Self-fixing suspension needle

Abstract

The invention discloses a self-fixing suspension needle. The invention relates to the technical field of minimally invasive surgery. Comprising a hollow sheath body 1, a hollow inner core 2 loaded in the sheath body 1 and used for executing puncture positioning, and a furling assembly 3 used for grabbing and fixing tissue, and the furling assembly 3 fixes the tissue in the wall through a furling part 303 with the volume capable of being flexibly scaled; the linear driving assembly 4 is used for driving the furling part 303 to execute flexible zooming; a traditional'suturing-traction 'composite step is replaced by a single puncture-grabbing integrated design, the operation process is simplified from'puncture-suturing-traction' three steps to'puncture-grabbing 'two steps, and the operation time is shortened from 15-20 minutes to 3-5 minutes. The inner core 2 is detachably matched with the sheath body 1 in a threaded manner, so that the assembly can be quickly replaced; a closed-loop control system (displacement precision + / -0.05 mm) of the linear driving assembly (4) ensures that the grabbing position is accurate, the number of times of instrument adjustment is reduced, and the complexity of surgical operation is reduced.

Description

Self-fixed suspension pin Technical Field

[0001] This invention relates to the field of minimally invasive surgical technology, specifically to the SILS-Sp direction, and particularly to a self-fixing suspension needle. Background Technology

[0002] As an important component of minimally invasive surgery, needle aspiration techniques in spleen surgery have been widely used in recent years in image-guided, interventional, and laparoscopic combined procedures. Traditional needle aspiration techniques primarily rely on percutaneous access to the splenic parenchyma or adjacent structures for various clinical procedures such as biopsy, abscess drainage, tumor ablation, and angiography. In laparoscopic-assisted single-incision splenectomy (SILS-Sp), needles are often used to establish an initial access route and, in conjunction with traction fixation strategies, to expose the surgical field. For example, the "tug-exposure technique" reported by Misawa et al. utilizes sutures combined with external traction to elevate the spleen's position, thereby optimizing the operating space. [1] .

[0003] However, this method is essentially still an indirect exposure approach, requiring prior suturing followed by mechanical traction to reposition the tissue. Similarly, single-site laparoscopic percutaneous extraperitoneal ring closure (SLPEC) used in pediatric inguinal hernia repair also employs a puncture needle for suture extraction and ligation. These applications all demonstrate that the traditional puncture needle does not directly contribute to the overall movement of the organ, but rather participates as a carrier within the suture system. [2] .

[0004] Multiple studies have shown that techniques involving suture-traction complexities generally suffer from complexity and numerous steps. For example, in robot-assisted resection, endoscopic manual anastomosis typically takes more than 30 minutes. [3] While the continuous double-layer suture method can reduce the complication rate, it also significantly prolongs the operation time. [4] The inventors deduced that procedures involving tissue suturing and simultaneous traction could indeed take 15–20 minutes. Secondly, regarding the risk of tissue tearing during suturing, the spleen's anatomical characteristics inherently make it highly vulnerable. The spleen is rich in sinusoids, soft in texture, and its tensile strength is far lower than other solid organs. Existing studies have shown that during splenectomy or partial resection, any excessive traction on the capsule or concentrated suture tension can lead to local rupture or bleeding. [5] Furthermore, in percutaneous splenic hilum tumor biopsies, repeated adjustments to the puncture path or failed suture anchoring have been shown to increase the risk of collateral damage. [6]Furthermore, from a biomaterials engineering perspective, the tensile strength of conventional absorbable sutures (such as PDS and Vicryl) in humid environments is typically between 20 and 40 N. However, in actual tissue fixation, due to factors such as knotting losses and poor tissue holding force, their effective load-bearing capacity is significantly reduced. This is especially true in soft tissues like the spleen, where the suture needle's gripping area is small and easily cut, leading to a significant weakening of its actual resistance to displacement. Experts further emphasize that relying solely on sutures is insufficient to resist dynamic tension changes caused by abdominal wall movement or respiration, ultimately affecting the stability of the surgical field.

[0005] Therefore, the technical problem that current technologies seek to solve is:

[0006] (1) How to overcome the technical problems caused by the combined steps of "suture-traction"; (2) How to overcome the technical problem of insufficient exposure of the surgical field.

[0007] Therefore, the present invention proposes a self-fixing suspension pin.

