Port arrangement determination device, surgical robot system, and control method thereof

Abstract

To determine an optimal port arrangement that can maximize the performance of a surgical robot.SOLUTION: A system 10 comprises: a plurality of arms 3 in which the number of drive shafts of each arm 3 is greater than the minimum degrees of freedom required to control a surgical instrument 40; an operation device 2 that receives an operator S's operation input for controlling the surgical instrument 40; and a control device 4 that controls the plurality of arms 3 on the basis of the operation input, defines at least one of the plurality of drive shafts as a redundant drive shaft and controls the redundant drive shaft on the basis of the operation input and constraint conditions related to the redundant drive shaft. A memory 302 stores information related to a required surgical procedure performed by the operator S using the surgical instrument 40 by operating the operation device 2 and information related to the constraint conditions. A processor 301 determines an optimal port arrangement for the required surgical procedure while adjusting the constraint conditions on the basis of the information related to the required surgical procedure and the information related to the constraint conditions acquired from the memory 302.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a port placement determination device, a surgical robot system, and a control method thereof. [Background technology]

[0002] Conventionally, surgical robot systems have been disclosed that use robots to operate surgical instruments instead of surgeons directly handling and operating surgical instruments. Surgical robot systems are used, for example, in minimally invasive surgery, which can reduce the burden on patients undergoing surgery.

[0003] A surgical robot system typically includes a surgical robot located near the patient and an operating device that allows a surgeon to remotely operate the surgical robot. The operating device operated by the surgeon is located, for example, 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 to be inserted, for example, into a port member provided in 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 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.

[0004] A surgeon (operator) can control the position and orientation of a surgical instrument attached to a robot arm by operating the operating device to operate the surgical robot. In cases where 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, in cases where a surgical instrument has a pair of jaws attached to the tip of a shaft, the surgeon can control the position and orientation of the entire surgical instrument by operating the operating device, as well as the opening and closing of the pair of jaws or the rotation around the pitch axis and / or yaw axis. Furthermore, in cases where the shaft itself is rotatable around its longitudinal axis, the surgeon can rotate the shaft of the surgical instrument (around the roll axis) by operating the operating device.

[0005] In conventional surgical robot systems, the robot arm of a surgical robot generally has multiple drive axes (joints). The multiple drive axes (joints) of the robot arm of a surgical robot generally include rotary joints, and may also have prismatic joints. The number of drive axes (joints) provided in the robot arm, i.e., the degrees of freedom of the robot arm, must be at least the same as the degrees of freedom required to control the position and orientation of the surgical instrument.

[0006] Among conventional surgical robot systems, there are those equipped with a surgical robot having a robot arm with more degrees of freedom than are necessary to control the position and orientation of a surgical instrument (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2021 / 112193 Summary of the Invention [Problem to be solved by the invention]

[0008] Patent Document 1 describes a surgical system and a method for controlling a surgical manipulator arm, and describes an invention for solving the problem of interference with other devices in the surgical system, such as an adjacent manipulator arm, or with the surrounding environment, when operating the manipulator arm. However, the invention described in Patent Document 1 leaves room for further improvement.

[0009] In particular, in conventional surgical robot systems and their control methods, the arrangement of multiple port members inserted into the patient's body wall (port arrangement) is positioned as a given condition when considering a control method for the surgical robot, and there is a lack of consideration for exploring the optimal port arrangement that can maximize the performance of the surgical robot.

[0010] This disclosure has been made to solve the above-mentioned problems, and one purpose of this disclosure is to provide a port placement determination device that can determine the optimal port placement that can maximize the performance of a surgical robot, as well as a surgical robot system equipped with the port placement determination device and a control method for the same. [Means for solving the problem]

[0011] (Aspect 1) Aspect 1 of this disclosure is 1. A port placement determination device for determining optimal port placement for a plurality of port members to be placed in a body wall of a patient in surgery using a surgical robot system, comprising: The surgical robot system includes: a plurality of robotic arms, each of which is equipped with a surgical instrument, each of which has a plurality of drive axes, the number of which is greater than the minimum number of degrees of freedom required to control the position and orientation of the surgical instrument; an operating device that receives an operation input from an operator to control the position and posture of the surgical instrument; a control device that controls the plurality of robot arms based on the operation input, the control device defining at least one of the plurality of drive shafts as a redundant drive shaft, and controlling the redundant drive shaft based on the operation input and a constraint condition related to the redundant drive shaft, a processor; a memory; the memory stores information about a required surgery to be performed by the operator using the surgical instrument by operating the operation device, and information about the constraint conditions; The processor is a port placement determination device that determines the optimal port placement by searching for the optimal port placement for the required surgery while adjusting the constraint conditions based on information about the required surgery and information about the constraint conditions obtained from the memory.

[0012] (Aspect 2) A second aspect of the present disclosure is the port placement determination device according to the first aspect, wherein the information regarding the required surgery includes information regarding a surgical field required to perform the required surgery.

[0013] (Aspect 3) Aspect 3 of this disclosure is the memory stores a virtual model of the required surgical field, a virtual model of the robot arm, and a virtual model of the surgical instrument; The processor is a port placement determination device according to aspect 2, wherein the processor determines the optimal port placement based on the results of a simulation performed by using the virtual model of the required surgical field, the virtual model of the robot arm, and the virtual model of the surgical instrument retrieved from the memory, and adjusting the constraints while causing the virtual model of the robot arm to perform a required operation that maximizes the operable range of the virtual model of the surgical instrument within the virtual model of the required surgical field.

[0014] (Aspect 4) Aspect 4 of this disclosure is the memory further storing a virtual model of the patient's anatomy; 4. The port placement determination device of aspect 3, wherein the processor further uses a virtual model of the patient's anatomy to determine the optimal port placement.

[0015] (Aspect 5) A fifth aspect of the present disclosure is the port placement determination device according to the third or fourth aspect, wherein the required movement of the virtual model of the robot arm includes a movement to avoid interference between the virtual models of the robot arm.

[0016] (Aspect 6) A sixth aspect of this disclosure is the surgical instrument has a longitudinal axis; Aspect 6 is the port placement determination apparatus of any one of aspects 1 to 5, wherein the redundant drive shaft rotates at least a portion of the surgical instrument about the longitudinal axis.

[0017] (Aspect 7) A seventh aspect of this disclosure is the robot arm has a tip end, a base end, a torsion joint disposed at the base end, and a bending joint disposed between the tip end and the base end, The control device Controlling the robot arm to intersect a rotation axis of the bending joint with a reference plane including the longitudinal axis, and fixing an orientation of the rotation axis of the bending joint with respect to the reference plane; A predetermined center point is set, and a reference point is set on a reference line that is an extension line of a rotation axis of the torsion joint or a line that is offset in a direction perpendicular to the extension line, and the robot arm is controlled to position the longitudinal axis at the center point and the reference plane at the reference point; The port arrangement determination device according to aspect 6 controls the movement direction and movement amount of the redundant drive shaft by changing the offset amount of the reference point in the direction orthogonal to the extension line.

[0018] (Aspect 8) Aspect 8 of this disclosure is The surgical robot system further includes an arm base to which the plurality of robot arms are attached, each of the plurality of robot arms includes a base end attached to the arm base, a tip end to which the surgical instrument is attached, and a plurality of links that connect the base end and the tip end and are connected to each other, and the link adjacent to the base end is connected to the base end via a torsion joint; The control device is a port placement determination device described in any one of aspects 1 to 7, which operates the robot arm so that, when viewed from a direction parallel to the axial direction of the rotation axis of the torsional joint, a first portion of one of the multiple links, which is located between the link connected to the base end and the link connected to the tip end, is positioned between a second portion of the base end and a third portion of the tip end.

[0019] (Aspect 9) A ninth aspect of this disclosure is The surgical instrument has an instrument base, a shaft portion extending from the instrument base, and an end effector provided at the tip of the shaft portion, the robot arm has a prismatic joint to which the instrument base is attached, the prismatic joint moving the surgical instrument in the axial direction of the shaft portion; The control device storing a remote center of motion of the surgical instrument; 9. The port placement determination device according to any one of aspects 1 to 8, wherein, when the shaft portion is inserted into a port member inserted into a body wall of a patient and the end effector is inside the patient's body cavity, the length of the surgical instrument from the remote center to the distal end of the surgical instrument within the body cavity is defined as L, the amount of linear displacement parallel to the axial direction from the origin position of the linear joint is defined as T0, and the amount of linear displacement parallel to the axial direction from the origin position of the linear joint to a current position is defined as T1, and when L≦T0, the relationship between L and T1 is T1≧L.

[0020] (Aspect 10) A tenth aspect of the present disclosure is a surgical robot system including the port placement determination device according to any one of the first to ninth aspects.

[0021] (Aspect 11) An eleventh aspect of this disclosure is the memory stores a plurality of sets including the optimal port allocation and the constraint conditions corresponding to the optimal port allocation, which are determined in advance by the port allocation determination device; In the surgical robot system of aspect 10, the control device selects an optimal set from the plurality of sets stored in the memory depending on the content of the required surgery.

[0022] (Aspect 12) A twelfth aspect of the present disclosure is a surgical robot system according to aspect 10 or 11, further comprising a port placement presentation means for presenting information about the optimal port placement determined by the port placement determination device.

[0023] (Aspect 13) Aspect 13 of this disclosure is a surgical robot system according to aspect 12, wherein the port placement presentation means presents the information about the optimal port placement on the body surface of the patient placed on an operating table.

[0024] (Aspect 14) Aspect 14 of this disclosure is a surgical robot system according to aspect 13, further comprising a patient position information acquisition means for acquiring position information of the patient placed on the operating table in a slave side coordinate system that serves as a reference for operating the multiple robot arms.

[0025] (Aspect 15) A fifteenth aspect of this disclosure is 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 according to any one of aspects 10 to 14, wherein the control device controls the multiple robot arms without affecting the movement of the surgical instrument by adjusting at least one of the position and the attitude of the arm base by the positioner control unit.

[0026] (Aspect 16) A sixteenth aspect of this disclosure is 1. A port placement determination method for determining an optimal port placement of a plurality of port members to be placed in a body wall of a patient in surgery using a surgical robot system, comprising: The surgical robot system includes: a plurality of robotic arms, each of which is equipped with a surgical instrument, each of which has a plurality of drive axes, the number of which is greater than the minimum number of degrees of freedom required to control the position and orientation of the surgical instrument; an operating device that receives an operation input from an operator to control the position and posture of the surgical instrument; a control device that controls the plurality of robot arms based on the operation input, the control device defining at least one of the plurality of drive shafts as a redundant drive shaft, and controlling the redundant drive shaft based on the operation input and a constraint condition related to the redundant drive shaft, storing information about a required surgery to be performed by the operator using the surgical instrument by operating the operation device and information about the constraint conditions in a memory; The port placement determination method involves a processor determining the optimal port placement by searching for the optimal port placement for the required surgery while adjusting the constraint conditions based on information about the required surgery and information about the constraint conditions obtained from the memory.

[0027] (Aspect 17) A seventeenth aspect of this disclosure is A computer-readable medium storing computer-readable instructions that, when executed by a processor, cause the processor to perform a port placement determination method for determining optimal port placement of a plurality of port members to be placed in a body wall of a patient during surgery using a surgical robotic system; The surgical robot system includes: a plurality of robotic arms, each of which is equipped with a surgical instrument, each of which has a plurality of drive axes, the number of which is greater than the minimum number of degrees of freedom required to control the position and orientation of the surgical instrument; an operating device that receives an operation input from an operator to control the position and posture of the surgical instrument; a control device that controls the plurality of robot arms based on the operation input, the control device defining at least one of the plurality of drive shafts as a redundant drive shaft, and controlling the redundant drive shaft based on the operation input and a constraint condition related to the redundant drive shaft; The port placement determination method includes: storing information about a required surgery to be performed by the operator using the surgical instrument by operating the operation device and information about the constraint conditions in a memory; The computer-readable medium determines the optimal port placement by the processor based on information about the required surgery and information about the constraints obtained from the memory, by searching for the optimal port placement for the required surgery while adjusting the constraints. [Effects of the Invention]

[0028] According to this disclosure, it is possible to provide a port placement determination device that can determine the optimal port placement that can maximize the performance of a surgical robot, as well as a surgical robot system equipped with the port placement determination device and a control method for the same. [Brief explanation of the drawings]

[0029] [Figure 1] FIG. 1 is a perspective view showing a schematic configuration of a surgical robot system according to one embodiment. [Figure 2] FIG. 1 is a plan view showing a schematic configuration of a surgical robot system according to one embodiment. [Figure 3] FIG. 1 is a side view showing a schematic configuration of a surgical robot system according to one embodiment. [Figure 4] FIG. 2 is another side view showing the schematic configuration of the surgical robot system according to the embodiment. [Figure 5] FIG. 1 is a side view showing a surgical robot of a surgical robot system according to one embodiment. [Figure 6] FIG. 1 is a perspective view showing a portion of a surgical robot of a surgical robot system according to one embodiment. [Figure 7] 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. [Figure 8] 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. [Figure 9] FIG. 1 is a block diagram illustrating a system configuration of a control device of a surgical robot system according to an embodiment. [Figure 10] 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. [Figure 11] 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. [Figure 12] 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. [Figure 13] 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. [Figure 14] FIG. 1 is a block diagram illustrating a schematic configuration of a drive control system of a surgical robot system according to one embodiment. [Figure 15] FIG. 10 is a diagram showing an example of the operation of the surgical robot system according to one embodiment. [Figure 16] FIG. 10 is a diagram showing an example of the operation of the surgical robot system according to one embodiment. [Figure 17] FIG. 10 is a diagram showing an example of the operation of the surgical robot system according to one embodiment. [Figure 18] FIG. 10 is a diagram showing an example of the operation of the surgical robot system according to one embodiment. [Figure 19] FIG. 10 is a diagram showing an example of the operation of the surgical robot system according to one embodiment. [Figure 20] FIG. 10 is a diagram showing an example of the operation of the surgical robot system according to one embodiment. [Figure 21] FIG. 10 is a diagram showing an example of the operation of the surgical robot system according to one embodiment. [Figure 22] FIG. 10 is a diagram showing an example of the operation of the surgical robot system according to one embodiment. [Figure 23] FIG. 10 is a diagram showing an example of the operation of the surgical robot system according to one embodiment. [Figure 24] 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. [Figure 25] FIG. 2 is a schematic diagram for explaining a control method of a surgical robot system according to one embodiment. [Figure 26A] FIG. 10 is another schematic diagram for explaining the control method of the surgical robot system according to one embodiment. [Figure 26B] FIG. 10 is yet another schematic diagram for explaining a control method of a surgical robot system according to one embodiment. [Figure 27] FIG. 10 is yet another schematic diagram for explaining a control method of a surgical robot system according to one embodiment. [Figure 28] FIG. 1 is a block diagram showing a schematic system of a surgical robot system according to one embodiment. [Figure 29A] 10A to 10C are diagrams illustrating an example of the operation of a surgical robot in a surgical robot system according to one embodiment. [Figure 29B] 10A and 10B are diagrams illustrating other examples of the operation of the surgical robot of the surgical robot system according to one embodiment. [Figure 29C]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. [Figure 30A] 1A and 1B are diagrams for explaining the operation of a surgical robot in a surgical robot system according to one embodiment. [Figure 30B] 10A and 10B are other diagrams for explaining the operation of the surgical robot of the surgical robot system according to one embodiment. [Figure 30C] FIG. 10 is yet another diagram for explaining the operation of the surgical robot of the surgical robot system according to one embodiment. [Figure 30D] FIG. 10 is yet another diagram for explaining the operation of the surgical robot of the surgical robot system according to one embodiment. [Figure 31A] 1A and 1B are diagrams for explaining the operation of a surgical robot in a surgical robot system according to one embodiment. [Figure 31B] 10A and 10B are other diagrams for explaining the operation of the surgical robot of the surgical robot system according to one embodiment. [Figure 32A] 1A and 1B are schematic diagrams for explaining a port placement determination method for a surgical robot system according to one embodiment. [Figure 32B] FIG. 10 is another schematic diagram illustrating the port placement determination method for the surgical robot system according to one embodiment. [Figure 33] 1A to 1D are diagrams showing various port arrangement patterns. [Figure 34] 1A to 1D are diagrams showing various port arrangement patterns. [Figure 35] (A) and (B) are schematic diagrams showing various port arrangement patterns. DETAILED DESCRIPTION OF THE INVENTION

[0030] Hereinafter, embodiments embodying the present disclosure will be described.

