Operating force feedback device and method for minimally invasive surgery simulation training instrument

Abstract

The invention discloses an operating force feedback device and method for a minimally invasive surgery simulation training instrument in the technical field of medical auxiliary equipment.The experimental table is provided with a supporting shaft rod, and first rotating platforms are symmetrically arranged on the supporting shaft rod and can rotate around the supporting shaft rod; the second rotating platform is installed on the first rotating platform and can horizontally rotate around the first rotating platform, the minimally invasive surgery instrument penetrates through the second rotating platform and can stretch out and draw back relative to the second rotating platform, and the VR glasses are used for being worn by an operator. By means of the force feedback mechanism, tactile feedback in the operation process can be simulated more truly, and therefore the effect and safety of operation training are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of medical auxiliary equipment, and in particular to an operating force feedback device and method for a minimally invasive surgery simulation training instrument. Background Art

[0002] Minimally invasive surgery is one of the important development directions of modern medicine. Compared with traditional open surgery, minimally invasive surgery significantly shortens the patient's recovery time by reducing trauma, reducing the risk of postoperative infection and the incidence of complications, and is deeply favored by both doctors and patients. However, the operating environment of minimally invasive surgery is usually limited by a narrow field of view and indirect image guidance, which places extremely high demands on the physician's hand-eye coordination, spatial perception, and operating accuracy. Especially for inexperienced physicians, how to master the operating skills of surgical instruments under a limited field of view is one of the main challenges currently facing minimally invasive surgery training.

[0003] As an important means of cultivating doctors' operation skills, the minimally invasive surgery simulation training system can provide trainees with a safe and controllable training environment to avoid harm to patients due to operational errors in real operations. The current simulation training system mainly relies on visual guidance to present surgical scenes and instrument movement trajectories through virtual models. However, relying solely on visual feedback cannot fully simulate the tactile and mechanical interaction characteristics in real surgery, and it is difficult to effectively improve trainees' ability to perceive the interaction between instruments and tissues and their ability to accurately control the operating force.

[0004] The introduction of force feedback technology provides important support for solving this problem. By capturing and feeding back the interaction force between surgical instruments and virtual tissues in real time, the force feedback system allows trainees to perceive the mechanical changes between instruments and tissues in real surgery during simulation training, helping them to master operating skills more intuitively and improve the accuracy and stability of operations. However, the current application of force feedback technology in simulation training still faces many challenges, such as insufficient feedback accuracy, high response delay, and high system complexity, which restricts its promotion and application in surgical simulation training.

[0005] Therefore, designing a high-precision, low-latency and easy-to-operate force feedback method and device for minimally invasive surgery simulation training equipment can provide physicians with a realistic mechanical interaction experience and help trainees improve their minimally invasive surgery skills in a safe and controllable training environment, thereby providing a strong guarantee for the successful implementation of real surgery and the safety of patients. It has important research value and application prospects. Summary of the invention

[0006] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0007] Therefore, the purpose of the present invention is to provide a minimally invasive surgery simulation training instrument operation force feedback device and method, through which the tactile feedback during the operation can be more realistically simulated, thereby improving the effect and safety of surgical training.

[0008] To solve the above technical problems, according to one aspect of the present invention, the present invention provides the following technical solutions: A minimally invasive surgery simulation training instrument operation force feedback device, comprising: A test bench having a supporting shaft; A first rotating platform is symmetrically arranged on the supporting shaft and can rotate around the supporting shaft; A second rotating platform, mounted on the first rotating platform and capable of horizontally rotating around the first rotating platform; A minimally invasive surgical instrument, which passes through the second rotating platform and can be extended and retracted relative to the second rotating platform; VR glasses are worn by the operator to see the virtual surgical environment and to operate the actual minimally invasive surgical instruments to achieve synchronous operation of the virtual instruments, thus completing the simulation training; Among them, a first force feedback device is arranged at the front end of the minimally invasive surgical instrument, and a second force feedback device is arranged at the handle of the minimally invasive surgical instrument.

