Control method of small animal operation platform and minimally invasive retractor

Abstract

The invention provides a small animal operation platform which comprises a platform part, the platform part comprises an operation table top and a minimally invasive traction device installed on the operation table top, and the minimally invasive traction device comprises a minimally invasive incision traction support, a suture stretching motor, a torque sensor, a suture disc and a suture. The suture stretching motor is installed on the minimally invasive incision traction support, the suture stretching motor is connected with the suture disc, the suture is tensioned on the suture disc, and the torque sensor can detect the tension of the suture. The invention discloses a control method of a minimally invasive retractor of a small animal operation platform. The robot has the advantages that the defects that in the prior art, precision is insufficient, the flexibility degree is low and repeatability is poor are overcome, the operation platform is electrically controlled to accurately move on the four degrees of freedom, the posture is precisely adjusted in real time to be matched with corresponding operation, and the robot is cooperatively controlled with various kinds of automatic operation equipment.

Description

TECHNICAL FIELD

[0001] The present application relates to medical equipment, in particular to a small animal surgery platform and a control method of a minimally invasive retraction device. BACKGROUND

[0002] Small animals, such as mice, are widely used in basic medicine, neuroscience, oncology, drug research and development, and disease model construction, as key model animals for medical research, due to their clear genetic background, short breeding cycle, and ease of genetic modification. Many key experimental steps, such as electrode implantation, optical fiber placement, tumor inoculation, and organ transplantation, need to be completed under microsurgical conditions. These operations require high positioning accuracy, stability, and flexibility of the surgery platform. A small animal surgery platform with multiple functions, high integration, and multiple degrees of freedom can effectively improve operation efficiency, experimental repeatability and data reliability, and intraoperative safety.

[0003] Currently, related commercial integrated platforms (such as RWD, Harvard Apparatus products) have rich functions, and some devices integrate temperature control and image systems, but are generally expensive. Traditional small animal surgery platforms are mostly static structures, usually only having basic fixing functions for the head and limbs. Adjustable surgery platforms are generally manually adjusted, lacking precise positioning, repeated positioning, intraoperative adjustment, remote control, and other functions. The range of adjustment of the surgery operation site fixing tool is small, and there is no integrated minimally invasive incision dedicated retraction fixing mechanism, and the surgery instrument causes unnecessary displacement and deformation of the small animal tissue. Few surgery tables integrate gas anesthesia masks, limiting operation efficiency and small animal intraoperative safety.

[0004] Existing small animal surgery platforms have been widely used in many scientific research scenarios, but still have deficiencies in operation accuracy, flexibility, functional integration, and automation, mainly in the following aspects:

[0005] 1. The platform operation accuracy and flexibility are insufficient. Many traditional platforms only provide static or manually adjustable structures, lacking electric control or three-dimensional precise movement capabilities. In experiments requiring surgery on multiple sites or multi-angle injection, the platform is difficult to adapt flexibly.

[0006] 2. Low functional integration and expandability. Existing platforms often need to be connected to multiple independent devices, and anesthesia, retraction fixation, and other functions may require multiple people to cooperate or frequently switch devices, resulting in low operation efficiency and incoherent surgery process. Existing platforms have fixed single functions and lack expansion interfaces to adapt to more tools or instruments.

[0007] 3. Lack of minimally invasive incision traction retraction method. The surgical operating part of the existing surgical platform is mostly fixed by retractor traction incision skin, thereby providing a clear and open view, which is mostly used for open surgery of small animal abdominal cavity. However, the incision fixation and support technology for minimally invasive surgery of small animals still needs to be studied. The technology needs to lift the skin and peritoneum of small animals away from the internal organs, to provide a clear view and open operation space for the endoscope entering the incision of minimally invasive surgery.

[0008] 4. Lack of automation and intelligent control. Most devices still rely on manual adjustment, and repetitive operations need to be performed manually, which is inefficient. The existing system generally does not support programmed path control and recording, remote operation or one-key automatic process execution. The experimental standardization is low, and the operator's experience is relied on, and the result stability and consistency are poor. SUMMARY

[0009] In order to solve the problems in the prior art, the present application provides a small animal surgical platform and a control method of a minimally invasive retraction device.

