Surgical robot and control unit of surgical robot

Abstract

The surgical robot includes a main device unit, a main control unit, a slave device unit, and a slave control unit. The slave control unit is configured to calculate a slave control value for controlling the surgical instrument based on the target state and the state of the surgical instrument, and control the slave device unit based on the slave control value. The target state is the state of the surgical instrument that operates based on the operation received by the main device unit. The main control unit is configured to calculate a main control value for controlling the reaction force based on the state of the surgical instrument, the target state, and the slave control value obtained from the slave control unit, and control the main device unit based on the main control value.

Description

Technical Field

[0001] The present disclosure relates to a master-slave surgical robot. Background Art

[0002] The master-slave surgical robot receives operations from medical practitioners such as doctors (hereinafter referred to as users) at the master device, and uses instruments for surgery such as forceps and scalpels as the slave device. Then, the slave device is controlled in accordance with the operations received at the master device, thereby performing surgery on a patient (hereinafter referred to as the subject). In addition, in the above surgical robot, the following technique is known: through two-way control, the force received by the surgical instrument during the surgery is fed back from the slave device to the master device, thereby performing force feedback to the user (for example, Patent Document 1).

[0003] In the master device and the slave device of the surgical robot that performs the above force feedback, proportional control is performed. Moreover, in order to improve the sensitivity of the force feedback, it is possible to consider increasing the gain of the proportional control of the master device.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent No. 7049069 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] However, for example, when there is slack in the wire for transmitting the driving force to the surgical instrument, there is a gap between the surgical instrument and the driving force transmission mechanism, or the control is delayed, etc., excessively increasing the proportional control gain of the master device may make it difficult to control the surgical instrument. Therefore, there is a limit to the increase in the proportional control gain.

[0009] In one aspect of the present disclosure, it is desired to improve the sensitivity of the force feedback.

[0010] Solutions to the Problems

[0011] One aspect of the present disclosure is a surgical robot, which includes a master device unit, a master control unit, a slave device unit, a slave control unit, and a slave device detection unit. The master device unit is configured to receive operations from a user and apply reaction forces to the user performing the operations. The master control unit is configured to control the master device unit and generate reaction forces. The slave device unit operates surgical instruments. The slave control unit is configured to control the slave device unit and operate the surgical instruments based on a target state, where the target state is the state of the surgical instruments that moves based on the operations received by the master device unit. The slave device detection unit is configured to detect the state of the surgical instruments, where the state of the surgical instruments is the state of the surgical instruments. The slave control unit is configured to calculate a slave control value for controlling the surgical instruments based on the state of the surgical instruments and the target state, and control the slave device unit based on the slave control value. The master control unit is configured to calculate a master control value for controlling the reaction forces based on the state of the surgical instruments, the target state, and the slave control value obtained from the slave control unit, and control the master device unit based on the master control value.

[0012] According to the above configuration, the master control is calculated with reference to the slave control value, and the reaction force on the user is controlled through the master control. As a result, changes in the slave control value can be quickly reflected in the master control value, and the sensitivity of force feedback can be improved.

[0013] In one aspect of the present disclosure, the slave control unit may be configured to calculate the slave control value by performing integration based on the state of the surgical instruments and the target state.

[0014] According to the above configuration, disturbances (in other words, steady-state deviations) in the slave control unit can be suppressed. Therefore, the slave control value can be calculated with higher accuracy.

[0015] In one aspect of the present disclosure, the slave control unit may be configured to calculate the slave control value through proportional control, where the proportional control is performed based on the difference between the state of the surgical instruments and the target state. The master control unit may be configured to calculate the master control value through proportional control, where the proportional control is performed based on the difference between the state of the surgical instruments and the target state. The gain of the proportional control in the master control unit may be greater than the gain of the proportional control in the slave control unit.

[0016] According to the above configuration, the sensitivity of force feedback can be improved.

[0017] In one aspect of the present disclosure, the master control unit may be configured to calculate the master control value through proportional control, where the proportional control is performed based on the difference between the state of the surgical instruments and the target state. The surgical robot may further include a display unit and an acceptance unit. The display unit is configured to display the gain of the proportional control. The acceptance unit is configured to accept an operation for changing the gain of the proportional control.

[0018] According to the above configuration, the sensitivity of force feedback can be adjusted.

[0019] In one aspect of the present disclosure, the slave control unit may be configured to calculate a slave control value through proportional control, where the proportional control is performed based on the difference between the surgical instrument state and the target state. The surgical robot may further include a display unit and an acceptance unit. The display unit is configured to display the gain of the proportional control. The acceptance unit is configured to accept an operation for changing the gain of the proportional control.

[0020] According to the above configuration, customization can be performed so that the surgical instrument can be controlled more appropriately.

[0021] In one aspect of the present disclosure, the slave control unit may be configured to calculate a slave control value by further performing integral control, where the integral control is performed based on the difference between the surgical instrument state and the target state. The display unit may be configured to further display the gain of the integral control. The acceptance unit may be configured to further accept an operation for changing the gain of the integral control.

[0022] According to the above configuration, customization can be performed so that the surgical instrument can be controlled more appropriately.