[0009] As a preferred solution of the minimally invasive surgery simulation training instrument operation force feedback device described in the present invention, wherein the first rotating platform has a built-in first servo motor, and the first servo motor collects the pitch angle change of the minimally invasive surgery instrument and provides corresponding force feedback according to the pitch angle change; The second rotating platform has a second servo motor and a third servo motor built therein, and the second servo motor is used to collect the yaw angle change of the minimally invasive surgical instrument and provide corresponding force feedback according to the yaw angle change; The third servo motor is used to collect depth changes of the minimally invasive surgical instrument and provide corresponding force feedback according to the depth changes; A fourth servo motor is disposed at the front end of the second rotating platform. The fourth servo motor is used to collect changes in the rolling angle of the minimally invasive surgical instrument and provide corresponding force feedback according to the changes in the rolling angle.

[0010] As a preferred solution of the minimally invasive surgery simulation training instrument operation force feedback device described in the present invention, the first force feedback device has a built-in fifth servo motor, and the fifth servo motor is used to simulate the mechanical response of the virtual tissue, calculate the interaction force in real time according to the hardness, friction and elastic properties of the virtual tissue, and convert it into force feedback to provide cutting resistance, friction and puncture force feedback; The second force feedback device has a built-in sixth servo motor. The sixth servo motor provides gripping force feedback, position feedback and fine control force perception based on the force feedback of the first force feedback device, the feedback of the first rotating platform and the second rotating platform, and the control action of the operator, so that the operator can accurately perceive the mechanical properties of the virtual tissue and adjust the force feedback intensity according to actual operation requirements.

[0011] An operation force feedback method of an operation force feedback device of a minimally invasive surgery simulation training instrument, comprising the following steps: S1. Virtual force calculation: The cutting force, friction force and puncture force of virtual tissue are calculated through nonlinear model, and the virtual interaction force is weighted and synthesized; S2. Posture feedback calculation: According to the pitch, yaw, roll angle and depth changes of the minimally invasive surgical instrument collected by the first rotating platform and the second rotating platform, a nonlinear model is used to calculate the posture interaction feedback force with the virtual tissue; S3. Force feedback simulation: The virtual interaction force and posture feedback force are converted into the operator's operating force feedback through the servo motor and nonlinear feedback formula; S4, force feedback control: Using PID control algorithm, the feedback force is adjusted in real time according to the feedback error to ensure the stability and responsiveness of the feedback system; S5, closed loop control: The virtual interaction force, posture feedback force and operation feedback force are integrated and compensated in real time through a closed-loop control system to ensure the synchronization of the operation force and the virtual environment.

[0012] As a preferred solution of the method for operating force feedback of a minimally invasive surgery simulation training device described in the present invention, in step S1, the cutting force calculation formula of the virtual tissue is as follows:

[0013] in, is the cutting stiffness coefficient of the virtual tissue, is the depth of the surgical instrument’s incision, is the nonlinear coefficient in the cutting process, indicating the transition from elasticity to plasticity, is the attenuation coefficient related to the virtual tissue cutting speed and material yield behavior; The friction force calculation formula of the virtual tissue is as follows:

[0014] in, is the dynamic friction coefficient, is the contact normal force, is the relative velocity of the contact point, and is the nonlinear friction adjustment coefficient associated with the contact surface, is the attenuation coefficient related to the contact surface material; The calculation formula of the puncture force of virtual tissue is as follows:

[0015] in, is the puncture stiffness coefficient of the virtual tissue, is the puncture depth, is the critical value of the puncture depth, indicating the nonlinear turning point. is the correlation coefficient of the puncture depth change rate, which describes the dynamic response during the puncture process. is the strain rate exponent of the puncture force; The calculation formula of virtual interaction force is as follows:

[0016] in, is the weight coefficient, satisfying Indicates the contribution of each force.

[0017] As a preferred solution of the method for operating force feedback of a minimally invasive surgery simulation training instrument described in the present invention, in step S2, the first rotating platform measures the pitch angle change value of the minimally invasive surgery instrument through the first servo motor. , calculate the first posture feedback force based on this change , the specific calculation formula is as follows:

[0018] in, is the stiffness coefficient related to the pitch angle change; The second rotating platform measures the yaw angle change of the minimally invasive surgical instrument through the second servo motor, the third servo motor and the fourth servo motor respectively. , Depth Change And the rolling angle Change, and calculate the second posture feedback force based on the change , the specific calculation formula is as follows:

[0019] in, are the stiffness coefficients related to yaw and roll angles, is the stiffness coefficient associated with depth variation.

