System and method for preparing surgical suture with controllable knotting force based on slipknot

Abstract

The invention relates to a system and method for preparing a surgical suture with controllable knotting force based on a slipknot, and the method comprises the steps: weaving a slipknot controller with a specific topological structure at the tail end of the surgical suture, inputting the required knotting force into a preset force calculation system based on a finite element algorithm, and carrying out the calculation to obtain a preset force; the force control stretching device loads the preset force to the prefabricated force bearing end of the slipknot controller until the slipknot controller reaches the preset load, and preparation of the operation suture with the controllable knotting force is completed. The knotting force can be accurately controlled in the actual suture knotting operation, and tissue cutting and ischemia caused by too large knotting force and tissue leakage caused by too small knotting force are avoided. In the suturing process, clear mechanical signals can be provided for surgeons, the consistency and accuracy of knotting operation are improved, and low-age doctors can complete high-quality knotting.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical surgical instruments, and in particular to a system and method for preparing surgical sutures with controllable knotting force based on a slipknot. Background Art

[0002] Suturing is a basic and important operation in surgery. In surgery, using surgical sutures to tie knots on the wound can achieve hemostasis, wound closure, and anastomosis of severed tissues. After the wound is sutured, the sutures need to be pulled tight to tightly close the wound. Clinically, the force used to tighten the sutures is called knotting force. The size of the knotting force will directly affect the quality of the suture, and thus determine the success or failure of the operation. The size of the knotting force depends on the doctor's personal clinical experience, and there are huge individual differences.

[0003] In digestive tract anastomosis surgery, excessive knotting force can cause tissue ischemia and necrosis, or even cut the tissue, resulting in suture failure and leakage. Too little knotting force can cause the anastomosis to be loosely closed, or even local cracks to exist, making it difficult to resist the pressure of the liquid in the digestive tract, resulting in leakage. Suturing with appropriate knotting force can provide appropriate tension for the anastomosing digestive tract tissues, allowing them to heal with sufficient blood supply and no leakage of digestive fluid.

[0004] In laparoscopic surgery, surgeons pass long-rod laparoscopic surgical instruments through small incisions in the abdominal cavity to perform surgical operations. Compared with traditional open surgery, laparoscopic surgery reduces trauma while also placing higher demands on surgeons' operations. In traditional open surgery, surgeons can directly tighten the two ends of the suture with both hands to intuitively feel and control the size of the knotting force. However, when using laparoscopic surgical instruments for surgery, the surgeon's sensitivity to the contact force at the end of the surgical instrument is greatly limited, making it difficult to accurately control the size of the knotting force.

[0005] Compared with laparoscopic instruments, surgical robots have a higher degree of freedom and more precise control. However, at the same time, most surgical robots currently used in clinical practice use displacement control and do not have force feedback capabilities. Therefore, surgeons performing remote operations cannot perceive and control the size of the knotting force, causing suture failure.

[0006] In summary, whether it is traditional open surgery, minimally invasive laparoscopic surgery or surgical robots, they all face the problem of difficulty in accurately controlling the knotting force.

[0007] Chinese patent CN202122748479 provides a tension-precisely controlled knob-type wound closure device, including a knob assembly, a base, a nylon steel rope, a guide buckle and a film; a rotating hole is provided at the center of the base, a sponge mucosa is provided at the bottom of the base, the knob assembly includes a knob and a rotating shaft, the rotating shaft is fixedly installed at the center of the knob, the rotating shaft is located in the rotating hole of the base, the rotating shaft and the rotating hole of the base are rotatably connected, the film is a rectangular sheet, the film has two sheets, a plurality of guide buckles are symmetrically fixedly installed on the two sheets of film, the guide buckle consists of an upper buckle cover, a lower buckle cover and a guide buckle shaft, the lower buckle cover is fixedly installed on the film, and the guide buckle shaft is located between the upper buckle cover and the lower buckle cover. The utility model has the advantages of being able to quickly close the wound, not being limited by the shape and size of the wound, reducing the risk of wound infection, accurately adjusting the pressure to promote wound healing, no sutures at the wound closure, and no obvious scars after the wound heals.

[0008] However, the above solutions have obvious shortcomings.

[0009] First, the device can only be used to close skin wounds, but not for deep wounds and anastomosis of internal abdominal organs. The reason is that the knobs, bases, nylon steel ropes, etc. contained in the device are not biodegradable and biocompatible, and will cause severe allergic reactions when used inside a living body.

