arm 3B, it is possible to prevent this chain reaction of increasing the number of robot arms to be adjusted.

Furthermore, by adjusting the robot arm 3 while it is in operation, the possibility of vibration occurring in the robot arm 3 due to adjustment can be reduced compared to when adjusting a stationary robot arm 3, thereby minimizing the impact of vibration on the surgery.

Furthermore, if both of a pair of robot arms 3 are operating, the robot arm operating in the direction that shortens the proximity distance may be selected. Alternatively, if both robot arms 3 are operating in directions that bring them closer to each other, the following processing can also be performed. First, imagine a virtual line connecting the reference locations of the virtual models of the pair of robot arms 3. The velocity vector components in the direction along this virtual line are calculated for each of the pair of robot arms 3. If the calculated value of the velocity vector component of one robot arm 3 is greater than the calculated value of the velocity vector component of the other robot arm 3, the robot arm 3 with the greater calculated value is selected as the robot arm 3 to be adjusted.

Next, the arm control unit 28 determines the adjustment direction of the offset of the reference point RD for the robot arm 3 selected in step S3 (step S4). That is, it determines whether the offset of the reference point RD for the selected robot arm 3 should be adjusted in the positive or negative direction in the first direction D1 shown in FIG. 17.

Specifically, the robot arm 3 to be adjusted is moved on the model to determine the offset adjustment direction. That is, on the model, the reference point RD is shifted slightly in either the positive or negative direction in the first direction D1 to slightly change the offset amount. This slightly changes the constraint condition for the ninth joint J39, which is set as a redundant axis. As a result, the configuration of the robot arm 3 to be adjusted changes slightly on the model. This also changes slightly the proximity distance between the arms on the model (see Figure 21). If the change in the proximity distance between the arms on the model when the reference point RD is shifted slightly in the positive direction in the first direction D1 is a change in the direction that increases the proximity distance, that direction, i.e., the positive direction in the first direction D1, is determined as the adjustment direction. Conversely, if the change in the proximity distance between the arms on the model when the reference point RD is shifted slightly in the positive direction in the first direction D1 is a change in the direction that decreases the proximity distance, the opposite direction, i.e., the negative direction in the first direction D1, is determined as the adjustment direction for the offset amount. Note that the direction in which the reference point RD is initially moved on the model can also be the negative direction instead of the positive direction described above.

In the calculation process on the model in step S4 described above, only the calculation related to the joint position of the ninth joint J39, which changes based on changes to the offset amount of the reference point RD, is performed, which requires a small amount of calculation and requires only a short calculation time.

The processing in step S4 can also be performed by actually moving the robot arm 3. That is, in actual control, rather than on a model, the reference point RD is shifted slightly in either the positive or negative direction in the first direction D1 to slightly change the offset amount. This slightly changes the constraint condition for the ninth joint J39, which is set as the redundant axis. As a result, the instrument driver 38 of the instrument holder 36 is driven, causing the ninth joint J39 to rotate slightly. The slight rotation of the ninth joint J39 causes a slight change in the configuration of the robot arm 3 to be adjusted. This slightly changes the proximity distance between the arms. If the change in the proximity distance between the arms when the reference point RD is shifted slightly in the positive (or negative) direction in the first direction D1 is a change in the direction that increases the proximity distance, the positive (or negative) direction in the first direction D1 is determined to be the adjustment direction. On the other hand, if the change in the proximity distance between the arms when the reference point RD is slightly shifted in the positive (or negative) direction in the first direction D1 results in a change that reduces the proximity distance, the negative (or positive) direction in the first direction D1 is determined to be the adjustment direction for the offset amount. Note that even when the robot arm 3 is actually moved in step S4, it is the redundant axis (ninth joint J39) that is driven, and therefore the movement of the surgical instrument 40, which is controlled based on operation input from the operating device 2, is not affected.

Once the offset adjustment direction is determined in step S4, the offset amount of the reference point RD in the first direction D1 is adjusted in the determined adjustment direction (step S5). Adjusting (changing) the offset amount of the reference point RD changes the constraint condition for the ninth joint J39, which is set as a redundant axis. As a result, the instrument driver 38 of the instrument holder 36 is driven and the ninth joint J39 rotates. At this time, the movement of the surgical instrument 40, which is controlled based on operation input from the operating device 2, is not affected. As the ninth joint J39 rotates due to the change in constraint condition, the configuration of the robot arm 3 to be adjusted changes, thereby increasing the proximity distance between the arms.

Next, it is determined whether the difference between the proximity distance between the arms, which has increased due to adjustment of the offset amount of the reference point RD, and the minimum allowable distance is equal to or greater than a predetermined threshold (step S6). When the difference between the proximity distance between the arms and the minimum allowable distance is equal to or greater than the predetermined threshold, adjustment of the offset amount of the reference point RD is terminated (step S6).

As described above, the arm control unit 28 adjusts the offset amount of the reference point RD, thereby controlling the instrument drive unit 38 of the instrument holder 36 to rotate the ninth joint J39 so as to maintain the proximity distance between the robot arms 3 at or above the minimum allowable distance. As described above, since the ninth joint J39 is set as a redundant axis, even if the constraint conditions are changed in conjunction with a change in the offset amount of the reference point RD and the ninth joint J39 is rotationally driven as a result, this can be prevented from affecting the movement of the surgical instrument 40.