[0023] One aspect of the present disclosure is a control unit for a surgical robot, which includes a master control unit and a slave control unit. The master control unit is configured to control the master device unit and generate a reaction force, where the master device unit is configured to accept an operation from a user and apply a reaction force to the user who performs the operation. The slave control unit is configured to control the slave device unit based on the target state and operate the surgical instrument, where the target state is the state of the surgical instrument that operates based on the operation accepted by the master device unit, and the slave device unit operates the surgical instrument. In addition, the slave control unit is configured to calculate a slave control value for controlling the surgical instrument based on the surgical instrument state and the target state, and control the slave device unit based on the slave control value, where the surgical instrument state is the state of the surgical instrument detected by the slave device detection unit. The master control unit is configured to calculate a master control value for controlling the reaction force based on the surgical instrument state, the target state, and the slave control value obtained from the slave control unit, and control the master device unit based on the master control value.

[0024] According to the above configuration, the master control is calculated with reference to the slave control value, and the reaction force applied to the user is controlled through the master control. Thus, changes in the slave control value can be quickly reflected in the master control value, and as a result, the sensitivity of force feedback can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is an explanatory diagram of a surgical robot.

[0026] Figure 2 It is a block diagram of a surgical robot.

[0027] Figure 3 It is an explanatory diagram of a master device / slave device modeled by a single-degree-of-freedom system.

[0028] Figure 4 It is a block diagram of an asymmetric side two-way control.

[0029] Figure 5 It is an explanatory diagram of a gain setting screen.

[0030] Explanation of Reference Signs

[0031] 1... Surgical robot: 2... Robot arm; 20... Connection part; 21... Arm part; 22... Joint part;

[0032] 23 - 25... First drive part - Third drive part; 26... Sensor part; 3... Control unit;

[0033] 30... Main control part; 31... Slave control part; 32... Gain adjustment part; 33... Storage device;

[0034] 4... Operating unit; 40... Operating device; 41... Position operating part; 41A... Movable part;

[0035] 41B... Drive part; 42... Grasping operating part; 42A... Movable part; 42B... Drive part;

[0036] 43... Display part; 44... Reception part; 5... Surgical instrument; 50... Grasping part;

[0037] 50A... Sensor part; 51... Opening and closing mechanism; 52... Wrist part; 52A... Sensor part;

[0038] 53... Axis; 54... Adapter; 6... Trocar; 7... Setting screen; 70 - 75... Display area;

[0039] 76... Cursor. Detailed implementation mode

[0040] The implementation modes of the present disclosure will be described below with reference to the accompanying drawings. In addition, the implementation modes of the present disclosure are not limited to the following implementation modes, and various implementation modes can be adopted within the technical scope to which the present disclosure pertains.

[0041] [1. Summary]

[0042] The surgical robot 1 of the present implementation mode includes: two robot arms \alpha having the same configuration, a control unit 3, and an operating unit 4 (refer to Figure 1 , Figure 2 ). In addition, a surgical instrument 5 is mounted on each of the robot arms 2. In addition, the number of the robot arms 2 can be one or three or more.

[0043] It should be noted that in the translation, for the sake of consistency with the original text, the symbol \alpha in the translated text is used to represent the number 2 in the original text where there is a lack of clear indication of the number. You can adjust it according to the actual situation.The surgical robot 1 is configured as a master-slave robot system. The surgical robot 1 operates the robot arm 2 and the surgical instrument 5 (in other words, the slave device) in response to the operation of the operation unit 4 (in other words, the master device) by the user, thereby performing surgery on the subject. In addition, the surgical robot 1 is configured to perform force feedback. As will be described in detail below, the surgical robot 1 is configured to allow the user to perceive the force received by the surgical instrument that moves according to the user's operation via the operation unit 4.

[0044] [2. Surgical Instrument]

[0045] The surgical instrument 5 is configured to insert the front end of the surgical instrument 5 into the body of the subject through a trocar 6 punctured into the abdomen or the like of the subject, and perform a treatment by moving the part provided at the front end in the body (see Figure 1 ). In the present embodiment, as an example, forceps are used as the surgical instrument 5. However, the present disclosure is not limited thereto, and other surgical instruments such as a scalpel may be used instead of forceps.

[0046] The surgical instrument 5 includes a holding portion 50, an opening / closing mechanism 51, a wrist portion 52, a shaft 53, and an adapter 54 (see Figure 1 , Figure 2 ).

[0047] The shaft 53 is an elongated cylindrical portion, and an adapter 54 is provided at an end opposite to the front end of the shaft 53.

[0048] The holding portion 50 is provided at the front end of the shaft 53 and is inserted into the body of the subject through the trocar 6, thereby performing a treatment such as holding the tissue in the body of the subject. The holding portion 50 includes a first portion, a second portion, and an opening / closing mechanism 51, and the opening / closing mechanism 51 is configured to move the first portion and the second portion closer to and farther from each other (hereinafter also referred to as an opening / closing operation). By moving the first portion and the second portion closer to each other, an object is held, and by moving the first portion and the second portion farther from each other, the held object is released.