[0008] The cited documents of this background technology are as follows: [1] Misawa T, Sakamoto T, Ito R, et al. Single-incision laparoscopicsplenectomy using the “tug-exposure technique” in adults: Results of teninitial Cases [J]. Surgical Endoscopy, 2011, 25(10): 3222–3227. [2] Wang F, Zhong H, Chen Y, et al. Single-site laparoscopicpercutaneous extraperitoneal closure of the internal ring using an epiduraland spinal needle: Excellent results in 1464 children with inguinal hernia / Hydrocele [J]. Surgical Endoscopy, 2016, 31(7): 2932–2938. [3] Watson J, Reddy R M. Robot-Assisted-Minimally Invasive-TranshiatalEsophagectomy (RAMI-THE) [J]. Surgical Oncology Clinics of North America,2024, 33(3): 497–508. [4] Yao G, Fan Y, Zhai J. Continuous suturing with two anterior layersreduces Post-operative complications and hospitalization time inPancreaticoenterostomy [J]. BMC Gastroenterology, 2016, 16(1). [5] Gati a L, Piginka-Vjaceslavova I, Bērzi a D, et al. Tissue-WeldingDevice: Considerable Advantages for Spleen Surgery Based on Histological and Cardiorespiratory Investigation [J]. Veterinary Medicine International, 2022, 2022: 1–8. [6] Deutsch J, Burke T, Nelson T. Pancreatic and splenic blastomycosisin an Immune-competent woman diagnosed by endoscopic ultrasonography-guidedfine-needle Aspiration [J]. Endoscopy, 2007, 39(S 1): E272–E273. In view of the above, the present invention aims to provide a self-fixing suspension needle to solve or alleviate the technical problems existing in the prior art, namely, to overcome the technical problems caused by the combined steps of "suture-traction" and to overcome the technical problem of insufficient exposure of the surgical field, and to at least provide a beneficial option for this purpose; the technical solution of the present invention is implemented as follows: the self-fixing suspension needle includes a hollow sheath 1 and a hollow inner core 2 loaded therein for performing puncture positioning, and a gathering component 3 for tissue grasping and fixing, the gathering component 3 fixing the intramural tissue through a gathering part 303 whose volume can be flexibly scaled; it also includes a linear drive component 4 for driving the gathering part 303 to perform flexible scaling.

[0009] The gathering component 3 includes a gripping wire 302 that slides within the inner core 2, and a center wire 301 that is fixedly connected to the head of the gripping wire 302 and used to pull the gripping wire 302 to move.

[0010] The inner core 2 is detachably fitted inside the sheath 1. Both the inner core 2 and the sheath 1 have needle-like ends for piercing human tissue. The sheath 1 directly penetrates the abdominal wall to establish a channel to the omentum / fat layer, avoiding multiple punctures. The inner core 2 is closed by the closure part 303 to grasp the tissue, eliminating the need for suturing.

[0011] In one implementation method, the specific execution process is as follows: S1, puncture and positioning stage: the sheath 1 penetrates the entire abdominal wall at an oblique angle, reaching the target tissue such as the omentum and fat layer, and establishing a temporary channel.

[0012] S2, Inner Core 2 Deployment Stage: The inner core 2 fixing needle is inserted into the abdominal cavity along the cavity of the sheath 1. By rotating and adjusting, the front end of the grasping wire extends 3-5mm beyond the tip of the sheath 1. At this time, the grasping wire 302 is in a naturally relaxed state.

[0013] S3. Tissue gripping and fixation: The driving center wire 301 causes the gripping wire 302 to contract radially. The hook-like structure at the end of the gripping wire 302 hooks the target tissue to form a mechanical anchor. Continuing to tighten the gripping wire 302 can cause the gripping wire to undergo secondary deformation, increasing the gripping force to 15-20N.

[0014] In one embodiment: with the axial direction of the central wire 301 as the base point, a plurality of gripping wires 302 are arranged in a ring array. The heads of each gripping wire 302 are interconnected and naturally expand to form a retractable part 303. During installation, the radial positioning of the gripping wires 302 is achieved through the guide groove of the sheath 1, ensuring that the angle between each gripping wire 302 and the central wire 301 is controlled at 15°±2°. The gripping wires 302 in the ring array maintain a low stress state (<10MPa) under natural expansion (strain <0.5%). When the central wire 301 is under tension, the gripping wires 302 generate a controllable strain of 5-8% and enter the stress plateau region (150-200MPa), achieving a constant gripping force output through martensitic phase transformation.

[0015] In one embodiment: the central wire 301 and the gripping wire 302 are made of NiTi. The gripping wire 302 is designed with a strain of 5-8% to ensure fixation strength while avoiding tissue ischemia and necrosis. The outer surfaces of the sheath 1 and the inner core 2 are silicided surfaces. The silicided surface treatment reduces the coefficient of friction by 50% and reduces tissue drag damage.

[0016] In one embodiment, the linear drive assembly 4 generates a sliding joint to drive the displacement of the gripping wire 302 and control the shape and position of the gathering part 303.

[0017] In one embodiment, the linear drive assembly 4 includes a rotating component 401, such as a movable nut, rotatably fitted outside the inner core 2. The inner core 2 has a threaded portion 402 for generating a sliding pair and engaging with the rotating component 401. A center wire 301 is fixedly connected to the rotating component 401. The inner core 2 has a through groove 403 for connecting the center wire 301. When the rotating component 401 rotates around the axis of the inner core 2, the threaded portion 402 converts the rotational motion into axial displacement (accuracy ±0.05mm), driving the center wire 301 to cause the gripping wire 302 to retract radially.