[0010] The present application provides a small animal surgical platform, comprising a platform part, the platform part comprising a surgical table top and a minimally invasive retraction device mounted on the surgical table top, the minimally invasive retraction device comprising a minimally invasive incision retraction support, a suture stretching motor, a torque sensor, a suture disc and a suture, the suture stretching motor being mounted on the minimally invasive incision retraction support, the suture stretching motor being connected with the suture disc, the suture being tensioned on the suture disc, and the torque sensor being capable of detecting the tension of the suture.

[0011] At least three minimally invasive retraction devices are provided on the surgical table top.

[0012] A gas anesthesia mask, a head fixation bandage, an upper limb fixator, a trunk fixation bandage, a lower limb fixator and a support seat are provided on the surgical table top, and the gas anesthesia mask is connected with an anesthesia gas pipeline.

[0013] The small animal surgical platform further comprises an electric control device, and the platform part is arranged on the electric control device, and the electric control device is a four-axis electric control device.

[0014] The four-axis electric control device includes a base, an x-axis linear motor module, a y-axis linear motor module, a z-axis linear motor module, a rotary motor support and a pitch-axis rotary motor module, the x-axis linear motor module is arranged on the base, the z-axis linear motor module is arranged on the x-axis sliding block of the x-axis linear motor module, the y-axis linear motor module is arranged on the z-axis sliding block of the z-axis linear motor module, the rotary motor support is arranged on the y-axis sliding block of the y-axis linear motor module, the pitch-axis rotary motor module is arranged on the rotary motor support, and the operating table surface is arranged on the pitch-axis rotary motor module.

[0015] The operating table surface is provided with threaded holes and notches for mounting and expanding functions of various surgical instruments.

[0016] A control method of a minimally invasive retraction device of a small animal surgery platform or a control method of a small animal surgery platform, the small animal surgery platform is provided, and the minimally invasive retraction device of the small animal surgery platform is controlled by the following steps:

[0017] S1, initialization stage;

[0018] Set the target opening angle, opening area and tension threshold;

[0019] Adjust the suture length by the suture stretching motor, so that the minimally invasive opening is supported and reaches the preset position;

[0020] Initialize and reset the suture stretching motor, and pre-tighten the suture;

[0021] Zero each suture tension;

[0022] S2, dynamic retraction control stage;

[0023] Real-time acquisition of the tension value F i of each suture by the torque sensor;

[0024] Compare the tension value F i of each suture with the target tension F target or the tension difference ΔF;

[0025] Adjust the rotation step or angle of the suture stretching motor by the control algorithm, change the suture length, so that the retraction reaches the set position shape, and the force is balanced;

[0026] Closed loop PID control is adopted, and the control strategy is as follows:

[0027]

[0028] Wherein:

[0029] θ i(t) - angular displacement control variable of the i-th suture wire tensioning motor;

[0030] K p - proportional coefficient, used to directly generate a correction variable according to the size of the current error e(t);

[0031] K i - integral coefficient, used to correct the accumulation of the tension error;

[0032] K d - derivative coefficient, used to predict the trend according to the error rate de(t) / dt, so as to suppress overshoot or system oscillation;

[0033] e(t) - current tension error, e(t) = F target -F i (t).

[0034] The control method further comprises a step S3, maintaining the fine-tuning phase:

[0035] The system maintains the tension within the set range;

[0036] If the intraoperative tissue slip or organ position movement causes the skin or peritoneal tension to drop, at this time the tension value F i of each suture wire will simultaneously drop and exceed the set fluctuation range, at this time the suture wire length is shortened until the tension value F i of each suture wire is back within the set range;

[0037] When the tension fluctuates within the set range, a threshold value is set for the tension difference value AF of each suture wire, if the tension difference value AF exceeds the threshold value, the length of the adjacent suture wire is automatically adjusted: taking the tension values F i and F i+1 of the adjacent two suture wires, taking the average value, shortening the suture wire with tension less than the average value, and elongating the suture wire with tension greater than the average value, and the cycle is judged for all suture wires, to realize shape-symmetrical distraction;

[0038] During the operation, the tension-length curve recording function is turned on to save the operation distraction process data.

[0039] The control method further comprises a step S3, emergency release and reset phase:

[0040] If the tension of any suture wire exceeds the maximum safety threshold value, the power-off or rapid rollback mechanism is immediately triggered;

[0041] After the operation, the suture wire is automatically retracted, and the suture wire tensioning motor is reset.