[0049] In addition, the holding portion 50 further has a sensor portion 50A (see Figure 2 ), and the sensor portion 50A is used to detect the state of the opening / closing operation (hereinafter referred to as the opening / closing state). Specifically, for example, the sensor portion 50A can detect the distance between the first portion and the second portion and / or the angle between the first portion and the second portion as the opening / closing state.

[0050] The wrist portion 52 is provided on the shaft 53 near the grip portion 50. The wrist portion 52 can rotate at at least one position and changes the direction (in other words, the posture) of the grip portion 50 by rotating at this position. In addition, the wrist portion 52 has a sensor portion 52A for detecting the direction of the grip portion 50.

[0051] In addition, the sensor portions 50A and 52A output sensor signals indicating the detection results to the control unit 3.

[0052] A plurality of wire rods are provided inside the cylindrical shaft 53. The plurality of wire rods are used to transmit driving force to the grip portion 50 and the wrist portion 52 to operate the above-mentioned parts.

[0053] [3. Robot arm]

[0054] The robot arm 2 is configured to hold the surgical instrument 5 mounted at its front end in a specified position and change the posture of the robot arm 2 according to the operation of the user, thereby adjusting the position and direction (in other words, the posture) of the surgical instrument 5 (refer to Figure 1 ).

[0055] A connection portion 20 capable of being attached to the adapter 54 of the surgical instrument 5 or detaching from the adapter 54 of the surgical instrument 5 is provided at the front end of the robot arm 2, and the surgical instrument 5 is attached via the connection portion 20. A variety of types of forceps and surgical instruments other than forceps can be attached to the connection portion 20 of the robot arm 2.

[0056] The robot arm 2 is configured as a link mechanism and has a plurality of arm portions 21 and a plurality of joint portions 22 (in other words, joints). The plurality of joint portions 22 are provided at the ends of the arm portions 21 and are used to rotate each arm portion 21. In addition, each arm portion 21 is connected to other arm portions 21 via the joint portion 22.

[0057] In addition, the robot arm 2 is provided with a first drive portion 23 to a third drive portion 25 (refer to Figure 2 ). In addition, the first drive portion 23 to the third drive portion 25 may each have, for example, at least one pneumatic actuator or at least one motor, etc.

[0058] The first drive portion 23 is configured to drive each joint portion 22 according to the operation of the user. The driving force generated by the first drive portion 23 is transmitted to each joint portion 22 via a transmission mechanism including a plurality of wire rods and a plurality of pulleys. By driving each joint portion 22 by the first drive portion 23, each arm portion 21 is displaced, the posture of the robot arm 2 changes, and thus the direction and position of the surgical instrument 5 also change.

[0059] In addition, the second drive unit 24 is configured to drive the wrist portion 52 of the surgical instrument 5 according to the operation of the user, and the driving force generated by the second drive unit 24 is transmitted to the wrist portion 52 via the transmission mechanism. By driving the wrist portion 52 with the second drive unit 24, the direction of the holding portion 50 is changed.

[0060] In addition, the third drive unit 25 is configured to drive the opening / closing mechanism 51 of the surgical instrument 5 according to the operation of the user, and the driving force generated by the third drive unit 25 is transmitted to the opening / closing mechanism 51 via the transmission mechanism. By driving the opening / closing mechanism 51 with the third drive unit 25, the opening / closing state of the holding portion 50 is changed.

[0061] In addition, the robotic arm 2 is provided with a sensor unit 26 for detecting the posture of the robotic arm 2. The sensor unit 26 can, for example, detect the angle by which each joint portion 22 rotates, or can also detect the state of the first drive unit 23 that drives each joint portion 22 (for example, the pressure of compressed air, etc.). In addition, the sensor unit 26 outputs a sensor signal indicating the detection result to the control unit 3.

[0062] [4. Operation Unit]

[0063] The operation unit 4 is configured to receive the operations of the user on the robotic arm 2 and the surgical instrument 5, and the operation unit 4 includes two operation devices 40, a display unit 43, and a reception unit 44 provided corresponding to each robotic arm 2 (refer to Figure 2 ). In addition, each operation device 40 includes a position operation unit 41 and a gripping operation unit 42.

[0064] The position operation unit 41 receives an operation for adjusting the position and direction of the holding portion 50 of the surgical instrument 5 mounted on the robotic arm 2, and the robotic arm 2 corresponds to the operation device 40 on which the position operation unit 41 is provided. That is, in response to the operation on the position operation unit 41, the posture of the robotic arm 2 is changed to adjust the position and direction of the surgical instrument 5, or the wrist portion 52 of the surgical instrument 5 is operated to adjust the direction of the holding portion 50.

[0065] The gripping operation unit 42 receives an operation for causing the holding portion 50 of the surgical instrument 5 mounted on the robotic arm 2 to perform an opening / closing action, and the robotic arm 2 corresponds to the operation device 40 on which the gripping operation unit 42 is provided.

[0066] Then, the operation device 40 outputs an operation signal indicating the content of the operations received by the position operation unit 41 and the gripping operation unit 42 to the control unit 3.

