Surgical instrument unit, force detection device, and surgical support system

Abstract

A surgical instrument unit including an external force detection function is provided. The surgical instrument unit includes a shaft including an end effector at a distal end thereof, a hollow base, and a deformable member supporting a root of the shaft within the base. The strain section includes a first layer of strain elements and a second layer of strain elements composed of multi-directional strain elements, each of the multi-directional strain elements supporting the root of the shaft with a plurality of legs sequentially arranged along a main axis direction of the shaft. The first strain elements are inclined by an amount corresponding to a predetermined angle θ with respect to a plane orthogonal to a long axis of the shaft, and the second strain elements are inclined by an amount corresponding to an angle -θ opposite to the angle of the legs of the first strain elements with respect to the plane.

Description

Technical Field

[0001] The technology disclosed in this specification (hereinafter referred to as "this disclosure") relates to surgical instrument units, force detection devices, and surgical support systems that are applied to, for example, surgical robots and have external force detection capabilities. Background Technology

[0002] In master-slave surgical robots, a technique has been proposed in which external forces acting on the end effector (e.g., external forces received from the affected area on the end of a surgical instrument) are detected and fed back to the operator on the master side to improve safety and operability (e.g., see Patent Document 1). Furthermore, to maintain a small diameter of the surgical instrument (a multi-degree-of-freedom end effector at the tip) while achieving multiple degrees of freedom at the tip, a cable-driven system is effective, in which the driving force of the actuator at the base is transmitted to the output shaft at the tip via multiple cables (lines).

[0003] If a force sensor is mounted on the root side of the cable actuator to sense the force applied to the tip of a surgical instrument, there is a possibility that the inertial force, due to the large weight of the force sensor, will be added as noise to the force sensor's measurement during arm movement. Furthermore, if the force sensor is mounted on the gripper component of the end effector, wires and optical fibers must be installed up to the gripper component. As a result, the range of motion of the tip is easily restricted. For example, if the force can be sensed in the shaft portion of the cable actuator, the above problems can be avoided. However, when strain sensors are simply arranged around the shaft, it is difficult to accurately measure the external force due to interference between the external force and the tension caused by multiple cables.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: WO2018 / 163680 Summary of the Invention

[0007] The problem to be solved by the present invention

[0008] The purpose of this disclosure is to provide a surgical instrument unit, a force detection device, and a surgical support system that are applicable to surgical robots and have external force detection functions that are not affected by cable tension.

[0009] Solution to the problem

[0010] The first aspect of this disclosure is

[0011] A surgical instrument unit, comprising:

[0012] The shaft has an end effector at its tip;

[0013] Hollow base; and

[0014] The strain-generating part is located at the root of the supporting shaft in the base.

[0015] The shaft allows the cable used to drive the end effector to pass through, and the motor for pulling the cable is arranged in the base.

[0016] The strain generating unit has a first layer of strain generating bodies and a second layer of strain generating bodies arranged sequentially along the long axis of the shaft. Each of the first and second layer strain generating bodies includes a multi-directional strain generating body that supports the root of the shaft with multiple legs. The first layer of strain generating bodies is inclined at a predetermined angle θ relative to a plane orthogonal to the long axis of the shaft, and the second layer of strain generating bodies is inclined at an angle -θ opposite to each leg of the first layer of strain generating bodies relative to the plane.

[0017] Furthermore, the second aspect of this disclosure is

[0018] Force detection device, including:

[0019] The strain-generating part supports the shaft in the hollow base, and

[0020] A strain sensor detects strain in the strain generation region.

[0021] Furthermore, the third aspect of this disclosure is:

[0022] Surgical support system, including:

[0023] Surgical instruments and the arm attached to the surgical instruments, wherein,

[0024] The surgical instrument includes: a shaft having an end effector at its tip; a hollow base; and a strain generating portion supporting the root of the shaft within the base.

[0025] However, it should be noted that the term “system” as used herein refers to a logical assembly of multiple devices (or functional modules that implement specific functions), and it is irrelevant whether each device or each functional module is housed in a single enclosure.

[0026] Effects of the present invention

[0027] According to this disclosure, a surgical instrument unit, a force detection device, and a surgical support system may be provided that have the function of detecting external forces by removing interference caused by the traction force of the line driving the end effector.

[0028] It should be noted that the effects described in this specification are merely examples, and the effects of this disclosure are not limited thereto. Furthermore, in addition to the effects described above, this disclosure may further exhibit other effects.

[0029] Other objectives, features, and advantages of this disclosure will become apparent from the more detailed description based on the embodiments and accompanying drawings described below. Attached Figure Description

[0030] Figure 1 This is a diagram showing an example of the external configuration of the surgical support robot 1.

[0031] Figure 2 This is a diagram showing an example of the configuration of a surgical instrument unit.

[0032] Figure 3 This is an enlarged view of the top component 101 of the surgical instrument unit.

[0033] Figure 4 This is an enlarged view of the surgical instrument unit driver 103.

[0034] Figure 5 This is a diagram showing an example of the degree-of-freedom configuration of the surgical instrument unit 100.

[0035] Figure 6 This is a diagram showing a simplified configuration of the surgical instrument unit 100.

[0036] Figure 7 This is a view showing the arrangement of the external force detection system in the surgical instrument unit 700.

[0037] Figure 8 This is a diagram showing a specific structural example of the surgical instrument unit 800.

[0038] Figure 9 This is a cross-sectional perspective view of the connection between the root of shaft 801 and base 803.

[0039] Figure 10 This is a cross-sectional view showing the connection between the root of shaft 801 and base 803.

[0040] Figure 11 This is a diagram showing the structure of a four-directional strain generator.

[0041] Figure 12 This is a cross-sectional view showing the structure of a four-directional strain generator.

[0042] Figure 13 This is a cross-sectional view showing the structure of a four-directional strain-generating body. Figure 12 (A variant example).

[0043] Figure 14 This is a diagram showing the structure of a three-directional strain generator.

[0044] Figure 15This is a diagram showing the structure of a five-directional strain-generating body.

[0045] Figure 16 This is a diagram showing the structure of a four-directional strain generator.

[0046] Figure 17 This is a diagram illustrating an example of the motion of the strain-generating bodies in layers a and b under cable traction mode.

[0047] Figure 18 This is a diagram illustrating an example of the motion of the strain-generating bodies in layers a and b under cable traction mode.

[0048] Figure 19 It shows F z A diagram illustrating examples of the motion of strain-generating bodies in the mode layer and the b layer.

[0049] Figure 20 It shows F z A diagram illustrating examples of the motion of strain-generating bodies in the mode layer and the b layer.

[0050] Figure 21 It shows F Y A diagram illustrating examples of motion of strain-generating bodies in layers a and b under the model.

[0051] Figure 22 It shows F Y A diagram illustrating examples of motion of strain-generating bodies in layers a and b under the model.

[0052] Figure 23 This is a diagram showing the structure of a three-directional strain generator.

[0053] Figure 24 This is a diagram showing the abstract structure of the surgical instrument unit 800.

[0054] Figure 25 It shows the effect on Figure 24 A diagram of the forces in the Y direction of the surgical instrument unit 800 shown.

[0055] Figure 26 It shows the effect on Figure 24 A diagram of the forces in the Z direction of the surgical instrument unit 800 shown.

[0056] Figure 27 This is a diagram illustrating a construction example of a strain generator using a metal plate.

[0057] Figure 28 This is a diagram illustrating an example configuration of a strain generator using a metal plate.

[0058] Figure 29 This is a diagram illustrating an example configuration of a strain generator using a metal plate.

[0059] Figure 30 This is a diagram illustrating an example configuration of a strain generator using a metal plate.

[0060] Figure 31 This is a diagram illustrating an example configuration of a strain generator using a metal plate.

[0061] Figure 32 This illustrates the use of strain generator-a layer 811 and strain generator-b layer 812. Figure 27 The diagram shows a perspective view of the surgical instrument unit 800 of the strain generator.

[0062] Figure 33 It is shown Figure 32 A cross-sectional view of a portion of the base 803 of the surgical instrument unit 800 shown.

[0063] Figure 34 This is a perspective view showing a portion of the base 803 before assembly.

[0064] Figure 35 This is a diagram showing a three-dimensional cross-sectional view of a portion of the base 803 before assembly.

[0065] Figure 36 This is a cross-sectional view showing a portion of the base 803 before assembly.

[0066] Figure 37 This is a perspective view showing a portion of the base 803 after assembly.

[0067] Figure 38 This is a cross-sectional perspective view showing a portion of the base 803 after assembly.

[0068] Figure 39 This is a cross-sectional view showing a portion of the base 803 after assembly. Detailed Implementation

[0069] In the following description, the technology according to this disclosure will be described in the following order with reference to the accompanying drawings.