[0042] The beneficial effects of the present application are: through the above scheme, a small animal operation platform and a control method of a minimally invasive retraction device are provided, the defects of insufficient precision, low flexibility and poor repeatability of the prior art are overcome, the operation platform is precisely moved on four degrees of freedom through electric control, and the pose is finely adjusted in real time to cooperate with corresponding operation operations and collaborative control with various automatic operation operation devices. BRIEF DESCRIPTION OF DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other solutions can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0044] Figure 1 is a general schematic diagram of a small animal operation platform of the present application.

[0045] Figure 2 is a schematic diagram of an electric control device of a small animal operation platform of the present application.

[0046] Figure 3 is a schematic diagram of a platform part of a small animal operation platform of the present application.

[0047] Figure 4 is a three-dimensional schematic diagram of a minimally invasive retraction device of a small animal operation platform of the present application.

[0048] Figure 5 is a side schematic diagram of a minimally invasive retraction device of a small animal operation platform of the present application. DETAILED DESCRIPTION

[0049] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0050] In the description of the present application, it needs to be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the scope of protection of the present application. In addition, the terms "first", "second" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" and the like can be explicitly or implicitly included one or more. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0051] In the description of the present application, it needs to be understood that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood through specific circumstances.

[0052] The present application will be further described below in conjunction with the description and specific embodiments of the drawings.

[0053] As shown in Figures 1 to 5 A small animal surgery platform, comprising an electric control device 1 and a platform part 2, the platform part 2 is arranged on the electric control device 1.

[0054] The electric control device 1 is preferably a four-axis electric control device, which is a four-degree-of-freedom adjusting mechanism driven by a motor.

[0055] The platform part 2 integrates a four-limb fixing, gas anesthesia, minimally invasive incision pulling fixed expandable surgery platform.

[0056] The small animal surgery platform integrates four-axis electric control adjustment and minimally invasive incision retractor (also known as minimally invasive retraction device), which can improve the consistency and safety of small animal surgery experiment, effectively guarantee the experiment efficiency and data quality, and play an important role in promoting the research process of related disciplines.

[0057] The electric control device 1 mainly consists of the following components: base 1-1, x-axis linear motor module 1-2, y-axis linear motor module 1-3, z-axis linear motor module 1-4, rotary motor bracket 1-5 and pitch axis rotary motor module 1-6.

[0058] Three linear motor modules are driven by motors and screw slides. When the motor is started, the slider on the linear motor module moves linearly along the screw slide. The x-axis linear motor module 1-2 is connected to the base 1-1, the z-axis linear motor module 1-4 is installed on the x-axis slider, the y-axis linear motor module 1-3 is installed on the z-axis slider, the rotary motor support 1-5 is fixed with the y-axis slider, and the pitch axis rotary motor module 1-6 is installed at the end of the support. The pitch axis rotary motor module 1-6 is fixed with the operation platform 2 and can directly drive the platform to rotate along the pitch axis. In the above manner, the operation platform 2 realizes four-degree-of-freedom movement controlled by the motor, improves the stability, precision and flexibility of the operation platform operation, and realizes automatic and intelligent control.

[0059] The operation platform 2 mainly comprises the following components: an operation table 2-1, a gas anesthesia mask 2-2, a head fixing band 2-3, an upper limb fixer 2-4, a trunk fixing band 2-5, a lower limb fixer 2-6, a supporting seat 2-7, a minimally invasive incision retraction support 2-8, a suture stretching motor 2-9, a torque sensor 2-10, a suture disc 2-11 and a suture 2-12.

[0060] The minimally invasive incision retraction support 2-8, the suture stretching motor 2-9, the torque sensor 2-10, the suture disc 2-11 and the suture 2-12 form a minimally invasive retraction device.

[0061] The operation table 2-1 is provided with a plurality of threaded holes and branch grooves for the installation and integration of various surgical instruments and the expansion of functions.

[0062] The gas anesthesia mask 2-2 is fixed to the operation table 2-1 and is connected to an anesthesia gas pipeline for the anesthesia of small animals during surgery.

[0063] The length and position of the head fixing band 2-3 and the trunk fixing band 2-5 can be adjusted and are adaptable to the size of small animals.