FIG. 22 shows how interference between the third robot arm 3C and the fourth robot arm 3D is avoided by the control method according to the present embodiment described above. In the example shown in FIG. 22, while the fourth robot arm 3D is stationary, the third robot arm 3C moves in a direction approaching the fourth robot arm 3D (step t). The arm control unit 28 determines the proximity distance between the reference portion of the third robot arm 3C and the reference portion of the fourth robot arm 3D based on the virtual model of the robot arms 3C and 3D (see FIG. 18) (step S1 in FIG. 19). As the third robot arm 3C approaches the fourth robot arm 3D, the proximity distance between the reference portion of the model of the third robot arm 3C and the reference portion of the model of the fourth robot arm 3D gradually decreases (step t+1).

When the third robot arm 3C approaches the fourth robot arm 3D and the difference between the proximity distance and the minimum allowable distance between the reference locations of the two models becomes equal to or less than the threshold, the arm control unit 28 begins the process of adjusting the offset amount of the reference point RD of the third robot arm 3C (step t+2). Specifically, the arm control unit 28 first selects the robot arm whose offset amount is to be adjusted (step S3 in Figure 19). In the example shown in Figure 22, the fourth robot arm 3D is stationary and the third robot arm 3C is moving, so the arm control unit 28 selects the moving third robot arm 3C as the adjustment target.

Next, the arm control unit 28 calculates the adjustment direction for the offset amount of the third robot arm 3C selected as the adjustment target (step S4 in Figure 19). Specifically, the offset of the third robot arm 3C on the model is moved slightly in one direction (e.g., the positive direction) in the first direction D1 shown in Figure 17. If this increases the proximity distance between the reference portion of the third robot arm 3C and the reference portion of the fourth robot arm 3D on the model, that direction (positive direction) is determined as the adjustment direction for the offset amount. Conversely, if this proximity distance decreases, the other direction (negative direction) in the first direction D1 is determined as the adjustment direction for the offset amount of the third robot arm 3C.

Next, the offset amount of the third robot arm 3C is adjusted in the calculated adjustment direction (step S5 in FIG. 19). As a result, the third robot arm 3C moves in a direction away from the fourth robot arm 3D (step t+2). The arm control unit 28 determines whether the proximity distance between the reference locations of the model of the third robot arm 3C and the model of the fourth robot arm 3D is equal to or greater than the minimum allowable distance (step S6 in FIG. 19), and ends adjustment of the offset amount of the third robot arm 3C when the proximity distance is equal to or greater than the minimum allowable distance.

The above operations maintain the proximity distance between the reference locations of the model of the third robot arm 3C and the model of the fourth robot arm 3D at or above the minimum allowable distance. This makes it possible to automatically avoid interference between the third robot arm 3C and the fourth robot arm 3D. As a result, it is possible to avoid the surgical robot 1 being put into a stopped state (locked state) due to interference between the robot arms, for example, and ensure the continuity of the surgery.

Furthermore, the arm control unit 28 automatically maintains the proximity distance between the reference locations of the adjacent robot arms 3C and 3D models at or above the minimum allowable distance, preventing interruptions to the control of the position and posture of the end effector by the operating robot arm 3C (following operation). This ensures the continuity of treatment by the operator S.

As mentioned above, the object to be avoided is typically the adjacent robot arm 3. However, by providing appropriate object detection means, other objects besides the adjacent robot arm 3, such as devices other than the robot arm 3 that make up the patient-side unit, or treatment assistants, can also be targets of interference avoidance. An example of an appropriate object detection means is a proximity sensor 60 (see Figure 10) that is provided at an appropriate position on the robot arm 3 and detects the proximity of surrounding objects. The proximity sensor 60 can be an inductive proximity sensor, magnetic proximity sensor, optical proximity sensor, ultrasonic proximity sensor, or capacitive proximity sensor. The detection signal from the proximity sensor 60 is transmitted to the arm control unit 28, which determines the distance between the target robot arm 3 and the surrounding object based on the detection signal, and performs the above-mentioned interference avoidance control based on the determined distance. Alternatively, an imaging device can be provided to capture images of surrounding objects, and the images from this imaging device can be analyzed using artificial intelligence techniques such as machine learning to determine the distance between the target robot arm 3 and the surrounding object.

Furthermore, for objects other than the robot arm 3 that are to be prevented from interfering with the surgical robot 1, the spatial region in which the object exists, or the spatial region in which the object may exist, may be modeled in advance as a no-entry region. The no-entry region may be set, for example, to a spatial region in which equipment other than the robot arm 3 constituting the surgical robot 1 exists, or to a spatial region in which the body of a surgical assistant may be present during surgery. The model of the no-entry region may be defined in a slave-side coordinate system recognized by the arm control unit 28. This allows the arm control unit 28 to determine the proximity distance between the model of the target robot arm 3 and the model of the no-entry region by calculation, without using a proximity sensor or the like. Alternatively, a method using the detection results of a proximity sensor and a method using the model of the no-entry region may be used in combination.

As described above, the surgical robot system and control method according to this embodiment can reliably avoid interference between the robot arm and objects around the robot arm, ensuring the continuity of surgery by the operator (surgeon) S.

In the surgical robot system 10 according to this embodiment, the positioner control unit 75 controls the positioner 7 during surgery to adjust at least one of the position and posture of the arm base 5. The arm control unit 28 controls the robot arm 3 without the movement of the surgical instrument 40 being affected by adjustments of the arm base 5 by the positioner control unit 75. In other words, even when at least one of the position and posture of the arm base 5 is adjusted by the positioner control unit 75, the arm control unit 28 controls the robot arm 3 so that the position and posture of the surgical instrument 40 are determined based on the operation input entered by the operator S from the operation device 2.