[0067] In addition, as described above, the surgical robot 1 is configured to perform force feedback. Therefore, the surgical instrument 5 operates according to the operation of the user, and thus the surgical instrument 5 receives a force from the subject or the like, and a reaction force corresponding to the force is applied to the user through the position operation unit 41 and the gripping operation unit 42.

[0068] Specifically, the position operation unit 41 and the gripping operation unit 42 each include a movable part 41A, 42A and a drive part 41B, 42B. The drive parts 41B, 42B drive the movable parts 41A, 42A by, for example, a pneumatic actuator or a motor. Moreover, the drive part 41B of the position operation unit 41 displaces the movable part 41A according to a control signal input from the control unit 3, thereby applying a reaction force to the user who is operating the position operation unit 41. Similarly, the drive part 42B of the gripping operation unit 42 displaces the movable part 42A according to a control signal input from the control unit 3, thereby applying a reaction force to the user who is operating the gripping operation unit 42.

[0069] As an example, the display unit 43 is configured as a liquid crystal display, and the display unit 43 operates according to a control signal from the control unit 3 to display, for example, a setting screen, an endoscopic image of the subject, the states of the robotic arm 2 and the surgical instrument 5, or information required to operate the surgical robot 1. In addition, the endoscopic image can be, for example, an image of the inside of the patient's body cavity obtained by an endoscope inserted into the patient's body cavity through another trocar punctured into the patient's abdomen or the like. Further, the endoscope can be held by another robotic arm or an endoscope holding device (not shown).

[0070] The reception unit 44 is a device that receives operations from the user or the like, and has, for example, a keyboard, a mouse, a touch panel, or a foot switch. The reception unit 44 outputs an operation signal indicating the content of the received operation to the control unit 3.

[0071] [5. Control Unit]

[0072] [(1) Overall Configuration]

[0073] The control unit 3 is configured to control each robotic arm 2, surgical instrument 5, and operation unit 4 (see Figure 2 ). The control unit 3 is configured as a computer system including a processor, a ROM (read only memory), a RAM (random access memory), a bus, and an input / output unit, etc. The functions of the control unit 3 are realized by the processor operating according to programs stored in the ROM or RAM. In addition, part or all of the functions realized by the processor can also be realized by hardware such as at least one IC (integrated circuit).

[0074] The control unit 3 includes a main control section 30, a slave control section 31, a gain adjustment section 32, and a storage device 33.

[0075] The storage device 33 is a non-volatile storage medium such as a hard disk or a flash memory, and programs required for the processing of the control unit 3, setting information related to the operation of the surgical robot 1, etc. are stored in the storage device 33.

[0076] On the other hand, the functions of the main control section 30 and the slave control section 31 are realized by the operation of a processor. The main control section 30 is configured to control the operation unit 4, and the slave control section 31 is configured to control each robotic arm 2 and the surgical instrument 5 mounted on each robotic arm 2. In addition, as will be described in detail below, the main control section 30 and the slave control section 31 calculate the driving force τm (in other words, the main control value) of the master device and the driving force τs (in other words, the slave control value) of the slave device by performing main control and slave control.

[0077] In addition, the driving force τm of the master device refers to the driving forces of the position operation section 41 and the holding operation section 42 of each operation device 40 of the operation unit 4, namely the driving sections 41B and 42B. The driving force τs of the slave device refers to the driving forces of the first driving section 23 to the third driving section 25 in each robotic arm 2.

[0078] The main control section 30 outputs control signals to the driving sections 41B and 42B of the position operation section 41 and the holding operation section 42, and controls the driving sections 41B and 42B to operate the movable sections 41A and 42A with the driving force τm respectively, thereby generating reaction forces.

[0079] In addition, the main control section 30 detects the operations performed by the user on the position operation section 41 and the holding operation section 42 based on the operation signals from the operation unit 4. Then, the main control section 30 identifies the target state (in other words, Xm) based on the detected operations, and this target state is the state regarding the current position, direction, and opening / closing action of the holding section 50. In addition, the target state and Xm will be described in detail below.

[0080] On the other hand, the slave control section 31 outputs control signals to the first driving section 23 to the third driving section 25 of the robotic arm 2. Thereby, the slave control section 31 controls the first driving section 23 and the second driving section 24 so that the first driving section 23 and the second driving section 24 operate the plurality of joint sections 22 and the wrist section 52 with the driving force τs. In addition, the slave control section 31 controls the third driving section 25 so that the third driving section 25 operates the opening / closing mechanism 51 with the driving force τs.

[0081] In addition, the control unit 31 identifies the current state of the opening / closing operation of the holding unit 50 based on the sensor signal from the sensor unit 50A provided on the holding unit 50 of the surgical instrument 5 as the surgical instrument state (in other words, Xs). In addition, the control unit 31 identifies the current position and orientation of the holding unit 50 based on the sensor signal from the sensor unit 52A provided on the wrist unit 52 of the surgical instrument 5 and the sensor signal from the sensor unit 26 provided on the robotic arm 2 as the surgical instrument state (in other words, Xs). Additionally, the surgical instrument state and Xs will be described in detail below.