[0020] As a preferred solution of the method for operating a minimally invasive surgery simulation training device according to the present invention, in step S3, the first force feedback device receives the interaction force from the virtual tissue. The first feedback force is applied by the fifth servo motor Passed to the operator, the specific formula is as follows:

[0021] in, is the virtual force feedback coefficient, is the attenuation factor related to the penetration depth; The second force feedback device receives the interactive force feedback from the first force feedback device and the posture feedback force from the first rotating platform and the second rotating platform, and transmits the second feedback force to the first rotating platform through six servo motors. Passed to the operator, the specific formula is as follows:

[0022] in, is the adjustment factor, which indicates the relative influence of different feedback forces.

[0023] As a preferred solution of the method for operating force feedback of a minimally invasive surgery simulation training device described in the present invention, in step S4, the formula of the PID control algorithm is as follows:

[0024] in, and It is an adaptive parameter of the control system, which is used to automatically adjust the response speed according to the error size.

[0025] As a preferred solution of the operation force feedback method of a minimally invasive surgery simulation training device described in the present invention, in step S5, the closed-loop control formula of the closed-loop control system is:

[0026] in, is the sum of virtual interaction forces, is the sum of the posture feedback forces provided by the rotating platform, is the sum of all force feedbacks, It is a real-time compensation force based on the operator's operating behavior.

[0027] Compared with the prior art, the present invention has the following beneficial effects: 1. The minimally invasive surgery simulation training instrument operation force feedback device and method provided by the present invention realizes highly realistic minimally invasive surgery simulation training. By integrating multiple servo motors and a rotating platform, the device can accurately simulate the pitch, yaw, roll angle and depth changes of minimally invasive surgical instruments in a virtual environment, and provide real-time feedback such as cutting force, friction force and puncture force interacting with virtual tissues, thereby significantly improving the operator's immersion and operation accuracy in simulation training.

[0028] 2. In addition, the present invention further optimizes the calculation and control process of force feedback through nonlinear models and PID control algorithms. This not only ensures the stability and responsiveness of the feedback system, but also achieves precise synchronization of the operating force and the virtual environment through a closed-loop control system, providing operators with a more realistic and accurate minimally invasive surgery simulation training experience, helping them to better cope with various complex situations in actual operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below in combination with the accompanying drawings and detailed embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them: Figure 1 It is a structural schematic diagram of an operation force feedback device of a minimally invasive surgery simulation training instrument of the present invention; Figure 2 The present invention is a flow chart of an operation force feedback method of an operation force feedback device of a minimally invasive surgery simulation training instrument. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0031] The present invention provides a minimally invasive surgery simulation training instrument operation force feedback device, such as Figure 1 As shown, the minimally invasive surgery simulation training instrument operation force feedback device includes two minimally invasive surgery instruments 400, two first rotating platforms 200, two second rotating platforms 300, two first force feedback devices 410, two second force feedback devices 420, a test bench 100 and VR glasses 500.

[0032] The experimental table 100 has a supporting shaft 110 and a first rotating platform 200, which are symmetrically arranged on the supporting shaft 110 and can rotate around the supporting shaft 110, a second rotating platform 300, which is installed on the first rotating platform 200 and can rotate horizontally around the first rotating platform 200, a minimally invasive surgical instrument 400, which passes through the second rotating platform 300 and can be extended and retracted relative to the second rotating platform 300, a first force feedback device 410 is located at the front end of the minimally invasive surgical instrument 400, and a second force feedback device 420 is located at the handle of the minimally invasive surgical instrument 400. After the operator wears the VR glasses 500, he can see the virtual surgical environment and realize the synchronous operation of the virtual instrument by operating the actual minimally invasive surgical instrument 400, thereby completing the simulation training.

[0033] Furthermore, the first rotating platform 200 has a built-in first servo motor, and the first servo motor is used to collect changes in the pitch angle of the minimally invasive surgical instrument 400 and provide corresponding force feedback according to the changes in the pitch angle.

[0034] Furthermore, the second rotating platform 300 has a second servo motor and a third servo motor built therein, and the second servo motor is used to collect the yaw angle change of the minimally invasive surgical instrument 400 and provide corresponding force feedback according to the yaw angle change; The third servo motor is used to collect the depth change of the minimally invasive surgical instrument 400 and provide corresponding force feedback according to the depth change; A fourth servo motor is disposed at the front end of the second rotating platform 300 , and the fourth servo motor is used to collect changes in the rolling angle of the minimally invasive surgical instrument 400 , and provide corresponding force feedback according to the changes in the rolling angle.