23, the positioner control unit 75 includes a surgical field designation means 76, a surgical field estimation means 77, a manual arm selection means 78, and an automatic arm selection means 79. Using these means, the positioner control unit 75 adjusts at least one of the position and posture of the arm base 5 based on the intraoperative conditions that change during surgery. The intraoperative conditions that change during surgery relate to, for example, changes in the surgical field imaged by the endoscope 12 due to changes in at least one of the position and posture of the endoscope 12 during surgery, changes in the virtually defined surgical field in relation to the control of the robot arm 3 due to the operator S manually designating the surgical field, and changes in the separation distance between the robot arms 3 operated by the operator S. The surgical field can be defined as a spherical region in the slave-side coordinate system in relation to the focal length and angle of view of the endoscope 12, based on, for example, at least one of the position and posture of the endoscope 12 that images the surgical site during surgery.

The surgical field designation means 76 of the positioner control unit 75 can designate a surgical field during surgery based on commands from the operator S input via, for example, the touch panel 23 of the operation device 2. Alternatively, the surgical field designation means 76 may designate the surgical field by having the operator S use the annotation function to circle the field of view image of the endoscope 12 with a digitizer pen. For example, when the operator S designates a point in a three-dimensional space within the body of the patient P that includes the surgical site, the surgical field designation means 76 designates a spatial region of a predetermined range (e.g., a spherical spatial region with a predetermined diameter) centered on the designated point as a virtual surgical field. The surgical field designated by commands from the operator S in this way does not necessarily have to perfectly match the actual surgical field imaged by the endoscope 12, and may be a virtually defined surgical field in relation to the control of the surgical robot 1. Furthermore, the arm control unit 28 may control the robot arm 3 to which the endoscope 12 is attached so that the surgical field designated by the operator S matches the surgical field imaged by the endoscope 12.

As shown in Figures 24A, 24B, and 24C, the positioner control unit 75 adjusts at least one of the position and orientation of the arm base 5 to adjust the instrument operable range, which is defined as the area in which the surgical instrument 40 (more specifically, the end effector 44) can operate within the surgical field specified by the operator S, for at least one target robot arm 3 out of multiple robot arms 3. This adjustment of the instrument operable range may be performed so as to maximize the instrument operable range. This point will be described in more detail later.

The surgical field estimation means 77 of the positioner control unit 75 is a means for automatically estimating the surgical field based on the inclination of the operating table 111. That is, if the inclination of the operating table 111 on which the patient P is placed changes during surgery, the surgical field estimation means 77 estimates the surgical field based on, for example, the inclination of the operating table 111 and the position and orientation of the endoscope 12. The positioner control unit 75 adjusts at least one of the position and orientation of the arm base 5 to adjust the instrument operable range, which is defined as the range within which the surgical instrument 40 (more specifically, the end effector 44) can operate within the surgical field estimated by the surgical field estimation means 77, for at least one target robot arm 3 out of the multiple robot arms 3. This adjustment of the instrument operable range may be performed so as to maximize the instrument operable range. This point will be described in more detail later.

The manual arm selection means 78 of the positioner control unit 75 has the function of selecting a target robot arm 3 based on a command from the operator S. Here, the target robot arm 3 refers to, for example, the robot arm 3 to which the target surgical instrument 40 is attached, whose range of motion is to be maximized when the positioner control unit 75 adjusts at least one of the position and orientation of the arm base 5 to maximize the range of motion of the surgical instrument 40. The target robot arm 3 also refers to the target robot arm 3 from which interference is to be avoided when the positioner control unit 75 adjusts at least one of the position and orientation of the arm base 5 to avoid interference between arms. There may be one target robot arm 3, or multiple target robot arms 3. The target robot arm 3 may also be automatically selected by the automatic arm selection means 79, for example, as the robot arm 3 being operated by operation input from the operator S.

The positioner control unit 75 may have a function to maintain a certain distance between the arm base 5 and a virtual space preset around the arm base 5. For example, for a surgical assistant working near the operating table 111 during surgery, a space to which the surgical assistant may move during surgery is preset as a virtual workspace and stored in the memory 302 of the control device 4, and when the positioner control unit 75 adjusts the position and/or posture of the arm base 5, it adjusts it so that the distance between the set workspace and the arm base 5 is maintained at a certain distance or more. This reduces the possibility of the arm base 5 moving during surgery interfering with the surgical assistant.

The positioner control unit 75 has the function of adjusting the position and/or posture of the arm base 5 during surgery to avoid interference between one robot arm 3 out of the multiple robot arms 3 and another robot arm 3 out of the multiple robot arms 3. In other words, the configuration of the robot arm 3 operating based on operation input from the operator S may be different if the position and posture of the arm base 5 is different, even if the position and posture of the surgical instrument 40 are the same. Therefore, even if the position and posture of the surgical instrument 40 are the same, the configuration of the robot arm 3 can be changed by changing the position and/or posture of the arm base 5. Therefore, in order to prevent the robot arm 3 operated by operation input from the operator S from interfering with another robot arm 3, the positioner control unit 75 controls the position and/or posture of the arm base 5 to change the configuration of the robot arm 3. By avoiding interference between the robot arms 3 in this way, the range of operation of the surgical instrument 40 can be maximized.

