Surgical instrument rollback control method, readable storage medium and surgical robot system

Abstract

The invention provides a surgical instrument rollback control method, a readable storage medium and a surgical robot system.The surgical instrument rollback control method comprises the steps that key point discretization is conducted according to the form of a surgical instrument before rollback, and a spline line is obtained through reconstruction according to the discretized key points; when the surgical instrument is in a form in a rollback process, constructing a cost function based on the distance between each key point and the spline line; the instruction speed of the elbow and wrist joint meeting the requirement that the derivative of the cost function to the time is minimum is found out; integrating the instruction speed to obtain an instruction position of the elbow and wrist joint, and controlling the surgical instrument to return based on the instruction speed and the instruction position. By means of the configuration, the surgical instrument roughly follows a path formed according to the form of the surgical instrument before the surgical instrument returns, the possibility of collision generated when the surgical instrument returns can be effectively reduced, the surrounding environment does not need to be perceived, and additional image support is not needed.

Description

Technical Field

[0001] The present invention relates to the technical field of medical instruments, and in particular to a surgical instrument retraction control method, a readable storage medium and a surgical robot system. Background Art

[0002] Currently, in single-arm single-port surgery, multiple surgical instruments are inserted into the patient's body in parallel through the poking card, and the single-port surgery is achieved by bending the elbow and wrist joints of the surgical instruments. When the instrument withdrawal command is issued, the surgical instrument needs to return to the zero position (i.e., the straight state) before it can be withdrawn. The application of traditional surgical robot exit planning strategies may cause the surgical instrument to injure tissue or damage the surgical instrument in the process of returning to the zero position. In addition, the surgical instruments may collide with each other in the process of returning to the zero position. Summary of the invention

[0003] The object of the present invention is to provide a surgical instrument retraction control method, a readable storage medium and a surgical robot system to solve the problem that existing surgical instruments are prone to collide with tissues or collide with each other when retracting.

[0004] In order to solve the above technical problems, the present invention provides a surgical instrument retraction control method, which comprises: discretizing key points according to the shape of the surgical instrument before retraction, and reconstructing splines according to the discretized key points;

[0005] When the surgical instrument is in a state of retreating, constructing a cost function based on the distance between each of the key points and the spline;

[0006] Finding the command speed of the elbow-wrist joint when the derivative of the cost function with respect to time is minimized;

[0007] The command speed is integrated to obtain the command position of the elbow-wrist joint, and the surgical instrument is controlled to retract based on the command speed and the command position.

[0008] Optionally, the cost function includes a weight of each of the key points, and the weight of each of the key points is set according to a mode type; the mode type is set based on a terminal type of the surgical instrument.

[0009] Optionally, the mode types include terminal optimization mode and global optimization mode;

[0010] When the mode type is the terminal optimization mode, the weight of the key point located at the far end is not less than the weight of the key point located at the near end;

[0011] When the mode type is the global optimization mode, the weights of all the key points are the same.

[0012] Optionally, after obtaining the command position of the elbow-wrist joint, the surgical instrument retraction control method further includes:

[0013] filtering the command speed and the command position;

[0014] Evaluate the filtered cost function, and if the cost function exceeds a preset threshold, feedback abnormal information and stop controlling the surgical instrument to retract;

[0015] If the cost function is within the preset threshold, the surgical instrument is controlled to retract according to the filtered command speed and the command position.

[0016] In order to solve the above technical problem, the present invention also provides a readable storage medium, on which a program is stored, and when the program is executed, the steps of the surgical instrument retraction control method as described above are implemented.

[0017] In order to solve the above technical problems, the present invention further provides a surgical robot system, characterized in that it includes a driving module and an elbow-wrist joint optimization module; the elbow-wrist joint optimization module includes a cost optimization module;

[0018] The cost optimization module is configured to: discretize key points according to the shape of the surgical instrument before retreating, and reconstruct a spline according to the discretized key points; when the surgical instrument is in the shape of retreating, construct a cost function based on the distance between each key point and the spline; find the command speed of the elbow-wrist joint when the derivative of the cost function with respect to time is minimized; integrate the command speed to obtain the command position of the elbow-wrist joint;

[0019] The drive module controls the surgical instrument to retract based on the command speed and the command position.

[0020] Optionally, the elbow-wrist joint optimization module also includes a mode selection module, which is used to select a mode type and configure different weights for each key point in the cost function according to the selected mode type.