[0035] Furthermore, the first force feedback device 410 has a built-in fifth servo motor, which is used to simulate the mechanical response of the virtual tissue, calculate the interaction force in real time according to the hardness, friction and elastic properties of the virtual tissue, and convert it into force feedback to provide cutting resistance, friction and puncture force feedback.

[0036] Furthermore, the second force feedback device 420 has a built-in sixth servo motor, which provides gripping force feedback, position feedback and fine control force perception based on the force feedback of the first force feedback device 410, the feedback of the first rotating platform 200 and the second rotating platform 300, and the control action of the operator, so that the operator can accurately perceive the mechanical properties of the virtual tissue and adjust the force feedback intensity according to actual operation requirements.

[0037] Based on the above-mentioned minimally invasive surgery simulation training instrument operation force feedback device, the present invention provides a minimally invasive surgery simulation training instrument operation force feedback method, the specific steps are as follows: S1. Virtual force calculation: The cutting force, friction force and puncture force of virtual tissue are calculated through nonlinear model, and the virtual interaction force is weighted and synthesized; S2. Posture feedback calculation: According to the pitch, yaw, roll angle and depth changes of the minimally invasive surgical instrument 400 collected by the first rotating platform 200 and the second rotating platform 300, a nonlinear model is used to calculate the posture interaction feedback force with the virtual tissue; S3. Force feedback simulation: The virtual interaction force and posture feedback force are converted into the operator's operating force feedback through the servo motor and nonlinear feedback formula; S4, force feedback control: Using PID control algorithm, the feedback force is adjusted in real time according to the feedback error to ensure the stability and responsiveness of the feedback system; S5, closed loop control: The virtual interaction force, posture feedback force and operation feedback force are integrated and compensated in real time through a closed-loop control system to ensure the synchronization of the operation force and the virtual environment.

[0038] In step S1, virtual force calculation is used to simulate the interaction process between minimally invasive surgical instruments and virtual tissues. These interaction forces include cutting force, friction force, puncture force, etc., which are mainly calculated by the physical properties of virtual tissues (such as elasticity, friction coefficient, hardness, etc.). The calculation formula of the cutting force of virtual tissues is as follows:

[0039] in, is the cutting stiffness coefficient of the virtual tissue, is the depth of the surgical instrument’s incision, is the nonlinear coefficient in the cutting process, indicating the transition from elasticity to plasticity, is the attenuation coefficient related to the virtual tissue cutting speed and material yield behavior; The friction force calculation formula of the virtual tissue is as follows:

[0040] in, is the dynamic friction coefficient, is the contact normal force, is the relative velocity of the contact point, and is the nonlinear friction adjustment coefficient associated with the contact surface, is the attenuation coefficient related to the contact surface material; The calculation formula of the puncture force of virtual tissue is as follows:

[0041] in, is the puncture stiffness coefficient of the virtual tissue, is the puncture depth, is the critical value of the puncture depth, indicating the nonlinear turning point. is the correlation coefficient of the puncture depth change rate, which describes the dynamic response during the puncture process. is the strain rate exponent of the puncture force; The calculation formula of virtual interaction force is as follows:

[0042] in, is the weight coefficient, satisfying Indicates the contribution of each force.

[0043] In step S2, the posture feedback calculation is to calculate the corresponding feedback force through the posture change (including pitch angle, yaw angle, roll angle and depth change) provided by the first rotating platform 200 and the second rotating platform 300. Specifically, the first rotating platform 200 measures the pitch angle change value of the minimally invasive surgical instrument 400 through the first servo motor. , calculate the first posture feedback force based on this change , the specific calculation formula is as follows:

[0044] in, is the stiffness coefficient related to the pitch angle change; The second rotating platform 300 measures the yaw angle change of the minimally invasive surgical instrument 400 through the second servo motor, the third servo motor and the fourth servo motor respectively. , Depth Change And the rolling angle Change, and calculate the second posture feedback force based on the change , the specific calculation formula is as follows:

[0045] in, are the stiffness coefficients related to yaw and roll angles, is the stiffness coefficient associated with depth variation.