In the surgical robot system 10 according to this embodiment, as described above, the positioner control unit 75 adjusts the position and/or posture of the arm base 5 based on the intraoperative condition (e.g., a change in the surgical field) that changes during surgery. For example, when the position and posture of the arm base 5 are as shown in FIG. 25A, if the second robot arm 3B equipped with the endoscope assembly 40B is operated based on operation input from the operator S, and the orientation (posture) of the endoscope 12 of the endoscope assembly 40B changes as shown in FIG. 25B, the position of the surgical field SF also changes accordingly. In response to this, the positioner control unit 75 changes the position and/or posture of the arm base 5 as shown in FIG. 25C. At this time, the arm control unit 28 controls the robot arms 3A, 3B, 3C, and 3D while ensuring that the movement of the arm base 5 does not affect the movement of any of the surgical instruments 40A, 40B, 40C, and 40D. That is, when the position and/or orientation of the arm base 5 is changed by the positioner control unit 75, the arm control unit 28 controls the robot arms 3A, 3B, 3C, and 3D while avoiding interference between the robot arms 3 and between the robot arms 3 and the positioner 7, so that the position and orientation of the forceps tip (end effector 44) and the endoscope 12 do not change. The changed position and orientation of the arm base 5 maximizes the operable range of the surgical instrument 40 in relation to the changed surgical field, allowing the operator S to continue the surgery without hindrance, as shown in FIG. 25D.

Next, we will explain a method for evaluating, through simulation using a virtual model, how to adjust the operable range of the surgical instrument 40 by controlling the position and/or posture of the arm base 5 in response to changes in the surgical field during surgery.

Figure 26 shows a schematic diagram of the shaft portions 43 of the endoscope assembly 40B attached to the central robot arm 3 and the forceps assemblies 40A attached to the robot arms 3 on both sides penetrating the body wall BW of the patient P via port members (not shown). When the robot arms 3 control the position and posture of the surgical instrument 40, all three shaft portions 43 rotate around a pivot point PP set near the body wall BW of the patient P. For example, a surgical field SF is formed in front of the endoscope 12 of the endoscope assembly 40B (forward in the axial direction of the shaft portions 43).

Figures 27A and 27B are diagrams illustrating a method for simulating the operable range (instrument operable range) of a surgical instrument 40 (more specifically, the end effector 44) using virtual models of an arm base 5, robot arm 3, surgical instrument 40, etc., in a virtual surgical field SF defined as a spherical area.

As shown in Figures 27A and 27B, a spherical surgical field SF defined inside the body is used as the evaluation area, and multiple grid points are created within the evaluation area. The size of the surgical field SF may be determined depending on the details of the target surgery (surgical site, surgical procedure, etc.). The reachability of the surgical instrument 40 for each of the multiple grid points created within the surgical field SF is then determined by simulation. The reachability of the surgical instrument 40 to each grid point is determined, for example, as reachable if the distance between the tool center point (TCP) of the surgical instrument 40 and the grid point is less than a predetermined threshold, and as unreachable if it exceeds the predetermined threshold. Furthermore, the reachability determination is performed by searching for each grid point while varying the position and orientation of the surgical instrument 40 in various ways. The greater the number of reachable grid points, the larger the operational range (instrument operational range) of the surgical instrument 40 is determined to be. The surgical field SF is the same in the state shown in Figure 27A and the state shown in Figure 27B, but the position and/or orientation of the arm base 5 as a virtual model are different.

27A, one robot arm 3 and the other robot arm 3 are interfering with each other, so the grid point being evaluated at this time is determined to be an unreachable grid point. In other words, the position and posture of the arm base 5 in the state shown in FIG. 27A are determined to be NG in relation to the target surgical field SF. On the other hand, in the state shown in FIG. 27B, one robot arm 3 and the other robot arm 3 are not interfering with each other, so the grid point being evaluated at this time is determined to be a reachable grid point. In other words, the position and posture of the arm base 5 in the state shown in FIG. 27B are determined to be OK in relation to the target surgical field SF. In this way, by changing the position and/or posture of the arm base 5, the same grid point can be reached in cases where the surgical instrument 40 cannot reach it (FIG. 27A) or can reach it (FIG. 27B). In the simulation of this example, the position and posture of the arm base 5 as a virtual model are variously changed, and the position of the spherical surgical field SF as a virtual model is variously changed, and the reachability of the surgical instrument 40 to each grid point is evaluated. Then, if the number of reachable grid points for the target surgical field SF is, for example, 100 in the first position and orientation of the arm base 5 and 150 in the second position and orientation of the arm base 5, then the second position and orientation is evaluated as being better for the target surgical field SF.

The above-mentioned evaluation simulation is then performed in advance of the actual surgery, and the results are stored in the memory 302 of the control device 4. The positioner control unit 75 controls the position and/or posture of the arm base 5 based on the simulation results stored in the memory 302, depending on the surgical field SF in the actual surgery. This ensures that the surgical instrument 40 can operate within a sufficient range in the changed surgical field SF, even if the surgical field SF is changed during surgery. Furthermore, in the above-mentioned simulation, searching for the position and posture of the arm base 5 that maximizes the surgical instrument 40's operating range within the surgical field SF also searches for the position and posture of the arm base 5 that prevents interference between the robot arms 3. Therefore, by controlling the position and/or posture of the arm base 5 based on the simulation results stored in the memory 302, interference between the robot arms 3 can be avoided. This avoids the need for recovery work, etc., that would be required if interference actually occurs, and ensures the continuity of the surgery.

Furthermore, in the above-mentioned simulation, it is possible to add a condition that a predetermined virtual space around the arm base 5 is maintained at a distance from the arm base 5. This virtual space can be defined as a space in which other objects (e.g., surgical assistants) are expected to be present during surgery, for example. By setting additional conditions in relation to the virtual space in this way and performing a simulation, it is possible to reduce the possibility of the arm base 5 coming into contact with other objects (e.g., surgical assistants) during surgery.