[0082] [(2) Asymmetric bidirectional control]

[0083] The master / slave devices of the present embodiment can be modeled as a single-degree-of-freedom system as shown in Figure 3 At this time, the dynamics of the master device and the slave device are represented by the following mathematical expressions:

[0084] [Mathematical formula 1]

[0085]

[0086] [Mathematical formula 2]

[0087]

[0088] Here, in the control of the position and orientation of the holding unit 50, the position operation unit 41 for operation corresponds to the master device, and the holding unit 50 corresponds to the slave device. In addition, in the control of the opening / closing operation of the holding unit 50, the holding operation unit 42 for operation corresponds to the master device, and the holding unit 50 corresponds to the slave device.

[0089] In addition, Xm represents the state that the slave device should reach (in other words, the target state of the slave device), and this state is determined based on the current state of the master device determined according to the operation from the user. More specifically, the target values of the position and orientation of the holding unit 50 and the target value of the opening / closing state can correspond to the target state. In addition, Mm represents the mass of the master device, Dm represents the viscous friction coefficient of the damper on the master device side, and Fm represents the external force applied to the master device by the user's operation. In addition, as described above, τm represents the driving force when the driving unit operates the movable unit in order to generate a reaction force in the position operation unit 41 and the holding operation unit 42.

[0090] In addition, Xs represents the current state of the slave device (in other words, the state of the surgical instrument). More specifically, the values representing the current position and orientation of the holding part 50, and the value representing the current open / closed state of the holding part 50 correspond to the state of the surgical instrument. In addition, Ms represents the mass of the slave device, Ds represents the viscous friction coefficient of the damper on the slave device side, and Fs represents the external force applied to the slave device by the subject during the operation. In addition, as described above, τs represents the driving force when the first driving unit 23 and the second driving unit 24 operate the joint part 22 and the wrist part 52 to make the position and orientation of the holding part 50 reach the target state. In addition, τs represents the driving force when the third driving unit 25 operates the opening / closing mechanism 51 to make the open / closed state of the holding part 50 reach the target state.

[0091] Moreover, the master control unit 30 and the slave control unit 31 execute asymmetric bidirectional control as shown in the block diagram of Figure 4 . In this control, at the summing point 3A, the difference between Xm and Xs is calculated, and this difference is input to the transfer element 3B. And, based on this difference, the transfer element 3B calculates the driving force τs of the slave device through proportional control and integral control, and outputs this driving force τs to the transfer element 3C and the summing point 3E representing the slave device. The transfer element 3C outputs Xs to the summing point 3A.

[0092] In addition, the difference between Xm and Xs calculated at the summing point 3A is input to the transfer element 3D that performs proportional control. The transfer element 3D calculates τm’ through proportional control based on this difference, and outputs τm’ to the summing point 3E. At the summing point 3E, the driving force τm of the master device is calculated by subtracting the driving force τs of the slave device from τm’, and this driving force τm is output to the transfer element 3F representing the master device. The transfer element 3F outputs Xm to the summing point 3A.

[0093] In addition, the transfer element 3B corresponds to the processing in the slave control unit 31, and performs proportional control with Kps as the gain and integral control with Kis as the gain. In addition, the transfer element 3D and the summing point 3E correspond to the processing in the master control unit 30, and proportional control with -Kpm as the gain is performed at the transfer element 3D.

[0094] That is, the master control unit 30 calculates the driving force τm of the master device based on Xm, Xs, and the driving force τs of the slave device obtained from the slave control unit 31. In addition, the absolute value of -Kpm (hereinafter referred to as |Kpm|) is greater than the absolute value of Kps (hereinafter referred to as |Kps|). More specifically, as an example, |Kpm| can be more than twice and less than three times |Kps|. However, it is not limited thereto, and |Kpm| and |Kps| can be set appropriately. In addition, for example, |Kpm| can be less than |Kps|.

[0095] In addition, the scaled driving force τm can also be input to the transmission element 3F representing the master device. Additionally, scaling means multiplying the driving force τm of the master device by a coefficient having a predetermined value greater than 1. Through the above scaling, a reaction force greater than the force received by the slave device can be applied to the user, enabling the user to appropriately treat or perform precise treatment on minute parts within the subject's body.

[0096] Figure 3 The block diagram is represented by the following mathematical formulas (3) and (4).

[0097] [Mathematical formula 3]

[0098] τ m =(K pm +K ps )(X s -X m )+K is ∫(X s -X m )dt (3)

[0099] [Mathematical formula 4]

[0100] τ s =K ps (X m -x s )+K is ∫(X m -X s )dt (4)

[0101] Here, by substituting the mathematical formulas (3) and (4) into the mathematical formulas (1) and (2) and performing Laplace transform, the following mathematical formula (5) can be obtained.

[0102] [Mathematical formula 5]

[0103]

[0104] Among them, G(s) satisfies the following mathematical formula (6).

[0105] [Mathematical formula 6]

[0106]

[0107] Here, if T and a satisfy the mathematical formulas (7) and (8), then the mathematical formula (9) holds.