[0031] The surgical robot system according to this embodiment is a robot system composed entirely of master-slave manipulators. The operating device constituting the master unit is provided with a hand control that allows the operator (the surgeon who is performing the operation) 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.

[0032] When the operator operates the hand control, the master coordinates change, and the slave coordinates change accordingly. The control device of the surgical robot system 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 posture). The control device controls the operation of the drive axes of the slave unit based on the axis values ​​calculated.

[0033] In this specification, the drive shaft of a robot arm may be a joint of the robot arm, or may be a drive shaft provided on the robot arm to drive a joint (driven shaft) included in a surgical instrument.

[0034] The robot arm of the surgical robot in the surgical robot system according to this embodiment has redundancy. That is, the number of degrees of freedom required for the task to be accomplished by the robot arm is fewer than the degrees of freedom (i.e., the number of drive axes) the robot arm has. Conversely, the degrees of freedom of the robot arm are greater than the degrees of freedom necessary for the task. The degrees of freedom required for the task to be accomplished by the robot arm are typically the degrees of freedom necessary 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, which determines the degrees of freedom of the robot arm, includes the number of drive axes for controlling the joints of the surgical instrument itself (the joints of the movable part of the surgical instrument) 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.

[0035] When the robot arm of the surgical robot that constitutes the slave unit has redundancy, the solution (combination of multiple axis values) for finding each axis value of the robot arm from the slave coordinates by inverse kinematics calculation cannot be determined uniquely, and 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 operation of the robot arm.

[0036] When a robot arm has redundancy, there are extra axes that do not necessarily need to be operated from the perspective of accomplishing a task. Such extra axes can be called redundant axes. Since the robot arm as a whole has an extra number of axes, a specific axis among the multiple axes that make up the robot arm is not necessarily determined as a redundant axis. In other words, in inverse kinematics calculations for a robot arm with redundancy, which axis is treated as a redundant axis is not a given condition that is necessarily determined by the configuration of the robot arm, but is something that must be determined ex post.

[0037] 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 has 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 the surgical instrument are, for example, six degrees of freedom related to the movement of an end effector attached to the tip of the shaft of the surgical instrument in three-dimensional space (e.g., inside the patient's body).

[0038] Furthermore, when the shaft of a 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 of the surgical instrument, which tilts along 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 of the surgical instrument always passes through or near the center of rotation (pivot point). This increases the number of degrees of freedom (n) required to control the position and orientation of the surgical instrument by two, for a total of eight.

[0039] In this specification, the term "shaft" refers to a member or section that constitutes the entire or part of a surgical instrument, and is an elongated section or section having a longitudinal axis. Shafts of surgical instruments include those that include joints and those that are flexible.

[0040] In the control method for the surgical robot system according to this embodiment, constraints are added for each redundant degree 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, among 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. While actual drive axes and redundant axes may correspond one-to-one, this is not a requirement. 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. That is, the constraint conditions impose restrictions on the configuration of the robot arm, and the operation of the redundant axis corresponding to the constraint conditions is controlled so that the change in the configuration of the robot arm falls within the range restricted by the constraint conditions. This point will be described in detail later with reference to Figure 15 etc.

[0041] By providing multiple constraints in the control of the robot arm in this manner, in this embodiment, which includes 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 orientation of the end effector of the surgical instrument. In other words, in this embodiment, once the position and orientation 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 orientation of the end effector. Since the axis values ​​of the redundant axes can be determined by the constraints in this manner, inverse kinematic calculations similar to those used when no redundant axes exist can be applied to multiple drive axes other than the redundant axes. The axis values ​​of the redundant axes can also be referred to as joint positions or joint angles.

[0042] 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 may 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, etc. 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.

[0043] As described above, the constraint conditions for the redundant axes can be determined from the viewpoint of avoiding interference between the arms, but the content of the constraint conditions determined is not always optimal. For example, when performing a certain surgery, even if an appropriate arm interference avoidance effect can be achieved in one phase of the surgery, the originally intended arm interference avoidance effect may not necessarily be achieved in another phase of the surgery.

[0044] In addition, since the actions required of the surgical robot may change depending on the content of the surgery (procedure, etc.), it is desirable to change the constraint conditions depending on the content of the surgery, etc. so that the surgical robot can perform the required actions to perform the required surgery.

[0045] Therefore, in this embodiment, the constraint conditions of the redundant axis 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. That is, in this embodiment, the constraint conditions of the redundant axis 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). Furthermore, with regard to the initial constraint conditions that are set before the start of surgery, it is possible to select the optimal constraint conditions for realizing the required operations required of the surgical robot to perform the required surgery.

[0046] Furthermore, in this embodiment, the arrangement of the multiple port members inserted into the patient's body wall (port arrangement) is not considered as a given condition when considering a control method for the surgical robot, but rather the optimal port arrangement is searched for and determined with consideration given to maximizing the performance of the surgical robot, as will be described in detail later.

[0047] When the constraint conditions of the redundant axis are changed, the axis values ​​of the multiple drive axes (joints) of the robot arm change accordingly. That is, the axis values ​​of the multiple drive axes of the robot arm are calculated by arithmetic processing based on command values ​​for the position and orientation of the end effector generated based on operation input from the operating device, and this arithmetic processing includes content related to the constraint conditions of the redundant axis. Therefore, when the constraint conditions of the redundant axis are changed, the content of the arithmetic processing when calculating 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 arithmetic processing also change.

[0048] Here, the operation of the robot arm's drive axes related to the constraints of the redundant axes does not affect the motion of the end effector. Therefore, even if the axis values ​​of the multiple drive axes of the robot arm change due to a change in the constraints of the redundant axes, the motion of the end effector is not affected. If the axis values ​​of the multiple drive axes of the robot arm 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 an absolute coordinate system (or a world coordinate system). Therefore, by changing the constraints of the redundant axes, the spatial region occupied by the robot arm in the absolute coordinate system can be changed. The change in the spatial region occupied by the robot arm due to a change in the constraints of the redundant axes can be realized without affecting the motion of the end effector. In other words, by changing the constraints of the redundant axes, the spatial region occupied by the robot arm can be changed without affecting the motion of the end effector.

[0049] 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, thereby preventing the arms from interfering with each other in advance, without interrupting the operator's treatment (i.e., without interrupting the following operation).

[0050] If interference between the arms occurs and the surgical robot stops, it is necessary to release the surgical robot from its stopped state (locked state) while considering the safety of the patient. For example, it may be necessary to withdraw the surgical instrument from the port member, reconfigure the robot arm to the appropriate shape, and then reattach the surgical instrument to the robot arm before releasing the stopped state of the surgical robot. Once the surgical robot stops due to interference between the arms, releasing the arm takes time and effort, interrupting the surgery during that time. In contrast, this embodiment can prevent interference between the arms in advance, thereby reliably preventing the surgical robot from stopping and the subsequent interruption of the surgery due to the need for recovery. Thus, this embodiment reliably ensures the continuity of the surgery by the operator in a surgery using a surgical robot system.

[0051] A surgical robot system and a control method thereof according to this embodiment will be described below with reference to the drawings.

[0052] As shown in FIGS. 1 to 3, a surgical robot system 10 according to this embodiment includes 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 an operating table 111 in an operating room. The operating device 2 may be placed at a location further away from the operating table 111 in the operating room, or may be placed outside the operating room. An operator (surgeon) S who performs surgery using the surgical robot system 10 is positioned on the operating device 2 side, not the surgical robot 1 side, during the procedure in order to operate the operating device 2. A patient P on whom surgery is to be performed is placed on the operating table 111 placed beside the surgical robot 1.

[0053] 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 constitutes 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).

[0054] 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.

[0055] The operation device 2 includes left and right operation manipulators 20A and 20B, multiple operation 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 disposed on a support bar 26. The operation manipulators 20A and 20B include left and right hand controls 21A and 21B that an operator operates with their left and right hands to input operation commands. The operation manipulators 20A and 20B are operation tools that accept operation inputs for generating movement commands for the position and posture of the surgical instrument 40. The operation pedal 22 is an operation tool that accepts commands such as zooming the endoscopic camera, switching control modes, and switching between robot arms 3 (3A, 3B, 3C, 3D) associated with the left and right operation manipulators 20A and 20B.

[0056] 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 control 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 remote control 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 and 21B of the operating manipulators 20A and 20B and the operating pedals 22 while visually checking the affected area of ​​the patient P on the monitor 24.

[0057] The surgical robot 1 constitutes an 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.

[0058] The surgical robot 1 includes a positioner 7, an arm base 5 attached to the tip of the positioner 7, and a plurality of robot arms 3 (3A, 3B, 3C, 3D) detachably attached to the arm base 5.

[0059] As shown in FIG. 4, in this embodiment, four robot arms 3A, 3B, 3C, and 3D are attached to an arm base 5. The number of installed robot arms 3 may be less than four or more than four. The tip end 32 (see FIG. 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 FIG. 11). In other words, the instrument holder 36 constitutes at least a part of the tip end 32 of the robot arm 3.

[0060] 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. The positioner control unit 75 does not necessarily need to be included in the control device 4, and may be provided outside the control device 4. A vertical articulated robot, for example, a seven-axis vertical articulated robot, can be used as the articulated robot constituting the positioner 7. 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 upper surface of a casing 71 of a 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 posture 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 (on the rotation axis of) the base end of the arm base 5 attached to the tip of the positioner 7.

[0061] As shown in FIG. 5 , the multiple links 91 and multiple joints 92 of the positioner 7 are connected in the following order from the base end to the tip end: first joint 92A, first link 91A, second joint 92B, second link 91B, third joint 92C, third link 91C, fourth joint 92D, fourth link 91D, fifth joint 92E, fifth link 91E, sixth joint 92F, sixth link 91F, seventh joint 92G, and seventh link 91G. The first joint 92A, fourth joint 92D, sixth joint 92F, and seventh joint 92G are configured as torsion joints. The second joint 92B, third joint 92C, and fifth joint 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.

[0062] The arm base 5 comprises an arm base main body 50, a positioner mounting section 51 provided on the back surface of the arm base main body 50 and to which the tip end 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 end of the positioner 7. The arm base 5 is provided with an imaging section 53. The imaging section 53 can capture an image of at least one of the operating table 111 and the patient P placed on the operating table 111.

[0063] In the surgical robot 1, the arm base 5 functions as a "hub" that serves as a base for multiple robot arms 3. Although the positioner 7 in this embodiment is configured as a vertical articulated robot, the positioner 7 may also be configured as 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 the movable cart 70. However, instead, the base of the positioner 7 may be attached to a fixed object such as the wall or floor of the operating room or a member fixed to these.

[0064] 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 a surgical procedure. 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 to permit movement of the positioner 7, an operator such as a nurse or technician operates the joystick 72b to move the positioner 7. In this way, the surgical robot system 10 has a manual mode in which the operator can manually move the positioner 7.

[0065] 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 grips and rotates to control the movement of the cart 70. The handle 73 is 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.

[0066] An enable switch 73b that permits or prohibits movement of the carriage 70 is provided near the handle 73 of the carriage 70. When the enable switch 73b is pressed down to permit movement of the carriage 70, and a throttle section 73a of the handle 73 is operated, the carriage 70 is moved forward, backward, left, and right by a traveling power section 74 that includes power such as an electric motor provided inside the carriage 70.

[0067] The positioner 7, the arm base 5, and the members 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 members 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.

[0068] 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 about the longitudinal axis of the shaft portion 43.

[0069] 8 shows an endoscope assembly 40B, which is an imaging device that is inserted into a patient's body to capture images of the condition of the surgical site, as another example of a surgical instrument 40. The endoscope assembly 40B includes an endoscope 12 and an endoscope holder 13. The endoscope holder 13 holds the endoscope 12 rotatably about its longitudinal axis. A drive unit (not shown) is provided inside the endoscope holder 13 for rotating the endoscope 12 about its longitudinal axis. The front portion (camera side portion) of the endoscope 12 is formed as a shaft portion 43.

[0070] As described above, the shaft portion 43 of the surgical instrument 40 may refer to an elongated member having the end effector 44 at its tip, or may refer to the front portion (camera side portion) of the endoscope 12 formed as an elongated member.

[0071] 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 the receiving portion have complementary shapes, and a retractable portion that resiliently protrudes and retracts on one of the locking portion and the receiving portion is releasably locked in a recessed portion on the other of the locking portion and the receiving portion. For example, an assistant surgeon can manually release the resiliently locked recessed portion to remove the forceps assembly 40A from the instrument holder 36. The endoscope holder 13 also has an attachment / detachment mechanism similar to that described above, and can be attached to and detached from the instrument holder 36 by manual operation by an assistant surgeon.

[0072] In the surgical robot 1 of this embodiment, an endoscope assembly 40B is detachably 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, for example, a forceps assembly 40A, is detachably 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, for example, a forceps assembly 40A, are attached to the first, third, and fourth robot arms 3A, 3C, and 3D.

[0073] 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 that faces 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 "distal end (of the series of components)."

[0074] The arm control unit 28, which controls the operation of the surgical robot 1 based on operation input from the operating device 2, may be composed of a single controller for centralized control, or may be composed of multiple controllers for distributed control in cooperation with each other. 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, a memory 302 such as a ROM and a RAM, an I / O unit (input / output unit) 303, and an interface 304. The memory 302 stores a control program and various data used to control the operation of the surgical robot 1. The interface 304 is used for communication with the operating device 2 and various sensors (such as an encoder that detects the rotation angle of a servo motor, which will be described later), etc.

[0075] FIG. 10 shows the schematic configuration of one robot arm 3 among the multiple robot arms 3 included in the surgical robot 1. A surgical instrument 40 is detachably attached to the tip 32 of the robot arm 3. In this embodiment, the multiple robot arms 3 included in the surgical robot 1 all have the same or similar configurations, but at least one of the multiple robot arms 3 may have a different configuration (e.g., different degrees of freedom) from the other robot arms 3. As shown in FIG. 10, the robot arm 3 includes 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) forms 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 end 32 of the robot arm 3 is movable three-dimensionally relative to the base end 80 of the robot arm 3 .