Furthermore, in the above-described simulation, for example, a condition may be added that, for virtual models of two or more target robot arms 3 selected from a plurality of robot arms 3, the sum of the differences from the optimal relative position and orientation of each target robot arm 3 is minimized. In other words, when the position and/or orientation of the arm base 5 changes, the positions and/or orientations of the multiple base ends 80 of the multiple robot arms 3 attached to the arm base 5 change simultaneously. For this reason, in terms of maximizing the operable range of the surgical instrument 40, the position and/or orientation of the arm base 5 that is optimal for one robot arm 3 is not necessarily optimal for another robot arm 3. Therefore, by performing a simulation with an additional condition that the sum of the differences from the optimal relative position and orientation of each target robot arm 3 is minimized for the multiple target robot arms 3, the operable range of each robot arm 3 (i.e., the operable range of the surgical instrument 40) is widened on average.

Similarly, a simulation can be performed for virtual models of two or more target robot arms 3 selected from a plurality of robot arms 3, with the additional condition that the maximum difference between the optimal relative position and posture of each target robot arm 3 is minimized. This makes it possible to prevent the emergence of robot arms 3 with extremely narrow operable ranges.

As described above, with the surgical robot system 10 and its control method according to this embodiment, the positioner control unit 75 adjusts at least one of the position and orientation of the arm base 5 during surgery, thereby ensuring a sufficient operating range for the surgical instrument 40 within the surgical field, and reliably avoiding interference between the robot arm 3 and other surrounding objects, ensuring the continuity of the surgery by the operator (surgeon) S.

Furthermore, with the surgical robot system 10 and its control method according to this embodiment, interference between the robot arm 3 and other surrounding objects can be reliably avoided by adjusting the constraint conditions of the redundant axes during surgery, thereby ensuring the continuity of the surgery by the operator S. In particular, the positioner 7 of the surgical robot 1 in this embodiment is configured using a vertical articulated robot (a seven-axis robot in this example), which enables precise control of the position and orientation of the arm base 5 that is not possible with, for example, a horizontal articulated robot. This enables precise control of the position and orientation of the arm base 5, which is necessary to achieve the goal of avoiding interference between the robot arms 3 and maximizing the operable range of the surgical instrument 40. Multiple robot arms 3 are attached to the arm base 5, and moving the arm base 5 moves the base ends of the multiple robot arms 3 simultaneously. Therefore, in order to maximize the operable range of the surgical instrument 40 for two or more robot arms 3, precise control of the position and orientation of the arm base 5 using a positioner 7 configured using a vertical articulated robot is preferable.

The above-mentioned method for adjusting the position and/or position of the arm base (arm base adjustment method) and the method for adjusting the constraint conditions of the redundant axis (constraint condition adjustment method) can be used either alone or both simultaneously. For example, the constraint condition adjustment method can be applied to avoid interference between the robot arm 3 and other surrounding objects (including other robot arms 3), while the arm base adjustment method can be applied to fully ensure the operable range of the surgical instrument 40 when the attitude of the endoscope 12 and/or the inclination of the operating table 111 is changed. Alternatively, the constraint condition adjustment method can be used as the basis, but the arm base adjustment method can be applied when the constraint condition adjustment method cannot be used. Or, conversely, the arm base adjustment method can be used as the basis, but the constraint condition adjustment method can be applied when the arm base adjustment method cannot be used.

In addition, in conventional surgical methods that do not use surgical robots, such as endoscopic surgery in which the surgeon directly grasps surgical instruments with their hands, the operating table may be tilted to position the patient P in a way that makes it easier for the surgeon to perform the surgery, depending on the type of surgery or the situation. In other words, by adjusting the tilt of the operating table, for example, a surgeon who directly grasps and operates surgical instruments such as forceps with their hands can more easily move their arms and hands, and it also makes it easier for a surgical assistant to operate an endoscope that is directly held in their hands.

In contrast, in the surgical robot system 10 according to this embodiment, the position and orientation of the arm base 5 can be adjusted by controlling the positioner 7 of the surgical robot 1 during surgery. This allows for effects similar to, or even greater than, adjusting the tilt of the operating table 111 to be achieved by adjusting the position and orientation of the arm base 5. For example, when changing the surgical field depending on the surgical situation, the robot arm 3 (e.g., the second robot arm 3B) holding the endoscope assembly 40B is operated to change the position and/or orientation of the endoscope 12. In conventional surgical methods in which a surgeon or surgical assistant directly grasps and operates surgical instruments (forceps, endoscope, etc.) with their hands rather than using a surgical robot, it may be necessary to tilt the operating table to ensure an appropriate surgical field given the constraints of the surgeon's or surgical assistant's hand and arm movements. Even in the case of the surgical robot 1, changing the surgical field requires changing the configuration of the second robot arm 3B holding the endoscope assembly 40B, and the surgery must be continued while avoiding interference between the second robot arm 3B with the changed configuration and the surrounding robot arms 3 (e.g., the first robot arm 3A). In this regard, the surgical robot system 10 according to this embodiment controls the position and/or orientation of the arm base 5 to avoid interference between the robot arms 3 even when the surgical field is changed, allowing surgery to be performed continuously in the changed surgical field. This reduces the need to tilt the operating table 111, or reduces the tilt angle when tilting the operating table 111, compared to conventional surgical methods in which the surgeon directly holds the surgical instruments with his or her hands. In particular, because this embodiment uses a vertical articulated robot for the positioner 7, more precise response is possible in terms of ensuring an optimal surgical field compared to conventional surgical methods in which the operating table is tilted.