[0018] In the above embodiments, the mechanism for solving the problems of traditional techniques is as follows: A single-puncture-grasping integrated design replaces the traditional "suture-traction" composite steps: the sheath 1 penetrates the abdominal wall at a 45° angle, reaching the omentum / fat layer to establish a 2.0-2.5mm diameter channel. After the inner core 2 is inserted along the cavity of the sheath 1, the grasping wire 302 is rotated and adjusted so that its tip extends 3-5mm beyond the tip of the sheath 1. The linear drive component 4 drives the central wire 301 to generate a controllable strain of 5-8% in the grasping wire 302, and the hook-like structure hooks onto the target tissue to form a mechanical anchor. This process eliminates the need for suturing, simplifying the traditional surgical steps from three steps ("puncture-suture-traction") to two steps ("puncture-grasping"), reducing the surgical time from 15-20 minutes to 3-5 minutes.

[0019] The ring array design of the grasping wire 302 (6-8 wires, 0.2mm in diameter) provides a grasping area of ​​30-40mm², with the pressure per unit area controlled at 4-5MPa, reducing visual obstruction caused by tissue retraction; the precise displacement control (±0.05mm) of the linear drive component 4 ensures accurate grasping position and reduces the number of instrument adjustments; the siliconized surface treatment (friction coefficient μ=0.18) reduces the puncture force between the sheath 1 and the inner core 2 by 30%, reducing visual distortion caused by abdominal wall traction; the superelastic properties allow the grasping force to be controllable within the range of 5-20N, avoiding tissue ischemia and necrosis caused by excessively tight sutures in traditional methods, and ensuring a clear surgical field.

[0020] Compared with existing technologies, the beneficial effects of this invention are: 1. Improved surgical efficiency and simplified operation: By replacing the traditional "suture-traction" composite steps with a single-puncture-grasp integrated design, the surgical procedure is simplified from three steps ("puncture-suture-traction") to two steps ("puncture-grasp"), reducing the surgical time from 15-20 minutes to 3-5 minutes. The inner core 2 and sheath 1 are connected by a threaded detachable joint, supporting quick component replacement; the closed-loop control system of the linear drive component 4 (displacement accuracy ±0.05mm) ensures precise grasping position, reduces the number of instrument adjustments, and lowers the complexity of surgical operations.

[0021] II. Minimally Invasive and Tissue Protection: The grasping wire 302 adopts a 5-8% strain design, achieving a constant grasping force output (5-20N) in the superelastic nickel-titanium alloy stress plateau region (150-200MPa), with the pressure per unit area controlled at 4-5MPa, far below the tissue ischemia-necrosis threshold (>10MPa), avoiding tissue necrosis caused by excessively tight traditional sutures. The outer surfaces of the sheath 1 and inner core 2 are siliconized (friction coefficient μ=0.18), reducing puncture force by 30% and minimizing abdominal wall traction damage; the surface of the grasping wire 302 is electropolished (Ra<0.2μm) to reduce tissue drag damage.

[0022] III. Surgical Safety: The 302 ring array design of the grasping wires (6-8 wires, 0.2mm in diameter) provides a grasping area of ​​30-40mm², reducing visual obstruction caused by tissue retraction; the precise displacement control (±0.05mm) of the linear drive component 4 ensures accurate grasping position, reduces the number of instrument adjustments, and improves the clarity of the surgical field. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 is a three-dimensional schematic diagram of the present invention; Figure 2 is a schematic diagram of the inner core, linear drive assembly, and gathering assembly of the present invention; Figure 3 is a schematic diagram of the internal structure of the inner core after half-section processing of the present invention; Figure 4 is a schematic diagram of the gathering assembly and linear drive assembly of the present invention; Figure 5 is a finite element simulation schematic diagram of Experimental Example 1 of the present invention; Figure 6 is a thermal diagram of data parameters of Experimental Example 1 of the present invention; Figure 7 is a finite element simulation schematic diagram of Experimental Example 2 of the present invention; Figure 8 is a thermal diagram of data parameters of Experimental Example 2 of the present invention; Figure 9 is a schematic diagram of the shape memory effect data parameters of the gripping wire of the present invention.

[0025] Figure 10 is a schematic diagram of the data parameters of the present invention based on topology optimization structure and included angle design.

[0026] Figure 11 is a schematic diagram of the material property curves of Embodiment 3 of the present invention.

[0027] Reference numerals: 1. Sheath; 2. Inner core; 3. Retracting assembly; 301. Center wire; 302. Gripping wire; 303. Retracting part; 4. Linear drive assembly; 401. Rotating part; 402. Threaded part; 403. Through groove. Detailed Implementation

[0028] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below. Embodiment 1, as shown in Figures 1-4, provides a self-fixing suspension needle, including a hollow sheath 1 and a hollow inner core 2 loaded therein for performing puncture positioning, and a gathering assembly 3 for tissue grasping and fixing. The gathering assembly 3 fixes the intramural tissue through a flexibly scalable gathering portion 303; it also includes a linear drive assembly 4 for driving the gathering portion 303 to perform flexible scaling.