[0064] The upper limb fixer 2-4 and the lower limb fixer 2-6 are fixed to the limbs of small animals by a binding line, the other end of the binding line is fixed to the threaded hole on the operation table 2-1 by a bolt, and the length and fixed position of the binding line can be adjusted.

[0065] The fixing hole of the supporting seat 2-7 is a slot hole, which is fixed to the screw hole on the operation table 2-1 and is finely adjusted in position, so as to assist in supporting the trunk of a small animal when the operation table 2-1 forms a large angle with the horizontal plane, reducing the stress on the limbs and head of the small animal and preventing the small animal from moving relative to the operation table 2-1 during surgery.

[0066] The minimally invasive incision retraction support 2-8 is installed and fixed on the threaded hole of the operating table surface 2-1, and the minimally invasive incision retraction support 2-8 can be adjusted in position, quantity and height on the operating table surface 2-1 according to actual operation requirements and the size characteristics of small animals.

[0067] The suture length can be changed by driving the suture disc 2-11 to rotate through the suture stretching motor 2-9 on the minimally invasive incision retraction support 2-8, and the tension of the suture is measured through the torque sensor 2-10.

[0068] 2-12 is connected with the edge of the minimally invasive incision through a surgical suture needle, and through the connection and traction of a plurality of sutures, the skin around the minimally invasive incision can be lifted up, so that a cavity is formed between the skin / peritoneum around the incision and the operation site, providing a clear view for the minimally invasive surgical endoscope after entering the incision and providing a wide operation space for surgical instruments.

[0069] After the operation is completed, the sutures near the minimally invasive incision are retained, the bolts on the support column are unscrewed, and one end of the suture is removed from the support column. The plurality of sutures are knotted and fixed to each other, the minimally invasive incision is contracted, and the suturing is completed.

[0070] Because the skin / peritoneum and the like can elastically deform within a certain range, by adjusting the length of the suture, the diameter size change and the slight position adjustment of the minimally invasive incision can be realized to adapt to the needs of different surgical instruments or intraoperative operation processes.

[0071] The present application provides a control method of a minimally invasive retraction device based on force feedback, which utilizes a plurality of retraction rope mechanisms with torque sensors, adjusts the length through a motor, and realizes dynamic controllable opening and position adjustment of the incision shape while keeping the tension of each suture within a preset range. The method is based on a closed-loop control strategy and combines multi-point tension sampling to finely control the retraction amplitude, prevent tissue damage, and has functions of automatic compensation, abnormality detection, and operation recording. The control process is as follows:

[0072] Initialization stage

[0073] Set the target opening angle, opening area or tension threshold;

[0074] The suture stretching motor 2-9 adjusts the length of the suture 2-12 to make the minimally invasive opening lift up and reach the preset position;

[0075] The suture stretching motor 2-9 is initialized to zero, and the pre-tightening suture 2-12 is initialized to zero.

[0076] Each suture 2-12 is tensioned to zero.

[0077] 2. Dynamic retraction control stage

[0078] Real-time acquisition of the tension value F of each suture 2-12 i(From the torque sensor 2-10)

[0079] The tension value F i of each suture 2-12 is compared with the target tension F target or the tension difference ΔF;

[0080] The suture tension motor 2-9 is adjusted by the control algorithm to change the length of the suture 2-12, so that the retraction reaches the set position shape and the force is balanced;

[0081] The closed-loop PID control is adopted, and the control strategy is as follows:

[0082]

[0083] Wherein

[0084] θ i (t) is the angular displacement control amount of the i-th suture tension motor 2-9;

[0085] K p is the proportional coefficient, which is used to directly produce the correction amount according to the size of the current error e(t);

[0086] K i is the integral coefficient, which corrects the accumulation of the tension error;

[0087] K d is the differential coefficient, which predicts the trend according to the error change rate de(t) / dt, so as to suppress overshoot or system oscillation;

[0088] e(t) is the current tension error, e(t) = F target -F i (t);

[0089] 3. Keep the fine-tuning stage

[0090] The system keeps the tension within the set range (e.g. ±5%);

[0091] If the intraoperative tissue slips or the organ position moves, causing the skin / peritoneum tension to drop, at this time the tension value F i of each suture will also drop and exceed the set fluctuation range. At this time, the suture length needs to be shortened until the tension value F i of each suture is back within the set range;

[0092] When the tension fluctuates within the set range, a threshold value is set for the tension difference ΔF of each suture, and if ΔF exceeds the threshold value, the length of the adjacent suture is automatically adjusted: take the tension values F i and F i+1, take average value, shorten the suture with tension less than average value, elongate the suture with tension greater than average value, and cycle to judge all sutures, to realize shape symmetric distraction;

[0093] During surgery, open the tension-length curve recording function, and save the surgery distraction data.