[0076] 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 a button, a joystick, etc., and a manual controller 39B that drives the translational movement mechanism 35 in response to commands input from the command input unit 39A. The commands input from the command input unit 39A include, for example, a command related to a retraction operation to retract the surgical instrument 40 inserted in the port member 112 to a retracted position. An assistant surgeon near 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.

[0077] The arm main body 30 includes a base end 80 that is detachably attached to the arm base 5, and a plurality of arm link sections that are sequentially connected from the base end 80 to the tip end. The arm main body 30 includes a plurality of joint sections (a plurality of drive shafts) that are sequentially connected so that one arm link section rotates relative to another arm link section. The arm link sections include a first link 81 to a sixth link 86. The joint sections include a first joint J31 to a seventh joint J37. Note that, although the joint sections (the first joint J31 to the seventh joint J37) of the arm main body 30 in this embodiment are configured as rotary joints equipped with rotary shafts, at least some of the joint sections may be configured as linear joints.

[0078] More specifically, a base end portion of a first link 81 is connected to the tip side of a base end portion 80 of the robot arm 3 via a first joint J31 (base end torsion joint), which is a torsion (roll) joint. A base end portion of a second link 82 is connected to the tip end portion of the first link 81 via a second joint J32, which is a bending (pitch) joint. A base end portion of a third link 83 is connected to the tip end portion of the second link 82 via a third joint J33, which is a torsion joint. A base end portion of a fourth link 84 is connected to the tip end portion of the third link 83 via a fourth joint J34, which is a bending joint. A base end portion of a fifth link 85 is connected to the tip end portion of the fourth link 84 via a fifth joint J35, which is a torsion joint. A base end portion of a sixth link 86 is connected to the tip end portion of the fifth link 85 via a sixth joint J36, which is a bending joint. The base end of the translation mechanism 35 is connected to the tip end of the sixth link 86 via a seventh joint J37 (tip side bending joint) which is a bending joint.

[0079] 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 end 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 end side. The angle between the first direction and the second direction of the first link 81 is, for example, 120 degrees or more and 160 degrees or less (for example, 140 degrees). The first portion 81a and the second portion 81b are smoothly connected, which makes it easier to pass wires such as electrical wiring through the arm link portions even if some of the arm link portions have a bent shape.

[0080] 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. 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 axes of the fourth joint J34 and 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 distal end 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 distal-side fifth joint J35. The angle between the first direction and the second direction of the fourth link 84 is, for example, 70 degrees or more and 110 degrees or less (for example, 90 degrees). The first portion 84a and the second portion 84b are smoothly connected.

[0081] 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 with each other.

[0082] Each arm link section is configured so that the cross-sectional area perpendicular to the longitudinal direction is smaller than that of the arm link section (or base end 80) connected to the base end side of that arm link section. As a result, the arm main body 30 is configured to gradually become thinner from the base end 80 toward the tip end. Furthermore, each of the joints J32, J34, and J36, which are bending joints, 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 rotation axis direction with respect to the center of the joint section in the rotation axis direction. Also, the base end of the tip end side arm link section 82, 84, and 86 is configured so that it faces the tip end of the base end side arm link section 81, 83, and 85 on the other side of the rotation axis direction with respect to the center of the joint section in the rotation axis direction.

[0083] Furthermore, the width in the rotational axis direction at the joint, i.e., the distance between the outer end of the tip of the arm link parts 81, 83, 85 on the base end side and the outer end of the rotational axis direction at the base end of the arm link parts 82, 84, 86 on the tip end side, is shorter than the diameter (maximum dimension) of the cross section perpendicular to the longitudinal direction of the part located closer to the base end than the tip of the arm link parts 81, 83, 85 on the base end side.

[0084] In this way, each joint and the arm link portion at its distal end are configured to be narrower than the arm link portion at its proximal end, which increases the range of movement of each arm body 30 (the range where it does not interfere with other arm bodies 30) in a workspace that becomes narrower as it approaches the treatment site 110 of the patient P.

[0085] 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 in the arm body 30 are covered with resin covers. By forming the covers from 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. Note that the outer shell of the arm body 30 itself may include a portion made of a resin material.

[0086] The translational movement mechanism 35 is a mechanism that can translate the surgical instrument 40 attached to the instrument holder 36 in the extension direction of the shaft portion 43 by translating the instrument holder 36, which is movably provided in the main body portion of the translational movement mechanism 35, in the longitudinal axis direction Dt (Figure 10).

[0087] The translational movement mechanism 35 is connected to the distal end of the sixth link 86 of the arm 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 the surgical instrument 40 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.

[0088] The instrument holder 36 detachably holds an instrument base 45 of the surgical instrument 40. As shown in Fig. 12, the instrument holder 36 includes an instrument driver 38 having a plurality of (four in this example) drive shafts 37 that are rotationally driven to apply a driving force to the surgical instrument 40. One of the plurality of 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.

[0089] 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 a drive shaft 37 of an 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 is provided with, for example, four drive shafts 37, and these drive shafts 37 are used, for example, for opening and closing a pair of jaws that are the end effector 44 of the forceps assembly 40A ( FIG. 7 ), for pitching or yawing the end effector 44, and for rolling the shaft portion 43 of the forceps assembly 40A around its longitudinal axis relative to the instrument base 45.

[0090] When 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.

[0091] 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 . That is, the end effector of the surgical instrument 40 can be selected from a group including, for example, instruments with a moving joint (e.g., forceps, scissors, graspers, needle holders, microdissectors, staple appliers, tackers, suction and irrigation tools, snare wires, clip appliers, etc.) and instruments without a joint (e.g., cutting blades, cauterizing probes, irrigators, catheters, suction orifices, etc.).

[0092] The base end of the shaft 43 is connected to the instrument base 45 via a ninth joint (ninth drive shaft) 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.

[0093] As described above, the eighth joint J38 located between the seventh joint J37 and the ninth joint J39 is a translatory 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 includes the rotation axis R9 of the ninth joint J39 and extends in the longitudinal direction Dt. 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.

[0094] 13, in this embodiment, a plurality of (four in this example) arm attachment parts 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 having a longitudinal axis, and the plurality of arm attachment parts 52 are arranged side by side in the longitudinal direction of the arm base 5 (the direction indicated by D1 in FIG. 13). By fixing the base ends 80 of the plurality of robot arms 3 to the plurality of arm attachment parts 52, respectively, the first link 81, which is the link on the side of the base end part 80 of the plurality of robot arms 3, is configured to be relatively rotatable around the rotation axis of the first joint J31.

[0095] Specifically, the arm attachment parts 52 are arranged such that the base ends 80 of the robot arms 3 are aligned 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 at the ready position (see FIG. 3 ). The first direction D1 is, for example, a horizontal direction that is the direction of the longitudinal axis of the elongated arm base 5, but is not limited to this. The first direction D1 is also a direction perpendicular to the rotation axis R1 of a first joint J31 (described later) of the robot arm 3. That is, the arm attachment parts 52 are aligned in a row in the first direction D1 (the direction into the depth of the paper in FIG. 3 ) when viewed from above with the arm base 5 positioned at the ready position, and face a second direction D2 that is perpendicular to the first direction D1. The arrangement of the arm attachment parts 52 is not limited to a single row, and they may be aligned in two rows. In addition, some of the arm attachment portions 52 may be offset in the second direction D2. In addition, 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).

[0096] 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.

[0097] 14 is a block diagram showing a schematic configuration example of a control system of the surgical robot system 10. The arm body 30 of the robot arm 3 is provided with, corresponding to each joint J31 to J37 of the arm body 30, drive servomotors (denoted as SM in FIG. 14) M31 to M37, encoders (denoted as EN in FIG. 14) E31 to E37 that detect the rotation angles of the servomotors M31 to M37, and reducers (not shown) that reduce the speed of the outputs of the servomotors M31 to M37 to increase the torque.

[0098] 14 representatively shows the first joint J31 and the seventh joint J37 of the arm main body 30 out of the joints J31 to J37, and omits the control systems for the other joints J32 to J36. Furthermore, the translational movement mechanism 35 is provided with a servo motor M38 (a servo motor that drives an 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 outputs of the servo motors M38 and M39 to increase the torque.

[0099] The encoders E31 to E39 are provided as an example of a rotational position detection means for detecting the rotational positions (rotation angles) of the servo motors M31 to M39, and a rotational position detection means such as a resolver may be used instead of the encoders E31 to E39.

[0100] The arm control unit 28 includes a control unit main body 29 that controls the movement of the 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 the servo motors M31 to M39 are electrically connected via amplifier circuits or the like.

[0101] 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 an operation input input to the operation 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, which 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 of the servo motors 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.

[0102] The arm control unit 28 is also provided with a storage unit 31 in the control unit main body 29 from which data can be read, and which stores in advance surgery information input via the operation device 2. This surgery information includes the combination of multiple robot arms 3 to be used in the surgery.

[0103] The memory unit 31 also 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).

[0104] Furthermore, the memory unit 31 stores in advance 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 of the arm base 5 and the multiple robot arms 3. The memory unit 31 can store multiple preparation positions according to the content (type) of treatment, the treatment area, etc. The above-mentioned predetermined preparation positions are sometimes called setup positions.

[0105] 15 to 23 are diagrams for explaining an example of the operation of the surgical robot system 10, mainly in relation to the constraint conditions. The constraint conditions are conditions for limiting the range of operation of the robot arm 3. In this embodiment, three constraint conditions are applied. FIGS. 15 to 17 correspond to the first constraint condition, FIGS. 18 to 20 correspond to the second constraint condition, and FIGS. 21 to 23 correspond to the third constraint condition.

[0106] The first constraint condition in the examples shown in FIGS. 15, 16, and 17 relates to a restriction on the movement of the robot arm 3 around the ninth joint (ninth drive axis) J39.

[0107] The surgical robot system and its control method according to this embodiment include a port placement determination device 65 (see FIG. 1, etc.) that determines a port placement that maximizes the performance of the surgical robot 1. This will be described in detail later. In the following description of the operation example of the surgical robot system 10, which will be described with reference to FIGS. 15 to 23, the optimal port placement determined by the port placement determination device 65 is assumed. In other words, in the following description of the operation example of the surgical robot system 10, the port placement is treated as a given condition, not as an optimization target. In this embodiment, the port placement determination device 65 is included in the control device 4 of the surgical robot 1. However, the port placement determination device 65 can also be provided separately from the control device 4 of the surgical robot 1. When the port placement determination device 65 is provided separately from the control device 4 of the surgical robot 1, the port placement determination device 65 may be provided as part of the configuration of the surgical robot 1, or it may be provided separately from the configuration of the surgical robot 1. When the port placement determination device 65 is provided separately from the configuration of the surgical robot 1, the port placement determination device 65 can be configured as a computer on a cloud, for example.

[0108] 15 and 16 show robot arm 3B and elements related to robot arm 3B among the four robot arms 3, and other elements are omitted as appropriate. Also, in Fig. 17, robot arm 3A and elements related to robot arm 3A among the four robot arms 3 are shown, and other elements are omitted as appropriate.

[0109] 1 to 3, in surgery using the surgical robot 1, first, the surgical assistant (or the operator S himself / herself) 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.

[0110] Port members 112, consisting of trocars or cannulas, are placed on the body surface of a patient P lying on an operating table 111, for example, in a line arranged side by side. In FIG. 3, the port members 112 are arranged in a line in the depth direction of the page. However, the arrangement of the multiple port members 112 is not limited to this arrangement. For example, in the case of laparoscopic surgery, port arrangements such as those shown in FIGS. 33(A), (B), (C), and (D) are possible. Also, FIGS. 34(A), (B), (C), and (D) are variations of the port arrangement patterns shown in FIGS. 33(A), (B), (C), and (D), in which, of the four ports, the ports for endoscopes (marked with black circles) are arranged in irregular positions. FIGS. 35(A) and 35(B) illustrate examples of port arrangement patterns for thoracoscopic surgery.

[0111] Then, the positioner 7 is controlled to position the arm base main body 50 so that the arm base main body 50 is located 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 faces in a generally horizontal direction. The angle between the rotation axis R1 of the first joint J31 and the horizontal plane is within a range of, for example, minus 30 degrees to plus 30 degrees. Furthermore, the positioner 7 is 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 faces, is generally perpendicular to the direction in which the multiple port members 112 are lined up.

[0112] The surgical assistant then performs the task of setting, 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 the tip of the teaching surgical instrument 40 is positioned at 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. In response to this, the arm control unit 28 performs a forward transformation 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, to calculate the position of the remote center RC.

[0113] The robot arms 3 and the 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.

[0114] 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 such a preliminary operation, the positioner 7, the arm base 5, and the multiple robot arms 3 are positioned so that the port member 112 placed on the body surface of the patient P, which is the treatment site 110, and the surgical instruments 40 attached to each robot arm 3 have a predetermined initial positional relationship.

[0115] In this initial posture, the robot arm 3 has a base end 80 that extends generally horizontally. The second link 82 and the third link 83 that are connected to the bent first link 81 extend diagonally downward. More specifically, the second link 82 and the third link 83 extend downward in a direction 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) in the direction in which the rotation axis R1 of the first joint J31 extends (second direction D2). The fourth link 84, the fifth link 85, and the sixth link 86 turn back at the elbow 11 and extend diagonally downward. More specifically, the fourth link 84, the fifth link 85, and the sixth link 86 extend downward in a direction from the tip end side of the base end 80 toward the base end side (toward the head side of the patient P on the operating table 111) in the direction in which the rotation axis R1 of the first joint J31 extends.

[0116] In this embodiment, the arm control unit 28 does not accept operation from the operating device 2 while the surgical robot 1 (the positioner 7, the arm base 5, and the multiple robot arms 3) is moving 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 operating device 2. During treatment after the surgical robot 1 is positioned at the preparation position, the arm control unit 28 generates an operation command based on an operation input generated by the operator S operating the operating device 2. Then, in accordance with the operation command generated based on the operation input from the operating 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 restricts the port member 112 from moving in the plane of the patient P's body surface.

[0117] The operation of moving the surgical instrument 40 to a target position and assume a target posture during the surgical procedure is realized, for example, by an operation including the operation of joints including nine axes, i.e., 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, a 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 43 of the surgical instrument 40 (or the configuration of the robot arm 3 determined by a set of these angular positions) is not uniquely determined. For example, the operation of rotating the shaft 43 in a circumferential direction about its central axis C can be realized not only by rotating the ninth joint J39, which is provided coaxially with the central axis C, but also by rotating the distal end 32 of the arm 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 rotational movement of the shaft unit 43 in the circumferential direction about 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 unit 43 in the circumferential direction about the central axis C or to maintain the shaft unit 43 at the same circumferential position without rotating it.

[0118] In setting the constraint conditions, as shown in FIG. 15, first, the arm control unit 28 sets a reference point RD for each robot arm 3. As shown in FIG. 13, the reference point RDB of the 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 the robot arm 3B. The reference point RDA of the 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 the 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 the 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 the 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 devices in the surgical robot system 10, such as an adjacent robot arm 3, and with the surrounding environment, such as assistants.

[0119] Next, as shown in FIG. 16 , the arm control unit 28 determines whether the length L of a perpendicular line vh from the reference point RD to the central axis C of the shaft unit 43, which will assume 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 performing the above determination.

