Minimally invasive surgery modular deformable suture needle and its morphology control method

Abstract

The present invention relates to the field of medical devices, and specifically to a minimally invasive surgical modular deformable suture needle and its morphology control method. The present invention realizes a small diameter of the needle body under the premise of ensuring overall safety by differentially connecting the deformation control unit in parallel, and the needle body segment has the ability to independently and controllably continuously deform in each degree of freedom and direction, and can quantitatively control the dynamic deformation in the surgical object through external voltage or thermal power input during the suturing process, with high suturing efficiency and strong device deformation ability. The main steps include constructing a differential parallel flexible deformable needle body, constructing a minimally invasive surgical modular deformable suture needle, quantitatively expressing the bending deformation characteristics, establishing a single-segment morphology control model, and coherent morphology control, which overcomes the limitation that traditional minimally invasive surgical instruments are difficult to smoothly perform turning, moving forward, retreating, and other actions in the complex environment of the surgical object.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to a minimally invasive surgery modular deformable suture needle and a morphology control method thereof. Background Art

[0002] Minimally invasive surgery mainly includes laparoscope and endoscopic surgery. Suturing tools are inserted through a narrow incision to perform suturing operations. It has the characteristics of small wounds and is conducive to the patient's postoperative recovery. However, when the sutured area is blocked or covered by tissues or organs, traditional suture needles are difficult to turn, move forward, or move backward smoothly in such a complex environment, making suturing difficult.

[0003] The suture needle with a wavy shape (application number 202030050860.2, application date 2020.02.13, authorization announcement number CN 305950465S) proposes a fixed-shape wavy needle body, which makes it difficult to adapt the needle body shape according to actual needs during the suturing process.

[0004] A surgical spiral puncture suture needle (application number 202410760769.7, application date 2024.06.13, application publication number CN 118526241A) proposes a spiral needle body with a fixed shape, which makes it difficult to adapt the needle body shape according to actual needs during the suturing process.

[0005] A double-eyelid suture needle with multiple specifications (application number 202121606808.6, application date 2021.07.15, authorization announcement number CN 214856994 U) proposes a split suture needle with a fixed shape, which makes it difficult to adapt the needle body shape according to actual needs during the suturing process.

[0006] The bendable suture needle (application number 201930457152.8, application date 2019.08.22, authorization announcement number CN305576726S) cannot be separated from the bending load application device to dynamically adjust the bending shape during the suturing process.

[0007] In order to achieve flexible deformation of slender arms in complex suturing environments, the commonly used deformation control methods currently include motor drive, hydraulic drive, pneumatic drive, rope drive, and memory alloy drive. Motor, hydraulic, and pneumatic drive have high control accuracy, but are difficult to achieve in micro-sizes. Rope and memory alloy drive have poor control accuracy, and because they are homogeneous flexible materials, they are difficult to perform complex deformations with multiple degrees of freedom.

[0008] The pneumatic and wire-controlled deformation system in an air-rope hybrid-driven flexible robotic arm (application number 202410723788.2, application publication number CN118544335A, application date 2024.06.05) is difficult to use for deformation control of suture needles with millimeter diameters due to component size and material strength issues.

[0009] A piezoelectrically driven flexible spring micro-pipeline inspection robot and its control method (application number 202211639177.7, application publication number CN 115854173 A, application date 2022.12.20) adopts an articulated morphological controller. The system has poor axial toughness and integrity, and is prone to breakage when used for suture needles with a diameter of millimeters.

[0010] The rope-spring assembly deformation system in a rope-driven flexible robotic arm (application (patent) number: CN202111371348.8, application publication number: CN113894840A, application date: 2021.11.18) cannot be used for the deformation control of suture needles with a diameter of millimeters due to component size and material strength issues.

[0011] The nickel-titanium memory alloy coils in the artificial muscle driven by nickel-titanium memory alloy (application (patent) number: CN202410349164.9, application publication number: CN118238119A, application date: 2024.03.26) will produce mutual heat conduction and electromagnetic induction interference when they are small in size, and the deformation control accuracy is poor, and it cannot be used for deformation control of suture needles with a diameter of millimeters.