[0010] Second, the above device cannot be used in laparoscopic and robotic surgery because the size of the device is much larger than the size of the abdominal opening in laparoscopic minimally invasive surgery and cannot enter the patient's abdominal cavity through the abdominal opening.

[0011] Third, the above device cannot adjust the tension at the local position of wound closure individually, but can only adjust the tension of the entire wound. In clinical experience, most wounds are not linear, but irregular, and even accompanied by tissue defects. Therefore, the closing tension required at each point in the entire wound is not the same. In the knob device, the nylon rope connects the knob assembly and the guide buckle together, so that the tension along the direction of the nylon rope is similar. This device is more reliable when dealing with regular wounds such as cuts, but when dealing with irregular wounds such as impact injuries and contusions, it is difficult to adjust the tension at each point along the direction of the wound individually, so it is impossible to achieve the closure of such common wounds.

[0012] Fourth, the device is connected to the tissue through sponge mucosa adhesion, and the wound closure force it can provide is extremely limited. Although it is possible to achieve wound closure without the use of sutures, the cost is that it is difficult to provide mechanical strength comparable to sutures. Summary of the invention

[0013] The purpose of the present invention is to overcome the shortcomings of the prior art and propose a surgical suture preparation system and method based on a slipknot with controllable knotting force, which can accurately control the opening force of the slipknot controller in the actual suturing operation, avoiding tissue cutting and ischemia caused by excessive knotting force and tissue leakage risks caused by too little knotting force. At the same time, during the suturing process, it can provide clear mechanical signals to the surgeon, improve the consistency and accuracy of the suturing operation, and enable junior doctors to achieve high-quality suturing.

[0014] The present invention solves the technical problem by adopting the following technical solutions:

[0015] A slipknot-based surgical suture preparation system with controllable knotting force comprises a slipknot controller with a specific spatial geometric structure, a precise force-controlled stretching device and a preset force solving system, wherein the end of the slipknot controller and the preset force-bearing end are connected to the precise force-controlled stretching device by clamping, the preset force solving system can calculate the preset force size corresponding to the specific slipknot opening force, and the precise force-controlled stretching device can load the corresponding preset force on the slipknot controller with a specific spatial geometric structure, so that the slipknot controller has a preset large opening force.

[0016] Moreover, the slipknot controller has a knot with a specific spatial geometric structure that can be pulled apart, and a slipknot including but not limited to a fisherman's knot, a slipknot, a hitching knot and the like is woven at the tail end of the surgical suture, and a preset force of a specified size is applied, thereby obtaining a slipknot controller with a specific opening force. The force-bearing structure of the slipknot controller includes a preset force-bearing end, an opening force-bearing end and a line tail. By applying a pulling force to the preset force-bearing end and the line tail, the slipknot controller can be locked, and by applying a pulling force to the opening force-bearing end and the line tail, the slipknot controller can be untied, and finally restored to a linear shape.

[0017] Moreover, the precise force-controlled stretching device is a stretching device that can stably clamp the force-bearing structure of the slipknot controller and apply a preset load and can maintain the load for any length of time. The two ends of the precise force-controlled stretching device are clamping devices that are not limited to pneumatic tooling. The clamping devices at both ends of the precise force-controlled stretching device respectively clamp the preset force-bearing end and the end of the thread in the force-bearing structure of the slipknot controller to prepare a slipknot controller with a specified output force; or respectively clamp the opening force-bearing end and the end of the thread in the force structure to measure the output force of the slipknot controller. The inner side of the clamping device is provided with an anti-slip structure to prevent slippage during the process of clamping the surgical suture.

[0018] Furthermore, the wire used in the slipknot controller is not limited by diameter and material, and includes but is not limited to silk, polylactic acid, polyglycolic acid, polyglycolide, polypropylene or collagen.

[0019] Moreover, the preset force solving system calculates the preset force according to the required output force of the slipknot controller, the spatial geometric structure, and the material parameters of the wire.

[0020] Moreover, the preset force is a force that stretches the slipknot controller to a predetermined load and maintains the load through the preset force-bearing end and the wire tail of the slipknot controller.