[0021] Optionally, the mode types include terminal optimization mode and global optimization mode;

[0022] When the mode type is the terminal optimization mode, the weight of the key point located at the far end is not less than the weight of the key point located at the near end;

[0023] When the mode type is the global optimization mode, the weights of all the key points are the same.

[0024] Optionally, the elbow-wrist joint optimization module further includes an optimization verification module, and the optimization verification module is configured to filter the instruction speed and the instruction position after the cost optimization module obtains the instruction position of the elbow-wrist joint; and evaluate the filtered cost function;

[0025] If the cost function exceeds the preset threshold, the optimization verification module feeds back abnormal information, and the driving module stops controlling the retraction of the surgical instrument; if the cost function is within the preset threshold, the driving module controls the retraction of the surgical instrument according to the command speed and the command position filtered by the optimization verification module.

[0026] Optionally, the surgical robot system further includes an instrument withdrawal trigger module and a telescopic joint planning module;

[0027] The exit trigger module is used to trigger the elbow-wrist joint optimization module and the telescopic joint planning module;

[0028] The telescopic joint planning module is used to plan the joint trajectory of the position and speed of the telescopic joint.

[0029] In summary, in the surgical instrument retraction control method, readable storage medium and surgical robot system provided by the present invention, the surgical instrument retraction control method includes: discretizing key points according to the shape of the surgical instrument before retraction, and reconstructing spline lines according to the discretized key points; when the surgical instrument is in the shape of the retraction process, constructing a cost function based on the distance between each key point and the spline line; finding the command speed of the elbow and wrist joint that satisfies the minimum value of the derivative of the cost function with respect to time; integrating the command speed to obtain the command position of the elbow and wrist joint, and controlling the retraction of the surgical instrument based on the command speed and the command position.

[0030] With such a configuration, the surgical instrument roughly follows the path formed by its shape before retreating when retreating, which can effectively reduce the possibility of collision when the surgical instrument retreats, and does not require perception of the surrounding environment and does not require additional image support. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Those skilled in the art will appreciate that the accompanying drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

[0032] Figure 1 is a schematic diagram of a surgical robot according to an embodiment of the present invention;

[0033] Figure 2 is a schematic diagram of an end instrument assembly according to an embodiment of the present invention;

[0034] Figure 3 is a schematic diagram of a retraction collision of an end instrument assembly according to an embodiment of the present invention;

[0035] Figure 4 is a schematic diagram of the surgical instrument retracting according to an embodiment of the present invention;

[0036] Figure 5a to Figure 5c is a schematic diagram of the rollback optimization of the elbow and wrist joint according to an embodiment of the present invention;

[0037] Figure 6 is a schematic diagram of a surgical instrument according to an embodiment of the present invention retreating along an optimized trajectory;

[0038] Figure 7 Schematic diagram of the construction principle of the cost function of an embodiment of the present invention;

[0039] Figure 8 is a schematic diagram of integrating the command speed to obtain the command position according to an embodiment of the present invention;

[0040] Fig. 9 It is a schematic diagram of the path planning of the telescopic joint according to an embodiment of the present invention. DETAILED DESCRIPTION

[0041] In order to make the purpose, advantages and features of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In addition, the structure shown in the drawings is often a part of the actual structure. In particular, the emphasis of each drawing is different, and sometimes different scales are used.

[0042] The terms "proximal end" and "distal end" are defined herein relative to a surgical instrument having an end for intervention with the human body and an end extending outside the body and connected to a robotic arm. The term "proximal end" refers to the end of the surgical instrument that is closer to the body, and the term "distal end" refers to the end of the surgical instrument that is closer to the body. Optionally, in manual or hand-operated applications, the terms "proximal end" and "distal end" are defined herein relative to an operator such as a surgeon or clinician. The term "proximal end" refers to a position closer to the operator, and the term "distal end" refers to a position closer to the surgical instrument and therefore farther away from the operator.

[0043] The purpose of the present invention is to provide a surgical instrument retraction control method, a readable storage medium and a surgical robot system to solve the problem that the existing surgical instruments are prone to collide with tissues or collide with each other when retracting.

[0044] Please refer to Figure 1, which exemplarily shows a surgical robot system, which includes a doctor's console 10 and a patient-side trolley 20, which are configured as a master-slave control relationship, that is, the doctor's console 10 is the master end, and the patient-side trolley 20 is the slave end. The operation of the doctor's console 10 can be mapped to the patient-side trolley 20, thereby realizing master-slave remote operation to perform surgery. Further, the patient-side trolley 20 includes a mechanical arm 21 and a terminal instrument assembly 22 mounted on the mechanical arm 21.