[0070] A. System Configuration

[0071] B. Configuration of the surgical instrument unit

[0072] C. Layout of the external force detection system

[0073] D. Configuration of the external force detection system

[0074] D-1. Structure of the strain-generating body

[0075] D-2. Strain mode of the strain-generating body set by external force

[0076] D-3 Force Estimation Equation

[0077] E. Installation example of strain generator

[0078] F. Specific structure and assembly method of surgical instrument units

[0079] A. System Configuration

[0080] Figure 1 An example of the external configuration of surgical support robot 1 is shown. Figure 1 The surgical support robot 1 shown includes an arm 12 with a multi-link structure, and a surgical instrument unit 11 is mounted at the end of the arm 12. The surgical instrument unit 11 can be replaced by detaching it from the surgical support robot 1 or the arm 12. The surgical support robot 1 is used, for example, in laparoscopic surgery, and the anterior end of the surgical instrument unit 11 is inserted into the abdominal cavity via a cannula (not shown) to perform actions such as grasping and cutting the affected area.

[0081] Figure 1 The surgical support robot 1 shown can be used as a slave device in, for example, a master-slave system, and drives the arm 12 and surgical instrument unit 11 according to commands from the master device (not shown). Furthermore, the surgical support robot 1 can be moved directly by an operator as an arm including surgical instruments.

[0082] Arm 12 can be a robot with any type of mechanism, such as a polar robot, cylindrical robot, Cartesian robot, vertically articulated robot, horizontally articulated robot, parallel link robot, or RCM (remote center of motion) robot. In cases where the surgical support robot 1 is intended for laparoscopic surgery, from the viewpoint of mechanism compactness and ease of pivoting at the cannula site, a vertically articulated arm or an RCM arm is preferably used as arm 12, wherein a remote center of rotation is arranged at a location away from the drive center of rotation to achieve pivoting (fixed-point) movement.

[0083] Figure 1 An example configuration of surgical support robot 1 that can be attached to only one surgical instrument unit is shown. However, surgical support robot 1 can be a surgical support robot capable of attaching multiple surgical instrument units simultaneously for laparoscopic surgery.

[0084] When the surgical support robot 1 is used as a slave device in a master-slave system, in order for the operator to accurately and efficiently remotely operate the surgical support robot 1, which is a slave device, without damaging the target object, it is desirable to feed back information such as the position of the arm 12 and the external force applied to the surgical instrument unit 11 to the master device.

[0085] B. Configuration of the surgical instrument unit

[0086] Figure 2 An example configuration of a surgical instrument unit applied to a surgical support robot 1 is shown. Figure 2 The surgical instrument unit 100 shown includes a hollow shaft 102 having a longitudinal axis, a surgical instrument unit tip 101 located at one end of the shaft 102, and a surgical instrument unit actuator 103 located at the other end of the shaft 102. The surgical instrument unit tip 101 includes: a wrist member rotatable relative to the shaft 102 about a first axis parallel to the yaw axis; and an end effector that opens and closes at the tip of the wrist member with a second axis parallel to the pitch axis as an opening / closing axis. The end effector includes a pair of opposing clamping members that rotate about the second axis to open and close. However, it should be noted that the second axis is arranged offset from the first axis. Additionally, the surgical instrument unit actuator 103 includes two actuators that drive the clamping members in the surgical instrument unit tip 101 and one actuator that drives the wrist member.

[0087] Figure 3 The tip 101 of the surgical instrument unit is shown in magnified view. Additionally, Figure 4 The surgical instrument unit driver 103 is shown in enlarged view. Additionally, Figure 5 An example of the degree-of-freedom configuration of the surgical instrument unit 100 is shown. Furthermore, Figure 6 A simplified configuration of the surgical instrument unit 100 is depicted.

[0088] The surgical instrument unit tip component 101 includes a wrist component WE and an open / close end effector. The end effector includes a pair of clamping members, a first clamping member J1 and a second clamping member J2, which are opposed to each other (e.g., see...). Figure 3 The wrist component WE is supported near its root so that it is rotatable at the tip (distal end) of shaft 102 about a first axis parallel to the yaw axis. Furthermore, a first clamping member J1 and a second clamping member J2, included in the end effector, are supported so that they are rotatable at the end of the wrist component WE about a second axis parallel to the pitch axis. The first clamping member J1 and the second clamping member J2 open and close by changing the opening angle with the second axis as the opening / closing axis.

[0089] Additionally, the surgical instrument unit driver 103 includes a first motor M1 for driving the first clamp member J1, a second motor M2 for driving the second clamp member J2, and a third motor M3 for driving the wrist member WE (see, for example, see...). Figure 4 and Figure 5 Furthermore, the first to third motor winches MC1, MC2, and MC3, which serve as drive winches, are respectively attached to the output shafts of the first to third motors M1 to M3 (for example, see...). Figure 5Although it is assumed that a rotary motor is used for each of the first to third motors M1 to M3, a motor with a speed reducer can be used.

[0090] The first reciprocating cable groups C1a and C1b are wound around the first motor winch MC1, and the first clamping member J1 is driven by a cable loop method by rotating the first motor winch MC1 with the first motor M1. Furthermore, the second reciprocating cable groups C2a and C2b are wound around the second motor winch MC2, and the second clamping member J2 is driven by a cable loop method by rotating the second motor winch MC2 with the second motor M2.

[0091] refer to Figure 4 and Figure 5 The first motor M1 is supported on a first sliding base SB1 that slides along the longitudinal axis of shaft 102, and the second motor M2 is supported on a second sliding base SB2 that slides along the longitudinal axis of shaft 102. Furthermore, third reciprocating cable assemblies C3a and C3b are wound around the third motor winch MC3 via third idler pulleys P3a and P3b. The other end of the third outward cable C3a is fixed to the first sliding base SB1, and the other end of the third return cable C3b is fixed to the second sliding base SB2. Then, by pulling the third reciprocating cable assemblies C3a and C3b using a cable loop method, the third motor M3 can move the first sliding base SB1 and the second sliding base SB2 forward and backward in opposite directions along the longitudinal axis of shaft 102.

[0092] Reference Figure 3 The first clamping member J1 is supported near its root by the wrist member WE so that it can rotate about the second axis. Similarly, the second clamping member J2 is supported near its root by the wrist member WE so that it can rotate about the second axis. Therefore, the opening and closing of the end effector is achieved by rotating each of the first clamping member J1 and the second clamping member J2 about the second axis, such that the opening angle between the first clamping member J1 and the second clamping member J2 increases or decreases (i.e., such that the angular difference between the first clamping member J1 and the second clamping member J2 about the second axis changes). In addition, the rotation of the end effector including the first clamping member J1 and the second clamping member J2 about the second axis is achieved by simultaneously rotating the first clamping member J1 and the second clamping member J2 about the second axis while keeping the opening angle between the first clamping member J1 and the second clamping member J2 constant (i.e., such that the sum of the angles of the first clamping member J1 and the second clamping member J2 about the second axis changes).

[0093] Reference Figure 3 and Figure 5 A first clamping reel JC1, having a second axis serving as the axis of rotation, is positioned near the root of the first clamping member J1. First reciprocating cable groups C1a and C1b are wound around the first clamping reel JC1. (The text repeats itself here.) Figure 4 and Figure 5 As shown, the first reciprocating cable groups C1a and C1b are wound around the first motor winch MC1 on the surgical instrument unit driver 103 side. Therefore, depending on the rotation direction of the first motor M1, a traction force is applied to one of the cables C1a and C1b, causing the first clamp member J1 to rotate about the second axis. Since the first clamp member J1 is driven by using the loop method of the first reciprocating cable groups C1a and C1b, a wide range of motion of the first clamp member J1 can be achieved.

[0094] In addition, refer to Figure 3 and Figure 5 A second clamping winch JC2, having a second axis serving as its rotation axis, is positioned near the root of the second clamping member J2. Second reciprocating cable groups C2a and C2b are wound around the second clamping winch JC2. (The text repeats itself here.) Figure 4 and Figure 5 As shown, the second reciprocating cable groups C2a and C2b are wound around the second motor winch MC2 on the side of the surgical instrument unit driver 103. Therefore, depending on the rotation direction of the second motor M2, a traction force is applied to one of the cables C2a and C2b, causing the second clamping member J2 to rotate about the second axis. By using the loop method of the second reciprocating cable groups C2a and C2b to drive the second clamping member J2, a wide range of motion of the second clamping member J2 can be achieved.

[0095] Next, the layout of the cables in the surgical instrument unit 100 and the specific operation of the surgical instrument unit tip component 101 will be described.

[0096] The idler pulley is used to change the direction of the first reciprocating cable groups C1a and C1b and the second reciprocating cable groups C2a and C2b near the first axis to allow the cables to pass through the shaft 102, and is also used to adjust the layout of the cables in the shaft 102.