The control method for the surgical robot system according to the present embodiment described above can be implemented by a computer program. The computer program can include computer code configured to instruct a computer to perform one or more functions of the control method described above. The computer program and/or code for executing such a control method can be provided on one or more computer-readable media. The computer-readable medium can be either transient or non-transient. The computer-readable medium can be, for example, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, or a propagation medium for data transmission, for example, for downloading code via the Internet. Alternatively, the computer-readable medium can take the form of one or more physical computer-readable media, such as semiconductor or solid-state memory, magnetic tape, removable computer diskettes, random access memory (RAM), read-only memory (ROM), rigid magnetic disks, or optical disks such as CD-ROMs, CD-R/Ws, and DVDs.

Furthermore, the functions of the components disclosed herein may be performed using circuits or processing circuits, including general-purpose processors, special-purpose processors, integrated circuits, ASICs (Application Specific Integrated Circuits), conventional circuits, and/or combinations thereof, configured or programmed to perform the disclosed functions. A processor is considered a processing circuit or circuit because it includes transistors and other circuitry. In this disclosure, a circuit, unit, or means is hardware that performs the recited functions or hardware that is programmed to perform the recited functions. The hardware may be hardware disclosed herein or other known hardware that is programmed or configured to perform the recited functions. Where the hardware is a processor, which is considered a type of circuit, the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and/or processor.

This disclosure also includes the following aspects.
(Aspect 1)
Aspect 1 of this disclosure is a surgical robot system comprising: a robotic arm having a tip end to which a surgical instrument having a longitudinal axis can be attached and a plurality of drive shafts, the number of the plurality of drive shafts being greater than the minimum degrees of freedom required to control the position and attitude of the surgical instrument; an operation device that receives operation input from an operator to control the position and attitude of the surgical instrument; and a control device that controls the robotic arm based on the operation input, wherein the tip end has an instrument drive unit that rotates at least a portion of the surgical instrument around the longitudinal axis, and the control device controls the instrument drive unit to maintain a proximity distance between the robotic arm and an object present around the robotic arm that is equal to or greater than the minimum allowable distance.

(Aspect 2)
Aspect 2 of this disclosure is a surgical robot system described in Aspect 1, wherein the control device operates the instrument drive unit to rotate at least a portion of the surgical instrument around the longitudinal axis in a direction that increases the proximity distance when the difference between the proximity distance and the minimum allowable distance becomes smaller than a predetermined threshold.

(Aspect 3)
Aspect 3 of this disclosure is a surgical robot system described in Aspect 1 or 2, wherein the proximity distance is the distance between a reference portion of the robot arm and the object, the robot arm has a translational movement mechanism that moves the surgical instrument along the longitudinal axis, and the reference portion includes at least a portion of the translational movement mechanism.

(Aspect 4)
Aspect 4 of this disclosure is a surgical robot system according to any one of Aspects 1 to 3, wherein at least a portion of the surgical instrument is configured to be inserted into a port member provided in a patient, and the number of the plurality of drive axes of the robot arm is greater than the minimum degrees of freedom required to control the position and orientation of the surgical instrument with at least a portion of the surgical instrument inserted into the port member.

(Aspect 5)
Aspect 5 of this disclosure is a surgical robot system described in any one of aspects 1 to 4, wherein the control device determines the proximity distance based on an arm model generated by modeling at least a portion of the robot arm.

(Aspect 6)
Aspect 6 of this disclosure is a surgical robot system described in aspect 5, wherein the control device operates the robot arm on the arm model to determine one of two rotational directions about the longitudinal axis of at least a portion of the surgical instrument that increases the proximity distance.

(Aspect 7)
Aspect 7 of this disclosure is a surgical robot system described in Aspect 5 or 6, wherein the robotic arm has a translational movement mechanism that moves the surgical instrument along the longitudinal axis, and the at least part of the robotic arm is at least part of the translational movement mechanism.

(Aspect 8)
Aspect 8 of this disclosure is a surgical robot system described in any one of aspects 1 to 7, wherein the object is another robotic arm to which another surgical instrument can be attached, the operating device accepts operation input from the operator to control the position and posture of the surgical instrument attached to the robotic arm and the position and posture of the other surgical instrument attached to the other robotic arm, and the control device controls the robotic arm and the other robotic arm based on the operation input.

(Aspect 9)
Aspect 9 of this disclosure is a surgical robot system according to Aspect 8, wherein the other robot arm has a tip end to which the other surgical instrument having a different longitudinal axis can be attached and a plurality of drive shafts, the number of the plurality of drive shafts being greater than the minimum degrees of freedom required to control the position and posture of the other surgical instrument, the tip end of the other robot arm has a different instrument drive unit that rotates at least a portion of the other surgical instrument around the different longitudinal axis, and the control device adjusts the proximity distance by operating at least one of the instrument drive unit and the other instrument drive unit.

(Aspect 10)
Aspect 10 of this disclosure is a surgical robot system according to aspect 9, wherein the control device selects, from among the robot arm and the other robot arm, a robot arm that is operating by operation through the operation input, as the robot arm to be adjusted, and adjusts the proximity distance by operating an instrument driving unit of the robot arm to be adjusted.

(Aspect 11)
Aspect 11 of the present disclosure is a surgical robot system according to any one of aspects 1 to 10, further comprising the surgical instrument provided at the tip of the robot arm.

(Aspect 12)
Aspect 12 of the present disclosure is a surgical robot system according to any one of Aspects 1 to 11, wherein the robot arm has a base end, a torsion joint disposed at the base end, and a bending joint disposed between the tip end and the base end, and the control device controls the robot arm to intersect a rotation axis of the bending joint with a reference plane including the longitudinal axis and fix the orientation of the rotation axis of the bending joint with respect to the reference plane, set a predetermined center point, set a reference point on a reference line that is an extension line of the rotation axis of the torsion joint or a line that is disposed offset in a direction perpendicular to the extension line, control the robot arm to position the longitudinal axis at the center point and position the reference plane at the reference point, and adjust the offset amount of the reference point in the direction perpendicular to the extension line to control the direction and amount of movement of the instrument driver, thereby maintaining the approach distance equal to or greater than the allowable minimum distance.