[0021] A method for preparing a slipknot-based surgical suture preparation system with controllable knotting force comprises the following steps:

[0022] Step 1, according to the spatial geometric structure of the slipknot controller, use surgical sutures to weave an untightened slipknot having the structure;

[0023] Step 2, clamp the thread tail of the slipknot prepared in step 1 and the force-bearing end of the slipknot controlling the preset force on the precise force-controlled stretching device respectively;

[0024] Step 3, inputting the required slipknot opening force, slipknot geometric parameters, and surgical suture material parameters into the preset force calculation system to calculate the preset force;

[0025] Step 4: The precise force-controlled stretching device applies the preset force obtained in step 3 to the slipknot controller and maintains the load, thereby obtaining a slipknot controller with a specific opening force;

[0026] Step 5, clamp the opening force control end and the thread tail of the slipknot controller with a specific opening force prepared in step 4 in a precise force control stretching device to measure the size of the slipknot opening force;

[0027] Step 6: Compare the measured value of the slipknot opening force obtained in step 5 with the preset value of the required slipknot opening force, optimize the preset force solving system in step 3, and repeat steps 1-5 until the measured value is the same as the preset value.

[0028] The advantages and positive effects of the present invention are:

[0029] 1. The present invention constructs a slipknot controller on the surgical suture, inputs the required knotting force into the preset force solution system to calculate the preset force, and the precise force-controlled stretching device applies the preset force to the preset force force-bearing end of the slipknot controller until the slipknot controller reaches the predetermined load, thereby completing the preparation of surgical sutures with controllable knotting force. The present invention can accurately control the size of the knotting force in the actual suturing operation, avoiding tissue cutting and ischemia caused by excessive knotting force, and the risk of tissue leakage caused by insufficient knotting force. During the suturing process, it can provide clear mechanical signals to the surgeon in charge, improve the consistency and accuracy of the suturing operation, and enable junior doctors to achieve high-quality suturing.

[0030] 2. The slipknot controller of the present invention can provide mechanical signals through visual feedback in clinical operations without direct tactile feedback, such as laparoscopic surgery and robotic surgery, so that the clinician's suturing operation is more accurate. In robotic surgery, the end of the mechanical arm is mostly missing a force feedback system, which makes the clinician in the remote operation (such as Fig. 9 The slipknot controller can provide clinicians with force-visual feedback and can work with the robotic arm to automatically unload after reaching the preset load, thus avoiding suture breakage and tissue cutting.

[0031] 3. The knotting force provided by the slipknot controller of the present invention can be adjusted to meet the suturing requirements of different tissues. By measuring the optimal knotting force for different tissues, accurate suturing of multiple tissues can be achieved. At the same time, due to the large individual differences in patient tissues, the adjustable knotting force also provides a basis for personalized medicine.

[0032] 4. The slipknot controller of the present invention can achieve accurate knotting force control only by the slipknot structure without adding any sensors, and the slipknot is untied after the function is achieved. There is no difference in structure and composition from conventional sutures, and its biocompatibility and safety are substantially equivalent to those of the original sutures.

[0033] 5. The slipknot controller of the present invention relies on its own braided structure to realize its function. Its main cost lies in the construction of the precise force-controlled stretching device and the writing of the preset force solution system. After it is put into use, it is spread over the preparation of large quantities of slipknot sutures, and the cost of adding the slipknot controller is negligible.

[0034] 6. The slipknot driver of the present invention is a universal construction strategy applicable to various types of sutures, is compatible with existing surgical sutures that have been put into clinical use, and does not affect the operating habits of the surgeon during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a two-ring-fishing knot slipknot controller structure diagram;

[0036] Figure 2 It is a schematic diagram of force loading when the slipknot controller is untied;

[0037] Figure 3 It is the force-displacement curve and state diagram when the slipknot controller is untied;

[0038] Figure 4 Simulate the moment when the slipknot is opened during suturing for robotic surgery;

[0039] Figure 5 Schematic diagram of the decomposition process for constructing the spatial structure of the slipknot controller;

[0040] Figure 6 This is a schematic diagram of the slipknot spatial structure (two rings - fishing knot) and the finished product;

[0041] Figure 7 Schematic diagram of the stretching slipknot of the precise force-controlled stretching device;

[0042] Figure 8 This is a diagram of the preset force solution system of the present invention;

[0043] Fig. 9 This is a schematic diagram of surgical robot teleoperation;

[0044] Fig.10 A schematic diagram of a slipknot controller in an embodiment of the present invention;

[0045] Fig.11 It is a schematic diagram of a preset force solving system and a silicone suture training module in an embodiment of the present invention;

[0046] Fig.12 A schematic diagram of a winding board for constructing a slipknot topology structure in an embodiment of the present invention;

[0047] Fig.13 Comparison of suturing effects of ordinary suture and suture with slipknot controller in the embodiment of the present invention;

[0048] Fig.14 An in vitro intestinal perforation suturing testing device in an embodiment of the present invention. DETAILED DESCRIPTION

[0049] The present invention is further described in detail below with reference to the accompanying drawings.