[0097] like Figure 3 and Figure 5 As shown, the first outward cable C1a is pulled in a direction orthogonal to the second axis and redirected to a direction orthogonal to the first axis by a first idler pulley P11a with the first axis of rotation as its axis of rotation. The layout is adjusted such that the first outward cable C1a is inserted into the shaft 102 via a first adjacent idler pulley P12a, which is adjacent to the first idler pulley P11a and has an axis of rotation parallel to the first axis of rotation. Then, the first outward cable C1a is inserted into the shaft 102 and then wound around the first motor winch MC1 via idler pulley P13a, as shown. Figure 4 As shown in the image.

[0098] On the other hand, the first return cable C1b is pulled in a direction orthogonal to the second axis and redirected to a direction orthogonal to the first axis by a first idler pulley P11b having the first axis as its axis of rotation. The arrangement is adjusted such that the first return cable C1b is inserted into the shaft 102 via a first adjacent idler pulley P12b adjacent to the first idler pulley P11b and having an axis of rotation parallel to the first axis. Then, the first return cable C1b is inserted into the shaft 102 and wound around the first motor winch MC1 in the opposite direction to the first outgoing cable C1a via the idler pulley P13b, as shown. Figure 4 As shown in the image.

[0099] In short, the first reciprocating cable groups C1a and C1b are arranged to transmit power between the first clamp winch JC1 and the first motor winch MC1 via a cable loop method. Therefore, as from... Figure 6 As can be seen, by using the first motor M1 to rotate the first motor winch MC1, the first clamp winch JC1 can be rotated to adjust the rotation angle of the first clamp member J1 around the second axis.

[0100] In addition, such as Figure 3 and Figure 5 As shown, the second outward cable C2a is pulled in a direction orthogonal to the second axis and redirected to a direction orthogonal to the first axis via a second idler pulley P21a with the first axis as its rotation axis. The layout is adjusted such that the second outward cable C2a is inserted into the shaft 102 via a second adjacent idler pulley P22a, which is adjacent to the second idler pulley P21a and has a rotation axis parallel to the first axis. Then, the second outward cable C2a is inserted into the shaft 102 and then wound around the second motor winch MC2 via idler pulley P23a.

[0101] On the other hand, the second return cable C2b is pulled in a direction orthogonal to the second axis and redirected to a direction orthogonal to the first axis by a second idler pulley P21b with the first axis as its rotation axis. The arrangement is adjusted such that the second return cable C2b is inserted into the shaft 102 via a second adjacent idler pulley P22b adjacent to the second idler pulley P21b and having a rotation axis parallel to the first axis. Then, the second return cable C2b is inserted into the shaft 102 and then wound around the second motor winch MC2 from the opposite direction of the second outward cable C2a via the idler pulley P23b.

[0102] In short, second reciprocating cable groups C2a and C2b are arranged to transmit power between the second clamp winch JC2 and the second motor winch MC2 via a cable loop method. Therefore, as from... Figure 6 As can be seen, by using the second motor M2 to rotate the second motor winch MC2, the second clamp winch JC2 can be rotated to adjust the rotation angle of the second clamp member J2 around the second axis.

[0103] By controlling the traction force of the first reciprocating cable groups C1a and C1b and the second reciprocating cable groups C2a and C2b by the first motor M1 and the second motor M2, the angular difference between the first clamping member J1 and the second clamping member J2 about the second axis changes, allowing the end effector of the pair of clamping members J1 and J2 to open and close. The opening / closing angle is determined by the angular difference between the first clamping member J1 and the second clamping member J2 about the second axis.

[0104] Furthermore, by controlling the traction force of the first reciprocating cable groups C1a and C1b and the second reciprocating cable groups C2a and C2b by the first motor M1 and the second motor M2, the sum of the angles of the first clamping member J1 and the second clamping member J2 around the second axis changes, thereby causing the end effector to rotate around the second axis. The average value of the angles of the first clamping member J1 and the second clamping member J2 around the second axis is the rotation angle of the end effector around the second axis.

[0105] On the other hand, the first motor M1, together with the first motor winch MC1 and idler pulleys P13a and P13b, is fixed to the first sliding base SB1. Furthermore, the second motor M2, together with the second motor winch MC2 and idler pulleys P23a and P23b, is fixed to the second sliding base SB2. Then, the third outward cable C3a is coupled to the first sliding base SB1 via idler pulley P3a. Furthermore, the third return cable C3b is coupled to the second sliding base SB2 via the third idler pulley P3b.

[0106] It should be noted that the third outward cable C3a in the section from the first sliding base SB1 to the third idler pulley P3a and the third return cable C3b in the section from the second sliding base SB2 to the third idler pulley P3b are ideally arranged parallel to the longitudinal axis of shaft 102.

[0107] In short, the third reciprocating cable assemblies C3a and C3b are arranged to transmit power between the third motor winch MC3 and the first sliding base SB1 and the second sliding base SB2. Therefore, by rotating the third motor winch MC3 by the third motor M3, the first sliding base SB1 and the second sliding base SB2 can move forward and backward in opposite directions along the longitudinal axis of shaft 102.

[0108] Reference Figure 5 and Figure 6The second reciprocating cable groups C2a and C2b are wound around the second idler pulleys P21a and P21b in a direction opposite to the winding direction of the first reciprocating cable groups C1a and C1b around the first idler pulleys P11a and P11b. Therefore, when the first reciprocating cable groups C1a and C1a retract and when the second reciprocating cable groups C2a and C2b retract, a rotational force is applied to the wrist component WE in the opposite direction around the first axis. Therefore, when the first sliding base SB1 advances to the tip (i.e., distal end) of the shaft 102 and the second sliding base SB2 retracts to the root side (i.e., proximal end) of the shaft 102, the first reciprocating cable groups C1a and C1b advance and the second reciprocating cable groups C2a and C2b retract. Therefore, the wrist component WE rotates in the positive direction around the first axis. Conversely, when the first sliding base SB1 retracts and the second sliding base SB2 advances, the first reciprocating cable groups C1a and C1b retract and the second reciprocating cable groups C2a and C2b advance. Therefore, the wrist component WE rotates about the first axis in the negative direction. Here, it is assumed that both the first reciprocating cable groups C1a and C1b and the second reciprocating cable groups C2a and C2b have a constant total length.

[0109] By using the third motor M3 to pull the third reciprocating cable groups C3a and C3b, and by moving the first reciprocating cable groups C1a and C1b and the second reciprocating cable groups C2a and C2b back and forth according to the sliding of the first sliding base SB1 and the second sliding base SB2, the wrist component WE can be rotated around the first axis. Furthermore, when the wrist component WE rotates around the first axis, the pretension of the first reciprocating cable groups C1a and C1b and the second reciprocating cable groups C2a and C2b remains unchanged.

[0110] An overview of the operation of the front end 101 of the treatment device unit is provided.

[0111] Motion of the first axis:

[0112] When the third motor winch MC3 rotates via the third motor M3, traction is generated in either of the third reciprocating cable groups C3a and C3b. As a result, the wrist component WE and the end effector mounted on the wrist component WE can rotate about the first axis in either the forward or reverse direction.

[0113] Motion of the second axis:

[0114] The average of the angles of the first clamping member J1 and the second clamping member J2 around the second axis is defined as the angle of the end effector around the second axis. The end effector rotates around the second axis by rotating the first clamping winch JC1 and the second clamping winch JC2 at the same speed and in the same direction.

[0115] Movement of the end effector:

[0116] The end effector includes a pair of clamping members, a first clamping member J1 and a second clamping member J2, facing each other (see, for example, see...). Figure 3 The opening angle between the first clamping member J1 and the second clamping member J2 is set as the opening / closing angle of the end effector. The end effector is opened and closed by rotating the first motor winch MC1 and the second motor winch MC2 in opposite directions at the same speed.

[0117] Note that for details of the surgical instrument unit 100, refer to Japanese Patent Application No. 2019-166763 (PCT / JP2020 / 031905), which has been assigned to the applicant.

[0118] Furthermore, the terminology will be described. In the surgical instrument unit 100 described above, two types of pulleys are used: "idler pulleys" and "winches." Idler pulleys are "free pulleys" and are used for cable layout adjustments and applying tension to the cables. Winches are used to apply electricity or conversely, to convert force from the cables into axial force.

[0119] Additionally, in the following description, unless otherwise specified, the surgical instrument unit includes a shaft, an end effector (such as forceps) attached to the tip of the shaft, and a base supporting the shaft, which is replaceable by removing the shaft from the base. A cable that applies traction to the end effector, such as forceps, is inserted into the shaft, and a motor that pulls the cable is disposed in the base. The aforementioned sliding base corresponds to the base. The cable may be referred to as an "electrical wire," but is uniformly referred to as "cable" in this specification.

[0120] C. Layout of the external force detection system

[0121] In order to feed back information such as the external forces applied to the surgical instrument unit to the main device, a detection system is needed to detect the external forces applied to the front end of the surgical instrument unit. In addition, it is desirable that the external force detection system has three degrees of freedom (DoF) capable of detecting external forces in at least three directions, including external forces acting in the Z direction, which is the longitudinal direction (or axial direction) of the surgical instrument unit, and external forces acting in the X and Y directions orthogonal to the Z direction.