[0046] In step S3, the first force feedback device 410 receives the interaction force from the virtual tissue The first feedback force is applied by the fifth servo motor Passed to the operator, the specific formula is as follows:

[0047] in, is the virtual force feedback coefficient, is the attenuation factor related to the penetration depth; The second force feedback device 420 receives the interactive force feedback from the first force feedback device 410 and the posture feedback force from the first rotating platform 200 and the second rotating platform 300, and converts the second feedback force into a second feedback force through six servo motors. Passed to the operator, the specific formula is as follows:

[0048] in, is the adjustment factor, which indicates the relative influence of different feedback forces.

[0049] In step S4, the PID control algorithm is used to adjust the feedback force in real time according to the force feedback error to ensure the stability and response speed of the feedback system. Different from the traditional PID control, this embodiment adopts an adaptive PID control formula based on the force feedback error: in, and It is an adaptive parameter of the control system, which is used to automatically adjust the response speed according to the error size.

[0050] In step S5, the system forms a closed-loop feedback through the operator's operation, virtual force calculation, and real-time adjustment of posture feedback. The closed-loop control formula of the closed-loop control system is:

[0051] in, is the sum of virtual interaction forces, is the sum of the posture feedback forces provided by the rotating platform, is the sum of all force feedbacks, It is a real-time compensation force based on the operator's operating behavior.

[0052] Through the above steps, the present invention can accurately simulate the interaction process between surgical instruments and virtual tissues, and provide the operator with instant and realistic operation force feedback through the rotating platform and the force feedback device, thereby enhancing the practicality and effectiveness of minimally invasive surgery simulation training.

[0053] Although the present invention has been described above with reference to the embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, as long as there is no structural conflict, the various features in the embodiments disclosed in the present invention may be used in combination with each other in any manner, and the fact that these combinations are not exhaustively described in this specification is only for the sake of omitting space and saving resources. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A minimally invasive surgery simulation training instrument operation force feedback device, characterized in that: include: A test bench (100) having a supporting shaft (110); A first rotating platform (200) is symmetrically arranged on the supporting shaft (110) and can rotate around the supporting shaft (110); A second rotating platform (300) is mounted on the first rotating platform (200) and can rotate horizontally around the first rotating platform (200); A minimally invasive surgical instrument (400), which passes through the second rotating platform (300) and can be extended and retracted relative to the second rotating platform (300); VR glasses (500) are worn by an operator. When the operator wears the VR glasses (500), he or she can see the virtual surgical environment and can operate the actual minimally invasive surgical instruments (400) to achieve synchronous operation of the virtual instruments, thereby completing simulation training; Wherein, a first force feedback device (410) is provided at the front end of the minimally invasive surgical instrument (400), and a second force feedback device (420) is provided at the handle of the minimally invasive surgical instrument (400).

2. The minimally invasive surgery simulation training instrument operation force feedback device according to claim 1, characterized in that: The first rotating platform (200) has a built-in first servo motor, the first servo motor collects changes in the pitch angle of the minimally invasive surgical instrument (400) and provides corresponding force feedback according to the changes in the pitch angle; The second rotating platform (300) has a second servo motor and a third servo motor built therein, the second servo motor being used to collect changes in the yaw angle of the minimally invasive surgical instrument (400) and to provide corresponding force feedback according to the changes in the yaw angle; The third servo motor is used to collect depth changes of the minimally invasive surgical instrument (400) and provide corresponding force feedback according to the depth changes; A fourth servo motor is arranged at the front end of the second rotating platform (300), and the fourth servo motor is used to collect changes in the rolling angle of the minimally invasive surgical instrument (400) and provide corresponding force feedback according to the changes in the rolling angle.

3. The minimally invasive surgery simulation training instrument operation force feedback device according to claim 2, characterized in that: The first force feedback device (410) has a built-in fifth servo motor, which is used to simulate the mechanical response of the virtual tissue, calculate the interaction force in real time according to the hardness, friction and elasticity characteristics of the virtual tissue, and convert it into force feedback to provide cutting resistance, friction and puncture force feedback; The second force feedback device (420) has a built-in sixth servo motor, which provides gripping force feedback, position feedback and fine control force perception based on the force feedback of the first force feedback device (410), the feedback of the first rotating platform (200) and the second rotating platform (300) and the control action of the operator, so that the operator can accurately perceive the mechanical properties of the virtual tissue and adjust the force feedback intensity according to actual operation requirements.