[0094] 4. Emergency release and reset phase

[0095] If the tension of any suture exceeds the maximum safety threshold (such as the risk of tissue tearing), immediately trigger the power-off or rapid fallback mechanism;

[0096] After the operation, automatically retract the rope length, and reset the traction device.

[0097] When in use, for the convenience of operation, the small animal needs to be placed in the anesthetic gas chamber for anesthesia in advance. First, use the electric control device 1 to adjust the operation platform 2 to a horizontal state. After the small animal enters the anesthetic state, the operator needs to place the small animal's abdomen upwards on the operation table surface 2-1, the small animal's head is placed in the gas anesthesia mask 2-2, and the anesthetic gas is turned on for continuous anesthesia. Then, respectively tighten the head fixing band 2-3, the trunk fixing band 2-5, and then tie the small animal's limbs with the fixing band on the upper limb fixing device 2-4 and the lower limb fixing device 2-6, and the other end of the fixing band is fixed through the bolt and the threaded hole on the operation table surface 2-1. Adjust the position of the supporting seat 2-7 to give the small animal's trunk a suitable supporting force. Next, the operator can operate the operation site of the small animal. Taking the abdominal surgery as an example, the operator opens a minimally invasive incision on the skin and peritoneum at the operation site, and uses the minimally invasive incision distraction system to distract the skin / peritoneum near the incision according to the method described above, so that the minimally invasive surgical instrument can pass through the incision to obtain a visual field and implement surgical operation. After the small animal is fixed and the incision is prepared, the operation is started, and the electric control device 1 is used to adjust the operation platform 2 in four degrees of freedom in real time to adapt to the specific operation. After the operation, the small animal is restored to the horizontal state, and the multiple sutures on the minimally invasive distraction device are directly used for suturing.

[0098] The control method of the small animal operation platform and the minimally invasive distraction device provided by the application has the following advantages:

[0099] 1. The platform operation precision and flexibility are high. The application overcomes the defects of insufficient precision, low flexibility and poor repeatability of the prior art. The electrically controlled operation platform is precisely moved in four degrees of freedom, and the pose is adjusted in real time and finely to cooperate with the corresponding operation and control various automatic operation devices.

[0100] 2. Multifunctional integration and scalability. The prior art has single function and independent equipment. The present application integrates the functions of small animal pose adjustment, fixation, anesthesia, retraction, etc., and designs multiple scalable interfaces, which can reduce equipment switching procedures, realize coherent surgical procedures, and improve operation efficiency.

[0101] 3. A minimally invasive incision retraction method is proposed. The surgical operation site of the existing surgical platform is mostly fixed by pulling the hook to stretch the incision skin. This method is suitable for open surgery with larger incisions. The minimally invasive incision retraction method based on force feedback proposed by the present application can finely control the retraction amplitude and incision position, provide a clear view and open operation space for minimally invasive surgery, prevent tissue damage, and has functions such as automatic compensation, abnormality detection, and surgical record. Postoperative suturing is fast and efficient, ensuring animal safety.

[0102] 4. Realize automation and intelligent control. The present application overcomes the shortcomings of the prior art, such as low efficiency of manual operation, low standardization of experiments, dependence on operator experience, poor stability and consistency of results, etc. Through the four-axis electric control device, the surgical platform can be controlled with four degrees of freedom and high precision, thereby realizing functions such as programmed path control and recording, remote operation, and one-key automatic process execution.

[0103] The above is a further detailed description of the present application in combination with specific preferred embodiments, and cannot be considered as limiting the specific implementation of the present application to these descriptions. For ordinary skilled persons in the technical field to which the present application belongs, without departing from the concept of the present application, a number of simple deductions or substitutions can be made, which should be considered as falling within the protection scope of the present application.