[0120] 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.

[0121] This restricts the orientation of the translational movement mechanism 35 and the instrument base 45 so that they 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 about its central axis C, the proportion of the operation of rotating the tip portion 32 of the robot arm 3 in a circumferential direction about the central axis C can be reduced. Furthermore, the proportion of the operation 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 an orientation facing outward from the reference point RD. This prevents the translational movement mechanism 35 and the instrument base 45 from assuming an orientation 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 the adjacent robot arm 3, and the surrounding environment can be prevented. Furthermore, since the robot arm 3 can be made to assume a posture in which 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, since multiple robot arms 3 assume a posture in which they spread out in a fan shape from the arm base main body 50, interference between adjacent robot arms can be reduced.

[0122] Furthermore, as shown in FIG. 16 , for example, when the shaft 43 swings about the remote center RC and approaches the reference point RD, the radius of rotation of the distal end 32 of the robot arm 3 around the central axis C during the operation of rotating the shaft 43 around the central axis C decreases. As a result, the movement of the robot arm 3 becomes sensitive, and large vibrations and reduced tracking performance may occur in the translational movement mechanism 35 and the instrument base 45 due to the 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 distal end 32 of the robot arm 3 around the central axis C from becoming smaller when the shaft 43 approaches the reference point RD, thereby suppressing sensitive movement of the robot arm 3. Furthermore, when 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, the occurrence of hypersensitive movements can be avoided.

[0123] In this way, the arm control unit 28 controls the robot arm 3 so that the shaft 43 of the surgical instrument 40 assumes the target posture at the target position. When 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 the subsequent processes.

[0124] The arm control unit 28 of the surgical robot 1 in this embodiment determines the above-mentioned first constraint condition based on the results of a simulation or the like, in relation to the required movement required of the robot arm 3 when the operator S operates the operation device 2 to perform a required surgery using the surgical instrument 40. This point will be described in detail later.

[0125] Next, the second constraint condition will be described with reference to Figures 18, 19, and 20. The second constraint condition relates to the first joint (first drive shaft) J31, and limits the range of motion of the bending portion (elbow) 11 of the fourth link 84 (see Figure 10).

[0126] The second constraint condition is a condition for restricting the movement range of each robot arm 3. Specifically, the second constraint condition includes content that associates the position of the constraint part set in each robot arm 3 with a constraint range, which is a range within which the constraint part can be located when the robot arm 3 moves. The second constraint condition is a condition regarding the relative movement of each robot arm 3 with respect to the arm base 5, and is based on the arm base 5.

[0127] The position of the restraint part may be set at any position on the robot arm 3, but in this example, it is set at the bent part (elbow) 11 of the fourth link 84. Specifically, the position of the restraint part is set at the bending point 11a (see FIG. 18) of the axis of the fourth link 84 at the bent part (elbow) 11.

[0128] For example, the surgical robot 1 bends and operates each robot arm 3 to vary the posture and insertion depth of each surgical instrument 40 relative to a remote center RC of posture rotation of each surgical instrument 40 at a treatment site of a patient P lying on an operating table 111. At this time, the robot arm 3 bends at a fourth link 84 located near the middle between the translational movement mechanism (distal link) 35 and the base end (base link) 80. In particular, when the robot arm 3 bends at an acute angle at the fourth link 84, the bent portion (elbow) 11 of the fourth link 84 may significantly protrude upward and / or sideways, possibly coming into contact with an adjacent robot arm 3. Therefore, in this example, the bending point 11a of the bent portion (elbow) 11 of the fourth link 84 is set as a restraint portion.

[0129] The constraint range of each robot arm 3 is not a range determined based on the positional relationship between that robot arm 3 and other robot arms 3, but is a range determined based on the state of that robot arm 3. The constraint range is not a range fixed to that robot arm 3, but is a range that varies depending on the state of that robot arm 3.

[0130] Specifically, the constraint range is a region between a specific position on the base end (base link) 80 and a specific position on the translational movement mechanism (tip link) 35. For example, the region may be a region when viewed from a direction parallel to the axial direction of the rotation axis R1 (see FIG. 13) of the rotational joint J31.

[0131] 18 and 19 are a side view and a plan view, respectively, of the robot arm 3 as viewed in the negative YA-axis direction and the negative ZA-axis direction. As shown in FIGS. 18 and 19, a specific position on the base end (base link) 80 is set as point 80a, and a specific position on the translational movement mechanism (tip link) 35 is set as point J37a. Point 80a is the intersection of the connection surface between the base end (base link) 80 and the arm attachment part 52 and the axis of the base end (base link) 80. Point J37a is located at the connection part between the translational movement mechanism (tip link) 35 and the sixth link 86, and specifically, is the center point of the connection part in the axial direction of the rotation axis of the seventh joint J37 that intersects with the connection part. Note that the constraint range may be, for example, an intermediate position between point 80a and point J37a. In this specification and claims, the term "intermediate position" may include a central position between two elements and a position near the central position.

[0132] Furthermore, the constraint range may be a three-dimensional region between a first plane that passes through point 80a and extends in a direction intersecting the XA axis, and a second plane that passes through point J37a and extends in a direction intersecting the XA axis. The first plane and the second plane may be parallel or non-parallel to each other. The axial direction of the XA axis is an example of the longitudinal direction of the arm base 5.

[0133] For example, as shown in FIGS. 18 and 19 , the first plane may be plane YZ8 perpendicular to the XA axis, and the second plane may be plane YZ7 perpendicular to the XA axis. Plane YZ7 passes through point J37a and is parallel to the YAZA plane. Plane YZ8 passes through point 80a and is parallel to the YAZA plane. Thus, the constraint range may be a three-dimensional region between the first plane passing through point 80a and extending in a direction perpendicular to the XA axis, and the second plane passing through point J37a and extending in a direction perpendicular to the XA axis. In this specification and the claims, the terms "vertical," "plumb," "horizontal," and "parallel" may each include cases where the plane is completely vertical, plumb, horizontal, or parallel, as well as cases where the plane can be considered substantially vertical, plumb, horizontal, or parallel, including close to completely vertical, plumb, horizontal, or parallel.

[0134] The constraint range may be an intermediate position between the first plane and the second plane, for example, an intermediate position between the plane YZ7 and the plane YZ8.

[0135] Furthermore, the constraint range may be a two-dimensional region on a third plane between the first and second planes. The third plane may be parallel to at least one of the first and second planes, or may be non-parallel to both. The third plane may be located midway between the first and second planes. For example, as shown in FIGS. 18 and 19, the third plane may be a plane YZE between planes YZ7 and YZ8. Plane YZE may be parallel to planes YZ7 and YZ8, but may also be non-parallel. The position of plane YZE may be between planes YZ7 and YZ8, for example, midway between planes YZ7 and YZ8.

[0136] The constraint range may also be a three-dimensional region between point 80a and a first curved surface having point 80a as its reference point. Examples of the first curved surface include spherical surfaces such as spheres and ellipsoids centered on the reference point, and axisymmetric surfaces such as surfaces of revolution centered on an axis passing through the reference point. Examples of the reference point include a center and a focus. For example, as shown in FIG. 20, the first curved surface may be a spherical surface S1. The spherical surface S1 is centered on point 80a and passes through point J37a. The constraint range may be an intermediate position between point 80a and the first curved surface, for example, an intermediate position between point 80a and the spherical surface S1. FIG. 20 is a side view similar to FIG. 18 showing another example of the constraint range.

[0137] Furthermore, the constraint range may be a region on a second curved surface between point 80a and the first curved surface. The shape of the second curved surface may be similar to or dissimilar to the shape of the first curved surface. The second curved surface may be located midway between point 80a and the first curved surface. For example, as shown in FIG. 20, the second curved surface may be a spherical surface S2 between point 80a and spherical surface S1. The spherical surface S2 is centered on point 80a, but may also be centered at a point different from point 80a. The position of spherical surface S2 may be between point 80a and spherical surface S1, for example, midway between point 80a and spherical surface S1.

[0138] The constraint range may also be an area on the line segment connecting point 80a and point J37a, or an area on a plane passing through the line segment and the YA axis or the rotation axis of joint J31.

[0139] Furthermore, the areas on the plane and the areas on the line segment shown above may each include areas in the vicinity of the plane and the line segment, such as areas within a predetermined distance from the plane and the line segment.

[0140] As described above, the constraint range of the bending point 11a is a range that is determined in accordance with the position of the base end portion (base link) 80 and the position of the translational movement mechanism (tip link) 35, and is a range that fluctuates in accordance with the position of the translational movement mechanism (tip link) 35.

[0141] Then, the arm control unit 28 of the surgical robot 1 in this embodiment determines the second constraint condition described above based on the results of a simulation or the like, in relation to the required movement required of the robot arm 3 when the operator S operates the operation device 2 to perform a required surgery using the surgical instrument 40. This point will be described in detail later.

[0142] Next, the third constraint condition will be described with reference to Figures 21, 22, and 23. The third constraint condition relates to the eighth joint J38, which is a prismatic joint.

[0143] FIG. 21 is a diagram showing the surgical instrument 40 at a retracted position from the body cavity BC of the patient P. As shown in FIG. 21 , when the distal end of the surgical instrument 40 is located at the retraction point EP, the entire end effector 44 is located inside the port member 112, or a part or all of the end effector 44 is outside the body from the port member 112, and the end effector 44 is not present in the body cavity BC of the patient P. The retraction point EP is set inside the port member 112 placed in the body wall BW of the patient P. The retraction point EP may be set at the entrance 112 in or the exit 112 out of the port member 112, but is preferably set between the entrance 112 in and the exit 112 out. The retraction point EP may be set at the same position as the remote center RC. The arm control unit 28 may set and store the retraction point EP based on the position of the remote center RC.

[0144] FIG. 22 shows the surgical instrument 40 in the insertion position. The shaft portion 43 of the surgical instrument 40 shown in FIG. 22 is inserted through the port member 112, and the end effector 44 is located within the body cavity BC of the patient P. The distance from the remote center RC to the inlet 112in of the port member 112 is defined as distance α. Note that, when the port member 112 is positioned on the patient in alignment with a reference line (not shown) of the port member 112, α can be a constant. The value of α varies depending on the type of port member 112. The distance from the remote center RC to the outlet 112out of the port member 112 is defined as distance β. Note that, when the port member 112 is positioned on the patient in alignment with a reference line (not shown) of the port member 112, β can be a constant.

[0145] When the end effector 44 of the surgical instrument 40 is located inside the body cavity BC of the patient P, the length from the remote center RC to the distal end of the surgical instrument 40 (i.e., the distal end of the end effector 44) is referred to as the "intra-body cavity length L" of the surgical instrument 40. The intra-body cavity length L of the surgical instrument 40 is determined based on an operation input input by the operator (surgeon) S using the hand controls 21A, 21B of the operating device 2.

[0146] When inserting or removing the surgical instrument 40 into or from the body cavity BC through the port member 112, the surgical instrument 40 is placed in a position (hereinafter referred to as the reference position) in which the shaft 43, wrist 47, and end effector 44 are aligned. The wrist 47 has at least one wrist joint. The length of the wrist 47 included in the body cavity length L is the length in the longitudinal direction Dt of the wrist 47 when the surgical instrument 40 is in the reference position. This length is approximately equal to the length passing through the central axis of the wrist 47. Furthermore, the length of the end effector 44 included in the body cavity length L is the length in the longitudinal direction Dt of the end effector 44 when the surgical instrument 40 is in the reference position. In other words, regardless of the current positions of the wrist 47 and the end effector 44, the body cavity length L of the surgical instrument 40 is calculated assuming that the surgical instrument 40 is virtually in the reference position.

[0147] In this example, the length L of the surgical instrument 40 inside the body cavity can be calculated based on the position and orientation of the instrument holder 36, the position of the remote center RC, and the external shape information of the surgical instrument 40. The external shape information of the surgical instrument 40 includes, for example, the size of the instrument base 45, the length of the shaft portion 43, the link length of the wrist portion 47, and the length of the jaw member of the end effector 44. The position and orientation of the instrument holder 36 can be calculated based on the rotation angle detected by the encoders E31 to E37 and the external shape information of the robot arm 3. However, the method of calculating the length L of the surgical instrument 40 inside the body cavity is not limited to the above.

[0148] An origin position S0 and an end position Se are defined in advance for the eighth joint J38 of the robot arm 3. The origin position S0 is defined at or near the proximal end of the rail portion 61 of the translational movement mechanism 35. The end position Se is defined at or near the distal end of the rail portion 61. The current travel position of the slider portion 62, which travels while being guided by the rail portion 61, is referred to as the "current position Sc." The amount of displacement of the eighth joint J38 parallel to the longitudinal axis direction Dt from the origin position S0 to the end position Se is referred to as the "possible linear displacement amount T0" of the eighth joint J38. The amount of displacement of the eighth joint J38 parallel to the longitudinal axis direction Dt from the origin position S0 to the current position Sc is referred to as the "first linear displacement amount T1" of the eighth joint J38.

[0149] During surgery, when the intracorporeal length L of the surgical instrument 40 is equal to or less than the maximum linear displacement T0, the first linear displacement T1 of the eighth joint J38 is maintained to be equal to or have a predetermined relationship with the intracorporeal length L of the surgical instrument 40. The arm control unit 28 controls the movement of the robot arm 3 so that the relationship between the intracorporeal length L of the surgical instrument 40 and the first linear displacement T1 of the eighth joint J38 is T1 = L. Specifically, the arm control unit 28 operates the eighth joint J38 so that the intracorporeal length L and the first linear displacement T1 are equal. At the same time, the arm control unit 28 operates the joints J31 to J37 of the robot arm 3 excluding the eighth joint J38 and the joints (e.g., three joints) of the surgical instrument 40 so that the position and posture of the end effector 44 correspond to the command. In other words, when the hand controls 21A and 21B issue a command to move the distal end of the surgical instrument 40 in the longitudinal direction Dt, and the distal end of the surgical instrument 40 can be moved to the commanded position using only the linear displacement of the eighth joint J38, the arm control unit 28 moves the surgical instrument 40 in the longitudinal direction Dt using only the eighth joint J38 without using the multiple rotary joints J31 to J37 of the robot arm 3.

[0150] In the above example, during the retraction control, the distal end of the end effector 44 of the surgical instrument 40 moves to the retraction point EP, but the distal end of the end effector 44 may also move beyond the retraction point EP to the outside of the body. From this perspective, the arm control unit 28 may control the movement of the robot arm 3 so that when the shaft portion 43 is passed through the port member 112 and the end effector 44 is inside the body cavity BC of the patient P, the relationship between the intra-body cavity length L of the surgical instrument 40 and the first linear displacement amount T1 of the linear joint (eighth joint J38) satisfies T1≧L.

[0151] In the above-described method for controlling the surgical robot 1, if the distal end of the end effector 44 moves outside the body far beyond the inlet 112in of the port member 112, bodily fluids adhering to the end effector 44 may be scattered, or the next operation of inserting the end effector 44 into the port member 112 may become complicated. From this perspective, when the shaft portion 43 is passed through the port member 112 and the end effector 44 is inside the body cavity BC of the patient P, the arm control unit 28 may control the movement of the robot arm 3 so that the relationship among the intrabody cavity length L of the surgical instrument 40, the first linear displacement T1 of the linear joint (eighth joint J38), the distance α from the remote center RC to the inlet 112in of the port member 112, and the distance β from the remote center RC to the outlet 112out of the port member 112 satisfies (L−β)≦T1≦(L+α).