[0045] like Figure 1 The surgical robot system shown is a single-port surgical robot system, and the end instrument assembly 22 performs the surgical operation only through a puncture hole opened on the patient's body surface. Figure 2 , which shows an end instrument assembly 22 mounted on a robotic arm 21, the end instrument assembly 22 specifically includes a puncture card 23 and a plurality of surgical instruments 24, the puncture card 23 is used to puncture a puncture hole on the patient's body surface, and has a through inner hole, and the distal end of the surgical instrument 24 extends into the patient's body through the inner hole of the puncture card 23. The surgical instrument 24 includes an endoscope and an execution instrument (such as arc shears, grasping forceps, etc.).

[0046] Please refer to Figure 2 and Figure 3 The surgical instrument 24 is generally deployed in a snake-like posture after being inserted into the patient's body through the inner hole of the puncture card 23. Optionally, the surgical instrument 24 includes an elbow-wrist joint 242 and a telescopic joint 241. During the operation, the telescopic joint 241 is used to adjust the forward and backward movement of the surgical instrument 24 as a whole, and the elbow-wrist joint 242 is used to adjust the end position and instrument posture of the surgical instrument 24.

[0047] Please refer to Figure 4 In some application scenarios, for example, after completing tissue freeing, it is necessary to replace the passive instrument with an active instrument to perform electrocuting and electrocoagulation operations. At this time, the surgical instrument 24 needs to be retracted to the uppermost position close to the poking card 23 to facilitate the removal of the surgical instrument 24. Figure 4 The middle dotted line shows the state of the surgical instrument 24 before retreating. Figure 3 Since the surgical instrument 24 is generally deployed in a snake-like posture in the patient's body, when it retreats ( Figure 3 When moving in the direction of the arrow, it is easy to collide with other surgical instruments 24 or tissues in the patient's body.

[0048] Based on this, an embodiment of the present invention provides a surgical instrument retraction control method, which includes:

[0049] Step S1: Discretize the key points 31 according to the shape of the surgical instrument 24 before retreating, and reconstruct the spline 32 according to the discretized key points 31. Figure 5a and Figure 5b The key points 31 are arranged discretely along the axial direction of the surgical instrument 24, and the key points 31 are fixed to the surgical instrument 24. The key points 31 move with the movement of the surgical instrument 24. When the surgical instrument 24 receives the retraction instruction, the coordinate values ​​of each key point 31 at the current moment are recorded, such as Figure 5a Then, based on the coordinate values ​​of each key point 31 at this moment, the spline line 32 in space can be reconstructed through spatial spline interpolation, as shown in Figure 5b It can be understood that if the surgical instrument 24 is retracted along the spline 32, the collision between the surgical instrument 24 and the surrounding tissue or other surgical instruments 24 can be effectively reduced.

[0050] Step S2: When the surgical instrument 24 is in the state of retreating, a cost function is constructed based on the distance between each key point and the spline. Figure 5c As shown, in order to make the shape of the surgical instrument 24 during the retraction process as much as possible within the contour range of the shape before the retraction, a response evaluation index can be achieved by constructing a cost function to evaluate the difference in the contour range between the shape during the retraction process and the shape before the retraction. The cost function can be constructed and calculated by the distance between each key point 31 and the spline 32 during the retraction process.

[0051] Step S3: Find the command speed of the elbow-wrist joint 242 when the derivative of the cost function with respect to time is minimized. After the cost function is defined, in order to optimize the cost function and meet the requirements of real-time control, this can be achieved by finding the command speed of the elbow-wrist joint 242.

[0052] Step S4: Integrate the command speed to obtain the command position of the elbow-wrist joint 242, and control the surgical instrument 24 to retract based on the command speed and the command position. In practice, the command speed of the elbow-wrist joint 242 found at each moment during the retraction process of the surgical instrument 24 is integrated to obtain the command position of the elbow-wrist joint 242.

[0053] Please refer to Figure 6 Steps S1 to S4 are to optimize the retraction motion trajectory of the elbow-wrist joint 242. Each control step of the elbow-wrist joint 242 executes the motion according to the command speed and command position optimized by the aforementioned steps S1 to S4. The surgical instrument 24 can roughly follow the path formed by its shape before retraction when retracting, which can effectively reduce the possibility of collision when the surgical instrument 24 retracts, and does not require perception of the surrounding environment and does not require additional image support.