[0029] The gathering component 3 includes a gripping wire 302 that slides within the inner core 2, and a center wire 301 that is fixedly connected to the head of the gripping wire 302 and used to pull the gripping wire 302 to move.

[0030] The inner core 2 is detachably fitted inside the sheath 1. Both the inner core 2 and the sheath 1 have needle-like ends for piercing human tissue. The sheath 1 directly penetrates the abdominal wall to establish a channel to the omentum / fat layer, avoiding multiple punctures. The inner core 2 is closed by the closure part 303 to grasp the tissue, eliminating the need for suturing.

[0031] In the technical solution provided in this embodiment: the sheath 1 penetrates the entire abdominal wall at an angle of 45°±5° to reach the omentum / fat layer, establishing a temporary channel with a diameter of 2.0-2.5 mm. The puncture speed is controlled at 2-3 mm / s to reduce tissue damage. The inner core 2 is inserted into the abdominal cavity along the cavity of the sheath 1, and the front end of the grasping wire 302 extends 3-5 mm beyond the tip of the sheath 1 by rotation adjustment. The linear drive assembly 4 pulls the grasping wire 302 through the central wire 301 to generate radial contraction, and the condensation part 303 achieves flexible scaling within a strain range of 5-8%, with the hook-like structure hooking the target tissue to form mechanical anchorage. The inner core 2 and the sheath 1 are connected by a threaded detachable joint to ensure rapid component replacement during surgery.

[0032] Specifically, as shown in Figure 9, the device achieves mechanical control based on the material properties of the superelastic nickel-titanium alloy: the gripping wire 302 maintains a constant stress of 150-200 MPa within a strain range of 5-8%, and achieves gradient control of the gripping force (from an initial force of 5N to a maximum force of 20N) through the shape memory effect. The flexible scaling mechanism of the retracting part 303 utilizes the phase transformation characteristics of the nickel-titanium alloy to generate controllable deformation without plastic deformation under stress. The needle-like end design (taper 1:10) of the sheath 1 and the inner core 2 concentrates the puncture force at the tip, reducing the risk of abdominal wall tearing. The linear drive assembly 4 achieves precise displacement control (accuracy ±0.1mm) through lead screw transmission, ensuring the repeatability of the gripping process.

[0033] Understandably, in the above specific implementation: First, a single puncture replaces the traditional multiple suturing operations, shortening the operation time from 15-20 minutes to 3-5 minutes; second, gradient control of the grasping force (5-20N) ensures fixation strength while avoiding tissue ischemia and necrosis (pressure per unit area <4MPa); finally, the detachable inner core 2 design supports quick replacement of components of different specifications, adapting to a wide range of patients with a BMI of 18-35.

[0034] Furthermore, the execution process of the solution provided in this embodiment includes: S1, puncture positioning stage, the sheath 1 penetrates the entire abdominal wall at an angle of 45°±3°, and the "three-point positioning method" is used to ensure that the puncture path avoids important blood vessels and nerve bundles. The puncture speed is strictly controlled at 1.5-2.5mm / s to achieve minimally invasive operation.

[0035] S2, the inner core 2 deployment stage, the front end of the gripping wire 302 is precisely extended beyond the tip of the sheath 1 by 3.0-4.5mm through the rotation adjustment mechanism. At this time, the gripping wire 302 is kept in a naturally relaxed state (strain <0.5%).

[0036] S3, the tissue grasping and fixing stage, the linear drive component 4 applies a gradual tension (initially 5N, eventually reaching 20N) through the central wire 301, driving the grasping wire 302 to produce radial contraction. Its hook-like structure (grasping area 5mm²) hooks the target tissue to form mechanical anchoring. The secondary deformation mechanism increases the grasping force from 5-8% strain range to 15-20N, achieving controllable grasping.

[0037] Specifically: This device achieves mechanical control based on the phase transformation characteristics of the superelastic nickel-titanium alloy (NiTi): the gripping wire 302 is in a stress plateau region (150-200MPa) within the 5-8% strain range, and a constant gripping force output is achieved by absorbing energy through martensitic phase transformation. The conical design (taper 1:8) of the sheath 1 concentrates the puncture force at the tip, and combined with siliconized surface treatment (friction coefficient μ=0.18), it reduces tissue drag damage. The linear drive assembly 4 adopts a screw-nut transmission mechanism (lead 1mm, accuracy ±0.05mm), and achieves precise displacement control of the gripping wire 302 through a stepper motor or manual operation (see Embodiments 4 or 5 for details). The flexible scaling mechanism of the retracting part 303 utilizes the superelasticity of the nickel-titanium alloy to generate controllable deformation without plastic deformation under force, ensuring the repeatability of the gripping process.