4. An operation force feedback method of an operation force feedback device of a minimally invasive surgery simulation training instrument as claimed in any one of claims 1 to 3, characterized in that: Here are the steps: S1. Virtual force calculation: The cutting force, friction force and puncture force of virtual tissue are calculated through nonlinear model, and the virtual interaction force is weighted and synthesized; S2. Posture feedback calculation: According to the pitch, yaw, roll angle and depth changes of the minimally invasive surgical instrument (400) collected by the first rotating platform (200) and the second rotating platform (300), a nonlinear model is used to calculate the posture interaction feedback force with the virtual tissue; S3. Force feedback simulation: The virtual interaction force and posture feedback force are converted into the operator's operating force feedback through the servo motor and nonlinear feedback formula; S4, force feedback control: Using PID control algorithm, the feedback force is adjusted in real time according to the feedback error to ensure the stability and responsiveness of the feedback system; S5, closed loop control: The virtual interaction force, posture feedback force and operation feedback force are integrated and compensated in real time through a closed-loop control system to ensure the synchronization of the operation force and the virtual environment.

5. The method for operating force feedback of a minimally invasive surgery simulation training device according to claim 4, characterized in that: In step S1, the cutting force calculation formula of the virtual tissue is as follows: ； in, is the cutting stiffness coefficient of the virtual tissue, is the depth of the surgical instrument's incision, is the nonlinear coefficient in the cutting process, indicating the transition from elasticity to plasticity, is the attenuation coefficient related to the virtual tissue cutting speed and material yield behavior; The friction force calculation formula of the virtual tissue is as follows: ； in, is the dynamic friction coefficient, is the contact normal force, is the relative velocity of the contact point, and is the nonlinear friction adjustment coefficient associated with the contact surface, is the attenuation coefficient related to the contact surface material; The calculation formula of the puncture force of virtual tissue is as follows: ； in, is the puncture stiffness coefficient of the virtual tissue, is the puncture depth, is the critical value of the puncture depth, indicating the nonlinear turning point. is the correlation coefficient of the puncture depth change rate, which describes the dynamic response during the puncture process. is the strain rate exponent of the puncture force; The calculation formula of virtual interaction force is as follows: ； in, is the weight coefficient, satisfying Indicates the contribution of each force.

6. The method for operating force feedback of a minimally invasive surgery simulation training device according to claim 4, characterized in that: In step S2, the first rotating platform (200) measures the pitch angle change value of the minimally invasive surgical instrument (400) through the first servo motor. , calculate the first posture feedback force based on this change , the specific calculation formula is as follows: ； in, is the stiffness coefficient related to the pitch angle change; The second rotating platform (300) measures the yaw angle change of the minimally invasive surgical instrument (400) respectively through the second servo motor, the third servo motor and the fourth servo motor , Depth Change And the rolling angle Change, and calculate the second posture feedback force based on the change , the specific calculation formula is as follows: ； in, are the stiffness coefficients related to yaw and roll angles, is the stiffness coefficient associated with depth variation.

7. The method for operating force feedback of a minimally invasive surgery simulation training device according to claim 4, characterized in that: In step S3, the first force feedback device (410) receives the interaction force from the virtual tissue The first feedback force is applied by the fifth servo motor Passed to the operator, the specific formula is as follows: ； in, is the virtual force feedback coefficient, is the attenuation factor related to the penetration depth; The second force feedback device (420) receives the interactive force feedback from the first force feedback device (410) and the posture feedback force from the first rotating platform (200) and the second rotating platform (300), and converts the second feedback force into Passed to the operator, the specific formula is as follows: ； in, is the adjustment factor, which indicates the relative influence of different feedback forces.

8. The method for operating force feedback of a minimally invasive surgery simulation training device according to claim 4, characterized in that ,In step S4, the formula of PID control algorithm is as follows: ； in, and It is an adaptive parameter of the control system, which is used to automatically adjust the response speed according to the error size.

9. The method for operating force feedback of a minimally invasive surgery simulation training device according to claim 4, characterized in that: In step S5, the closed-loop control formula of the closed-loop control system is: ； in, is the sum of virtual interaction forces, is the sum of the posture feedback forces provided by the rotating platform, is the sum of all force feedbacks, It is a real-time compensation force based on the operator's operating behavior.

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