[0054] The following is a further explanation of the specific steps of constructing the cost function in step S2 and finding the command speed of the elbow-wrist joint 242 in step S3 in conjunction with the accompanying drawings and an example.

[0055] Please refer to Figure 7 , assuming that the number of key points 31 is N, and the serial numbers of the key points 31 from the far end to the near end are arranged from small to large, then the cost function can be defined as:

[0056]

[0057] In the formula, dist(A,spline b ) represents point A to spline b The shortest distance, such as Figure 7 q is the generalized coordinate vector of the joints of the surgical instrument 24 (including the telescopic joint 241 and the elbow-wrist joint 242); spline is the spline 32; P i represents the coordinates of the i-th key point 31; w i is the weight of the i-th key point 31 in the cost function (which is a fixed-valued scalar).

[0058] It should be noted that the cost function shown here is only an example and not a limitation on the construction method of the cost function. Those skilled in the art can construct different cost functions according to the existing technology and actual needs.

[0059] Find the command speed of elbow wrist joint 242 It can be transformed into solving the following mathematical problem: Given the current position q of the telescopic joint 241 1 ,speed and the current position q of the elbow-wrist joint 242 ew， Search Make

[0060]

[0061]

[0062]

[0063] in, is the derivative of the cost function with respect to time, f constriant is the constraint vector of the surgical instrument 24 (e.g., instrument joint angle limit), is the maximum speed allowed by the elbow-wrist joint 242.

[0064] It should be noted that this embodiment is to find The specific method is not limited, for example, the common algorithms in the field such as "gradient method", "steepest descent method" or "genetic algorithm" can be used.

[0065] Furthermore, the command speed of the elbow-wrist joint 242 found by the surgical instrument 24 at each moment during the retraction process is By integrating, the command position of the elbow-wrist joint 242 can be obtained, such as Figure 8 shown.

[0066] Optionally, the cost function includes a weight w of each of the key points 31 , and the weight w of each of the key points 31 is set according to a mode type; and the mode type is set based on a terminal type of the surgical instrument 24 .

[0067] The surgical instrument 24 includes many different types, and in particular, the distal end (i.e., the tip) of the surgical instrument 24 has different harmfulness, and the focus of the backoff control optimization is also different for surgical instruments 24 with different harmfulness. Optionally, the mode type includes a tip optimization mode and a global optimization mode.

[0068] If the distal end of the surgical instrument 24 is harmful (such as arc shears and other instruments), which may cause harm to the human body, the terminal optimization mode is adopted, and the weight w of the key point 31 at the distal end is not less than the weight w of the key point 31 at the proximal end. Therefore, for i=1,2,…,N-1, w i ≥w i+1 ,and For example, we can take w 1 =1, and the weights of the other key points 31 are all set to 0. In the terminal optimization mode, the focus of the retraction control optimization is the trajectory of the distal end (i.e., the distal end) of the surgical instrument 24, so as to ensure that the recovery trajectory of the harmful distal part does not exceed the contour range of the surgical instrument 24 before retraction.

[0069] If the distal end of the surgical instrument 24 is not harmful or is relatively less harmful (such as grasping forceps, endoscopes, etc.), the global optimization mode is adopted, and the weights w of all the key points 31 are the same. i =1 / N, i=1, 2, ..., N. In the global optimization mode, the focus of the retraction control optimization is the overall configuration of the instrument, so as to make the overall configuration not exceed the contour range of the shape of the surgical instrument 24 before retraction as much as possible.

[0070] Optionally, after obtaining the command position of the elbow-wrist joint 242, the surgical instrument retraction control method further includes:

[0071] Step S5: filtering the command speed and the command position;

[0072] Step S6: Evaluate the filtered cost function. If the cost function exceeds a preset threshold, feedback abnormal information and stop controlling the surgical instrument 24 to retreat.

[0073] If the cost function is within the preset threshold, the surgical instrument 24 is controlled to retract according to the filtered command speed and the command position.

[0074] Steps S5 and S6 filter and smooth the optimization results of steps S1 to S4, and verify the results after filtering and smoothing. For each control step, the command speed and command position are filtered, and the filtered cost function is re-evaluated. The preset threshold here can be set according to the needs. If the filtered cost function exceeds the preset threshold, it means that the optimization is abnormal. At this time, the movement of the telescopic joint 241 and the elbow-wrist joint 242 can be stopped, and the control of the surgical instrument 24 to retreat can be stopped. The filter can be further reset, and the operator can be prompted by images, force, sound, etc. that the path optimization has failed, so that the operator can re-optimize or manually perform the retreat operation.