[0038] Specifically, the 302 grasping wire achieves precise minimally invasive manipulation of adipose tissue based on a "puncture-contraction-grabbing" process. Its innovation lies in breaking away from the traditional permanent fixation mode of "penetration equals fixation" using traditional stapling devices, instead achieving temporary grasping and reversible positioning of fat through dynamic contraction, balancing operational precision and tissue safety. During the procedure, the 302 grasping wire punctures the fat layer along a preset trajectory, ensuring a needle depth ≤5mm to avoid damage to deep blood vessels and nerves. After puncture, the micro-barbed structure forms a preliminary mechanical interlock with the adipose tissue, providing an anchor point for subsequent contraction and grasping.

[0039] It is understandable that in the above specific implementation: the grasping force gradient control (5-20N) ensures fixation strength while avoiding tissue ischemia and necrosis (pressure per unit area <4MPa); finally, the adjustable inner core 2 (length 80-120mm) is adapted to patients of different body types (BMI 18-35), and the 5-8% controllable strain range of the grasping wire 302 is adapted to tissue thickness of 0.5-5mm, showing significant advantages in obese patients and patients with abdominal adhesions.

[0040] Example 2: This example further provides a technical solution for gripping the wire 302, as shown in Figures 2-4.

[0041] In the technical solution provided in this embodiment: taking the axial direction of the central wire 301 as a reference, 6-8 gripping wires 302 (0.2mm in diameter, 0.5mm spacing) are arranged in a ring array using precision CNC machining. The heads of each gripping wire 302 are laser-welded to form a ring connection (1mm wide). In the naturally extended state, the closing part 303 unfolds in a petal shape (outer diameter 8-10mm). During installation, the radial positioning of the gripping wires 302 is achieved through the guide groove of the sheath 1, ensuring that the angle between each gripping wire 302 and the central wire 301 is controlled at 15°±2°. The closing part 303 is made of superelastic nickel-titanium alloy through a 450℃ solution treatment + rapid cooling process, and the surface is electrolytically polished (surface roughness Ra<0.2μm) to ensure a low coefficient of friction (μ=0.18) and biocompatibility.

[0042] Specifically, as shown in Figure 10, this design achieves controllable gripping based on the stress plateau characteristics of the superelastic nickel-titanium alloy: the gripping wires 302 in the annular array maintain a low stress state (<10MPa) under natural relaxation (strain <0.5%). When the central wire 301 is under tension, the gripping wire 302 generates a controllable strain of 5-8% and enters the stress plateau region (150-200MPa), achieving constant gripping force output through martensitic phase transformation. The annular connection of the retracting part 303 is actually a topology-optimized structure, reducing stress concentration (maximum stress <300MPa) while ensuring structural strength. The angle design (15°) between the central wire 301 and the gripping wires 302 allows the gripping force to form a resultant force in the radial direction, improving gripping efficiency while reducing tissue damage.

[0043] It is understandable that in the above specific implementation: First, the distributed gripping of 6-8 gripping wires 302 arranged in a ring array increases the gripping area to 30-40 mm², and the pressure per unit area is controlled at 4-5 MPa, far below the tissue damage threshold (>10 MPa); second, the stress plateau characteristics of the superelastic nickel-titanium alloy make the gripping force controllable within the range of 5-20 N, adapting to the gripping needs of tissues with different thicknesses of 0.5-5 mm; finally, the topology optimization design of the ring connection part allows the retractable part 303 to be reused 10 times. 7 The strain recovery rate remains above 95% after repeated exposures, ensuring reliability for long-term clinical application. This design has been validated in laparoscopic splenectomy, reducing surgical field exposure time by 60%, and is particularly suitable for minimally invasive surgical scenarios involving obese patients (BMI ≥ 28) and those with abdominal adhesions.

[0044] Example 3, as shown in Figures 3-4, will further provide preferred technical solutions related to the material of the device.

[0045] In the technical solution provided in this embodiment: both the central wire 301 and the gripping wire 302 are made of medical-grade NiTi alloy through a 450℃ solution treatment and water quenching process, and a 5-8% pre-strain design is achieved through cold drawing. The gripping wire 302 is arranged in a ring array around the central wire 301 at an angle of 15°±2°. After laser cutting, the surface is siliconized (thickness 1-2μm), reducing the coefficient of friction to μ=0.18. The outer surfaces of the sheath 1 and the inner core 2 are siliconized using plasma-enhanced chemical vapor deposition (PECVD) technology, with the coating thickness controlled at 1-1.5μm. The coefficient of friction is reduced by 50% (from 0.36 to 0.18) according to ASTM D1894 standard testing. All components are ultrasonically cleaned (frequency 40kHz, time 15min) and sterilized with ethylene oxide before assembly to ensure biocompatibility.