[0122] Consider a configuration method for an external force detection system that detects external forces applied to a surgical instrument unit. Section B above describes a surgical instrument unit 100 with a total of three degrees of freedom: a first axis that allows the wrist component to rotate about a yaw axis, e.g., relative to the tip of the axis; a second axis that allows the end effector to rotate about a pitch axis, e.g., relative to the wrist component; and a third axis (open / close axis) that allows the clamping member to open and close. The surgical instrument unit 100 described in Section B uses three reciprocating cables and three motors.

[0123] Here, for simplicity, as Figure 7As shown, as an example, a surgical instrument unit 700 is described, which includes a cable 701 for opening and closing a forceps member, and two motors 702 and 703 for pulling the cable 701 outward and return sides.

[0124] Force sensors are used to detect external forces. Typically, a force sensor includes a strain-generating body that is easily torn by external forces, and a strain sensor mounted on the strain-generating body that outputs a signal corresponding to the strain of the strain-generating body. Signal processing is then performed on the output signal of the strain sensor to convert the strain of the strain-generating body into an external force. Figure 7 In the surgical instrument unit 700 shown, the location where this force sensor is installed is roughly divided into three regions: the root side (or proximal side) region 711 located on the part pulled by the cable 701, the middle region 712 where the cable 701 is inserted, and the tip side (or distal side) region 713 located on the cable.

[0125] When the force sensor is installed in the intermediate region 712, not only external forces but also the traction force of the cable 701 (or the torque of the motors 702 and 703) act on it. Therefore, there is a concern that the external force may not be accurately measured due to interference with the traction of the cable 701. On the other hand, the traction force of the cable 701 does not act on either the root-side region 711 or the tip-side region 713. Therefore, if the force sensor is arranged in either the root-side region 711 or the tip-side region 713, the external force can be measured without interfering with the traction of the cable 701.

[0126] However, when the force sensor is installed in the root side region 711, the inertial force caused by the weight of the surgical instrument unit 700 acts on the force sensor, and therefore, it is difficult to accurately measure the external force.

[0127] Furthermore, with the force sensor installed in the tip-side region 713, external forces can be accurately measured without interference from the traction or inertial forces of the cable 701. However, the surgical instrument unit 700 needs to be sterilized each time it is used in surgery, and the force sensor may deteriorate during the sterilization process. Additionally, if the force sensor is installed at the tip, complicating the structure, there is a possibility that contaminants may remain even after cleaning. Moreover, when a force sensor is installed, it is difficult to reduce the size of the tip.

[0128] Therefore, this disclosure proposes arranging a force sensor in the intermediate region 712 of the surgical instrument unit 700 to eliminate interference caused by wire traction. According to this disclosure, the force sensor is arranged on the distal side of the root-side region 711, thus reducing the influence of inertial forces caused by the weight of the surgical instrument unit 700. Furthermore, according to this disclosure, the force sensor is not arranged at the tip of the surgical instrument unit 700. Therefore, problems such as degradation due to sterilization, residual contamination, and miniaturization of the tip can be solved.

[0129] D. Specific configuration examples of external force detection systems

[0130] Figure 8 A specific construction example of a surgical instrument unit 800 in which the external force detection system is contained in the aforementioned "intermediate region" is shown.

[0131] The surgical instrument unit 800 includes a shaft 801, an end effector 802 (e.g., forceps) attached to the tip of the shaft 801, and a base 803 supporting the shaft 801. A cable is provided for applying traction to the end effector 802, such as the forceps. Figure 8 (Not shown in the image) is inserted into shaft 801, and is used for a motor that pulls the cable. Figure 8 (Not shown) is disposed in base 803. Since the specific configuration of the end effector 802, cable drive system and motor arrangement has been described in section B above, its description will be omitted here.

[0132] D-1. Structure of the strain-generating body

[0133] Shaft 801 is supported at its root by base 803. Figure 9 This is a perspective view of the cross-section of the connection between the root of shaft 801 and base 803. Figure 10 A cross-section of the connection between the root of shaft 801 and base 803 is shown. It is assumed that shaft 801 can be removed from base 803 and replaced. Generally, whenever shaft 801 is replaced, the components of end effector 802 are cleaned and disinfected.

[0134] In this disclosure, such as Figures 8 to 10 As shown, the root of shaft 801 is supported by two strain generators 811 and 812. In the following text, strain generator 811 on the tip side is also referred to as "layer a" strain generator, and strain generator 812 on the root side is also referred to as "layer b" strain generator.

[0135] exist Figure 11In the diagram, the base 803 is drawn transparently to visualize strain generators 811 and 812. Each of strain generator-a layer 811 and strain generator-b layer 812 is a "four-directional strain generator" that supports the root of shaft 801 in four directions via four legs extending outward from the root of shaft 801 to the base 803. Figure 11 In the example shown, the legs of the four-directional strain generators have the same shape and size, are arranged at equal intervals (90-degree intervals around the major axis of shaft 801), and support shaft 801 at substantially the center of the hollow cylindrical base 803. Furthermore, it is assumed that the rotational positions of strain generator-a layer 811 and strain generator-b layer 812 about the major axis of shaft 801 are substantially aligned with each other. Strain sensors are then attached to each leg of strain generator-a layer 811 and strain generator-b layer 812, and the strain of each leg is measured when an external force is applied to the end effector 802 at the end of shaft 801. Figure 11 In the process, strain generator-a layer 811 and strain generator-b layer 812 are sprayed with light gray. In addition, the strain sensors of the legs attached to strain generator-a layer 811 and strain generator-b layer 812 are painted dark gray.

[0136] The strain generator is manufactured using materials such as stainless steel (Stainless Steel for Steel: SUS), Co-Cr alloys, or titanium-based materials, which are known as metal-based materials with excellent biocompatibility. From the perspective of medical devices such as surgical instrument units 800, it is preferable to manufacture the strain generator using materials such as titanium alloys that have mechanical properties such as high strength and low stiffness (low Young's modulus).

[0137] In this embodiment, it is assumed that a fiber Bragg grating (FBG) sensor made of optical fiber is used as the strain sensor. Here, the FBG sensor is formed by engraving a diffraction grating (grating) along the long axis of the optical fiber. It can detect changes in the spacing between the diffraction gratings, which are caused by the force of changes in the wavelength of the reflected light relative to the incident light of a predetermined wavelength band (Bragg wavelength) or by strain resulting from expansion or contraction due to temperature changes (as is well known). The wavelength change detected by the FBG sensor can then be converted into strain, stress, or temperature changes as the cause. Of course, it is also conceivable to use other types of strain sensing elements widely known in the art as strain sensors, such as capacitive sensors, semiconductor strain gauges, foil strain gauges, etc. However, considering its advantages such as low transmission loss, sterilization requirements for medical applications, and handling in strong magnetic field environments, the FBG sensor is considered more preferable.

[0138] Figure 12The diagram shows a side view (or YZ section) of a set of strain generators—a layer 811 and b layer 812—in a four-directional strain generator, viewed from a direction orthogonal to the major axis (or Z-axis) of axis 801. Each leg of strain generator a layer 811 in each of the four directions is tilted at a predetermined angle relative to a plane orthogonal to the Z-axis (or Y-axis). Hereinafter, the tilt angle is represented by θ. Furthermore, opposite to strain generator a layer 811, each leg of strain generator b layer 812 in each of the four directions is tilted at an angle -θ relative to a plane orthogonal to the Z-axis (or Y-axis). Therefore, the cross-sections of strain generator a layer 811 and strain generator b layer 812 form a “V” shape, as seen from... Figure 12 As can be seen, for example, θ is approximately three degrees.

[0139] also, Figure 13 The deformation of a set of strain generators 811 and 812 included in a four-directional strain generator is shown. Figure 13 In the example shown, each leg of strain generator-a layer 811 in each of its four directions is tilted at an angle -θ relative to a plane orthogonal to the Z-axis (or Y-axis). Furthermore, in contrast to strain generator-a layer 811, each leg of strain generator-b layer 812 in each of its four directions is tilted at an angle θ relative to a plane orthogonal to the Z-axis (or Y-axis). Therefore, the cross-sections of strain generator-a layer 811 and strain generator-b layer 812 form an inverted "V" shape, as shown from... Figure 13 visible.

[0140] It should be noted that the structures of strain-generating layer-a 811 and strain-generating layer-b 812 are not limited to those shown below. Figure 11 The shaft 801 shown is a "four-direction strain generator" whose root is supported by legs in four directions relative to the base 803. (As shown...) Figure 14 As shown, the base of shaft 801 can be a "three-directional strain generator" 1401 and 1402 that supports the root in three directions relative to base 803 via legs, or as... Figure 15 As shown, the base of shaft 801 can be a "five-directional strain generator" 1501 and 1502 that supports the root in five directions relative to base 803 via legs. Alternatively, although not shown, a multi-directional strain generator that supports the root in six or more directions via legs can be used. However, it should be noted that in the case of a "two-way strain generator" where the root of shaft 801 is supported by legs in two directions, the external force acting on the end of shaft 801 cannot be separated into components in each of the XYZ directions.