[0012] The amphibious snake-like robot based on a multi-degree-of-freedom flexible motion unit (application (patent) number: CN201210336869.4, application publication number: CN102837307A, application date: 2012.09.13) adopts a dielectric deformation drive device. The system has poor axial toughness and integrity and cannot be used for deformation control of suture needles with a diameter of millimeters.

[0013] The shape memory alloy controlled adjustable curved conduit (application (patent) number: CN202410660611.2, application publication number: CN118576868A, application date: 2024.05.27) adopts a symmetrical memory alloy wire arrangement method and cannot perform "S" shape deformation.

[0014] A shape memory alloy wire-driven flexible robotic arm mechanism and its flexible robotic arm (application (patent) number: CN201210433479.9, application publication number: CN102962850A, application date: 2012.11.05) adopts a segmented series deformation control system. The system has poor axial toughness and integrity, and is prone to breakage when used for micro-sized devices.

[0015] In order to dynamically adjust the shape of the needle body during the suturing process and adapt to the complex suturing environment, it is necessary to develop a minimally invasive surgical modular deformable suture needle that can undergo "S"-shaped deformation and has strong axial toughness and integrity, and propose a matching and applicable deformation control method to solve the suturing problem encountered in minimally invasive surgery when the sutured area is blocked or covered by tissues and organs. Summary of the invention

[0016] In view of the above problems, the present invention proposes the following technical solutions:

[0017] The present invention provides a minimally invasive surgery modular deformable suture needle, comprising a short needle, a differential parallel flexible deformable needle body, and a heating unit or a power supply unit;

[0018] The differential parallel flexible deformable needle body includes a needle body sleeve, I deformation control units, and one or more wire feeding units; wherein I≥1, the number of the deformation control unit is i, 1≤i≤I;

[0019] The wire feeding unit comprises a suture and a suture sleeve, wherein the suture sleeve wraps the suture;

[0020] The deformation control unit includes a memory metal wire, a conductive metal wire, aerogel particles, and a film sleeve, wherein the memory metal wire and the conductive metal wire are connected end to end in sequence to form a deformation control unit core, the film sleeve is wrapped outside the deformation control unit core, and the aerogel particles are filled between the film sleeve and the deformation control unit core; when the minimally invasive surgical modular deformable suture needle includes a power supply unit, the deformation control unit also includes an electric loop metal wire, and the tail end of the electric loop metal wire is connected to the head end of the memory metal wire;

[0021] The needle body sleeve is wrapped around the deformation control unit and the wire feeding unit, the electric circuit metal wire is inside the needle body sleeve and outside the film sleeve, and the head end extends to the tail end of the needle body sleeve;

[0022] The arrangement of the deformation control unit in the needle sleeve satisfies:

[0023] L,(i)>L,(i+1); s,(i),(i+1)>0;

[0024] s,(i),(i+1)=L,(i)-L,(i+1)-L,(i,1);

[0025] Wherein, L,(i) represents the length of the i-th deformation control unit extending into the minimally invasive surgical wound, which is numerically equal to the sum of the length of the memory metal wire of the i-th deformation control unit extending into the minimally invasive surgical wound and the length of the conductive metal wire extending into the minimally invasive surgical wound;

[0026] L,(i,1) represents the length of the memory wire of the i-th deformation control unit extending into the minimally invasive surgical incision;

[0027] s,(i),(i+1) represents the distance between the tail end of the memory metal wire in the i-th deformation control unit and the head end of the memory metal wire in the i+1-th deformation control unit;

[0028] The head end of the needle sleeve is fixedly and sealedly connected to the outer edge of the head end of the suture sleeve, and the parts of each deformation control unit and the wire feeding unit extending into the wound are isolated from the organs and tissues in the body of the surgical object by the needle sleeve;

[0029] The tail end of the short needle is connected to the suture;

[0030] The heating unit is connected to the tail end of the conductive metal wire to provide a heat source;

[0031] The power supply unit is connected to the tail end of the conductive metal wire and the head end of the electric loop metal wire to provide power;

[0032] The tail end of the memory metal wire is electrically connected to the head end of the conductive metal wire to form a deformation control unit core of a single deformation control unit. The head end of the deformation control unit core is the head end of the memory metal wire, and the tail end of the deformation control unit core is the tail end of the conductive metal wire.