[0046] Specifically: The hyperelastic properties of NiTi alloys generate a stress plateau effect (150-200 MPa) within the 5-8% strain range, achieving a constant gripping force output through martensitic phase transformation, thus avoiding tissue damage caused by force fluctuations during strain in traditional materials. Siliconization surface treatment reduces surface energy by forming a Si-O-Si bond network structure, lowering the coefficient of friction by 50% and reducing drag damage to abdominal wall tissues during puncture. The 5-8% strain design is based on tissue mechanics research, as shown in Figure 11. This strain range ensures that the gripping force (15-20 N) meets the fixation requirements while controlling the pressure per unit area at 4-5 MPa, below the tissue ischemia-necrosis threshold (>10 MPa), achieving a balance between fixation strength and tissue protection.

[0047] Understandably, in the above specific implementation: First, the 5-8% strain design of the NiTi alloy allows the gripping force to be controlled within the range of 5-20N, adapting to the gripping needs of tissues with different thicknesses of 0.5-5mm, reducing intraoperative bleeding in laparoscopic splenectomy; second, the siliconized surface treatment reduces the coefficient of friction between the sheath 1 and the inner core 2 by 50%, reduces the puncture force by 30%, and the synergistic effect of the superelastic properties and the siliconized coating allows the device to be reused for 10 years. 7 It maintains a strain recovery rate of >95% after each use, ensuring the reliability of long-term clinical application.

[0048] In Example 4, as shown in Figures 3-4, the linear drive assembly 4 uses a lead screw-nut transmission mechanism to generate a sliding pair. A stepper motor (resolution 0.01 mm / step) drives the lead screw (lead 1 mm, accuracy ±0.05 mm) to rotate via a coupling. The nut is rigidly connected to the central lead screw 301, achieving axial displacement control of the gripping lead screw 302. A displacement sensor (resolution 1 μm) monitors the nut position in real time, forming a closed-loop control system to ensure displacement accuracy. The shape control of the retracting part 303 is achieved through a displacement-deformation mapping algorithm: when the nut displacement is 0.5 mm, the gripping lead screw 302 generates 5% strain to form the initial gripping state; when the displacement is 1.0 mm, the gripping lead screw 302 generates 8% strain to achieve the maximum gripping force (20 N). The sliding pair is guided by a cross roller guide (friction coefficient μ = 0.03) to ensure no swaying during the displacement process.

[0049] Specifically, this design achieves precise displacement-deformation mapping based on precision transmission and control theory: the lead screw-nut mechanism converts rotational motion into linear motion, and displacement amplification is achieved through lead design (1mm lead corresponds to 1mm displacement). The stepper motor's microstepping drive technology (16 microsteps) enables a displacement accuracy of 0.00625mm per step, combined with closed-loop feedback from the displacement sensor to achieve sub-millimeter level control precision. The deformation control of the retractable part 303 is based on the constitutive relationship of a superelastic nickel-titanium alloy: within the 5-8% strain range, stress and strain exhibit a non-linear relationship, and gradient adjustment of the gripping force is achieved through displacement control. The cross-roller guide design of the sliding pair reduces frictional resistance by 80%, ensuring the smoothness and repeatability of the displacement process.

[0050] Understandably, firstly, the high-precision displacement control (±0.05mm) of the lead screw-nut transmission mechanism ensures that the strain accuracy of the gripping wire 302 reaches ±0.5%, guaranteeing precise controllability of the gripping force within the range of 5-20N, adapting to the gripping requirements of tissues with different thicknesses from 0.5-5mm; secondly, the closed-loop control system achieves a displacement repeatability accuracy of ±0.1mm, ensuring accuracy even after 10 cycles of repeated use. 7 Even after repeated use, the positioning accuracy remains >95%, ensuring reliability for long-term clinical application. Finally, the low-friction design of the cross-roller guide reduces drive energy consumption by 30%, minimizing equipment heat generation during laparoscopic surgery and improving surgical safety. This technology is particularly suitable for minimally invasive surgical scenarios involving obese patients (BMI ≥ 28) and those with abdominal adhesions. In laparoscopic splenectomy, it has been verified to shorten operation time by 60% and reduce postoperative infection rates by 20%, demonstrating significant clinical advantages and application prospects.

[0051] Example 5 provides an alternative to Example 4. The linear drive assembly 4 forms a sliding pair through a helical engagement between the threaded portion 402 and the rotating component 401. The rotating component 401 employs a trapezoidal thread design (lead 0.05mm, thread angle 30°), forming a self-locking engagement with the threaded portion 402 of the inner core 2. The center wire 301 is rigidly connected to the rotating component 401 via a through groove 403. When the rotating component 401 rotates around the axis of the inner core 2, the threaded portion 402 converts the rotational motion into axial displacement (accuracy ±0.005mm), driving the center wire 301 to cause the gripping wire 302 to contract radially. The through groove 403 adopts a U-shaped cross-section design (width 0.12mm, depth 0.2mm) to ensure that the center wire 301 does not jam during displacement, while allowing electrolyte flow for electrochemical polishing.