[0141] D-2. Strain mode of the strain-generating body set by external force

[0142] Next, the strain mode of the strain-generating body when an external force is applied to shaft 801 will be described. Here, for convenience, we will use... Figure 11 and Figure 12 The “four-directional strain generator” shown in the figure, which supports the root of the shaft 801 in four directions relative to the base 803, is used as an example to describe the strain mode.

[0143] The four legs of strain generator-a layer 811 and strain generator-b layer 812 have the same shape and size, are arranged at equal intervals (90-degree intervals around the major axis of shaft 801), and support shaft 801 at substantially the center of hollow cylindrical base 803. Furthermore, it is assumed that the rotational positions of strain generator-a layer 811 and strain generator-b layer 812 about the major axis of shaft 801 are substantially aligned with each other. Strain sensors are then attached to each leg of strain generator-a layer 811 and strain generator-b layer 812, and the strain of each leg is measured when an external force is applied to the end effector 802 at the tip of shaft 801.

[0144] Here, as Figure 16 As shown, the four legs of the strain-generating body -a layer 811 are represented by a1 to a4, and the four legs of the strain-generating body -b layer 812 are represented by b1 to b4. Furthermore, the strain of the legs a1 to a4 of the strain-generating body -a layer 811 is represented by ε. a1 To ε a4 This indicates that the strain of the legs b1 to b4 of the strain generator-b layer 812 is respectively determined by ε b1 To ε b4 This indicates the strain detected by strain sensors arranged in the outriggers a1 to a4 and b1 to b4. Furthermore, Figure 16 The XYZ coordinates are also shown. The Z-axis coincides with the major axis of axis 801. The X-axis and Y-axis are orthogonal to the Z-axis and are also orthogonal to each other. Although not shown, it is assumed that the external force detection system according to this disclosure includes a signal processing device that processes the detection signals from strain sensors arranged in each of the legs a1 to a4 and b1 to b4. The signal processing device calculates the strain ε of the legs a1 to a4 and b1 to b4. a1 To ε a4 and ε b1 To ε b4 Based on the dependent variable ε a1 To ε a4 and ε b1 To ε b4 The strain mode of the surgical instrument unit 800 was further determined, and the external force F acting on the surgical instrument unit 800 along the XYZ direction was converted. X F Y and F ZThe details of determining the strain mode and calculating the external forces will be described later.

[0145] The strain modes of strain generator-a layer 811 and strain generator-b layer 812 include a "cable traction mode," in which strain is generated when a traction force is applied to the cable; "F Z "Mode", in which an external force in the ±Z direction acts on the tip of shaft 801; and "F Y The "Fx mode" refers to the external force in the ±Y direction acting on the tip of shaft 801, and the "Fx mode" refers to the external force in the ±X direction acting on the tip of shaft 801.

[0146] Note that the cables mentioned here are any one of the first reciprocating cable groups C1a and C1b, the second reciprocating cable groups C2a and C2b, or the third reciprocating cable groups C3a and C3b described in Part B above.

[0147] Figure 17 and Figure 18 An example of motion of strain generator-a layer 811 and strain generator-b layer 812 in cable traction mode is shown. Figure 17 An example of the action when the cable is pulled outwards is shown, and Figure 18 An example of the action is shown when the return side cable is pulled.

[0148] in addition, Figure 19 and Figure 20 The motion examples of strain generator-a layer 811 and strain generator-b layer 812 in Fz mode are shown. Figure 19 An example of motion is shown when a compressive force in the Z direction (or an external force in the -Z direction) acts on the tip of shaft 801, and Figure 20 An example of motion is shown when a traction force in the Z direction (or an external force in the +Z direction) acts on the tip of shaft 801.

[0149] also, Figure 21 and Figure 22 Show F Y Motion instances of strain generator-a layer 811 and strain generator-b layer 812 in the model. Figure 21 An example of motion is shown when an external force in the -Y direction is applied to the tip of shaft 801, and Figure 22 This illustrates an example of motion when an external force in the +Y direction is applied to the tip of shaft 801. Note that F... X The motion of strain-generating bodies -a layer 811 and -b layer 812 in the model Figure 21 and Figure 22 F shown in YThe motion in the pattern is the same when rotating 90 degrees around the Z-axis, so its illustration and description are omitted here.

[0150] Figures 17 to 22 Each of the figures shows a cross-section of the surgical instrument unit 800 when viewed in the X direction. Therefore, legs a1 and a3 of the strain generator-a layer 811 and legs b1 and b3 of the strain generator-b layer 812 are shown. As described above, the strain of legs a1, a3, b1, and b3, measured by strain sensors, is respectively determined by ε a1 ε a3 ε b1 and ε b3 express.

[0151] It should be noted that, Figures 17 to 22 For simplicity, the cable refers to any one of the first reciprocating cable groups C1a and C1b, the second reciprocating cable groups C2a and C2b, and the third reciprocating cable groups C3a and C3b described in Part B above. It should be understood that the following description also applies to each cable group.

[0152] Legs a1 and a3 of strain generator-a layer 811 and legs b1 and b3 of strain generator-b layer 812 contract or extend according to the strain mode of the strain generator. Figures 17 to 22 In each strain mode, the retracted and extended outriggers are distinguished by the difference in shading.

[0153] Reference Figure 17 When the cable is pulled outwards, legs a1 of strain generator-a layer 811 and legs b1 of strain generator-b layer 812 contract, while legs a3 of strain generator-a layer 811 and legs b3 of strain generator-b layer 812 extend. This is because, due to the pulling of the cable outwards, compressive force acts on legs a1 of strain generator-a layer 811 and legs b1 of strain generator-b layer 812, while tensile force acts on legs a3 of strain generator-a layer 811 and legs b3 of strain generator-b layer 812. Furthermore, as... Figure 18 As shown, when the return-side cable is pulled, leg a1 of strain generator-a layer 811 and leg b1 of strain generator-b layer 812 extend, while leg a3 of strain generator-a layer 811 and leg b3 of strain generator-b layer 812 contract. This is because, due to the pulling of the return-side cable, compressive force acts on leg a3 of strain generator-a layer 811 and leg b3 of strain generator-b layer 812, while tension acts on leg a1 of strain generator-a layer 811 and leg b1 of strain generator-b layer 812.

[0154] refer to Figure 19When an external force Fz in the -Z direction is applied to the end of shaft 801 in Fz mode, legs a1 and a3 of strain generator layer-a 811 extend, while legs b1 and b3 of strain generator layer-b 812 contract. This is because when the external force Fz compresses shaft 801, tension acts on legs a1 and a3 (although not shown, legs a2 and a4) of strain generator layer-a 811 on the front end side, while compressive force acts on legs b1 and b3 (although not shown, legs b2 and b4) of strain generator layer-b 812 on the root side. Furthermore, refer to... Figure 20 When an external force Fz in the +Z direction is applied to the end of shaft 801, legs a1 and a3 of strain generator-a layer 811 contract, while legs b1 and b3 of strain generator-b layer 812 extend. This is because when the external force Fz pulling shaft 801 is applied, tension acts on legs b1 and b3 (although not shown, legs b2 and b4) of strain generator-b layer 812 on the root side, and conversely, compressive force acts on legs a1 and a3 (although not shown, legs a2 and a4) of strain generator-a layer 811 on the front end side.

[0155] As described above, the strain-generating body - layer a 811 on the tip side and the strain-generating body - layer b 812 on the root side are tilted relative to each other at angles to the plane orthogonal to the Z-axis. Therefore, as... Figure 19 and Figure 20 As shown, in response to the external force F in the Z-axis direction z The strain generator-a layer 811 on the front end and the strain generator-b layer 812 on the root end exhibit opposite behavior, one contracting and the other stretching.

[0156] Reference Figure 21 When in F Y External force F along the -Y direction in the mode Y When the force F acting on the tip of shaft 801 extends the legs a1 of strain-generating body-a layer 811 and b3 of strain-generating body-b layer 812, and contracts the legs a3 of strain-generating body-a layer 811 and b1 of strain-generating body-b layer 812, this is because when the external force F bends shaft 801 along the -Y direction... Y When in action, a counterclockwise torque is generated in the plane of the attached drawing, about the intermediate point between strain-generating body-a layer 811 and strain-generating body-b layer 812. Furthermore, refer to... Figure 22 When the external force F in the +Y direction Y When the force F acting on the tip of shaft 801 contracts, the legs a1 of strain generator-a layer 811 and b3 of strain generator-b layer 812 contract, while the legs a3 of strain generator-a layer 811 and b1 of strain generator-b layer 812 extend. This is because when the external force F bends shaft 801 along the Y direction...Y When in action, a clockwise torque is generated in the plane of the attached drawing, around the middle of the strain-generating body-a layer 811 and the strain-generating body-b layer 812.