[0152] According to the above-described surgical robot system 10 and its control method, the linear displacement amount T0 of the linear joint (eighth joint J38) of the robot arm 3 is equal to or greater than the length L of the surgical instrument 40 within the body cavity, so that the end effector 44 of the surgical instrument 40 can be retracted from the body cavity BC of the patient P into the port member 112 simply by controlling (retraction control) the linear joint (eighth joint J38) of the robot arm 3 to return to the origin position S0.

[0153] In the above-described retraction control, the shaft portion 43 of the surgical instrument 40 moves only parallel to the longitudinal axis direction Dt. This suppresses vibration of the shaft portion 43, making it less likely that galling will occur between the port member 112 and the shaft portion 43. In this way, the shaft portion 43 can be smoothly pulled out of the port member 112, thereby reducing the load on the body wall BW of the patient P.

[0154] In the above example, the arm control unit 28 controls the movement of the eighth joint J38, which is a linear joint, when the length L of the surgical instrument 40 inside the body cavity is equal to or less than the maximum linear displacement T0 (L≦T0). This movement of a single joint is advantageous in that it allows for suppression of vibration of the shaft portion 43 passing through the port member 112 and pursuit of speed. On the other hand, the following describes the movement control of the robot arm 3 by the arm control unit 28 when the length L of the surgical instrument 40 inside the body cavity is longer than the maximum linear displacement T0 (L>T0).

[0155] As shown in FIG. 23, the amount of linear displacement of the distal end of the surgical instrument 40 parallel to the longitudinal axis direction Dt by at least one of the rotary joints J31 to J37, excluding the eighth joint J38, of the robot arm 3 is referred to as the "second linear displacement amount T2." However, the second linear displacement amount T2 is not strictly limited to a linear displacement amount. Each of the rotary joints J31 to J37 rotates around a rotation center, but if the amount of rotation is small, the portion of the surgical instrument 40 passing through the remote center RC can move in a generally linear manner. It is preferable that the second linear displacement amount T2 be performed by six of the rotary joints J31 to J37, excluding the eighth joint J38, of the robot arm 3, in order to improve the linearity of the linear displacement.

[0156] The second linear displacement amount T2 may be a value that varies depending on the difference between the intracavitary length L of the surgical instrument 40 and the possible linear displacement amount T0. From the viewpoint of realizing a rapid retraction operation in the retraction process, the second linear displacement amount T2 is preferably set to a value smaller than the first linear displacement amount T1.

[0157] As described above, when the shaft portion 43 of the surgical instrument 40 is passed through the port member 112 and the end effector 44 is located inside the body cavity of the patient P, the arm control unit 28 may control the movement of the robot arm 3 so that the relationship between L, T1, and T2 is (T1 + T2) ≧ L, where L is the length of the surgical instrument 40 inside the body cavity from the remote center RC to the distal end of the surgical instrument 40, T1 is the linear displacement amount parallel to the longitudinal axis direction Dt from the origin position of the eighth joint (linear joint) J38 of the robot arm 3 to its current position, and T2 is a predetermined linear displacement amount parallel to the longitudinal axis direction Dt of the distal end of the robot arm 3 by at least one of the multiple rotary joints J31 to J37 of the robot arm 3. In other words, when the hand controls 21A and 21B issue a command to move the distal end of the surgical instrument 40 in the longitudinal direction Dt, and the linear displacement of the eighth joint J38 alone is insufficient to move the distal end of the surgical instrument 40 to the commanded position, the arm control unit 28 can use the eighth joint J38 and at least one of the multiple rotational joints J31 to J37 of the robot arm 3 to move the surgical instrument 40 in the longitudinal direction Dt.

[0158] The arm control unit 28 of the surgical robot 1 in this embodiment determines the third constraint condition described above based on the results of a simulation or the like, in relation to the required movement required of the robot arm 3 when the operator S operates the operation device 2 to perform a required surgery using the surgical instrument 40. This point will be described in detail below.

[0159] The surgical robot system 10 and its control method according to this embodiment apply the following technique to the control of the robot arm 3 by the arm control unit 28 in relation to the above-mentioned constraint conditions.

[0160] The arm control unit 28 of the surgical robot 1 defines at least one of the multiple drive axes of each robot arm 3 as a redundant drive axis, and controls the redundant drive axis based on operation input from the operation device 2 and constraint conditions related to the redundant drive axis. The arm control unit 28 determines constraint conditions related to the required motion required of the robot arm 3 when the operator S operates the operation device 2 to perform a required surgery using a surgical instrument 40.

[0161] The above-mentioned "constraint condition" may include at least one of the first constraint condition related to the ninth joint (ninth drive shaft) J39, the second constraint condition related to the first joint (first drive shaft) J31, and the third constraint condition related to the eighth joint (eighth drive shaft) J38.

[0162] With regard to the first constraint condition related to the ninth joint (ninth drive shaft) J39 described above, the surgical instrument 40 has a central axis (longitudinal axis) C, and the ninth drive shaft (ninth joint) J39, which is a redundant drive shaft, rotates at least a portion of the surgical instrument 40 (e.g., the shaft portion 43) about the central axis (longitudinal axis) C. The arm control unit 28 controls the robot arm so that the rotation axis R7 of the seventh joint J37, which is a bending joint disposed between the distal end 32 and the proximal end 80 of the robot arm 3, intersects with a reference plane RP including the central axis (longitudinal axis) C, and fixes the orientation of the rotation axis R7 of the seventh joint J37 with respect to the reference plane RP. The arm control unit 28 also sets a remote center (predetermined center point) RC, sets a reference point RD on a reference line RLB that is an extension line of the rotation axis R1 of the first joint J31, which is a torsion joint, or on a reference line RLA that is a line offset in a direction perpendicular to the extension line, and controls the robot arm 3 so that the central axis (longitudinal axis) C is positioned at the remote center (predetermined center point) RC and the reference plane RP is positioned at the reference point RD. The arm control unit 28 then changes the offset amount of the reference point RD in the direction perpendicular to the reference line (extension line) RLB to control the movement direction and movement amount of the instrument drive unit 38 of the instrument holder 36.

[0163] With regard to the second constraint condition related to the first joint (ninth drive axis) J31 described above, the arm control unit 28 operates the robot arm 3 so that, when viewed from a direction parallel to the axial direction of the rotation axis R1 of the first joint J31, which is a torsion joint, the elbow (first part) 11a of the fourth link 84, which is between the first link 81 connected to the base end 80 and the sixth link 86 connected to the tip end 32, among the multiple links of the robot arm 3, is positioned between a point (second part) 80a of the base end 80 and a point (third part) J37a of the tip end 32 (35).

[0164] Regarding the third constraint condition related to the eighth joint (eighth drive axis) J38 described above, the arm control unit 28 stores the remote center RC, which is the center of movement of the surgical instrument 40, and controls the operation of the robot arm 3 based on the remote center RC. In the operation of the robot arm 3, when the shaft portion 43 of the surgical instrument 40 is inserted into the port member 112 inserted into the body wall BW of the patient P and the end effector 44 is inside the body cavity BC of the patient P, the length of the surgical instrument 40 within the body cavity from the remote center RC to the distal end of the surgical instrument 40 is defined as L, the possible linear displacement amount parallel to the axial direction of the shaft portion 43 from the origin position of the translational movement mechanism (linear joint) 35 is defined as T0, and the linear displacement amount parallel to the axial direction of the shaft portion 43 from the origin position of the translational movement mechanism (linear joint) 35 to the current position is defined as T1. When L≦T0, the relationship between L and T1 is T1≧L.

[0165] The content of the above-mentioned "required surgery" is determined by, for example, the surgical procedure to be performed (radical prostatectomy, sacral colpopexy, pyeloplasty, bladder malignant tumor surgery, partial gastrectomy, cholecystectomy, spontaneous pneumothorax, lung resection, etc.), the placement of the port member 112 (port placement) to be installed in the body wall BW of patient P, the surgical field required for the required surgery (required surgical field), the angle of the operating table on which patient P is placed, the anatomical structure of patient P (skeleton, organs, body shape, etc.), the age and sex of patient P, the position of patient P during surgery (supine position, lateral position, lithotomy position, prone position, jackknife position, park bench position, etc.), the type of surgical instrument 40, etc. The "required surgical field" in the "required surgery" may be defined as, for example, a field in which the target of surgery is located approximately in the center of the screen, a field that is necessary and sufficient for the operator S to perform the surgery, and a field in which the operator S can most easily perform the surgery. The "required surgical field" may differ depending on the surgical procedure, etc. The "patient's anatomical structure" may be, for example, a three-dimensional model created from images (preoperative MRI) from a magnetic resonance imaging (MRI) test performed before surgery.

[0166] The content of the above-mentioned "required surgery" is also a prerequisite condition (given condition) when the port placement determination device 65, which will be described later, searches for and determines the optimal placement (port placement) of the port members 112 to be installed in the body wall BW of the patient P. However, among the content of the above-mentioned "required surgery," the port placement is an object to be searched for and determined (an object to be optimized) by the port placement determination device 65, and therefore, in relation to the port placement determination method using the port placement determination device 65, information on port placement is not included in the content of the "required surgery" (given condition).

[0167] The arm control unit 28 of the surgical robot 1 determines the constraint conditions based on the results of a simulation performed by causing the virtual model of the robot arm 3 to perform required operations. Conditions to be set when performing a simulation include, for example, the details of the "required surgery" described above, the minimum allowable separation distance between the robot arms 3, and the setting of a spatial model in which other objects (e.g., a surgical assistant) are expected to be present during surgery. For example, for objects other than the robot arm 3 that are targets for interference avoidance, a spatial region in which the object exists or a spatial region in which the object may be present 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 devices other than the robot arm 3 constituting the surgical robot 1 exist, 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.

[0168] Furthermore, the movement of the virtual model of the surgical instrument 40 and the movement of the virtual model of the robot arm 3 to be executed in the simulation may be determined using data related to the motion history of the surgical instrument 40 and / or the robot arm 3 in an actual surgery. For example, when performing a simulation for a certain surgical procedure, the simulation may be limited to the movement patterns (typical movement patterns) of the surgical instrument 40 that are frequently performed in that procedure. The typical movement patterns may be extracted from movement data related to an actual surgery using a pattern recognition method that employs artificial intelligence technology such as machine learning.

[0169] The arm control unit 28 of the surgical robot 1 may be configured to select an appropriate constraint condition set according to the content of the required surgery from among multiple constraint condition sets created in advance based on the results of the simulation described above. The multiple constraint condition sets may be created based on the results of a simulation performed while changing setting conditions related to the content of the surgery, including the surgical procedure. For example, a first constraint condition set for a first surgical procedure and a second constraint condition set for a second surgical procedure may be created in advance through the simulation described above and stored in the memory 302. When performing surgery using the first surgical procedure, the operator S may operate the touch panel 23 or the like to input information indicating that the surgery to be performed will use the first surgical procedure, causing the arm control unit 28 to select the first constraint condition set.

[0170] The arm control unit 28 may also determine the constraint conditions using a machine learning model trained using the results of the simulation as training data. For example, the training data may be labeled data including the position and orientation of the virtual model of the surgical instrument 40 when accessing discrete grid points set in the virtual model of the surgical field and constraint conditions that prevent interference between the virtual models of the robot arm 3. A trained model can be created by training the machine learning model through supervised learning using the labeled data. The machine learning model may be, for example, a neural network model. The arm control unit 28 uses the trained model to change the constraint conditions in response to changing conditions during surgery. By controlling the robot arm 3 using the trained model in this way, the arm control unit 28 can respond in a timely manner to changing conditions during surgery.

[0171] The above-mentioned "required motion" of the robot arm 3 achieved by the arm control unit 28 may include motion of the robot arm 3 that maximizes the operable range of the surgical instrument 40 within a treatment area set inside the body of the patient P, into which the surgical instrument 40 is inserted. The treatment area may include a surgical field related to the surgical site in the above-mentioned required surgery. The surgical field may be defined based on at least one of the position and orientation of an imaging device that captures images of the surgical site. The "surgical field" in the model for performing the above-mentioned simulation may be defined two-dimensionally or three-dimensionally. When the surgical field is defined three-dimensionally, it may be defined as, for example, a sphere with a diameter of several centimeters. Furthermore, the surgical field used in an actual surgery may be modeled based on image data of the surgical field in the actual surgery and / or axis value data of the joints of the robot arm 3 (the arm holding the endoscope) corresponding to the surgical field in the actual surgery. Furthermore, the above-mentioned "required motion" may include motion to avoid interference between the robot arms 3. Generally, the "surgical field" can change during surgery, but in this example, optimal arm movement can be achieved according to the "surgical field" at that time, thereby avoiding interference between the robot arms 3 and reliably ensuring the required movement of the surgical instrument 40 within the surgical field.

[0172] Next, we will explain an evaluation method using a simulation with a virtual model to adjust the constraint conditions described above to maximize the operable range of the surgical instrument 40. Note that in the present specification and claims, "maximization" or "maximizing" does not necessarily require obtaining the theoretical maximum level (maximum value), but also includes obtaining the practical maximum level (maximum value) required for the surgical robot 1 to accomplish its task.

[0173] In this embodiment, at least a portion of each of the multiple robot arms 3 is modeled to perform a simulation to find optimal constraint conditions according to the content of the surgery, etc. For example, as shown in FIG. 24 , the robot arm 3 may be modeled so that at least a portion of the robot arm 3 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 a reference portion. In FIG. 24 , the reference portion is represented by a capsule indicated by a solid line. The reference portion may be a portion of the adjacent robot arms 3 that is expected to be most likely to approach each other during surgery. For example, a portion of the translational movement mechanism 35 may be selected as the reference portion. The robot arm 3 may also be modeled to include the elbow 11 (see FIG. 10 ) described above.

[0174] 25 schematically shows how 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 penetrate the body wall BW of the patient P via port members (not shown). When the position and posture of the surgical instrument 40 are controlled by the robot arms 3, all three shaft portions 43 rotate about 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).

[0175] Figures 26A and 26B are diagrams for explaining 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, a robot arm 3, a surgical instrument 40, etc. for a virtual surgical field SF defined as a spherical area.

[0176] As shown in Figures 26A and 26B, a spherical surgical field SF defined within 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 is then determined for each of the multiple grid points created within the surgical field SF through 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 equal to or less than a predetermined threshold, and as unreachable if it exceeds the predetermined threshold. The reachability determination is performed by searching for each grid point while varying the position and orientation of the surgical instrument 40. 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 and the position and orientation of the surgical instrument 40 are the same in the state shown in Figure 26A and the state shown in Figure 26B, but the position and / or orientation of the robot arm 3 as a virtual model are different. 26A and 26B are different in position and / or posture of the virtual model of the robot arm 3 because the constraint conditions are different. That is, even if the position and posture of the surgical instrument 40 are the same, the shape of the robot arm 3 changes due to the different constraint conditions, and as a result, the interference state between the arms may change.