[0075] Based on the surgical instrument retraction control method as described above, an embodiment of the present invention further provides a surgical robot system, which includes a driving module and an elbow-wrist joint optimization module; the elbow-wrist joint optimization module includes a cost optimization module;

[0076] The cost optimization module is configured as follows: discretizing the key points 31 according to the shape of the surgical instrument 24 before retraction, and reconstructing the spline 32 according to the discretized key points 31; constructing a cost function based on the distance between each key point 31 and the spline 32 when the surgical instrument 24 is in the shape of retraction; finding the command speed of the elbow-wrist joint 242 that satisfies the minimum value of the derivative of the cost function with respect to time; integrating the command speed to obtain the command position of the elbow-wrist joint 242; and the driving module controls the retraction of the surgical instrument 24 based on the command speed and the command position.

[0077] Optionally, the elbow and wrist joint optimization module further includes a mode selection module, which is used to select a mode type and configure different weights for each of the key points 31 in the cost function according to the selected mode type. Further, the mode type includes a terminal optimization mode and a global optimization mode; when the mode type is the terminal optimization mode, the weight of the key point 31 at the far end is not less than the weight of the key point 31 at the near end; when the mode type is the global optimization mode, the weights of all the key points 31 are the same.

[0078] Optionally, the elbow-wrist joint optimization module also includes an optimization verification module, which is configured to filter the instruction speed and the instruction position after the cost optimization module obtains the instruction position of the elbow-wrist joint 242; evaluate the cost function after filtering; if the cost function exceeds a preset threshold, the optimization verification module feeds back abnormal information, and the drive module stops controlling the surgical instrument 24 to retract; if the cost function is within the preset threshold, the drive module controls the surgical instrument 24 to retract according to the instruction speed and the instruction position filtered by the optimization verification module.

[0079] Optionally, the surgical robot system also includes an instrument exit trigger module and a telescopic joint planning module; the exit trigger module is used to trigger the elbow-wrist joint optimization module and the telescopic joint planning module; the telescopic joint planning module is used to plan the joint trajectory of the position and speed of the telescopic joint 241.

[0080] The exit trigger module can issue the instrument exit command in a variety of ways, including but not limited to single-clicking, double-clicking, long pressing, sliding, etc. on the doctor's console 10 or the patient-side trolley 20 through the interactive screen or physical buttons. After receiving the instrument exit command, the elbow-wrist joint optimization module and the telescopic joint planning module begin to perform joint trajectory planning for the position and speed of the telescopic joint 241. The elbow-wrist joint optimization module optimizes the retraction trajectory of the elbow-wrist joint 242 according to the position and speed of the telescopic joint 241, and then the driving module drives the surgical instrument 24 to retract along the optimized trajectory.

[0081] Optionally, after receiving the instrument exit instruction, the telescopic joint planning module performs the following two steps:

[0082] Step SA1: Record the command position of the current telescopic joint 241; the command position of the telescopic joint 241 is the starting point of the path planner, and the end point of the path planner is the predetermined retraction position, which is a position preset in the program, and the surgical instrument 24 can be easily replaced at the predetermined retraction position. In particular, if the predetermined retraction position is lower than the current command position, the current command position can be directly configured as the predetermined retraction position.

[0083] Step SA2: Perform path planning with maximum acceleration and maximum speed limits. It is understandable that the path planning of the telescopic joint 241 is limited by the maximum speed and maximum acceleration. In some embodiments, the complete path planning is as follows: Fig. 9As shown, the path includes three stages: an acceleration stage, a uniform speed stage, and a deceleration stage. In the acceleration stage, the speed increases, and the acceleration amplitude must be less than or equal to the maximum acceleration; the command speed of the uniform speed stage remains at the maximum speed, the command position increases linearly, and the command acceleration is zero; in the deceleration stage, the speed decreases, and the acceleration amplitude must be less than or equal to the maximum acceleration. In particular, in other embodiments, when the path starting point and the path end point are close, the maximum speed may not be reached. In this case, there is no uniform speed stage, and only the acceleration stage and the deceleration stage are retained.

[0084] An embodiment of the present invention further provides a readable storage medium having a program stored thereon, and when the program is executed, the steps of the above surgical instrument retraction control method are implemented.