(Aspect 13)
Aspect 13 of the present disclosure is a surgical robot system according to aspect 12, wherein the direction perpendicular to the extension line is horizontal.

(Aspect 14)
Aspect 14 of this disclosure is a surgical robot system described in Aspect 12 or 13, further comprising an arm base that holds the base end of the robot arm and the base end of another robot arm, the arm base having a longitudinal axis, and the perpendicular direction of the extension line being parallel to the longitudinal axis of the arm base.

(Aspect 15)
Aspect 15 of this disclosure is a control method for a surgical robot system comprising: a robotic arm having a tip end to which a surgical instrument having a longitudinal axis is attached and a plurality of drive shafts, the number of the plurality of drive shafts being greater than the minimum degrees of freedom required to control the position and attitude of the surgical instrument; an operation device that receives operation input from an operator to control the position and attitude of the surgical instrument; and a control device that controls the robotic arm based on the operation input, wherein the control method for a surgical robot system comprises: an instrument drive unit that constitutes at least a part of the tip end, rotating at least a portion of the surgical instrument around the longitudinal axis; and controlling the instrument drive unit to maintain a proximity distance between the robotic arm and an object present around the robotic arm that is greater than or equal to a minimum allowable distance.

(Aspect 16)
Aspect 16 of this disclosure is a control method for a surgical robot system described in Aspect 15, in which, when the difference between the proximity distance and the minimum allowable distance becomes smaller than a predetermined threshold, the instrument drive unit is operated to rotate at least a portion of the surgical instrument around the longitudinal axis in a direction that increases the proximity distance.

(Aspect 17)
Aspect 17 of the disclosure is a computer-readable medium storing computer-readable instructions that, when executed by a processor of a surgical robot system, cause the processor to execute a control method for the surgical robot system, the surgical robot system comprising: a robotic arm having a tip end to which a surgical instrument having a longitudinal axis is attached and a plurality of drive shafts, the number of the plurality of drive shafts being greater than the minimum degrees of freedom required to control the position and orientation of the surgical instrument; an operation device that accepts operation input from an operator to control the position and orientation of the surgical instrument; and a control device that controls the robotic arm based on the operation input, the control method comprising: rotating at least a portion of the surgical instrument about the longitudinal axis using an instrument drive unit that constitutes at least a part of the tip end; and controlling the instrument drive unit to maintain a proximity distance between the robotic arm and an object present around the robotic arm to be equal to or greater than a minimum allowable distance.

(Aspect 18)
Aspect 18 of this disclosure is a computer-readable medium described in aspect 17, wherein the control method operates the instrument driver to rotate at least a portion of the surgical instrument around the longitudinal axis in a direction that increases the proximity distance when the difference between the proximity distance and the minimum allowable distance becomes smaller than a predetermined threshold.

(Aspect 19)
Aspect 19 of this disclosure is a surgical robot system comprising: a robot arm having a tip end to which a surgical instrument can be attached and a plurality of drive shafts, the number of the plurality of drive shafts being greater than the minimum degrees of freedom required to control the position and attitude of the surgical instrument; an operation device that receives operation input from an operator to control the position and attitude of the surgical instrument; and a control device that controls the robot arm based on the operation input, wherein the control device defines at least one of the plurality of drive shafts as a redundant drive shaft, controls the redundant drive shaft based on the operation input and constraint conditions, and adjusts the constraint conditions to maintain a proximity distance between the robot arm and an object present around the robot arm at or above an allowable minimum distance.

(Aspect 20)
Aspect 20 of the present disclosure is a surgical robot system according to aspect 19, wherein the surgical instrument has a longitudinal axis and the redundant drive shaft rotates at least a portion of the surgical instrument about the longitudinal axis.

(Aspect 21)
Aspect 21 of this disclosure is a surgical robot system described in Aspect 20, wherein the control device operates the instrument drive unit to rotate at least a portion of the surgical instrument around the longitudinal axis in a direction that increases the proximity distance when the difference between the proximity distance and the minimum allowable distance becomes smaller than a predetermined threshold.

(Aspect 22)
Aspect 22 of this disclosure is a control method for a surgical robot system comprising: a robot arm having a tip end with a surgical instrument attached and a plurality of drive shafts, the number of which is greater than the minimum degrees of freedom required to control the position and attitude of the surgical instrument; an operation device that accepts operation input from an operator to control the position and attitude of the surgical instrument; and a control device that controls the robot arm based on the operation input, wherein the control method defines at least one of the plurality of drive shafts as a redundant drive shaft, controls the redundant drive shaft based on the operation input and constraint conditions, and adjusts the constraint conditions to maintain a proximity distance between the robot arm and an object present around the robot arm equal to or greater than a minimum allowable distance.

(Aspect 23)
Aspect 23 of this disclosure is a control method for a surgical robot system described in aspect 22, wherein the surgical instrument has a longitudinal axis and the redundant drive shaft rotates at least a portion of the surgical instrument around the longitudinal axis.

(Aspect 24)
Aspect 24 of this disclosure is a control method for a surgical robot system described in Aspect 23, in which, when the difference between the proximity distance and the minimum allowable distance becomes smaller than a predetermined threshold, the instrument drive unit is operated to rotate at least a portion of the surgical instrument around the longitudinal axis in a direction that increases the proximity distance.