[0177] In the state shown in FIG. 26A, one robot arm 3 and the other robot arm 3 interfere with each other, and therefore the grid point being evaluated at this time is determined to be an unreachable grid point. That is, the constraint conditions corresponding to the configuration of the robot arms 3 in the state shown in FIG. 26A are determined to be NG in relation to the target surgical field SF. On the other hand, in the state shown in FIG. 26B, one robot arm 3 and the other robot arm 3 do not interfere with each other, and therefore the grid point being evaluated at this time is determined to be a reachable grid point. That is, the constraint conditions corresponding to the configuration of the robot arms 3 in the state shown in FIG. 26B are determined to be OK in relation to the target surgical field SF. In this way, by changing the constraint conditions related to the redundant axes, the same grid point can be reached in both cases ( FIG. 26A ) and cases ( FIG. 26B ). In the simulation of this example, the reachability of the surgical instrument 40 to each grid point is evaluated while variously changing the settings of the constraint conditions and variously changing the position of the spherical surgical field SF as a virtual model. Then, if the number of reachable grid points for the target surgical field SF is, for example, 100 under one constraint and 150 under another constraint, the other constraint is evaluated as being better for the target surgical field SF.

[0178] The above-described evaluation simulation is performed in advance of the actual surgery, and the results are stored in the memory 302 of the control device 4. The arm control unit 28 changes the constraint conditions of the redundant axis based on the simulation results stored in the memory 302 in accordance with the surgical field SF in the actual surgery. This ensures that the operable range of the surgical instrument 40 is sufficient in the changed surgical field SF, even if the surgical field SF is changed during the surgery. Furthermore, in the above-described simulation, searching for constraint conditions that maximize the operable range of the surgical instrument 40 in the surgical field SF also searches for constraint conditions that prevent interference between the robot arms 3. Therefore, by adjusting the constraint conditions 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.

[0179] Furthermore, in the above-described simulation, it is possible to add a condition that a predetermined virtual space around the robot arm 3 is maintained at a distance from the robot arm 3. This virtual space can be defined as a space in which other objects (e.g., a surgical assistant) are expected to be present during surgery, for example. By setting an additional condition in relation to the virtual space and performing a simulation in this way, it is possible to reduce the possibility of the robot arm 3 coming into contact with other objects (e.g., a surgical assistant) during surgery.

[0180] 27 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. In the example shown in FIG. 27, the third robot arm 3C moves in a direction approaching the fourth robot arm 3D while the fourth robot arm 3D is stationary. When the third robot arm 3C approaches the fourth robot arm 3D and the difference between the proximity distance between the two arms and the minimum allowable distance becomes equal to or less than a threshold, the arm control unit 28 adjusts the offset amount of the reference point RD of the third robot arm 3C based on the results of the simulation, and ends adjustment of the offset amount of the third robot arm 3C when the proximity distance between the arms becomes equal to or greater than the minimum allowable distance.

[0181] By performing the above operations, the proximity distance between the third robot arm 3C and the fourth robot arm 3D is maintained at or above the minimum allowable distance. This automatically prevents interference between the third robot arm 3C and the fourth robot arm 3D. As a result, it is possible to prevent the surgical robot 1 from being stopped (locked) due to interference between the robot arms, for example, and ensure the continuity of the surgery.

[0182] Furthermore, the proximity distance between the adjacent robot arms 3C and 3D is automatically maintained at or above the minimum allowable distance by the arm control unit 28, so that the control of the position and posture of the end effector by the operating robot arm 3C (following operation) can be prevented from being interrupted. This ensures the continuity of the treatment by the operator S.

[0183] As described above, the surgical robot system and its control method according to this embodiment can reliably avoid interference between the robot arm and objects around the robot arm, thereby ensuring the continuity of surgery by the operator (surgeon) S.

[0184] In the surgical robot system of this embodiment, in addition to the arm control unit 28 controlling the robot arm 3 during surgery in relation to the above-mentioned constraint conditions, the positioner control unit 75 may also control the positioner 7 during surgery as described below.

[0185] 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 the adjustment of the arm base 5 by the positioner control unit 75. In other words, even when the positioner control unit 75 adjusts at least one of the position and posture of the arm base 5, the arm control unit 28 controls the robot arm 3 so that the position and posture of the surgical instrument 40 are the position and posture determined based on the operation input input by the operator S via the operation device 2.

[0186] As shown in FIG. 28 , the positioner control unit 75 includes a surgical field designation unit 76, a surgical field estimation unit 77, a manual arm selection unit 78, and an automatic arm selection unit 79. Using these units, 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, a change in the surgical field imaged by the endoscope 12 due to a change in at least one of the position and posture of the endoscope 12 during surgery, a change 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 a change in the 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, for example, based on at least one of the position and posture of the endoscope 12 that images the surgical site during surgery.

[0187] The surgical field designation means 76 of the positioner control unit 75 can designate a surgical field during surgery based on a command from the operator S input via, for example, the touch panel 23 of the operation device 2. For example, when the operator S designates a point in a three-dimensional space within the body of the patient P, including the surgical site, the surgical field designation means 76 designates a spatial region of a predetermined range (e.g., a spherical spatial region having a predetermined diameter) centered on the designated point as a virtual surgical field. The surgical field designated by the command from the operator S does not necessarily have to completely match the actual surgical field captured by the endoscope 12, but 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 captured by the endoscope 12.

[0188] 29A, 29B, and 29C, 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 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 detail later.

[0189] 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, when the inclination of the operating table 111 on which the patient P is placed is changed during surgery, the surgical field estimation means 77 estimates the surgical field based on, for example, the relative relationship between the inclination of the operating table 111 and the posture of the endoscope 12. The positioner control unit 75 adjusts at least one of the position and posture 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 among 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 detail later.

[0190] The manual arm selection means 78 of the positioner control unit 75 has a 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, a robot arm 3 to which a target surgical instrument 40 whose operable range is to be maximized when the positioner control unit 75 adjusts at least one of the position and posture of the arm base 5 to maximize the operable range of the surgical instrument 40. The target robot arm 3 also refers to a 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 posture 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, a robot arm 3 operated by operation input from the operator S.

[0191] The positioner control unit 75 may have a function to maintain a certain distance or more between the arm base 5 and a virtual space set in advance 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 set in advance as a virtual workspace and stored in the memory 302 of the control device 4, and when the arm control unit 28 adjusts the position and / or posture of the arm base 5, the adjustment is made so as to maintain a certain distance or more between the set workspace and the arm base 5. This can reduce the possibility that the arm base 5 moving during surgery will interfere with the surgical assistant.

[0192] The positioner control unit 75 has a function of adjusting the position and / or posture of the arm base 5 during surgery to avoid interference between one robot arm 3 among the multiple robot arms 3 and another robot arm 3 among the multiple robot arms 3. That is, 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 operable range of the surgical instrument 40 can be maximized.

[0193] 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 state (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. 30A, if the second robot arm 3B to which the endoscope assembly 40B is attached is operated based on an operation input from the operator S, and the orientation (posture) of the endoscope 12 of the endoscope assembly 40B changes as shown in FIG. 30B, 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. 30C. At this time, the arm control unit 28 controls the robot arms 3A, 3B, 3C, and 3D while preventing the movement of the arm base 5 from affecting the movement of any of the surgical instruments 40A, 40B, 40C, and 40D. The changed position and posture of the arm base 5 maximizes the range of motion of the surgical instrument 40 in relation to the changed surgical field, allowing the operator S to continue the surgery without any hindrance, as shown in Figure 30D.

[0194] Next, a simulation for searching for the position and posture of the arm base 5 that can avoid interference between the robot arms 3 and maximize the operable range of the surgical instrument 40 will be described with reference to Figures 31A and 31B. Note that the robot arm 3, arm base 5, surgical instrument 40, and surgical field SF shown in Figures 31A and 31B are each modeled for the purpose of the simulation.

[0195] In the state shown in FIG. 31A, one robot arm 3 and the other robot arm 3 are interfering with each other, and therefore the grid point to be evaluated at this time is determined to be an unreachable grid point. That is, the position and posture of the arm base 5 in the state shown in FIG. 31A are determined to be NG in relation to the target surgical field SF. On the other hand, in the state shown in FIG. 31B, one robot arm 3 and the other robot arm 3 are not interfering with each other, and therefore the grid point to be evaluated at this time is determined to be a reachable grid point. That is, the position and posture of the arm base 5 in the state shown in FIG. 31B 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 may be unreachable ( FIG. 31A ) or reachable ( FIG. 31B ) by the surgical instrument 40. In the simulation of this example, the reachability of the surgical instrument 40 to each grid point is evaluated while variously changing the position and posture of the arm base 5 as a virtual model and while variously changing the position of the spherical surgical field SF as a virtual model. Then, if the number of reachable grid points for the target surgical field SF is, for example, 100 in the first position and posture of the arm base 5 and 150 in the second position and posture of the arm base 5, then the second position and posture is evaluated as being better for the target surgical field SF.

[0196] The above-described evaluation simulation is 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 operational range of the surgical instrument 40 is sufficient in the changed surgical field SF, even if the surgical field SF is changed during the surgery. Furthermore, in the above-described simulation, searching for the position and posture of the arm base 5 that maximizes the operational range of the surgical instrument 40 in the surgical field SF also means searching 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.

[0197] Furthermore, in the above-described simulation, it is also 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 an additional condition in relation to the virtual space and performing a simulation in this way, it is possible to reduce the possibility of the arm base 5 coming into contact with other objects (e.g., surgical assistants) during surgery.

[0198] 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 the multiple robot arms 3, the sum of the differences from the optimal relative positions and postures of the target robot arms 3 is minimized. In other words, when the position and / or posture of the arm base 5 changes, the positions and / or postures 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 posture 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 positions and postures of the target robot arms 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.

[0199] Similarly, a simulation may be performed by adding a condition that the maximum value of the difference between the optimal relative position and posture of each of the target robot arms 3 is minimized for virtual models of two or more target robot arms 3 selected from a plurality of robot arms 3. This makes it possible to prevent the occurrence of a robot arm 3 with an extremely narrow operable range.

[0200] As described above, according to the surgical robot system 10 and its control method of this embodiment, the positioner control unit 75 adjusts at least one of the position and posture 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, thereby reliably ensuring the continuity of the surgery by the operator (surgeon) S.

[0201] In particular, since 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), it is possible to achieve precise control of the position and posture of the arm base 5, which is not possible with, for example, a horizontal articulated robot. This makes it possible to achieve precise control of the position and posture 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 posture of the arm base 5 using a positioner 7 configured using a vertical articulated robot is preferable.

[0202] In the case of conventional surgical methods that do not use surgical robots, such as endoscopic surgery in which the surgeon directly grasps surgical instruments with his or her hands, the operating table may be tilted to position the patient P in a direction that makes it easier for the surgeon to perform the surgery, depending on the content or situation of the surgery. That is, by adjusting the tilt of the operating table, for example, a surgeon who directly grasps and operates surgical instruments such as forceps with his or her hands can more easily move his or her arms and hands, and it also makes it easier for a surgical assistant to operate an endoscope that is directly held in his or her hands.

[0203] On the other hand, 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 those achieved by 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 position and / or orientation of the endoscope 12 is changed by manipulating the robot arm 3 (e.g., the second robot arm 3B) holding the endoscope assembly 40B. In conventional surgical methods in which a surgeon or a surgical assistant directly grasps and operates surgical instruments (forceps, endoscope, etc.) with their hands rather than using a surgical robot, tilting the operating table may be necessary to ensure an appropriate surgical field given the constraints imposed by 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. The surgery must be continued while avoiding interference between the second robot arm 3B with the changed configuration and the surrounding robot arm 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 posture of the arm base 5 so as to avoid interference between the robot arms 3 even when the surgical field is changed, allowing surgery to be performed continuously under 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, since this embodiment employs a vertical articulated robot for the positioner 7, more detailed responses are possible in terms of ensuring an optimal surgical field compared to conventional surgical methods in which the operating table is tilted.

[0204] As described above, according to the surgical robot system 10 and its control method of this embodiment, the arm control unit 28 can change the constraint conditions of the redundant axis during surgery, thereby reliably avoiding interference between the robot arm 3 and other surrounding objects and reliably ensuring the continuity of the surgery by the operator S.

[0205] The method for adjusting the constraint conditions of the redundant axis (constraint condition adjustment method) and the method for adjusting the position and / or location of the arm base (arm base adjustment method) can be used either alone or 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 sufficiently 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 significantly 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. 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.

[0206] An example of the operation of the surgical robot system 10 has been described above, assuming the optimal port arrangement determined by the port arrangement determination device 65 according to this embodiment.

[0207] The following describes a port arrangement determination method for searching for and determining an optimal port arrangement that can maximize the performance of the surgical robot 1 using the port arrangement determination device 65 according to this embodiment.

[0208] In the simulation described above with reference to Figures 26A and 26B, the port placement was treated as a given condition rather than as an object of optimization, and the objective was to optimize the constraints under given conditions including the port placement. In contrast, in the simulation described below, the port placement itself is treated as an object to be optimized together with the constraints. That is, the simulation described below optimizes the constraints and the port placement as a set while adjusting both the constraints and the port placement when evaluating the reachability of the surgical instrument 40 to the grid points in the virtual model of the required surgical field SF. Therefore, the information obtained as a result of the simulation is information regarding the optimal set of "constraints and port placement" for the required surgical field SF.

[0209] The virtual model of the "required surgical field" set in the simulation executed by the port placement determination device 65 may be created based on the experience of a surgeon or scopist in conventional surgery (such as endoscopic surgery) in which the surgeon directly grasps surgical instruments with their hands. Alternatively, data regarding the "required surgical field" in the "required surgery" may be obtained based on actual data from robot-assisted surgery previously performed using a surgical robot (for example, control data regarding the position and orientation of the endoscope, image data acquired by the endoscope), and the virtual model of the "required surgical field" may be created using the obtained data.

[0210] As shown in FIG. 9 , the port placement determination device 65 in this embodiment includes a processor 301 and a memory 302. The memory 302 stores information about the required surgery to be performed by the operator S using the surgical instrument 40 by operating the operation device 2, as well as information about the constraints described above. Here, the information about the required surgery and the information about the constraints are generally the same as those used in the simulation described with reference to FIGS. 26A and 26B . However, with regard to the port placement information, because the port placement itself is the target of optimization in this simulation, the content of the required surgery to be performed does not include information about the port placement itself. However, with regard to information about operation data related to a surgery performed in the past, rather than the required surgery to be performed in the future, the port placement information from that time (the past surgery) may be used, for example, as an initial value for searching when performing the current simulation.

[0211] Processor 301 determines the optimal port placement by searching for the optimal port placement for the required surgery while adjusting the constraint conditions, based on the information about the required surgery and the information about the constraint conditions obtained from memory 302. The information about the required surgery includes information about the surgical field required to perform the required surgery.

[0212] There is not necessarily one surgical field required for a given surgery, and the optimal surgical field may change depending on the progress or stage of the surgery. When searching for the optimal port placement using simulation for such a surgery, for example, the surgical field required at the most critical stage of the surgery (e.g., the stage where the procedure is most difficult) may be defined as the "necessary surgical field." Alternatively, the surgical field required most frequently in the surgery may be defined as the "necessary surgical field."