[0033] The tail end of the electric loop wire is electrically connected to the head end of the memory wire and is located outside the film sleeve.

[0034] The length of the film sleeve is greater than the length of the deformation control unit core wrapped inside.

[0035] The inner diameter of the film sleeve is larger than the outer diameter of the deformation control unit core.

[0036] The film sleeve is made of insulating and flame-retardant materials.

[0037] The elastic modulus of the memory metal wire is not lower than that of the conductive metal wire.

[0038] The material of the memory metal wire is a memory metal that undergoes elastic deformation when the temperature or current changes. The curvature of the memory metal wire undergoes elastic deformation when the temperature or current changes.

[0039] Aerogel particles are low-density solid insulation materials;

[0040] During the operation, the front end of the needle cannula is inserted into the minimally invasive surgical wound, and the length of the needle cannula is such that the rear end of the needle cannula is always located outside the minimally invasive surgical wound.

[0041] The electrical circuit wire is located inside the needle casing and outside the suture casing.

[0042] The lengths of the memory metal wire, the conductive metal wire and the electric loop metal wire are such that the tail end of the conductive metal wire and the head end of the electric loop metal wire are always located outside the minimally invasive surgical incision during the operation.

[0043] Preferably, the friction coefficient and elastic modulus of the film sleeve satisfy that when the deformation control unit core in the film sleeve is bent or stretched, the lengthwise strain of the film sleeve is less than 5% of the lengthwise strain of the deformation control unit core.

[0044] Preferably, the curvature of the conductive metal wire and the electric loop metal wire does not change when the temperature or current changes, and the side surfaces are coated with an insulating coating.

[0045] Preferably, the aerogel particles with the largest Feret diameter have a Feret diameter of less than 0.1 mm.

[0046] Preferably, the arrangement of the control unit and the wire feeding unit in the differential parallel flexible deformable needle body also satisfies that the cross-sectional diameter is the smallest at the location where the cross-sectional diameter of the differential parallel flexible deformable needle body is the largest.

[0047] Preferably,

[0048] When I=1 and the number of the wire feeding unit is 1, the deformation control unit is adjacent to the wire feeding unit on the cross section of the needle body;

[0049] When I=2 and the number of wire feeding units is 1, the two deformation control units are adjacent to each other on the cross section of the needle body and are both adjacent to the wire feeding unit;

[0050] When I≥3 and the number of the wire feeding units is 1, each deformation control unit is located outside the wire feeding unit on the cross section of the needle body.

[0051] Preferably, the differential parallel flexible deformable needle body control unit and the wire feeding unit also meet the following requirements:

[0052] |lL,(1|×10≤L,(1)

[0053] Wherein, l represents the length of the suture cannula inserted into the minimally invasive surgical incision.

[0054] The present invention also provides a method for controlling the shape of a modular deformable suture needle for minimally invasive surgery, based on the above-mentioned modular deformable suture needle for minimally invasive surgery, comprising the following steps:

[0055] By means of a statistical learning model, a quantitative relationship between the bending deformation characteristics of the deformation control unit of each deformation control unit and the heat power provided by the corresponding heating unit or the voltage provided by the corresponding power supply unit is obtained;

[0056] The turning control of the corresponding memory metal wire is achieved by rotating the tail end of the deformation control unit and adjusting the corresponding thermal power or voltage;

[0057] Controlling the voltage or thermal power of the deformation control unit or rotating the tail end of the deformation control unit in the order of i increasing, so as to realize the forward coherent morphological control;

[0058] Control the voltage or thermal power of the deformation control unit or rotate the tail end of the deformation control unit in the order of i decreasing, so as to realize the backward coherent morphological control;

[0059] Preferably, the statistical learning model is a nonlinear function with characteristics related to voltage or characteristics related to thermal power as independent variables and bending deformation characteristics of the deformation control unit as dependent variables.

[0060] Preferably,

[0061] The bending deformation characteristics of the i-th deformation control unit are: arc-chord ratio αi, peak position βi, arc mouth direction; wherein the arc mouth direction includes the first direction The second direction θi'δiζi;

[0062] According to the boundary between the memory metal wire and the conductive metal wire of the i-th deformation control unit, the central axis of the i-th deformation control unit is divided into a deformation section and a non-deformable section.