[0108] [Mathematical formula 7]

[0109]

[0110] [Mathematical formula 8]

[0111]

[0112] [Mathematical formula 9]

[0113]

[0114] That is to say, as can be seen from the mathematical formula (9), the asymmetric bidirectional control has the characteristic of phase lead compensation. Therefore, by making the gain |Kpm| of the proportional control of the master device higher than the gain |Kps| of the proportional control of the slave device, the gain of G(s) becomes a in the high-frequency region and 1 in the low-frequency region. That is to say, when the external force Fs applied to the slave device changes greatly, such as at the moment when the slave device contacts the object, a multiple of the force will be fed back to the master device, and in the stable state, a force of 1 times will be fed back to the master device. Therefore, the asymmetric bidirectional control is beneficial to achieving the high-precision following performance and high-sensitivity force feedback of the slave device through integral control.

[0115] [(3) Variant examples of master control / slave control]

[0116] As shown in the mathematical formulas (10) and (11), the inertial force and the viscous force can be compensated by using acceleration and velocity respectively in the mathematical formulas (3) and (4).

[0117] [Mathematical formula 10]

[0118]

[0119] [Mathematical formula 11]

[0120]

[0121] From the mathematical formula (10) and the mathematical formula (11), the mathematical formula (12) can be obtained.

[0122] [Mathematical formula 12]

[0123] F m (s) = G(s)F s (12)

[0124] As can be seen from the mathematical formula (12), the dynamic influence in the master device and the slave device can be suppressed by adding compensation as shown in the mathematical formula (10) and the mathematical formula (11).

[0125] In addition, in the slave control unit 31, the driving force τs of the slave device is calculated by proportional control and integral control. However, instead of integral control, the driving force τs of the slave device can also be calculated by a disturbance observer.

[0126] In addition, in the asymmetric bidirectional control, the main control unit 30 calculates the driving force τm of the master device by subtracting the driving force τs of the slave device from τm’ output from the transmission element 3D. However, the calculation method of τm is not limited to this and can be determined appropriately. Specifically, for example, τs’ can be calculated by performing a prescribed operation based on the driving force τs of the slave device, and τm can be calculated by subtracting τs’ from τm’. Additionally, the prescribed operation means that, for example, a prescribed coefficient can be multiplied by or added to τs. Furthermore, for example, τm can be calculated by multiplying τm’ by τs (or τs’), dividing τm’ by τs’ (or τs’), or adding τs’ (or τs’) to τm’.

[0127] In addition, in the transmission element 3B, integral control and a disturbance observer may not be used to calculate τs. Additionally, in the transmission elements 3B and 3D, τs or τm’ can be further calculated by performing differential control respectively.

[0128] [(4) Adjustment of Gain]

[0129] The function of the gain adjustment unit 32 is implemented by the operation of the processor of the control unit 3 (refer to Figure 2 ). The gain adjustment unit 32 adjusts the gains of the proportional control and the integral control in the asymmetric bidirectional control in accordance with the operations from users, etc. accepted by the acceptance unit 44.

[0130] That is, in the storage device 33, the gain Kpm of the proportional control in the main control unit 30, the gain Kps of the proportional control in the slave control unit 31, and the gain Kis of the integral control are stored corresponding to each robot arm 2. Then, for example, when the surgical robot 1 is started, etc., the control unit 3 reads the Kpm, Kps, and Kis corresponding to each robot arm 2 from the storage device 33, and then performs the above-mentioned bidirectional control using the read Kpm, Kps, and Kis.

[0131] In addition, when the gain adjustment unit 32 accepts an operation signal indicating gain adjustment from the acceptance unit 44, it outputs a control signal to the display unit 43 and displays a gain setting screen 7 on the display unit 43 (refer to Figure 5 ). The gain setting screen 7 is set corresponding to each robot arm 2 and is used to adjust the gains in the bidirectional control of the corresponding robot arm 2. In accordance with the operation signal input from the acceptance unit 44, the gain adjustment unit 32 outputs a control signal to the display unit 43 to switch the gain setting screen 7 displayed on the display unit 43 to the gain setting screen 7 corresponding to a different robot arm 2.

[0132] The gain setting screen 7 has display areas 70, 71, and 72. Among them, the display areas 70 and 71 display the gain of the proportional control and the gain of the integral control of the device in the control of the position and direction of the holding part 50, and the display area 72 displays the gain of the proportional control of the master device. In addition, the gain setting screen 7 of the gain also has display areas 73, 74, and 75. Among them, the display areas 73 and 74 display the gain of the proportional control and the gain of the integral control of the slave device in the control of the opening and closing state of the holding part 50, and the display area 75 displays the gain of the proportional control of the master device. The gain adjustment unit 32 outputs a control signal to the display unit 43 and causes the above display areas 70 to 75 to display the current value of the gain in the corresponding proportional control or integral control.

[0133] In addition, on the gain setting screen 7, a cursor 76 is superimposed and displayed on any one of the display areas 70 to 75. The gain adjustment unit 32 selects any one of the display areas 70 to 75 according to the operation signal input from the reception unit 44 and outputs a control signal to the display unit 43 to superimpose and display the cursor 76 on the selected display area. In addition, the gain adjustment unit 32 accepts the change of the gain value displayed in the selected display area according to the operation signal input from the reception unit 44, and displays the changed gain value in the display area by outputting a control signal to the display unit 43.