[0213] The memory 302 stores a virtual model of the necessary surgical field SF, a virtual model of the robot arm 3, and a virtual model of the surgical instrument 40. These virtual models may be the same as the virtual models described above with reference to Figures 24 and 25.

[0214] The processor 301 executes a simulation using the virtual model of the required surgical field SF, the virtual model of the robot arm 3, and the virtual model of the surgical instrument 40 acquired from the memory 302, while adjusting the constraint conditions described above, to cause the virtual model of the robot arm 3 to perform a required operation that maximizes the operable range of the virtual model of the surgical instrument 40 within the virtual model of the required surgical field SF. Then, based on the results of the executed simulation, an optimal port arrangement for the required surgical field of the required surgery is determined.

[0215] 32A and 32B are diagrams illustrating a method for evaluating, by simulation, the operable range (instrument operable range) of a surgical instrument 40 (more specifically, the end effector 44) in a virtual surgical field SF defined as a spherical region, using virtual models of the arm base 5, robot arm 3, surgical instrument 40, etc. Figures 32A and 32B show a state in which the shaft portion 43 of the virtual model of the surgical instrument 40 is inserted into ports PT1 and PT2 formed in a virtual model of the patient's body wall BW.

[0216] As shown in Figures 32A and 32B, a spherical surgical field SF defined within 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 based 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 each grid point is equal to or less than a predetermined threshold, and as unreachable if the distance exceeds the predetermined threshold. The greater the number of reachable grid points, the greater the operational range (instrument operational range) of the surgical instrument 40 is determined to be. The state shown in Figure 32A and the state shown in Figure 32B have the same surgical field SF and the same target grid points, but the positions of the ports PT1 and PT2 and the shape of the robot arm 3 as a virtual model are different. The reason why the shape of the virtual model of the robot arm 3 differs between Figures 32A and 32B is that the positions and constraint conditions of ports PT1 and PT2 are different between Figures 32A and 32B. That is, even if the target lattice point in the surgical field SF is the same, the shape of the robot arm 3 changes due to the differences in the positions and constraint conditions of ports PT1 and PT2, and as a result, the interference state between the arms may change.

[0217] In the state shown in FIG. 32A, one robot arm 3 and the other robot arm 3 interfere with each other, and the grid point being evaluated at this time is determined to be an unreachable grid point. That is, the constraint conditions and port arrangement corresponding to the configuration of the robot arms 3 in the state shown in FIG. 32A are determined to be NG in relation to the target surgical field SF. On the other hand, in the state shown in FIG. 32B, one robot arm 3 and the other robot arm 3 do not interfere with each other, and the grid point being evaluated at this time is determined to be a reachable grid point. That is, the constraint conditions and port arrangement corresponding to the configuration of the robot arms 3 in the state shown in FIG. 32B are determined to be OK in relation to the target surgical field SF. In this way, by changing the constraint conditions and port arrangement related to the redundant axis, the same grid point can be reached in both cases (FIG. 32A) and cases (FIG. 32B) where the surgical instrument 40 cannot reach it. In the simulation of this example, the constraint conditions and port arrangement settings are variously changed, and the reachability of the surgical instrument 40 to each grid point is evaluated. Then, if the number of reachable lattice points for the target surgical field SF is, for example, 100 under certain constraint conditions and port arrangements and 150 under other constraint conditions and port arrangements, then the other constraint conditions and port arrangements are evaluated as being better for the target surgical field SF.

[0218] Preferably, the memory 302 of the port placement determination device 65 further stores a virtual model of the anatomical structure as a virtual model of the patient P's body, and the processor 301 of the port placement determination device 65 further uses the virtual model of the anatomical structure of the patient P to determine the above-mentioned optimal port placement. The virtual model of the anatomical structure of the patient P can be created using data on the anatomical structure of the patient P acquired by preoperative MRI, for example. A scan can be performed using a transmission sensor attached to the robot arm 3 to acquire 3D data on the anatomical structure of the patient P, and the virtual model of the anatomical structure of the patient P can be created using the 3D data.

[0219] Preferably, the port placement determination device 65 preliminarily excludes from the simulation search areas unsuitable for placing ports PT1 and PT2, such as areas where bones are present, based on a virtual model of the patient P's anatomical structure. This reduces the computational resources required for the simulation and shortens the required computation time. For example, in the case of thoracoscopic surgery (see FIGS. 35(A) and 35(B)), areas on the body surface corresponding to the positions of ribs are excluded from the simulation search areas for port placement. Furthermore, areas unsuitable for placing ports PT1 and PT2 are excluded from the simulation search areas based on the details of the required surgery (such as the surgical procedure and patient position). Alternatively, the search area for ports PT1 and PT2 may be preliminarily narrowed down based on the surgeon's past surgical experience (experience in conventional surgery in which surgical instruments are directly held by hand or experience in robot-assisted surgery) and / or information on recommended port placements in medical textbooks, etc.

[0220] Among the required surgeries, there are some (laparoscopic surgery, etc.) that are performed by creating an insufflated state by injecting gas such as carbon dioxide into the abdomen of the patient P. When determining the optimal port position on the premise of such an insufflated state, the insufflated state of the patient P may be imaged using a 3D camera or the like to obtain 3D data regarding the body surface of the patient P, and a model of the patient P (a virtual model of the patient's body) created based on the 3D data may be used in the above-mentioned simulation.

[0221] The position data regarding the optimal port placement obtained by the above-mentioned simulation is data that can identify the position of the port on the body surface of patient P. In other words, the model of the surgical field SF used in the above-mentioned simulation is set at a position corresponding to the treatment site on the model of patient P, and the position of the optimal port placement obtained by the simulation can be defined based on the positional relationship between the surgical field SF and patient P. The position of the surgical field SF may be defined in relation to a characteristic part of the anatomical structure of patient P.

[0222] Once the optimal port placement and set of constraint conditions are obtained through the above-described simulation, the obtained results are stored in memory 302 .

[0223] The surgical robot system 10 according to this embodiment preferably includes a port placement presentation means for presenting information about the optimal port placement determined by the port placement determination device 65. The port placement presentation means presents information about the optimal port placement obtained by simulation, for example, on the body surface of the patient P placed on the operating table 111. The information may be presented, for example, by operating the robot arm 3 with the tip of the shaft 43 (or other appropriate shaft-shaped member) of the surgical instrument 40 (e.g., endoscope 40B) attached to the tip 32 of the robot arm 3, or by using beam irradiation means such as a laser beam pointer provided on the robot arm 3, and pointing or touching the optimal port placement position on the body surface of the patient P with the tip or beam.

[0224] The surgical robot system 10 according to this embodiment preferably further includes a patient position information acquisition unit that acquires position information of the patient P placed on the operating table 111 in a slave-side coordinate system that serves as a reference for operating the multiple robot arms 3. The patient position information acquired by the patient position information acquisition unit can be used to accurately teach the optimal port placement on the patient's body surface. The patient position information acquisition unit may include, for example, an imaging unit 53 provided on the arm base 5. The patient position information acquisition unit may also include an analytical model that analyzes image information acquired by the imaging unit 53 to acquire position information of the patient P placed on the operating table 111 in the slave-side coordinate system. The analytical model may be configured, for example, with a machine learning model suitable for image analysis, such as a convolutional neural network (CNN). For example, a trained model can be acquired by training the machine learning model using supervised learning using multiple image data of the body surfaces of multiple humans as training data. In this case, labeled data identifying a characteristic part of the body surface (e.g., the navel) can be used as the training data. Data on the body surface model of patient P on which the required surgery will be performed can be input into the trained machine learning model generated in this way, and information regarding the position of characteristic parts of patient P (e.g., the navel) in the slave coordinate system can be obtained.

[0225] Furthermore, in the above-described simulation, it is possible to add a condition that a predetermined virtual space around the robot arm 3 is maintained at a distance from the robot arm 3. This virtual space can be defined as a space in which other objects (e.g., a surgical assistant) are expected to be present during surgery, for example. By setting an additional condition in relation to the virtual space and performing a simulation in this way, it is possible to reduce the possibility of the robot arm 3 coming into contact with other objects (e.g., a surgical assistant) during surgery.

[0226] Then, for example, the above-mentioned evaluation simulation is performed in advance of the actual surgery, and the results (data related to the optimal port placement and constraint conditions) are stored in memory 302 of control device 4. The optimal port placement and constraint conditions stored in memory 302 are optimized in relation to the surgical field SF required for the required surgery to be performed on patient P.

[0227] The port placement presentation means described above presents information about optimal port placement on the body surface of the patient P placed on the operating table 111 based on optimal port placement data stored in memory 302, for example, in response to instructions input by a surgical assistant or the like via the operation unit 72 (FIG. 6). For example, the port placement presentation means may operate the robot arm 3 using the arm control unit 28 based on the optimal port placement data stored in memory 302, and point or touch the optimal port placement position on the body surface of the patient P with the tip of the shaft 43 (or other appropriate shaft-shaped member) of a surgical instrument 40 (e.g., endoscope 40B) attached to the distal end 32 of the robot arm 3. Alternatively, a beam irradiation means such as a laser beam pointer provided on the robot arm 3 may be used to indicate the optimal port placement position on the body surface of the patient P with a beam. The surgeon S performing the surgery or the surgical assistant forms a port on the body surface of the patient P at the position indicated by the port placement presentation means. For example, a port is formed by inserting a trocar into a hole formed in the body wall of the patient P.

[0228] After multiple ports are formed according to the optimal port arrangement determined by the port arrangement determination device 65, for example, a surgical assistant operates the arm manual operation mechanism 39 (FIG. 11) to drive each robot arm 3 and insert the shaft portion 43 of a predetermined surgical instrument 40 into each port. Then, the operator S operates the operation device 2 to operate the surgical instrument 40 and perform the required surgery. At this time, the arm control unit 28 controls the robot arm 3 based on the optimal constraint conditions for the required surgical field SF for the required surgery, which are stored in the memory 302. This ensures a sufficient operational range for the surgical instrument 40 in the required surgical field SF. Furthermore, in the above-mentioned simulation, searching for the constraint conditions that maximize the operational range of the surgical instrument 40 within the surgical field SF also searches for the constraint conditions that prevent interference between the robot arms 3. Therefore, controlling the robot arms 3 using the optimal constraint conditions stored in the memory 302 can avoid interference between the robot arms 3. This avoids the situation where the surgical instrument 40 cannot reach the position intended by the operator S, and furthermore, it avoids the trouble of recovery work that would be necessary if interference actually occurs, thereby ensuring the continuity of the surgery.

[0229] As described above, the surgical robot system 10 according to this embodiment is equipped with a port placement determination device 65 that determines the optimal port placement for performing the required surgery. By installing the port member 112 in the optimal port placement determined by the port placement determination device 65, the operating range of the surgical instrument 40 in the required surgical field SF can be sufficiently secured, allowing the required surgery to be performed without any problems.

[0230] In particular, in this embodiment, when determining the optimal port placement by simulation, the constraint conditions of the redundant axis are not set fixedly, but the constraint conditions of the redundant axis themselves are also subject to adjustment (optimization), thereby increasing the range on the body surface in which ports can be placed. In other words, the degree of freedom in selecting port placement is increased. Since the priority condition that must be ensured in order to perform the required surgery without any problems is that the surgical instrument 40 can be fully operated within the required surgical field SF, it can be said that when determining the location of the port, it is better to have a larger range of candidate body surface areas.

[0231] Furthermore, some patients P (or surgeons S) may place importance on cosmetic considerations (such as the position of scars remaining after surgery), and in such cases, the range of candidate port positions for performing the above-described simulation may be limited in advance. For example, one of the multiple ports may be limited in advance to a specific position on the body surface of the patient P (for example, the position of the navel), and optimal positions for the other ports (for example, three ports) may be searched for through the above-described simulation.

[0232] Conventional surgery, in which a surgeon holds surgical instruments directly in his or her hands, and robot-assisted surgery, in which a surgeon S operates a robot arm 3 equipped with surgical instruments 40 using an operating device 2, involve different circumstances regarding ensuring the triangulation between surgical instruments, which is necessary to ensure operating space for the surgical instruments. Therefore, determining the optimal port arrangement according to the characteristics of the surgical robot 1 (particularly the operability of the robot arm 3 having redundancy), as in the surgical robot system 10 of this embodiment, is extremely beneficial in terms of performing the required surgery without any problems.

[0233] Depending on the content of the required surgery (such as the surgical procedure), the surgical field required for performing the required surgery may change during the surgery. In such a case, when performing the above-described simulation, the most important surgical field (priority surgical field) may be selected from among multiple surgical fields required during the surgery, and a model of the selected surgical field may be used to perform the simulation. The port placement determined in this manner may not necessarily be the “optimal” port placement if a surgical field other than the “most important surgical field (priority surgical field)” is set during the surgery. Therefore, in this embodiment, by appropriately applying a control method (constraint condition adjustment mode) that dynamically adjusts the first to third constraint conditions described above during the surgery and / or a control method (arm base adjustment mode) that dynamically adjusts the position and orientation of the arm base described above during the surgery, it is possible to control the robot arm 3 appropriate for the surgical field at that time. In other words, even if a surgical field different from the surgical field SF used in the simulation is set during the surgery, applying the optimal constraint conditions and / or the optimal position and orientation of the arm base 5 in relation to the current surgical field can prevent interference between the robot arms 3 and maximize the operable range of the surgical instrument 40 in the current surgical field.

[0234] The memory 302 of the port placement determination device 65 may store multiple sets including optimal port placements and constraints corresponding to the optimal port placements, which have been determined in advance by the port placement determination device 65. For example, the control device 4 can select an optimal set according to the content of the required surgery from the multiple sets stored in the memory 302 based on information regarding the content of the required surgery input by a surgical assistant through the operation unit 72 (see FIG. 6). For example, a first set of optimal port placements and constraints obtained for a first condition related to a certain surgical procedure and a certain physique, and a second set of optimal port placements and constraints obtained for a second condition related to a different surgical procedure and a different physique, may be created in advance through the above-described simulation and stored in the memory 302. Then, when performing surgery corresponding to the first condition, the operator S may operate the touch panel 23 or the like to input information indicating that the surgery to be performed corresponds to the first condition, causing the control device 4 to select the first set.

[0235] By selecting from multiple sets (port placements and constraints) prepared in advance, it is possible to quickly determine the port placement appropriate for the upcoming surgery. Note that while this method of preparing multiple sets in advance may result in lower optimization accuracy than determining the optimal port placement by performing a simulation for each individual patient, indicating candidate port placement locations can be useful, especially in urgent surgeries, assuming that the final port placement decision (fine-tuning of port positions) will be made by the surgeon on-site.

[0236] The control method of the surgical robot system according to the present embodiment described above can be implemented by a computer program. The computer program may 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 may be provided on one or more computer-readable media. The computer-readable medium may be either transient or non-transitory. The computer-readable medium may be, for example, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, or a propagation medium for data transmission, for example, downloading code via the Internet. Alternatively, the computer-readable medium may take the form of one or more physical computer-readable media, such as a semiconductor or solid-state memory, magnetic tape, removable computer diskette, random access memory (RAM), read-only memory (ROM), rigid magnetic disk, or optical disk such as a CD-ROM, CD-R / W, or DVD.