[0063] Define the spatial rectangular coordinate system oi-xiyizi: the normal plane of the non-deformable segment of the axis of the i-th deformation control unit at the boundary between the deformation segment and the non-deformable segment is taken as the coordinate plane zi-oi-yi, the axis of the i-th deformation control unit passes through the origin oi, and the normal vector of the coordinate plane zi-oi-yi passing through the origin oi is taken as the xi axis;

[0064] Define spherical coordinate system The transformation relationship between the two coordinate systems is: let the coordinates of point A in the rectangular coordinate system be (xi, yi, zi), and the spherical coordinates of point A be The coordinate ri is the distance from point A to the origin oi, is the angle formed by the half plane passing through the zi axis and point A and the coordinate plane zi-oi-xi; θi is the angle between the line segment oiA and the positive direction of the zi axis

[0065] The origin oi is the end point of the deformation segment of the axis of the i-th deformation control unit 5. The point on the axis of the i-th deformation control unit 5 that is farthest from the origin oi is defined as the beginning point gi of the deformation segment of the axis of the i-th deformation control unit 5. The distance between gi and oi along the axis of the i-th deformation control unit 5 is the length of the deformation segment of the axis of the i-th deformation control unit. The midpoint of the deformation segment of the axis of the i-th deformation control unit is denoted as mi.

[0066]

[0067] Wherein, Lgioi represents the length of the deformation section of the axis of the i-th deformation control unit;

[0068] lgioi is the length of the straight line segment gioi;

[0069]

[0070] Among them, γi is the shortest distance from mi to the middle surface;

[0071] The middle plane is the normal plane of the straight line segment gioi passing through ζi;

[0072] ζi is the midpoint of the straight line segment gioi;

[0073] ηi is the bias attribute;

[0074] lmioi is the length of the straight line segment mioi;

[0075] lmigi is the length of the straight line segment migi;

[0076]

[0077] θi'δiζi=θi'δiζi'v / 1rad

[0078] Among them, the spherical coordinates of the vector δiζi are (ri'δiζi'v, θi'δiζi'v);

[0079] δi is the arc bottom point, specifically the intersection of the middle surface and the deformation segment of the axis of the i-th deformation control unit;

[0080] When the suture site is blocked or covered by tissues or organs, the premise is that the part of the minimally invasive surgical modular deformable suture needle extending into the wound can smoothly turn, move forward, and retreat, and the workload is minimized with continuous morphological control, that is, the control target is to minimize the overall bending deformation degree ∑αi of the part of the minimally invasive surgical modular deformable suture needle extending into the wound, where ∑αi is the sum of the αi of the deformation control units of all memory wires extending into the minimally invasive surgical incision.

[0081] Beneficial effects:

[0082] The needle body of the modular deformable suture needle for minimally invasive surgery is composed of a differential parallel connection of tough deformation control units, which has the advantages of segmented controllable deformation of the needle body and axial toughness-strong integrity, overcoming the limitations of existing technologies:

[0083] (1) The structure has a small diameter, and the parallel structure has strong axial toughness and integrity, which avoids the disadvantage of easy fracture of the series structure and has high safety of the equipment;

[0084] (2) It can quantitatively control dynamic deformation in the surgical object through external voltage or heat power input during suturing, and does not need to repeatedly remove the suturing equipment from the body and then return it to the surgical object, thus improving the suturing efficiency;

[0085] (3) The modular deformable suture needle morphology control method for minimally invasive surgery can quantitatively control the independent and controllable continuous deformation of the needle body segments in all degrees of freedom and directions, so that the suture needle can smoothly turn, move forward, and retreat when the suture site is blocked or covered by tissues or organs. The device has a strong deformation ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] Figure 1 This is the core structure diagram of the deformation control unit;

[0087] Figure 2 This is the axial differential structure diagram of the deformation control unit cluster;

[0088] Figure 3 This is a diagram of a differential parallel flexible deformable needle in a straight state;

[0089] Figure 4 is a schematic diagram of coordinate system transformation of the i-th deformation control unit;

[0090] Figure 5 is a schematic diagram of segmented deformation of the i-th deformation control unit;