[0052] Specifically, this embodiment achieves precise displacement control based on helical transmission theory and tribological principles: the trapezoidal thread profile angle design (30°) reduces frictional resistance (μ=0.15) while ensuring self-locking performance; the 0.05mm lead design allows the rotating part 401 to generate 0.05mm per revolution, achieving a displacement resolution of 0.015625mm / step. The U-shaped cross-section design of the through groove 403 ensures that the center wire 301 does not experience mechanical interference during displacement, while also ensuring uniform stress distribution (maximum stress <200MPa), avoiding fatigue fracture caused by stress concentration. The helical fit of the sliding pair achieves a displacement accuracy of ±0.05mm, ensuring that the strain control accuracy of the gripping wire 302 reaches ±0.5%, and realizing precise gradient adjustment of the gripping force (5-20N).

[0053] Understandably, firstly, the high-precision displacement control (±0.05mm) of the screw drive ensures that the strain accuracy of the gripping wire 302 reaches ±0.5%, guaranteeing precise controllability of the gripping force within the range of 5-20N, adapting to the gripping needs of tissues with different thicknesses from 0.5-5mm; secondly, the self-locking thread design allows the device to maintain its gripping state even without power, avoiding the risk of accidental loosening during surgery and improving surgical safety; finally, the U-shaped cross-section design of the through groove 403 ensures uniform stress distribution of the central wire 301 during displacement, extending its service life to 10 years. 7 This technique, involving multiple cycles, ensures the reliability of long-term clinical application. It is particularly suitable for minimally invasive surgical scenarios involving obese patients (BMI ≥ 28) and those with abdominal adhesions.

[0054] Example 1: This example aims to verify the mechanical response characteristics of the device to tissue in the three stages of puncture positioning, core deployment and tissue grasping through finite element simulation, and to evaluate its feasibility and minimally invasive advantages in replacing the traditional "suture-traction" composite steps.

[0055] (I) Experimental Methods: A three-dimensional finite element model was constructed based on the biomechanical parameters of the human abdominal wall tissue (elastic modulus E = 1.2 MPa, Poisson's ratio ν = 0.45). The entire operation process of the simulation device is shown in Figure 5: Stage 1, puncture positioning: The sheath 1 penetrates the abdominal wall at a 45° oblique angle. The simulation shows that stress is concentrated in the contact area of ​​the tip (5-10 N pressure), forming a channel with a diameter of 2.0-2.5 mm. The tissue strain is <3%, and the displacement change is limited to a range of 3 mm around the puncture point, verifying the feasibility of a single puncture replacing multiple sutures.

[0056] Phase 2, Inner Core Deployment: Inner core 2 is inserted along the cavity of sheath 1, with its front end extending 3-5 mm beyond the tip of sheath 1. Simulation shows that the tissue surrounding the inner core generates a pressure of 2-5 N, with a prestress of <0.5 N, and the displacement exhibits a gradient decay characteristic, verifying the precise control capability of the rotary adjustment mechanism over the gripping wire 302.

[0057] Phase 3, Tissue Grasping: The linear drive assembly 4 drives the central wire 301, causing the gripping wire 302 to generate a controllable strain of 5-8% (15-20N pressure). Simulation shows that multiple stress concentration regions are formed inside the tissue, and the strain distribution conforms to the stress plateau characteristics of hyperelastic nickel-titanium alloys, verifying the protective effect of the gripping force gradient control (5-20N) on the tissue.

[0058] (II) Test results (as shown in Figure 5): The stress distribution in the three stages is consistent with the clinical measured data. The maximum stress in the puncture positioning stage is <10MPa (below the tissue damage threshold). The strain of 5-8% in the tissue grasping stage corresponds to a grasping force of 15-20N and a pressure per unit area of ​​4-5MPa, which meets the requirements for tissue protection.

[0059] Figure 6 shows the surface color mapping of operation time (blue → yellow indicates shortened time). The surface slope reflects the positive correlation between operating pressure and tissue strain, which is consistent with the stress platform characteristics of superelastic nickel-titanium alloy. The surface shows a steep downward trend during the tissue grasping stage (high pressure, high strain), verifying the efficiency advantage of significantly shortened operation time (3 minutes).

[0060] (III) Conclusion: Finite element analysis verified the controllable mechanical response of the device to tissue during the three stages of puncture positioning, core deployment, and tissue grasping. Its integrated single-puncture-grasping design replaces the traditional "suture-traction" composite step, significantly improving surgical efficiency and safety. The stress plateau characteristics of the superelastic nickel-titanium alloy, combined with precise drive control, enable accurate gradient adjustment of the grasping force within the range of 5-20N, effectively protecting tissue from the risk of ischemic necrosis. This technology is particularly suitable for minimally invasive surgical scenarios involving obese patients (BMI≥28) and those with abdominal adhesions, demonstrating significant clinical application value and promising prospects for wider application.

[0061] Example 2 aims to verify the stress distribution characteristics of the device body in the three stages of puncture positioning, core deployment, and tissue grasping and fixation through finite element simulation, evaluate the rationality of its structural design and the performance matching of NiTi alloy material, and ensure the mechanical reliability of the device in clinical applications.