[0050] A slipknot-based surgical suture preparation system with controllable knotting force comprises a slipknot controller, a precise force-controlled stretching device and a preset force solving system, wherein the tail end of the slipknot controller line and the preset force-bearing end of the slipknot controller are respectively connected to the precise force-controlled stretching device, and the precise force-controlled stretching device is connected to the preset force solving system, so as to actuate the slipknot controller according to the result calculated by the preset force solving system.

[0051] like Figure 1 As shown, the slipknot controller has a specific spatial geometric structure, and is a one-ring, two-ring or three-ring fishing knot or other structure slipknot structure woven at the end of the surgical suture. The preset force-bearing end of the slipknot controller is the force-bearing end of the slipknot, such as Figure 2 and Figure 3As shown in the figure, the slipknot will be untied and restored to its original linear state when the tensile load reaches a specific preset value, which is determined by the preset force and the structural parameters. The load is cut off at the moment the slipknot is untied, thereby preventing the load applied by the suture to the biological tissue from exceeding the preset value, so it is called its controller. The untying of the slipknot realizes mechanical feedback and control functions in both vision and touch. Visually, whether in open surgery, laparoscopic surgery or robotic surgery, the process of the slipknot being untied is an extremely obvious visual signal.

[0052] like Figure 4 As shown, in laparoscopic surgery and robotic surgery, the visual magnification effect of the endoscope makes the size of the slipknot observed by the surgeon on the display screen much larger than its actual size, so the visual signal is more obvious.

[0053] During robotic surgery, due to the intervention of the robotic arm and machine vision system, the robot can automatically stop stretching the slipknot when it recognizes the visual signal of the slipknot being untied, avoiding overloading and suture breakage. In terms of touch, there will be an obvious idle distance at the moment the slipknot is untied. In open surgery and laparoscopic surgery, the hand can directly feel the generation of this idle distance and stop stretching the suture, thus avoiding excessive knotting force. In robotic surgery, this idle distance can also be sensed by the surgeon's teleoperation terminal.

[0054] like Figure 5 and Figure 6 As shown, the winding board is a space structure of the required slipknot controller that can be reproduced by winding the surgical suture along the wire groove on the surface of the board once, thereby ensuring the repeatability and consistency of the slipknot controller.

[0055] like Figure 7 As shown, the precise force-controlled stretching device is a uniaxial stretching device that applies a specific preset load. The two ends of the precise force-controlled stretching device are clamping devices. The clamping devices at both ends of the precise force-controlled stretching device clamp the surgical suture at one end of the slipknot controller and the pre-forced end of the slipknot controller respectively. The clamping inner side of the clamping device is provided with an anti-slip structure to prevent the surgical suture from being displaced during the clamping process. The preset is the force that stretches the slipknot controller to a predetermined load through the line tail end of the slipknot controller and the pre-forced end of the slipknot controller.

[0056] like Figure 8 As shown, the pre-setting force is obtained by inversely solving the required opening force based on the pre-setting force solving system. Through the solving system, after inputting the required knotting force, the corresponding preset force size can be obtained, and then the preset force is input into the force-controlled stretching device to obtain a slipknot controller with a specific knotting force.

[0057] A method for preparing a slipknot-based surgical suture preparation system with controllable knotting force comprises the following steps:

[0058] Step 1, according to the spatial geometric structure of the slipknot controller, use surgical sutures to weave an untightened slipknot having the structure;

[0059] Step 2, clamp the thread tail of the slipknot prepared in step 1 and the force-bearing end of the slipknot controlling the preset force on the precise force-controlled stretching device respectively;

[0060] Step 3, inputting the required slipknot opening force, slipknot geometric parameters, and surgical suture material parameters into the preset force calculation system to calculate the preset force;

[0061] Step 4: The precise force-controlled stretching device applies the preset force obtained in step 3 to the slipknot controller and maintains the load, thereby obtaining a slipknot controller with a specific opening force;

[0062] Step 5, clamp the opening force control end and the thread tail of the slipknot controller with a specific opening force prepared in step 4 in a precise force control stretching device to measure the size of the slipknot opening force;

[0063] Step 6: Compare the measured value of the slipknot opening force obtained in step 5 with the preset value of the required slipknot opening force, optimize the preset force solving system in step 3, and repeat steps 1-5 until the measured value is the same as the preset value.