(Aspect 25)
Aspect 25 of the disclosure is a computer-readable medium storing computer-readable instructions that, when executed by a processor of a surgical robot system, cause the processor to execute a control method for the surgical robot system, the surgical robot system comprising: a robot arm having a tip end with a surgical instrument attached and a plurality of drive shafts, the number of the plurality of drive shafts being greater than the minimum degrees of freedom required to control the position and orientation of the surgical instrument; an operation device that accepts operation input from an operator to control the position and orientation of the surgical instrument; and a control device that controls the robot arm based on the operation input, the control method defining at least one of the plurality of drive shafts as a redundant drive shaft, controlling the redundant drive shaft based on the operation input and constraint conditions, and adjusting the constraint conditions to maintain a proximity distance between the robot arm and an object present around the robot arm to be equal to or greater than a minimum allowable distance.

(Aspect 26)
Aspect 26 of the disclosure is a computer-readable medium described in aspect 25, wherein the surgical instrument has a longitudinal axis and the control method rotates at least a portion of the surgical instrument about the longitudinal axis by the redundant drive shaft.

(Aspect 27)
Aspect 27 of this disclosure is a computer-readable medium described in Aspect 26, wherein the control method operates the instrument driver to rotate at least a portion of the surgical instrument around the longitudinal axis in a direction that increases the proximity distance when the difference between the proximity distance and the minimum allowable distance becomes smaller than a predetermined threshold.

1 Surgical robot 2 Operation device 3, 3A, 3B, 3C, 3D Robot arm 4 Control device 5 Arm base 7 Positioner 10 Surgical robot system 23 Touch panel 28 Arm control unit 32 Tip of robot arm 35 Translational movement mechanism 36 Instrument holder 40 Surgical instrument 40A Endoscope assembly 40B Forceps assembly 38 Instrument drive unit 43 Shaft portion of surgical instrument 60 Proximity sensor 75 Positioner control unit 76 Surgical field designation means 77 Surgical field estimation means 78 Manual arm selection means 79 Automatic arm selection means BW Patient's abdominal wall C Central axis of shaft portion (longitudinal axis of surgical instrument)
J31 to J39 Joints (drive shafts)
P Patient PP Pivot points R1 to R9 Rotation axis RC Remote center RD Reference points RL, RLA, RLB Reference line RP Reference plane S Operator (practitioner)
SF surgical field

Claims (15)

a plurality of robotic arms, each of the plurality of robotic arms having a surgical instrument attached thereto;
an operating device that receives an operation input from an operator to control the position and posture of the surgical instrument;
an arm control unit that controls the plurality of robot arms based on the operation input;
a positioner having an arm base on which the plurality of robot arms are mounted;
a positioner control unit that controls the positioner to adjust the position and attitude of the arm base,
the positioner control unit adjusts at least one of the position and the attitude of the arm base during surgery;
A surgical robot system in which the arm control unit controls the multiple robot arms without the movement of the surgical instrument being affected by adjustment of at least one of the position and the attitude of the arm base by the positioner control unit. The surgical robot system of claim 1, wherein the positioner control unit adjusts at least one of the position and the orientation of the arm base based on intraoperative conditions that change during surgery. The surgical robot system of claim 2, wherein the positioner control unit adjusts at least one of the position and the orientation of the arm base to adjust an instrument operating range, defined as an area within the surgical field in which the surgical instrument can operate, for a target robot arm that is at least one of the plurality of robot arms. The surgical robot system of claim 3, wherein the positioner control unit adjusts at least one of the position and the posture of the arm base based on the surgical field, which changes during surgery. The surgical robot system of claim 4, wherein the surgical field is defined based on at least one of the position and orientation of an imaging device that images the surgical site during surgery. The surgical robot system of claim 4, further comprising a surgical field designation means for designating the surgical field during surgery based on a command from the operator. The surgical robot system of claim 4, further comprising a surgical field estimation means for automatically estimating the surgical field based on the inclination of the operating table. The surgical robot system of claim 3 or 4, further comprising a manual arm selection means for selecting the target robot arm based on a command from the operator. The surgical robot system of claim 3 or 4, further comprising an automatic arm selection means for selecting the robot arm being operated by the operation input from the operator as the target robot arm. The surgical robot system of claim 1 or 2, wherein the positioner control unit maintains a distance between the arm base and a virtual space preset around the arm base at or above a certain level. The surgical robot system of claim 1 or 2, wherein the positioner control unit adjusts at least one of the position and the orientation of the arm base during surgery to avoid interference between one robot arm of the plurality of robot arms and another robot arm of the plurality of robot arms. each of the plurality of robot arms has a plurality of drive axes, the number of the plurality of drive axes being greater than a minimum number of degrees of freedom required to control the position and orientation of the surgical instrument;
the arm control unit defines at least one of the plurality of drive shafts as a redundant drive shaft and controls the redundant drive shaft based on the operation input and constraint conditions;
3. The surgical robot system according to claim 1, wherein the constraint conditions are adjusted to maintain a proximity distance between the robot arm and an object present around the robot arm at or above an allowable minimum distance. the surgical instrument has a longitudinal axis;
The surgical robotic system of claim 12 , wherein the redundant drive shaft rotates at least a portion of the surgical instrument about the longitudinal axis. The surgical robot system of claim 13, wherein the arm control unit rotates at least a portion of the surgical instrument around the longitudinal axis in a direction that increases the proximity distance when the difference between the proximity distance and the minimum allowable distance becomes smaller than a predetermined threshold. The surgical robot system according to claim 1 or 2, wherein the positioner includes a vertical articulated robot.