[0237] Additionally, the functions of the components disclosed herein can be performed using circuits or processing circuits, including general-purpose processors, special-purpose processors, integrated circuits, application-specific integrated circuits (ASICs), 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.

[0238] This disclosure also includes the following aspects. (Aspect 1) Aspect 1 of this disclosure is a plurality of robotic arms, each of which is equipped with a surgical instrument, each of which has a plurality of drive axes, the number of which is greater than the minimum number of degrees of freedom required to control the position and orientation of the surgical instrument; an operating device that receives an operation input from an operator to control the position and posture of the surgical instrument; a control device that controls the plurality of robot arms based on the operation input, The control device defining at least one of the plurality of drive shafts as a redundant drive shaft, and controlling the redundant drive shaft based on the operation input and constraint conditions related to the redundant drive shaft; The surgical robot system determines the constraint conditions in relation to the required movements required of the robot arm when the operator operates the operating device and performs the required surgery using the surgical instrument.

[0239] (Aspect 2) Aspect 2 of this disclosure is a surgical robot system described in aspect 1, wherein the control device determines the constraint conditions based on the results of a simulation performed by causing a virtual model of the robot arm to perform the required movement.

[0240] (Aspect 3) Aspect 3 of this disclosure is a surgical robot system described in aspect 2, in which the control device selects an appropriate set of constraint conditions according to the content of the required surgery from among multiple sets of constraint conditions created in advance based on the results of the simulation, and the multiple sets of constraint conditions are created based on the results of the simulation performed while changing the setting conditions related to the content of the surgery.

[0241] (Aspect 4) Aspect 4 of this disclosure is a surgical robot system described in aspect 2, in which the control device determines the constraint conditions using a machine learning model that has been trained using the results obtained by the simulation as training data.

[0242] (Aspect 5) A fifth aspect of this disclosure is a surgical robot system according to the fourth aspect, wherein the control device changes the constraint conditions in response to changing conditions during the required surgery.

[0243] (Aspect 6) Aspect 6 of this disclosure is a surgical robot system described in any one of aspects 1 to 5, wherein the required movement includes movement of the robot arm that maximizes the range of motion of the surgical instrument within a treatment area set within the patient's body into which the surgical instrument is inserted.

[0244] (Aspect 7) A seventh aspect of this disclosure is The treatment area includes a surgical field related to a surgical site in the required surgery, In the surgical robot system of aspect 6, the surgical field is defined based on at least one of the position and orientation of an imaging device that images the surgical site.

[0245] (Aspect 8) An eighth aspect of the present disclosure is a surgical robot system according to any one of the first to sixth aspects, wherein the required operation includes an operation to avoid interference between the robot arms.

[0246] (Aspect 9) A ninth aspect of this disclosure is the surgical instrument has a longitudinal axis; A surgical robot system according to any one of aspects 1 to 8, wherein the redundant drive shaft rotates at least a portion of the surgical instrument about the longitudinal axis.

[0247] (Aspect 10) A tenth aspect of this disclosure is 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, The control device determines the constraint conditions for the redundant drive shaft as follows: Controlling the robot arm to intersect a rotation axis of the bending joint with a reference plane including the longitudinal axis, and fixing an orientation of the rotation axis of the bending joint with respect to the reference plane; A predetermined center point is set, and a reference point is set on a reference line that is an extension line of a rotation axis of the torsion joint or a line that is offset in a direction perpendicular to the extension line, and the robot arm is controlled to position the longitudinal axis at the center point and the reference plane at the reference point; A surgical robot system according to aspect 9, wherein the direction and amount of movement of the redundant drive axis are controlled by changing the offset amount of the reference point in a direction perpendicular to the extension line.

[0248] (Aspect 11) An eleventh aspect of this disclosure is further comprising an arm base on which the plurality of robot arms are mounted, each of the plurality of robot arms includes a base end attached to the arm base, a tip end to which the surgical instrument is attached, and a plurality of links that connect the base end and the tip end and are connected to each other, and the link adjacent to the base end is connected to the base end via a torsion joint; The surgical robot system is described in any one of aspects 1 to 10, wherein the control device operates the robot arm such that, with respect to the constraint condition regarding the redundant drive axis, when viewed from a direction parallel to the axial direction of the rotation axis of the torsional joint, a first portion of the link among the plurality of links, which is located between the link connected to the base end and the link connected to the tip end, is positioned between a second portion of the base end and a third portion of the tip end.

[0249] (Aspect 12) A twelfth aspect of this disclosure is The surgical instrument has an instrument base, a shaft portion extending from the instrument base, and an end effector provided at the tip of the shaft portion, the robot arm has a prismatic joint to which the instrument base is attached, the prismatic joint moving the surgical instrument in the axial direction of the shaft portion; The control device determines the constraint conditions for the redundant drive shaft as follows: storing a remote center of motion of the surgical instrument; 12. A surgical robot system according to any one of aspects 1 to 11, wherein the operation of the robot arm is controlled based on the remote center, and wherein, in the operation of the robot arm, when the shaft portion is inserted into a port member inserted into a body wall of a patient and the end effector is inside the patient's body cavity, the length of the surgical instrument from the remote center to the distal end of the surgical instrument within the body cavity is defined as L, the amount of linear displacement parallel to the axial direction from the origin position of the linear joint is defined as T0, and the amount of linear displacement parallel to the axial direction from the origin position of the linear joint to a current position is defined as T1, and when L≦T0, the relationship between L and T1 is T1≧L.

[0250] (Aspect 13) A thirteenth aspect of this disclosure is 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 control device is a surgical robot system according to any one of aspects 1 to 12, wherein the control device controls the multiple robot arms without affecting the movement of the surgical instrument by adjusting at least one of the position and the attitude of the arm base by the positioner control unit.

[0251] (Aspect 14) A fourteenth aspect of this disclosure is A control method for a surgical robot system, the surgical robot system comprising: a plurality of robot arms, each of which is equipped with a surgical instrument, each of which has a plurality of drive axes, the number of which is greater than the minimum degree of freedom required to control the position and orientation of the surgical instrument; an operation device that receives an operation input from an operator to control the position and orientation of the surgical instrument; and a control device that controls the plurality of robot arms based on the operation input, defining at least one of the plurality of drive shafts as a redundant drive shaft, and controlling the redundant drive shaft based on the operation input and constraint conditions related to the redundant drive shaft; A method for controlling a surgical robot system, which determines the constraint conditions in relation to the required movements required of the robot arm when the operator operates the operating device and performs a required surgery using the surgical instrument.

[0252] (Aspect 15) A fifteenth aspect of this disclosure is A computer-readable medium storing computer-readable instructions, which, 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 plurality of robot arms, each having a surgical instrument attached thereto, each having a plurality of drive axes, the number of the drive axes being greater than a minimum degree of freedom required to control the position and orientation of the surgical instrument; an operation device that receives an operation input from an operator to control the position and orientation of the surgical instrument; and a control device that controls the plurality of robot arms based on the operation input, the control method comprising: defining at least one of the plurality of drive shafts as a redundant drive shaft, and controlling the redundant drive shaft based on the operation input and constraint conditions related to the redundant drive shaft; A computer-readable medium that determines the constraints in relation to required movements of the robot arm when the operator operates the manipulation device to perform a required surgery using the surgical instrument. [Explanation of symbols]

[0253] 1. Surgical robot 2 Control 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 the robot arm 35 Translation mechanism 36 Instrument holder 40 Surgical instruments 40A Endoscope Assembly 40B Forceps Assembly 38 Instrument drive unit 43 Shaft of surgical instrument 65 Port placement determination device 75 Positioner control unit 76 Surgical field designation means 77 Surgical field estimation method 78 Manual Arm Selection Means 79 Automatic arm selection means Abdominal wall of BW patient C. Central axis of the shaft (longitudinal axis of the surgical instrument) J31~J39 Joints (drive shafts) P patient PT1, PT2 ports PP pivot point R1~R9 rotation axis RC Remote Center RD reference point RL, RLA, RLB reference line RP reference plane S Operator (practitioner) SF field

Claims

1. 1. A port placement determination device for determining optimal port placement for a plurality of port members to be placed in a body wall of a patient in surgery using a surgical robot system, comprising: The surgical robot system includes: a plurality of robotic arms, each of which is equipped with a surgical instrument, each of which has a plurality of drive axes, the number of which is greater than the minimum number of degrees of freedom required to control the position and orientation of the surgical instrument; an operating device that receives an operation input from an operator to control the position and posture of the surgical instrument; a control device that controls the plurality of robot arms based on the operation input, the control device defining at least one of the plurality of drive shafts as a redundant drive shaft, and controlling the redundant drive shaft based on the operation input and a constraint condition related to the redundant drive shaft, a processor; a memory; the memory stores information about a required surgery to be performed by the operator using the surgical instrument by operating the operation device, and information about the constraint conditions; The processor determines the optimal port placement by searching for the optimal port placement for the required surgery while adjusting the constraint conditions based on information about the required surgery and information about the constraint conditions obtained from the memory.

2. 2. The port placement determination device according to claim 1, wherein the information about the required surgery includes information about a surgical field required to perform the required surgery.

3. the memory stores a virtual model of the required surgical field, a virtual model of the robot arm, and a virtual model of the surgical instrument; 3. The port arrangement determination device according to claim 2, wherein the processor determines the optimal port arrangement based on results of a simulation performed by using the virtual model of the required surgical field, the virtual model of the robot arm, and the virtual model of the surgical instrument retrieved from the memory, and by causing the virtual model of the robot arm to perform a required operation that maximizes an operable range of the virtual model of the surgical instrument within the virtual model of the required surgical field while adjusting the constraint conditions.

4. the memory further storing a virtual model of the patient's anatomy; The port placement determination device of claim 3 , wherein the processor further uses a virtual model of the patient's anatomy to determine the optimal port placement.

5. 5. The port placement determination device according to claim 3, wherein the required movement of the virtual model of the robot arm includes a movement that avoids interference between the virtual models of the robot arm.

6. the surgical instrument has a longitudinal axis; The port placement determination apparatus of claim 1 , wherein the redundant drive shaft rotates at least a portion of the surgical instrument about the longitudinal axis.

7. the robot arm has a tip end, a base end, a torsion joint disposed at the base end, and a bending joint disposed between the tip end and the base end, The control device Controlling the robot arm to intersect a rotation axis of the bending joint with a reference plane including the longitudinal axis, and fixing an orientation of the rotation axis of the bending joint with respect to the reference plane; A predetermined center point is set, and a reference point is set on a reference line that is an extension line of a rotation axis of the torsion joint or a line that is offset in a direction perpendicular to the extension line, and the robot arm is controlled to position the longitudinal axis at the center point and the reference plane at the reference point; 7. The port arrangement determination device according to claim 6, wherein the direction and amount of movement of the redundant drive shaft are controlled by changing an offset amount of the reference point in a direction perpendicular to the extension line.

8. The surgical robot system further includes an arm base to which the plurality of robot arms are attached, each of the plurality of robot arms includes a base end attached to the arm base, a tip end to which the surgical instrument is attached, and a plurality of links that connect the base end and the tip end and are connected to each other, and the link adjacent to the base end is connected to the base end via a torsion joint; 5. The port arrangement determination device according to claim 1, wherein the control device operates the robot arm such that, when viewed from a direction parallel to an axial direction of the rotation axis of the torsional joint, a first portion of one of the plurality of links, which is located between the link connected to the base end and the link connected to the tip end, is located between a second portion of the base end and a third portion of the tip end.

9. The surgical instrument has an instrument base, a shaft portion extending from the instrument base, and an end effector provided at the tip of the shaft portion, the robot arm has a prismatic joint to which the instrument base is attached, the prismatic joint moving the surgical instrument in the axial direction of the shaft portion; The control device storing a remote center of motion of the surgical instrument; 5. The port placement determination device of claim 1, wherein, when the shaft portion is inserted into a port member inserted into a body wall of a patient and the end effector is inside the patient's body cavity, the length of the surgical instrument from the remote center to the distal end of the surgical instrument within the body cavity is defined as L, the amount of linear displacement parallel to the axial direction from the origin position of the prismatic joint is defined as T0, and the amount of linear displacement parallel to the axial direction from the origin position of the prismatic joint to a current position is defined as T1, and when L≦T0, the relationship between L and T1 is T1≧L.

10. A surgical robot system comprising the port arrangement determination device according to any one of claims 1 to 4.

11. the memory stores a plurality of sets including the optimal port allocation and the constraint conditions corresponding to the optimal port allocation, which are determined in advance by the port allocation determination device; 11. The surgical robot system according to claim 10, wherein the control device selects an optimum set from the plurality of sets stored in the memory according to the content of the required surgery.

12. The surgical robot system according to claim 10 , further comprising a port placement presentation means for presenting information about the optimal port placement determined by the port placement determination device.

13. The surgical robot system according to claim 12 , wherein the port placement presenting means presents the information about the optimal port placement on a body surface of the patient placed on a surgical table.

14. 14. The surgical robot system according to claim 13, further comprising a patient position information acquisition means for acquiring position information of the patient placed on the operating table in a slave side coordinate system that serves as a reference when operating the plurality of robot arms.

15. 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 surgical robot system of claim 10 , wherein the control device controls the plurality of robot arms without the movement of the surgical instrument being affected by the adjustment of at least one of the position and the orientation of the arm base by the positioner control unit.

16. 1. A port placement determination method for determining an optimal port placement of a plurality of port members to be placed in a body wall of a patient in surgery using a surgical robot system, comprising: The surgical robot system includes: a plurality of robotic arms, each of which is equipped with a surgical instrument, each of which has a plurality of drive axes, the number of which is greater than the minimum number of degrees of freedom required to control the position and orientation of the surgical instrument; an operating device that receives an operation input from an operator to control the position and posture of the surgical instrument; a control device that controls the plurality of robot arms based on the operation input, the control device defining at least one of the plurality of drive shafts as a redundant drive shaft, and controlling the redundant drive shaft based on the operation input and a constraint condition related to the redundant drive shaft, storing information about a required surgery to be performed by the operator using the surgical instrument by operating the operating device and information about the constraint conditions in a memory; A port placement determination method in which a processor determines the optimal port placement by searching for the optimal port placement for the required surgery while adjusting the constraint conditions based on information about the required surgery and information about the constraint conditions obtained from the memory.

17. A computer-readable medium storing computer-readable instructions that, when executed by a processor, cause the processor to perform a port placement determination method for determining optimal port placement of a plurality of port members to be placed in a body wall of a patient during surgery using a surgical robotic system; The surgical robot system includes: a plurality of robotic arms, each of which is equipped with a surgical instrument, each of which has a plurality of drive axes, the number of which is greater than the minimum number of degrees of freedom required to control the position and orientation of the surgical instrument; an operating device that receives an operation input from an operator to control the position and posture of the surgical instrument; a control device that controls the plurality of robot arms based on the operation input, the control device defining at least one of the plurality of drive shafts as a redundant drive shaft, and controlling the redundant drive shaft based on the operation input and a constraint condition related to the redundant drive shaft; The port placement determination method includes: storing information about a required surgery to be performed by the operator using the surgical instrument by operating the operating device and information about the constraint conditions in a memory; A computer-readable medium that determines, by the processor, the optimal port placement by searching for the optimal port placement for the required surgery while adjusting the constraints based on information about the required surgery and information about the constraints obtained from the memory.

Images