[0157] In conclusion, Figure 17 and Figure 18 In the cable traction mode shown, the extension and retraction directions of the legs of strain generator-a layer 811 and strain generator-b layer 812, which are located at the same position, are consistent with each other, while... Figure 19 and Figure 20 The F shown Z Pattern and Figure 21 and Figure 22 The F shown Y In this mode, the extension and retraction directions of the legs of strain generators - layer a 811 and strain generator - layer b 812, which are located at the same position, are opposite. The cable traction mode is a mode where the external force detection system is interfered with by the traction of the cable (i.e., the torque of the motor). Therefore, when the extension and retraction directions of the legs of strain generators - layer a 811 and strain generator - layer b 812, which are located at the same position, are detected to be consistent, the interference of cable traction can be eliminated by removing the cable traction from the measurement.

[0158] In addition, Figure 19 and 20 The F shown z In this model, the extension and contraction directions of the legs of strain generators in the same layer are consistent, while the extension and contraction directions of the legs of strain generators in different layers are opposite. On the other hand, in Figure 21 and Figure 22 F shown in Y In this mode, the extension and contraction directions of the legs in opposite positions within the same layer are opposite. Therefore, the signal processing device that processes the detection signals from the strain sensor can distinguish F based on the extension and contraction directions of the legs of the strain-generating bodies within and between layers. z Pattern and F Y model.

[0159] Note that F z Pattern and F Y The motion of the strain-generating body in the model was also confirmed through simulation calculations.

[0160] D-3 Force Estimation Equation

[0161] Figure 19 and Figure 20 The F shown z External force F in mode z The estimated equation is the same as equation (1) below.

[0162] [Expression 1]

[0163] FZ =K z ×((ε b1 -ε a1 )+(ε b3 -ε a3 ))…(1)

[0164] also, Figure 21 and Figure 22 F shown in Y External force F in the model Y The estimated equation is the same as that in equation (2) below.

[0165] [Expression 2]

[0166] F Y =K Y ×((ε b1 -ε a1 )-(ε b3 -ε a3 ))…(2)

[0167] However, note that equations (1) and (2) above only consider the strain of the two legs a1 and a3 of the strain-generating body-a layer 811 and the two legs b1 and b3 of the strain-generating body-b layer 812. Figure 16 As shown, in the case of a four-directional strain generator (where the four legs of strain generator-a layer 811 are a1 to a4, and the four legs of strain generator-b layer 812 are b1 to b4), the external force F X F Y and F Z The estimated equations are shown in equations (3) to (5) below. Where, Δ1=ε b1 -ε a1 Δ2=ε b2 -ε a2 Δ3=ε b3 -ε a3 and Δ4=ε b4 -ε a4 .

[0168] [Expression 3]

[0169] F X =K X (Δ4-Δ2)…(3)

[0170] [Expression 4]

[0171] F Y =K Y (Δ3-Δ1)…(4)

[0172] [Expression 5]

[0173] F Z =K Z (Δ1+Δ2+Δ3+Δ4)…(5)

[0174] In addition, such as Figure 23 As shown, in the case of a three-directional strain generator with three legs of strain generator-a layer 811 being a1 to a3 and three legs of strain generator-b layer 812 being b1 to b3, the external force F X F Y and F Z The estimated equations are shown in equations (6) to (8) below. Where, Δ1=ε b1 -ε a1 Δ2=ε b2 -ε a2 And Δ3=ε b3 -ε a3 .

[0175] [Expression 6]

[0176]

[0177] [Expression 7]

[0178]

[0179] [Expression 8]

[0180] F Z =K Z (Δ1+Δ2+Δ3)…(8)

[0181] Next, the derivation of K will be described. Y The method (for a four-directional strain-generating body). Coefficient K. Y This indicates the sensitivity of the strain sensor using strain generator-a layer 811 and strain generator-b layer 812 in the Y direction. Here, as... Figure 24 As shown, the structure of the surgical instrument unit 800 is abstractly illustrated. Figure 24 In this configuration, the distance between strain-generating layer-a 811 and strain-generating layer-b 812 is A, and the distance from the end of axis 801 (or end effector 802) to strain-generating layer-a 811 is B. Furthermore, strain-generating layer-a 811 is tilted at an angle θ relative to a plane orthogonal to the Z-axis (or Y-axis), and strain-generating layer-b 812 is tilted at an angle -θ relative to a plane orthogonal to the Z-axis (or Y-axis).

[0182] Here, as Figure 25 As shown, the tip force acting on the tip of the end effector 802 along the Y direction is defined as F. YThe estimated value of the tip force of the end effector 802 is defined as F. Y_pre The force applied along the Y direction to the strain-generating body -a layer 811 is defined as F. Y1 And the force applied along the Y direction to the strain-generating body -b layer 812 is defined as F. Y2 Furthermore, the thickness of strain generator-a layer 811 and strain generator-b layer 812 is represented by t, the width of strain generator-a layer 811 and strain generator-b layer 812 is represented by w, and the Young's modulus of strain generator-a layer 811 and strain generator-b layer 812 is represented by E.

[0183] Based on the balance of force and torque, the force F applied in the Y direction to the strain-generating body -a layer 811 is... Y1 and the force F applied in the Y direction to the strain-generating body - layer 812 Y2 They are represented by the following equations (9) and (10), respectively.

[0184] [Expression 9]

[0185]

[0186] [Expression 10]

[0187]

[0188] Based on the relationship between force and strain, the strain ε of the legs a1 and a3 of the strain generator layer 811 is shown in the following equations (11) and (12), respectively. a1 and ε a3 And the strain ε of legs b1 and b3 of strain generator layer 812. b1 and ε b3 .

[0189] [Expression 11]

[0190]

[0191] [Expression 12]

[0192]

[0193] Tip force F of end effector 802 Y The estimated value F Y_pre It is represented by the following equation (13).

[0194] [Expression 13]

[0195]

[0196] When the estimated tip force F of the end effector 802 Y_preEqual to the tip force F acting in the Y direction at the tip of the end effector 802 Y When, that is, when F Y_pre =F Y At the time of its establishment, K Y It is represented by the following equation (14).

[0197] [Expression 14]

[0198]

[0199] It should be noted that, although not described, K X It is also expressed by the above equation (14). The coefficient K X This indicates the sensitivity in the X direction of the strain sensor using strain generator-a layer 811 and strain generator-b layer 812.

[0200] Next, the derivation of K will be described. Z The method (for a four-directional strain-generating body). Coefficient K. Z This indicates the sensitivity of the strain sensor using strain generator-a layer 811 and strain generator-b layer 812 in the Z direction. Here, as... Figure 24 As shown, the structure of the surgical instrument unit 800 is abstracted (same as described above). Here, as... Figure 26 As shown, the tip force F acting along the Z direction at the tip of the end effector 802 Z Evenly distributed.

[0201] Based on the relationship between force and strain, the strain ε of the legs a1 and a3 of the strain-generating body - layer 811 is... a1 and ε a3 And the strain ε of legs b1 and b3 of strain generator layer 812. b1 and ε b3 As shown in equation (15) below.

[0202] [Expression 15]

[0203]

[0204] The end force F of the end effector 802 is expressed by the following equation (16). Z The estimated value F Z_pre .

[0205] [Expression 16]

[0206]

[0207] When the estimated tip force F of the end effector 802 Z_pre Equal to the tip force F acting in the Z direction at the tip of the end effector 802Z When, that is, when F Z_pre =F Z At the time of its establishment, K Z It is represented by the following equation (17).

[0208] [Expression 17]

[0209] K Z =(twE)·sinθ…(17)

[0210] Next, K will be described. Y =K Z The conditions for its validity. From equations (14) and (17) above, K Y With K Z The ratio is expressed as the following equation (18).

[0211] [Expression 18]

[0212]

[0213] Therefore, K Y =K Z The condition for this to hold is that the parameters θ, A, and B satisfy the following equation (19).

[0214] [Expression 19]

[0215]

[0216] From equations (14) and (17) above, by forming the cross-sections of strain generating body-a layer 811 and strain generating body-b layer 812 into a “V” shape, it can be deduced that the sensitivity of the strain sensor can be adjusted by the tilt angle θ of strain generating body-a layer 811 and strain generating body-b layer 812. The features of the strain sensor according to this disclosure will now be described.

[0217] (a)K z With K x or K Y The sensitivity balance between the two can be adjusted by changing the tilt angle θ of the strain generator.

[0218] (b)K x and K Y The sensitivity can be adjusted by the ratio of the distance B from the tip of shaft 801 to strain generator-a layer 811 to the distance A between strain generator-a layer 811 and strain generator-b layer 812.