[0064] According to the above-mentioned slipknot-based surgical suture preparation system and method with controllable knotting force, experiments were conducted to verify the effect of the present invention.

[0065] Embodiment 1:

[0066] like Fig.10 As shown, this embodiment uses conventional 4-0 suture silk ( Figure 10-1 ), Ring-Fishing Knot Knot Plate( Figure 10-2 ), precise force control stretching device, ( Figure 10-4 and Figure 10-5 ), preset force solving system ( Fig.11 Left) and Silicone Suture Test Module ( Fig.11 right).

[0067] like Fig.12 As shown in the figure, the 4-0 suture silk thread is wound along the grooves provided on the knotting plate in sequence to obtain the desired slipknot spatial geometry ( Figure 10-3 ), then the force-bearing end and the lower left clamp of the slipknot controller are clamped with a precise force control stretching system. Then the required knotting force is input into the preset force solving system, the corresponding preset force size is obtained, and it is input into the stretching system for stretching, thereby tightening the slipknot to the required degree ( Figure 10-4 and Figure 10-5). Next, the suture with the slipknot controller was used for suturing test. A common silicone suture practice board was used for testing. The simulated wound was 7 cm long. 0.15 mm round holes were opened at 0.5 cm on both sides of the wound to serve as needle insertion and exit positioning holes. A pair of positioning holes were placed every 1 cm along the direction of the simulated wound. After the surgeon passed the round needle through the positioning hole and the simulated wound, he threw a square knot on the wound, then stretched the two ends of the suture until the slipknot was untied. At this time, the corresponding knotting force was exactly the preset knotting force.

[0068] Pressure-sensitive paper can directly reflect the pressure of sutures on tissues, thus indirectly evaluating the consistency and repeatability of knotting. The cut pressure-sensitive paper is placed in the simulated wound to be sutured. The clinician first uses ordinary sutures without slipknots to suture, then measures the pressure of the corresponding area on the pressure-sensitive paper, and then repeats the above operation using sutures with slipknot controllers.

[0069] Test results such as Fig.13 As shown: Each time, five stitches are sutured according to the preset openings on the silicone suture training module, and then the pressure-sensitive paper is replaced and the pressure value is collected. The above operation is repeated 5 times using ordinary sutures and slipknot sutures, and the data is collected and analyzed. The depth of the color on the pressure-sensitive paper can reflect the magnitude of the pressure, and the positive pressure value can be read by comparing the color with the standard color card. The positive pressure value marked in the figure is the average pressure of the upper pressure area after each stitch.

[0070] The test results show that in the same suturing operation, the relative error of pressure using slipknot sutures is 10.2%, while the relative error of pressure using ordinary sutures is as high as 19.4%. The stability and consistency of suturing with slipknot sutures are far superior to suturing with ordinary sutures.

[0071] Embodiment 2:

[0072] like Fig.14 As shown, the method for preparing the suture with a slipknot controller used in this embodiment is basically the same as that in Example 1. In this embodiment, as shown in FIG. Figure 5 As shown, it was applied to the intestinal rupture repair test of SD rats. A biopsy punch with a diameter of 1.5 mm was used to construct an intestinal rupture on the colon of the SD rat, and then a slipknot suture was used to suture it. When pulling the suture, it was not pulled by hand, but stretched with a screw, and a dynamometer was used to record the size of the knotting force in real time.

[0073] It is known from preliminary verification tests that the optimal knotting force for repairing rat intestinal rupture is 1.30N. Therefore, 1.30N is used as the preset knotting force. After inputting the preset force into the inverse solution system, it is known that the required preset force is 0.57N. Five slipknot sutures are prepared using this preset force, and then applied to the rat intestinal rupture repair experiment, and the knotting force is recorded when the slipknot controller is opened.