[0091] Figure 6 The maximum cross section of the differential parallel flexible deformable needle body when I=1;

[0092] Figure 7 It is a front view of the modular deformable suture needle for minimally invasive surgery in the second embodiment;

[0093] Figure 8 It is a side view of the modular deformable suture needle for minimally invasive surgery in the second embodiment;

[0094] Fig. 9 The maximum cross section of the differential parallel flexible deformable needle body when I=2;

[0095] Fig.10 This is a front view of a modular deformable suture needle for minimally invasive surgery in Example 3, in which the needle body sleeve is hidden;

[0096] Fig.11 A side view of the modular deformable suture needle for minimally invasive surgery in Example 3;

[0097] Fig.12 This is a front view of a modular deformable suture needle for minimally invasive surgery in the fourth embodiment, in which the needle body sleeve is hidden;

[0098] Fig.13It is a side view of the modular deformable suture needle for minimally invasive surgery in the fourth embodiment;

[0099] Fig.14 is the maximum cross section of the differential parallel flexible deformable needle body in the fourth embodiment;

[0100] Fig.15 This is a bending deformation diagram of each deformation control unit in the needle body sleeve of Example 5;

[0101] Fig.16 is the maximum cross section of the differential parallel flexible deformable needle body in the fifth embodiment;

[0102] Figure numerals: 1 - memory metal wire, 2 - conductive metal wire, 3 - aerogel particles, 4 - film sleeve, 5 - deformation control unit, 6 - suture, 7 - suture sleeve, 8 - wire feeding unit, 9 - needle sleeve, 10 - curved needle, 11 - straight needle, 15 electric loop metal wire. DETAILED DESCRIPTION

[0103] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0104] like Figures 1 to 16 As shown in the figure, the following steps are used to introduce the product construction process and control method in detail:

[0105] Step 1: Construct a differential parallel flexible deformable needle

[0106] (1) Structure of a single deformation control unit 5

[0107] A single deformation control unit 5 comprises a memory metal wire 1, a conductive metal wire 2, aerogel particles 3, a film sleeve 4, and an electric loop metal wire 15.

[0108] The tail end of the memory metal wire 1 is electrically connected to the head end of the conductive metal wire 2 to form a deformation control unit core of a single deformation control unit 5. The head end of the deformation control unit core is the head end of the memory metal wire 1, and the tail end of the deformation control unit core is the tail end of the conductive metal wire 2.

[0109] The film sleeve 4 wraps the memory metal wire 1 and the conductive metal wire 2, the end of the film sleeve 4 closest to the head end of the memory metal wire 1 is the head end of the film sleeve 4, and the other end of the film sleeve 4 except the head end is the tail end of the film sleeve 4.

[0110] Aerogel particles 3 are filled between the film sleeve 4 and the wrapped memory metal wire 1 and the conductive metal wire 2.

[0111] The tail end of the electric loop wire 15 is electrically connected to the head end of the memory wire 1 and is located outside the film sleeve 4.

[0112] The length of the film sleeve 4 is greater than the length of the deformation control unit core wrapped inside.

[0113] The inner diameter of the film sleeve 4 is larger than the outer diameter of the deformation control unit core.

[0114] The film sleeve 4 is made of insulating and flame-retardant material.

[0115] The friction coefficient and elastic modulus of the film sleeve 4 satisfy that when the deformation control unit core in the film sleeve 4 is bent or stretched, the strain in the length direction of the film sleeve 4 is less than 5% of the strain in the length direction of the deformation control unit core.

[0116] The elastic modulus of the memory metal wire 1 is not lower than the elastic modulus of the conductive metal wire 2.

[0117] The material of the memory metal wire 1 is a memory metal that undergoes elastic deformation when the temperature or current changes. The curvature of the memory metal wire 1 undergoes elastic deformation when the temperature or current changes.

[0118] The curvature of the conductive metal wire 2 and the electric loop metal wire 15 does not change when the temperature or current changes, and the side is coated with an insulating coating.

[0119] The Feret diameter of the aerogel particle 3 with the largest Feret diameter is less than 0.1 mm.