[0219] (c) By setting the distance B from the tip of shaft 801 to strain generator-a layer 811 to an appropriate distance, a cable can be arranged between strain generator-a layer 811 and strain generator-b layer 812.

[0220] (d) Strain generators can be manufactured using sheet metal. Sheet metal offers high thickness accuracy and low cost, and strain generators with desired shapes can be produced through laser processing.

[0221] E. Installation example of strain generator

[0222] Figure 27 Examples of configurations (front view and perspective view) of strain generators that can be used as strain generator-a layer 811 and strain generator-b layer in a surgical instrument unit according to this disclosure are shown. Figure 27 The strain-generating body in the middle has its central axis ( Figure 27 (Not shown) The structure of a four-directional strain generator supported by four legs. This is the result of determining the shape of the strain generator using finite element method (FEM) analysis with optimal sensitivity. (See reference...) Figure 27 The grid shape is formed near the center of each of the four legs and is configured to deform more easily than the other parts of the legs. Then, optical fibers, including those in the FBG sensor, are attached to each of the four legs, and gratings are formed on the optical fibers in the portions that overlap with the grid shape to arrange the FBG sensor.

[0223] Figure 28 Another configuration example (front view and perspective view) of the strain generator that can be used as strain generator-a layer 811 and strain generator-b layer in a surgical instrument unit according to this disclosure is shown. Figure 28 The strain-generating body in the middle has its central axis ( Figure 28 (Not shown) A structure of a four-directional strain generator supported by four legs. Two longitudinally cut openings are formed near the center of each of the four legs and are configured to be more susceptible to strain than the rest of the legs. An optical fiber is then attached between the two openings in each leg, on which a grating is formed to serve as an FBG sensor.

[0224] Figure 29 Another configuration example (front view and perspective view) of strain generators that can be used as strain generator-a layer 811 and strain generator-b layer in a surgical instrument unit according to this disclosure is shown. Figure 29 The strain-generating body in the middle has its central axis ( Figure 29 (Not shown) A structure of a four-directional strain generator supported by four legs. An optical fiber, on which a grating used as an FBG sensor is formed, is attached to each of the four legs.

[0225] Figure 30Another configuration example (front view and perspective view) of strain generators that can be used as strain generator-a layer 811 and strain generator-b layer in a surgical instrument unit according to this disclosure is shown. Figure 30 The strain-generating body in the middle has its central axis ( Figure 30 (Not shown) A structure of a four-directional strain generator supported by four legs. Each of the four legs is thin, with its two ends near the center scraped off, and is configured to be more susceptible to strain than the rest of the legs. Furthermore, optical fibers forming gratings as FBG sensors are mounted in the details of each leg.

[0226] Figure 31 Another configuration example (front view and perspective view) of strain generators that can be used as strain generator-a layer 811 and strain generator-b layer in a surgical instrument unit according to this disclosure is shown. Figure 31 The strain-generating body in the middle has its central axis ( Figure 31 (Not shown) A structure of a four-directional strain generator supported by four legs. A folded structure is formed near the center of each of the four legs and is configured to be more susceptible to strain than the other parts of the legs. An optical fiber, on which a grating for use as an FBG sensor is formed, is then attached to a portion of the folded structure of each leg.

[0227] When metal plates such as SUS are used as materials for strain-generating bodies, they have highly precise thickness t and have, for example, the following conditions are met: Figures 27 to 31 The strain generator of the shape shown can be manufactured at low cost through laser processing.

[0228] F. Specific structure and assembly method of surgical instrument units

[0229] Figure 32 It shows that Figure 27 The diagram shows a perspective view of a surgical instrument unit 800 comprising strain generators for strain generator-a layer 811 and strain generator-b layer 812. Additionally, Figure 33 Show Figure 32 A cross-sectional view of a portion of the base 803 of the surgical instrument unit 800 shown.

[0230] The base 803 is divided into a hollow external motor base and a shaft base. The motor for pulling the cable is attached to the hollow external motor base at its root side (not shown), and the shaft 801 is attached to the center of the shaft base. Then, the shaft base is attached to the motor base via strain generator-a layer 811 and strain generator-b layer 812.

[0231] Figures 34 to 36 A perspective view, a cross-sectional perspective view, and a cross-sectional view of a portion of the base 803 before assembly are shown. Furthermore, Figures 37 to 39A perspective view, a cross-sectional perspective view, and a cross-sectional view of a portion of the base 803 after assembly (or after incorporating the strain generator).

[0232] The motor base is divided into three parts: the front section of the motor base on the tip side; the rear section of the motor base on the root side; and the middle section of the motor base sandwiched between the front and rear sections. Similarly, the shaft base is divided into three parts: the front section of the shaft base on the tip side; the rear section of the shaft base on the root side; and the middle section of the shaft base sandwiched between the front and rear sections.

[0233] During the assembly process, such as from Figure 35 and Figure 36 As can be seen, the middle section of the shaft base is sandwiched near the center of strain generator-a layer 811 and strain generator-b layer 812, and the middle section of the motor base is sandwiched between the outer peripheral edges of strain generator-a layer 811 and strain generator-b layer 812. Furthermore, the outer peripheral edge of strain generator-a layer 811 is sandwiched between the front section and the middle section of the motor base, and the outer peripheral edge of strain generator-b layer 812 is sandwiched between the intermediate section and the rear section of the motor base. The front section, middle section, and rear section of the motor base can be secured, for example, with threaded connections, but other fixing methods can also be used.

[0234] Note that in this state, strain generator-a layer 811 and strain generator-b layer 812, as well as the FBG sensor attached to strain generator-a layer 811 and strain generator-b layer 812, are in their natural length state without applied pretension. Furthermore, as from... Figure 36 It can be seen that, in this state, the cross-sections of strain-generating body-a layer 811 and strain-generating body-b layer 812 are basically parallel and do not form a "V" shape. In addition, the front surface near the center of strain-generating body-a layer 811 and the middle section of the shaft base, and the rear surface near the center of strain-generating body-b layer 812 and the middle section of the shaft base do not contact each other, but are separated from each other.

[0235] Next, as from Figure 38 and Figure 39 It can be seen that the center of strain-generating layer 811 is located between the front and middle sections of the shaft base, and the center of strain-generating layer 812 is located between the middle and rear sections of the shaft base. The front, middle, and rear sections of the shaft base can be secured using screws, but other securing methods may also be used. Although in Figures 37 to 39 The details are omitted, but the shaft 801 of the surgical instrument unit 800 is used by inserting into the tip of the front section of the shaft base.

[0236] like Figure 36 and Figure 39 As shown, the longitudinal dimension of the middle section of the shaft base is smaller than the longitudinal dimension of the middle section of the motor base. Therefore, as... Figures 37 to 39 As shown, when the front portion of the shaft base is attached to the front center of the strain generator-a layer 811 and presses against the front surface of the middle portion of the shaft base, and the rear portion of the shaft base is attached to the rear center of the strain generator-b layer 812 and presses against the rear surface of the middle portion of the shaft base, the cross-sections of the strain generator-a layer 811 and the strain generator-b layer 812 form a "V" shape. In this state, pretension is applied to the strain generator-a layer 811 and the strain generator-b layer 812, as well as to the FBG sensor attached to the strain generator-a layer 811 and the strain generator-b layer 812. When pretension is applied to the strain generator and the FBG sensor, there is an effect that almost no buckling occurs when compressive force is applied.

[0237] Industrial applicability

[0238] The present disclosure has been described in detail above with reference to specific embodiments. However, it is self-evident that those skilled in the art can modify or substitute the embodiments without departing from the spirit of the present disclosure.

[0239] This specification has primarily described embodiments of the present disclosure applied to surgical instruments used in surgical robots, but the scope of this disclosure is not limited thereto. This disclosure can be applied to robots in various fields beyond healthcare, such as precision surgical robots.

[0240] In short, this disclosure has been described by way of example, but should not be construed as limiting. The claims should be considered in order to determine the essence of this disclosure.

[0241] It should be noted that this disclosure can also be configured as follows.

[0242] (1) A surgical instrument unit, comprising:

[0243] The shaft has an end effector at its tip;

[0244] Hollow base; and

[0245] The strain-generating part is located at the root of the supporting shaft in the base.

[0246] (2) The surgical instrument unit according to (1) above, wherein

[0247] The shaft allows the cable used to drive the end effector to pass through, and

[0248] The motor for pulling the cable is located in the base.

[0249] (3) The surgical instrument unit according to (1) or (2) above, wherein

[0250] The strain generating unit includes a first layer of strain generating bodies and a second layer of strain generating bodies arranged sequentially along the long axis of the shaft.

[0251] (4) The surgical instrument unit according to (3) above, wherein

[0252] Each of the first and second layer strain generators is a multi-directional strain generator, which is supported at the root of the shaft by multiple legs from multiple directions relative to the inner wall of the base.