Claims

1. A small animal surgical platform, characterized in that: The device includes a platform, which comprises an operating table and a minimally invasive retraction device mounted on the operating table. The minimally invasive retraction device includes a minimally invasive incision retraction bracket, a suture tension motor, a torque sensor, a suture reel, and sutures. The suture tension motor is mounted on the minimally invasive incision retraction bracket and is connected to the suture reel. The sutures are tensioned on the suture reel, and the torque sensor can detect the tension of the sutures.

2. The small animal surgical platform according to claim 1, characterized in that: The operating table is equipped with at least three minimally invasive retraction devices.

3. The small animal surgical platform according to claim 1, characterized in that: The operating table is equipped with a gas anesthesia mask, a head fixation strap, an upper limb fixation device, a torso fixation strap, a lower limb fixation device, and a support. The gas anesthesia mask is connected to an anesthetic gas pipeline.

4. The small animal surgical platform according to claim 1, characterized in that: The small animal surgical platform also includes an electronic control device, and the platform is partially mounted on the electronic control device, which is a four-axis electronic control device.

5. The small animal surgical platform according to claim 4, characterized in that: The four-axis electronic control device includes a base, an x-axis linear motor module, a y-axis linear motor module, a z-axis linear motor module, a rotary motor bracket, and a pitch axis rotary motor module. The x-axis linear motor module is mounted on the base, the z-axis linear motor module is mounted on the x-axis slider of the x-axis linear motor module, the y-axis linear motor module is mounted on the z-axis slider of the z-axis linear motor module, the rotary motor bracket is mounted on the y-axis slider of the y-axis linear motor module, the pitch axis rotary motor module is mounted on the rotary motor bracket, and the operating table is mounted on the pitch axis rotary motor module.

6. The small animal surgical platform according to claim 1, characterized in that: The operating table surface is provided with threaded holes and slots for the installation, integration, and functional expansion of various surgical instruments.

7. A control method for a minimally invasive retraction device on a small animal surgical platform, characterized in that: Provides a small animal surgical platform as described in any one of claims 1 to 6, controlling the minimally invasive retraction device through the following steps: S1, Initialization phase; Set the target opening angle, opening area, and tension threshold; The suture length is adjusted by a suture stretching motor, which helps to open the minimally invasive incision and reach the preset position. The suture tensioning motor is initialized to zero, and the suture is pre-tightened. All suture tensions were zeroed; S2, Dynamic Towing Control Stage; The tension value F of each suture is collected in real time by a torque sensor. i ; The tension value F of each suture i With target tension F target Or compare with the tension difference ΔF; By adjusting the rotation steps or angle of the suture stretching motor through the control algorithm, the suture length is changed so that it is stretched to the set position and shape, and the force is balanced. Closed-loop PID control is adopted, and the control strategy is as follows: in: θ i (t)——Angular displacement control amount of the i-th thread tensioning motor; K p —The proportionality coefficient is used to directly generate a correction amount based on the magnitude of the current error e(t); K i —Integral coefficient, used to correct for the accumulation of tension error; K d —The differential coefficients predict the trend based on the error change rate de(t) / dt, thereby suppressing overshoot or system oscillation; e(t) — Current tension error, e(t) = F target -F i (t).

8. The control method for the minimally invasive retraction device of the small animal surgical platform according to claim 7, characterized in that: The control method further includes step S3, a holding and fine-tuning phase: The system maintains tension within a set range; If tissue slippage or organ displacement during surgery leads to a decrease in skin or peritoneum tension, the tension value F of each suture will be affected. i If the tension drops simultaneously and exceeds the set fluctuation range, shorten the suture length until the tension value F of each suture is reached. i Return to the set range; When the tension fluctuates within a set range, a threshold is set for the tension difference ΔF between each suture. If the tension difference ΔF exceeds the threshold, the lengths of adjacent sutures are automatically and synchronously adjusted: the tension values ​​F of two adjacent sutures are taken. i and F i+1 Take the average value, shorten the sutures with tension less than the average value, and lengthen the sutures with tension greater than the average value, and cyclically judge all sutures to achieve symmetrical shape expansion; During the surgery, the tension-length curve recording function is activated to save the data of the surgical dissection process.

9. The control method for the minimally invasive retraction device of the small animal surgical platform according to claim 8, characterized in that: The control method further includes step S3, an emergency release and reset phase: If the tension of any suture exceeds the maximum safety threshold, the power-off or rapid retraction mechanism will be triggered immediately. The sutures retract automatically after the procedure, and the suture stretching motor resets.

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