[0134] Then, when an operation signal indicating the determination of the gain value is input from the reception unit 44, the gain adjustment unit 32 updates the gain value of the proportional control or the integral control corresponding to the display areas 70 to 75 to the gain value displayed in the display area. Thereafter, the updated gain value is used in the bidirectional control. In addition, the gain adjustment unit 32 stores the updated respective gain values in the storage device 33.

[0135] [6. Effects]

[0136] (1) In the bidirectional control of the prior art, a symmetric or force feedback method of proportional control and integral control is widely used. Moreover, in order to improve the control accuracy, in the case of using pliers as surgical instruments, even when a large external force (for example, an external force of about 5 to 20 N) is applied to the tip of the pliers, it is necessary to suppress the error to the minimum. For this purpose, it is necessary to increase the proportional control gain in the control of the slave device. However, as described above, there is a limit to the increase of the proportional control gain. Therefore, it is necessary to use a method using integration such as integral control or disturbance observer to control the slave device, but introducing such a method may cause a delay in force feedback.

[0137] In this regard, in the asymmetric two-way control of the present embodiment, τs is calculated in the slave control unit 31 by proportional control and integral control. Therefore, the disturbance in the slave control unit 31 can be well suppressed, and the accuracy of τs can be improved. In addition, the master control unit 30 calculates τm based on τs obtained from the slave control unit 31, and controls the reaction force generated in the position operation unit 41 and the grip operation unit 42 as the master device by τm. Therefore, the sensitivity of the force feedback can be improved. That is, in the present embodiment, even if the slave device is controlled by using the integral method, the delay of the force feedback can be suppressed.

[0138] (2) In addition, the gain |Kpm| of the proportional control of the master device is greater than the gain |Kps| of the proportional control of the slave device. Therefore, the sensitivity of the force feedback can be improved.

[0139] (3) In addition, in the gain adjustment unit 32, each gain in the two-way control corresponding to each robot arm is adjusted according to the operation received via the reception unit 44. Therefore, the sensitivity of the force feedback can be adjusted, and customization can be performed so that the surgical instrument can be controlled more appropriately.

[0140] [7. Other Embodiments]

[0141] A plurality of functions of one component in the above embodiment can be realized by a plurality of components, or one function of one component can be realized by a plurality of components. In addition, a plurality of functions of a plurality of components can be realized by one component, or one function of a plurality of components can be realized by one component. In addition, a part of the configuration of the above embodiment can be omitted. In addition, at least a part of the configuration of the above embodiment can be added to the configuration of the above other embodiments, or at least a part of the configuration of the above embodiment can be replaced with the configuration of the above other embodiments, etc.

[0142] [8. Correspondence of Terms]

[0143] The position operation unit 41 and the grip operation unit 42 of the operation device 40 correspond to an example of the master device unit. In addition, the first drive unit 23 to the third drive unit 25 of the robot arm 2 correspond to an example of the slave device unit, and the sensor unit 26 of the robot arm 2 and the sensor units 50A and 52A of the surgical instrument correspond to an example of the slave device detection unit.

[0144] [9. Technical Idea Disclosed in this Specification]

[0145] [Item 1]

[0146] A surgical robot, characterized by comprising:

[0147] A main device unit, which is configured to receive an operation from a user and apply a reaction force to the user who performs the operation;

[0148] A main control unit, which is configured to control the main device unit and generate the reaction force;

[0149] A slave device unit, which operates a surgical instrument;

[0150] A slave control unit, which is configured to control the slave device unit based on a target state and operate the surgical instrument, wherein the target state is the state of the surgical instrument that operates based on the operation received by the main device unit; and

[0151] A slave device detection unit, which is configured to detect the state of the surgical instrument, wherein the state of the surgical instrument is the state of the surgical instrument, and

[0152] the slave control unit is configured to calculate a slave control value for controlling the surgical instrument based on the state of the surgical instrument and the target state, and control the slave device unit based on the slave control value,

[0153] the main control unit is configured to calculate a main control value for controlling the reaction force based on the state of the surgical instrument, the target state, and the slave control value obtained from the slave control unit, and control the main device unit based on the main control value.

[0154] [Item 2]

[0155] The surgical robot according to Item 1, characterized in that

[0156] the slave control unit is configured to calculate the slave control value by performing integration based on the state of the surgical instrument and the target state.

[0157] [Item 3]

[0158] The surgical robot according to Item 1 or 2, characterized in that

[0159] the slave control unit is configured to calculate the slave control value by proportional control, wherein the proportional control is performed based on the difference between the state of the surgical instrument and the target state,

[0160] the main control unit is configured to calculate the main control value by proportional control, wherein the proportional control is performed based on the difference between the state of the surgical instrument and the target state,

[0161] the gain of the proportional control in the main control unit is greater than the gain of the proportional control in the slave control unit.

[0162] [Project 4]

[0163] The surgical robot according to any one of Items 1 to 3, characterized in that

[0164] The main control unit is configured to calculate the main control value by proportional control, wherein the proportional control is performed based on the difference between the surgical instrument state and the target state.

[0165] And the surgical robot further comprises:

[0166] A display unit configured to display the gain of the proportional control; and

[0167] An acceptance unit configured to accept an operation for changing the gain of the proportional control.