[0074] The data from the experimental results showed that the knotting force achieved by the slipknot controller was within 10% of the preset value, and in all five groups of experiments, the intestinal ruptures of rats were successfully closed.

[0075] It should be emphasized that the embodiments described in the present invention are illustrative rather than restrictive. Therefore, the present invention includes but is not limited to the embodiments described in the specific implementation manner. Any other implementation manners derived by those skilled in the art based on the technical solution of the present invention also fall within the scope of protection of the present invention.

Claims

1. A surgical suture preparation system with controllable knotting force based on a slipknot, characterized in that: It includes a slipknot controller with a specific spatial geometric structure, a precise force-controlled stretching device and a preset force solving system, wherein the end of the slipknot controller and the preset force-bearing end are connected to the precise force-controlled stretching device by clamping, the preset force solving system can calculate the preset force size corresponding to the specific slipknot opening force, and the precise force-controlled stretching device can load the corresponding preset force on the slipknot controller with a specific spatial geometric structure, so that the slipknot controller has a preset large opening force.

2. The system for preparing surgical sutures with controllable knotting force based on a slipknot according to claim 1, characterized in that: The slipknot controller has a knot with a specific spatial geometric structure that can be pulled apart, and a slipknot including but not limited to a fisherman's knot, a slipknot, a hitching knot and the like is woven at the tail end of the surgical suture, and a preset force of a specified size is applied, thereby obtaining a slipknot controller with a specific opening force. The force-bearing structure of the slipknot controller includes a preset force-bearing end, an opening force-bearing end and a line tail. By applying a pulling force to the preset force-bearing end and the line tail, the slipknot controller can be locked, and by applying a pulling force to the opening force-bearing end and the line tail, the slipknot controller can be untied, and finally restored to a linear shape.

3. The surgical suture preparation system with controllable knotting force based on a slipknot according to claim 2, characterized in that: The precise force-controlled stretching device is a stretching device that can stably clamp the force-bearing structure of the slipknot controller, apply a preset load, and maintain the load for any length of time. The two ends of the precise force-controlled stretching device are clamping devices that are not limited to pneumatic tooling. The clamping devices at both ends of the precise force-controlled stretching device respectively clamp the preset force-bearing end and the end of the thread in the force-bearing structure of the slipknot controller to prepare a slipknot controller with a specified output force; or respectively clamp the opening force-bearing end and the end of the thread in the force-bearing structure to measure the output force of the slipknot controller. The inner side of the clamping device is provided with an anti-slip structure to prevent slippage during the process of clamping the surgical suture.

4. The surgical suture preparation system with controllable knotting force based on a slipknot according to claim 2, characterized in that: The wire used in the slipknot controller is not limited by diameter and material, and includes but is not limited to silk, polylactic acid, polyglycolic acid, polyglycolide, polypropylene or collagen.

5. The system for preparing surgical sutures with controllable knotting force based on a slipknot according to claim 1, characterized in that: The preset force solving system calculates the preset force according to the required output force of the slipknot controller, the spatial geometric structure, and the material parameters of the wire.

6. The system for preparing surgical sutures with controllable knotting force based on a slipknot according to claim 5, characterized in that: The preset force is a force that stretches the slipknot controller to a predetermined load and maintains the load through the preset force-bearing end of the slipknot controller and the wire tail.

7. A method for preparing a slipknot-based surgical suture preparation system with controllable knotting force as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: Step 1, according to the spatial geometric structure of the slipknot controller, use surgical sutures to weave an untightened slipknot having the structure; Step 2, clamp the thread tail of the slipknot prepared in step 1 and the force-bearing end of the slipknot controlling the preset force on the precise force-controlled stretching device respectively; Step 3, inputting the required slipknot opening force, slipknot geometric parameters, and surgical suture material parameters into the preset force calculation system to calculate the preset force; Step 4: The precise force-controlled stretching device applies the preset force obtained in step 3 to the slipknot controller and maintains the load, thereby obtaining a slipknot controller with a specific opening force; Step 5, clamp the opening force control end and the thread tail of the slipknot controller with a specific opening force prepared in step 4 in a precise force control stretching device to measure the size of the slipknot opening force; Step 6: Compare the measured value of the slipknot opening force obtained in step 5 with the preset value of the required slipknot opening force, optimize the preset force solving system in step 3, and repeat steps 1-5 until the measured value is the same as the preset value.

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