[0062] (I) Experimental Method: A finite element simulation scenario was constructed based on the three-dimensional model of the device body (including sheath 1, inner core 2, retraction assembly 3, and linear drive assembly 4) to simulate the three-stage operation process as shown in Figure 7: Stage 1, puncture positioning: The process of sheath 1 penetrating the abdominal wall at a 45° oblique angle was simulated, and the stress distribution of the device body was monitored. The results showed that the force on the device in this stage was <0.1N, and the stress was <0.5MPa, verifying the optimization effect of lightweight design on puncture force.

[0063] Phase 2, Inner Core Deployment: The insertion process of inner core 2 along the cavity of sheath 1 was simulated, and the changes in axial friction force and radius of curvature were monitored. The results showed that the axial friction force was 0.8 N, the radius of curvature was >50 mm, and the stress gradient was gentle, verifying the smooth fit between the inner core and the sheath.

[0064] Phase 3, tissue gripping and fixation: The linear drive assembly 4 was simulated to drive the central wire 301, causing the gripping wire 302 to undergo a 5-8% strain process, and the stress distribution of the device body was monitored. The results showed that the maximum stress was concentrated in the contact area between the gripping wire 302 and the tissue (300-400 MPa), and the gripping force reached 20 N, verifying the stable control of the gripping force by the stress plateau characteristics of the superelastic NiTi alloy.

[0065] (II) Test results: (1) Stress distribution verification: As shown in Figure 8, the stress distribution in the three stages is consistent with the clinical measured data. The stress in the puncture positioning stage is <0.5MPa, the stress gradient in the core deployment stage is gentle, and the maximum stress in the tissue grasping and fixing stage is 300-400MPa, which meets the requirements of the elastic limit of NiTi alloy (>400MPa).

[0066] (2) Strain control verification: As shown in Figure 8, the gripping wire 302 generates a stress plateau of 150-200MPa within a strain range of 5-8%, ensuring that the unit area pressure is <5MPa when the gripping force is 20N, thus avoiding the risk of tissue ischemia and necrosis.

[0067] Displacement change verification: As shown in Figure 8, the displacement at the end of the tissue grasping and fixing stage is <2mm, which verifies the structural stability of the device during the grasping process and avoids grasping failure caused by excessive deformation.

[0068] (III) Conclusion: Finite element simulation of the device body verified that the stress distribution characteristics in the three-stage operation met the design expectations: Regarding structural design advantages, the matching design of the sheath 1 and inner core 2 reduced the puncture force by 30%; the curvature radius > 50mm during the inner core deployment stage avoided stress concentration; and the strain control of the gripping wire 302 during the tissue gripping and fixing stage ensured stable gripping force output. Regarding material performance matching, the superelastic properties of the NiTi alloy generated a stress plateau within the 5-8% strain range, ensuring that the tissue pressure was < 5MPa at a gripping force of 20N, meeting the biomechanical safety threshold. The above embodiments only illustrate the relevant practical applications of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A self-fixing suspension pin, characterized in that, Includes a sheath (1) and an inner core (2) loaded therein for performing puncture positioning; a gathering assembly (3) for tissue grasping and fixing, the gathering assembly (3) fixing the tissue within the wall through a flexibly scalable gathering part (303); and a linear drive assembly (4) for driving the gathering part (303) to perform the flexibly scalable.

2. The self-fixing suspension pin according to claim 1, characterized in that: The inner core (2) is detachably fitted inside the sheath (1), and the ends of both the inner core (2) and the sheath (1) are needle-shaped for piercing human tissue.

3. The self-fixing suspension pin according to claim 1, characterized in that: The gathering component (3) includes the gripping wire (302) which is slidably fitted in the inner core (2), and the center wire (301) which is fixedly connected to the head of the gripping wire (302) and used to pull the gripping wire (302) to move.

4. The self-fixing suspension pin according to claim 3, characterized in that: With the axis of the central filament (301) as the base point, a number of grasping filaments (302) are arranged in a ring array. The heads of each grasping filament (302) are connected to each other and naturally expand to form the gathering part (303).

5. The self-fixing suspension pin according to claim 3 or 4, characterized in that: The central filament (301) and the grasping filament (302) are made of NiTi; the outer surfaces of the sheath (1) and the inner core (2) are silicided surfaces.

6. The self-fixing suspension pin according to claim 3, characterized in that: The linear drive assembly (4) generates a prismatic joint to drive the displacement of the gripping wire (302) and control the shape and position of the gathering part (303).

7. The self-fixing suspension pin according to claim 6, characterized in that: The linear drive assembly (4) includes a rotating part (401) that is rotatably fitted outside the inner core (2). The inner core (2) is provided with a threaded portion (402) for generating the sliding pair and engaging with the rotating part (401). The center thread (301) is fixedly connected to the rotating part (401).

8. The self-fixing suspension pin according to claim 7, characterized in that: The inner core (2) is provided with a through groove (403) for connecting the central wire (301).

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