[0085] In summary, in the surgical instrument retraction control method, readable storage medium and surgical robot system provided by the present invention, the surgical instrument retraction control method includes: discretizing key points according to the shape of the surgical instrument before retraction, and reconstructing splines according to the discretized key points; when the surgical instrument is in the shape of the retraction process, constructing a cost function based on the distance between each key point and the spline; finding the command speed of the elbow-wrist joint when the derivative of the cost function with respect to time is minimized; integrating the command speed to obtain the command position of the elbow-wrist joint, and controlling the retraction of the surgical instrument based on the command speed and the command position. With such a configuration, the surgical instrument roughly follows the path formed according to its shape before retraction when retracting, which can effectively reduce the possibility of collision when the surgical instrument retracts, and does not require perception of the surrounding environment, and does not require additional image support.

[0086] It should be noted that the above embodiments can be combined with each other. The above description is only a description of the preferred embodiments of the present invention, and does not limit the scope of the present invention. Any changes and modifications made by ordinary technicians in the field of the present invention based on the above disclosure are within the protection scope of the present invention.

Claims

1. A surgical instrument retraction control method, characterized in that: include: Discretize key points according to the shape of the surgical instrument before retreating, and reconstruct splines according to the discretized key points; When the surgical instrument is in a state of retreating, constructing a cost function based on the distance between each of the key points and the spline; Finding the command speed of the elbow-wrist joint when the derivative of the cost function with respect to time is minimized; The command speed is integrated to obtain the command position of the elbow-wrist joint, and the surgical instrument is controlled to retract based on the command speed and the command position.

2. The surgical instrument retraction control method according to claim 1, characterized in that: The cost function includes the weight of each of the key points, and the weight of each of the key points is set according to the mode type; the mode type is set based on the end type of the surgical instrument.

3. The surgical instrument retraction control method according to claim 2, characterized in that: The mode types include terminal optimization mode and global optimization mode; When the mode type is the terminal optimization mode, the weight of the key point located at the far end is not less than the weight of the key point located at the near end; When the mode type is the global optimization mode, the weights of all the key points are the same.

4. The surgical instrument retraction control method according to claim 1, characterized in that: After obtaining the command position of the elbow-wrist joint, the surgical instrument retraction control method further includes: filtering the command speed and the command position; Evaluate the filtered cost function, and if the cost function exceeds a preset threshold, feedback abnormal information and stop controlling the surgical instrument to retract; If the cost function is within the preset threshold, the surgical instrument is controlled to retract according to the filtered command speed and the command position.

5. A readable storage medium having a program stored thereon, characterized in that: When the program is executed, the steps of the surgical instrument retraction control method according to any one of claims 1 to 4 are implemented.

6. A surgical robot system, characterized in that: It includes a driving module and an elbow-wrist joint optimization module; the elbow-wrist joint optimization module includes a cost optimization module; The cost optimization module is configured to: discretize key points according to the shape of the surgical instrument before retreating, and reconstruct a spline according to the discretized key points; when the surgical instrument is in the shape of retreating, construct a cost function based on the distance between each key point and the spline; and find the command speed of the elbow-wrist joint that satisfies the minimum value of the derivative of the cost function with respect to time; Integrating the command speed to obtain the command position of the elbow-wrist joint; The drive module controls the surgical instrument to retract based on the command speed and the command position.

7. The surgical robot system according to claim 6, characterized in that: The elbow-wrist joint optimization module also includes a mode selection module, which is used to select a mode type and configure different weights for each key point in the cost function according to the selected mode type.

8. The surgical robot system according to claim 7, characterized in that: The mode types include terminal optimization mode and global optimization mode; When the mode type is the terminal optimization mode, the weight of the key point located at the far end is not less than the weight of the key point located at the near end; When the mode type is the global optimization mode, the weights of all the key points are the same.

9. The surgical robot system according to claim 6, characterized in that: The elbow-wrist joint optimization module further includes an optimization verification module, and the optimization verification module is configured to filter the instruction speed and the instruction position after the cost optimization module obtains the instruction position of the elbow-wrist joint; evaluating the filtered cost function; If the cost function exceeds a preset threshold, the optimization verification module feeds back abnormal information, and the driving module stops controlling the surgical instrument to retract; If the cost function is within the preset threshold, the driving module controls the surgical instrument to retract according to the command speed and the command position filtered by the optimization verification module.

10. The surgical robot system according to claim 6, characterized in that: The surgical robot system also includes an instrument withdrawal trigger module and a telescopic joint planning module; The exit trigger module is used to trigger the elbow-wrist joint optimization module and the telescopic joint planning module; The telescopic joint planning module is used to plan the joint trajectory of the position and speed of the telescopic joint.

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