[0253] (5) The surgical instrument unit according to (4) above, wherein

[0254] Each leg of the first strain generator is tilted at a predetermined angle θ relative to a plane orthogonal to the major axis of the axis, and each leg of the second strain generator is tilted at an angle -θ relative to the plane, opposite to that of each leg of the first strain generator.

[0255] (6) The surgical instrument unit according to (5) above, wherein

[0256] The strain sensor is attached to each leg of the first strain generator and the second strain generator.

[0257] (7) The surgical instrument unit according to (6) above, wherein

[0258] Based on the strain of each outrigger, determine the strain mode of the shaft or end effector.

[0259] (8) The surgical instrument unit according to (7) above, wherein

[0260] When the extension and retraction directions of the legs of the first strain generator and the legs of the second strain generator in the same position are consistent, it is determined to be a cable traction mode in which strain occurs due to the traction force of the cable of the traction end actuator.

[0261] (9) The surgical instrument unit according to (7) above, wherein

[0262] When the extension and contraction directions of the feet of the first strain generator are consistent, and the extension and contraction directions of the feet of the second strain generator are consistent, and the extension and contraction directions of the feet of the first strain generator are opposite to those of the feet of the second strain generator, it is determined that the strain is caused by an external force acting on the length direction of the shaft.

[0263] (10) The surgical instrument unit according to (7) above, wherein

[0264] When the extension and retraction directions of the opposing legs in each of the first and second strain generators are opposite, it is determined that the strain is caused by an external force acting in a direction orthogonal to the length direction of the axis.

[0265] (11) The surgical instrument unit according to any one of (6) to (10) above, wherein

[0266] Strain sensors include FBG sensors.

[0267] (12) The surgical instrument unit according to any one of (2) to (11) above, wherein

[0268] The first and second strain generating bodies consist of metal sheets.

[0269] (13) The surgical instrument unit according to any one of (6) to (12) above, wherein

[0270] Pretension is applied to the first strain generator, the second strain generator, and the strain sensor.

[0271] (14) A force detection device, comprising:

[0272] The strain-generating part supports the shaft in the hollow base, and

[0273] A strain sensor detects strain in the strain-generating part.

[0274] (14-2) According to the force detection device described in (14) above, wherein

[0275] The shaft allows the cable used to drive the end effector to pass through, and

[0276] The motor for pulling the cable is located in the base.

[0277] (14-3) According to the force detection device described in (14) or (14-2) above, wherein,

[0278] The strain generating unit includes a first layer of strain generating bodies and a second layer of strain generating bodies arranged sequentially along the long axis of the shaft.

[0279] (14-4) According to the force detection device described in (14-3) above, wherein

[0280] Each of the first and second layer strain generators is a multi-directional strain generator, which is supported at the root of the shaft by multiple legs from multiple directions relative to the inner wall of the base.

[0281] (14-5) According to the force detection device described in (14-4) above, wherein,

[0282] Each leg of the first strain generator is tilted at a predetermined angle θ relative to a plane orthogonal to the major axis of the axis, and each leg of the second strain generator is tilted at an angle -θ relative to the plane, opposite to that of each leg of the first strain generator.

[0283] (14-6) According to the force detection device described in (14-5) above, wherein,

[0284] The strain sensor is attached to each leg of the first strain generator and the second strain generator.

[0285] (14-7) According to the force detection device described in (14-6) above, wherein,

[0286] Based on the strain of each outrigger, determine the strain mode of the shaft or end effector.

[0287] (14-8) According to the force detection device described in (14-7) above, wherein,

[0288] When the extension and retraction directions of the legs of the first strain generator and the legs of the second strain generator, which are in the same position, are consistent with each other, it is determined that the strain is caused by the traction force of the cable of the traction end actuator.

[0289] (14-9) According to the force detection device described in (14-7) above, wherein

[0290] When the extension and contraction directions of the feet of the first strain generator are consistent, and the extension and contraction directions of the feet of the second strain generator are consistent, but the extension and contraction directions of the legs of the first strain generator are opposite to the extension and contraction directions of the feet of the second strain generator, it is determined that the strain is caused by an external force acting on the length direction of the shaft.

[0291] (14-10) According to the force detection device described in (14-7) above, wherein

[0292] When the extension and retraction directions of the opposing legs in each of the first and second strain generators are opposite, it is determined that the strain is caused by an external force acting in a direction orthogonal to the length direction of the axis.

[0293] (14-11) The force detection device according to any one of (14-6) to (14-10) above,

[0294] in,

[0295] Strain sensors include FBG sensors.

[0296] (14-12) The force detection device according to any one of (14-2) to (14-11) above,

[0297] in,

[0298] The first and second strain generating bodies consist of metal sheets.

[0299] (14-13) The force detection device according to any one of (14-6) to (14-12) above,

[0300] in,

[0301] Pretension is applied to the first strain generator, the second strain generator, and the strain sensor.

[0302] (15) A surgical support system, comprising:

[0303] Surgical instruments and the arm attached to the surgical instruments, wherein,

[0304] The surgical instrument includes: a shaft with an end effector at its tip; a hollow base; and a strain-generating part that supports the root of the shaft within the base.

[0305] Symbol Explanation

[0306] 1 Surgical support robot

[0307] 11 Surgical Instrument Unit

[0308] 12 arms

[0309] 100 Surgical Instrument Units

[0310] 101 Surgical Instrument Unit Tip

[0311] 102 shafts

[0312] 103 Surgical Instrument Unit Driver

[0313] 800 surgical instrument units

[0314] 801 axis

[0315] 802 End effector

[0316] 803 base

[0317] 811 Strain-generating body - layer a

[0318] 812 Strain-generating body - layer b

[0319] 1401, 1402 Tri-directional Strain Generator

[0320] 1501, 1502 Five-directional strain generators.

Claims

1. A surgical instrument unit, comprising: A shaft (801) has an end effector at its tip, the shaft allowing a cable for driving the end effector (802) to pass through; Hollow base (803); A motor for pulling the cables (C2a, C2b, 701) is arranged in the base; as well as The strain generating part supports the root of the shaft in the base. The strain generating part includes a first layer of strain generating body (811) and a second layer of strain generating body (812) arranged sequentially in the long axis direction of the shaft (801). Each of the first layer strain generator (811) and the second layer strain generator (812) is a multi-directional strain generator, which supports the root of the shaft relative to the inner wall of the base with multiple legs from multiple directions. Each leg of the first layer strain generator (811) is inclined at a predetermined angle θ relative to a plane orthogonal to the major axis of the axis, and each leg of the second layer strain generator (812) is inclined at an angle -θ opposite to that of the legs of the first layer strain generator relative to the plane. Strain sensors are attached to each leg of the first layer strain generator (811) and the second layer strain generator (812) to determine the strain mode of the shaft or the end effector based on the strain of each leg.

2. The surgical instrument unit according to claim 1, wherein, When the extension and retraction directions of the legs of the first strain generator and the second strain generator, which are in the same position, are consistent with each other, it is determined that the strain is caused by the traction force of the cable pulling the end effector.

3. The surgical instrument unit according to claim 1, wherein, When the extension and retraction directions of the legs of the first strain generator are consistent, and the extension and retraction directions of the legs of the second strain generator are consistent, but the extension and retraction directions of the legs of the first strain generator are opposite to those of the legs of the second strain generator, it is determined that the strain is caused by an external force acting on the length direction of the shaft.

4. The surgical instrument unit according to claim 1, wherein, When the extension and retraction directions of the opposing legs in each of the first and second strain generators are opposite, it is determined that the strain is caused by an external force acting in a direction orthogonal to the length direction of the axis.

5. The surgical instrument unit according to claim 1, wherein, The strain sensor includes a fiber Bragg grating (FBG) sensor.

6. The surgical instrument unit according to claim 1, wherein, The first strain generating body and the second strain generating body both comprise metal sheets.

7. The surgical instrument unit according to claim 1, wherein, Pretension is applied to the first strain generator, the second strain generator, and the strain sensor.

8. A surgical support system, comprising: Surgical instruments and an arm attached to said surgical instruments, wherein, The surgical instrument includes: a shaft having an end effector at its tip, the shaft allowing a cable for driving the end effector to pass through; a hollow base; a motor for pulling the cable, disposed in the base; and a strain generating section supporting the root of the shaft in the base, the strain generating section comprising a first layer of strain generating bodies and a second layer of strain generating bodies arranged sequentially along the long axis of the shaft. Each of the first and second strain generating bodies is a multi-directional strain generating body, which supports the root of the shaft relative to the inner wall of the base with multiple legs from multiple directions. Each leg of the first layer of strain generator is inclined at a predetermined angle θ relative to a plane orthogonal to the major axis of the axis, and each leg of the second layer of strain generator is inclined at an angle -θ opposite to that of the legs of the first layer of strain generator. Strain sensors are attached to each leg of the first layer of strain generator and the second layer of strain generator to determine the strain mode of the shaft or the end effector based on the strain of each leg.

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