[0168] [Project 5]

[0169] The surgical robot according to any one of Items 1 to 4, characterized in that

[0170] The slave control unit is configured to calculate the slave control value by proportional control, wherein the proportional control is performed based on the difference between the surgical instrument state and the target state.

[0171] And the surgical robot further comprises:

[0172] A display unit configured to display the gain of the proportional control; and

[0173] An acceptance unit configured to accept an operation for changing the gain of the proportional control.

[0174] [Project 6]

[0175] The surgical robot according to Item 5, characterized in that

[0176] The slave control unit is configured to calculate the slave control value by further performing integral control, wherein the integral control is performed based on the difference between the surgical instrument state and the target state.

[0177] A display unit configured to further display the gain of the integral control; and

[0178] An acceptance unit configured to further accept an operation for changing the gain of the integral control.

[0179] [Project 7]

[0180] A control unit of a surgical robot, characterized by comprising:

[0181] A main control unit configured to control a main device unit and generate a reaction force, where the main device unit is configured to receive an operation from a user and apply the reaction force to the user who performs the operation; and

[0182] A slave control unit configured to control a slave device unit and operate a surgical instrument based on a target state, where the target state is the state of the surgical instrument that operates based on the operation received by the main device unit, the slave device unit operates the surgical instrument, and

[0183] the slave control unit is configured to calculate a slave control value for controlling the surgical instrument based on the surgical instrument state and the target state, and control the slave device unit based on the slave control value, where the surgical instrument state is the state of the surgical instrument detected by a slave device detection unit,

[0184] the main control unit is configured to calculate a main control value for controlling the reaction force based on the surgical instrument state, the target state, and the slave control value obtained from the slave control unit, and control the main device unit based on the main control value.

Claims

1. A surgical robot, characterized in that, Comprising: A main device unit configured to receive an operation from a user and apply a reaction force to the user who performs the operation; A main control unit configured to control the main device unit and generate the reaction force; A slave device unit that operates a surgical instrument; A slave control unit configured to control the slave device unit based on a target state and operate the surgical instrument, where the target state is the state of the surgical instrument that operates based on the operation received by the main device unit; and A slave device detection unit configured to detect the state of the surgical instrument, where the state of the surgical instrument is the state of the surgical instrument, and The slave control unit is configured to calculate a slave control value for controlling the surgical instrument based on the difference between the state of the surgical instrument and the target state, and control the slave device unit based on the slave control value, The main control unit is configured to calculate an intermediate value through proportional control based on the difference between the state of the surgical instrument and the target state, calculate a main control value for controlling the reaction force by performing an operation using the intermediate value and the slave control value obtained from the slave control unit, and control the main device unit based on the main control value.

2. The surgical robot according to claim 1, wherein The slave control unit is configured to calculate the slave control value by performing integration based on the state of the surgical instrument and the target state.

3. The surgical robot according to claim 1 or 2, wherein The slave control unit is configured to calculate the slave control value through proportional control, where the proportional control is performed based on the difference between the state of the surgical instrument and the target state, The main control unit is configured to calculate the main control value through proportional control, where the proportional control is performed based on the difference between the state of the surgical instrument and the target state, The gain of the proportional control in the main control unit is greater than the gain of the proportional control in the slave control unit.

4. The surgical robot according to claim 1 or 2, wherein The main control unit is configured to calculate the main control value through proportional control, where the proportional control is performed based on the difference between the state of the surgical instrument and the target state, And the surgical robot further comprises: A display unit configured to display the gain of the proportional control; and A reception unit configured to receive an operation for changing the gain of the proportional control.

5. The surgical robot according to claim 1 or 2, wherein The slave control unit is configured to calculate the slave control value through proportional control, where the proportional control is performed based on the difference between the state of the surgical instrument and the target state, And the surgical robot further comprises: A display unit configured to display the gain of the proportional control; and A reception unit configured to receive an operation for changing the gain of the proportional control.

6. The surgical robot according to claim 5, wherein The slave control unit is configured to calculate the slave control value by also performing integral control, where the integral control is performed based on the difference between the surgical instrument state and the target state. The display unit is configured to also display the gain of the integral control. The reception unit is configured to also receive an operation for changing the gain of the integral control.

7. A control unit of a surgical robot, characterized in that, It includes: A main control unit configured to control a main device unit and generate a reaction force, where the main device unit is configured to receive an operation from a user and apply the reaction force to the user who performs the operation; and A slave control unit configured to control a slave device unit based on a target state and operate a surgical instrument, where the target state is the state of the surgical instrument that operates based on the operation received by the main device unit, the slave device unit operates the surgical instrument, and The slave control unit is configured to calculate a slave control value for controlling the surgical instrument based on the difference between the surgical instrument state and the target state, and control the slave device unit based on the slave control value, where the surgical instrument state is the state of the surgical instrument detected by a slave device detection unit. The main control unit is configured to calculate an intermediate value by proportional control based on the difference between the surgical instrument state and the target state, calculate a main control value for controlling the reaction force by using the intermediate value and performing an operation on the slave control value obtained from the slave control unit, and control the main device unit based on the main control value.

Images