[0120] Aerogel particles 3 are low-density solid insulating material. Compared with inert gas, oil, foam plastic and rubber, they can effectively insulate and heat-insulate while reducing the mass of the filling body, making it less likely to leak and be lost, reducing the load on the core of the deformation control unit and improving the deformation control accuracy of the deformation control unit.

[0121] (2) Wire feeding unit

[0122] The single wire feeding unit 8 comprises a suture 6 and a suture sleeve 7, wherein the suture sleeve 7 wraps the suture 6.

[0123] The inner diameter of the suture sleeve 7 is greater than the outer diameter of the suture 6.

[0124] The elastic modulus of the material of the suture sleeve 7 is lower than that of the material of the film sleeve 4.

[0125] (3) Needle structure

[0126] The differential parallel flexible deformation needle body includes a deformation control unit 5 and a wire feeding unit 8.

[0127] The number of deformation control units 5 where the memory wire 1 extending into the minimally invasive surgical wound is located in a single differential parallel flexible deformation needle body is I≥1, and the deformation control units in the needle body are numbered i, 1≤i≤I,

[0128] The number of wire feeding units 8 is not less than 1,

[0129] The arrangement of the control unit 5 and the wire feeding unit 8 in the differential parallel flexible deformable needle body satisfies the minimum cross-sectional diameter at the maximum cross-sectional diameter of the differential parallel flexible deformable needle body, ensuring that the Feret diameter of the pore through which the differential parallel flexible deformable needle body can pass is the minimum, thus having the widest range of applicability, which is the most fundamental principle of the needle body structure.

[0130] 1) Cross-sectional structure

[0131] In order to reduce the position control error of the suture needle and the head end of the suture thread, the distance between the central axis of the needle body sleeve 9 and the central axis of the suture thread sleeve 7 should be minimized under the premise of ensuring that the cross-sectional diameter at the maximum cross-sectional diameter of the differential parallel flexible deformation needle body is minimized, so that the spatial position of the head end of the suture thread 6 is closest to the spatial position of the head end of the differential parallel flexible deformation needle body, thereby minimizing the control error. The corresponding cross-sectional structure is:

[0132] like Figure 6 As shown, when I=1, the deformation control unit and the wire feeding unit are adjacent to each other on the cross section of the needle body and are both located inside the needle body sleeve 9 [Example 1];

[0133] like Figures 7 to 11 As shown, when I=2, two deformation control units 5 are adjacent to each other and are adjacent to the wire feeding unit 8 on the cross section of the needle body, and each deformation control unit and wire feeding unit are located inside the needle body sleeve 9 [Examples 2 and 3];

[0134] like Figures 12 to 16 As shown, when I≥3, each deformation control unit 5 is located outside the wire feeding unit and each deformation control unit 5 is located inside the needle body sleeve 9 on the cross section of the needle body [Examples 4 and 5];

[0135] ②Axial differential structure of deformation control unit cluster

[0136] The length of the i-th deformation control unit 5 extending into the minimally invasive surgical incision is L,(i), where L,(i) is equal to the sum of the length of the memory metal wire L,(i,1) extending into the minimally invasive surgical incision and the length of the conductive metal wire L,(i,2) extending into the minimally invasive surgical incision, L,(i)>L,(i+1), L,(1)>L,(2)>L,(3)>…>L,(I).

[0137] The combined differential structure of the deformation control unit is shown in formula (1), where s,(i),(i+1) is the distance between the tail end of the memory wire 1 in the i-th deformation control unit 5 and the head end of the memory wire 1 in the i+1-th deformation control unit 5,

[0138] s,(i),(i+1)>0 ensures that the deformation of the memory wire 1 in each deformation control unit is independent of each other and does not interfere with each other, thereby realizing that the part of the differential parallel flexible deformation needle body inserted into the wound can be segmented to perform multi-degree-of-freedom and multi-directional bending-straightening deformation, so that the entire segment of the needle body has the ability to controllably and continuously deform in all degrees of freedom and directions.

[0139] If the length of the memory metal wire 1 extending into the minimally invasive surgical wound is greater than zero, the deformation control unit 5 where the memory metal wire 1 is located is the deformation control unit 5 where the memory metal wire 1 extending into the minimally invasive surgical wound is located.

[0140] s,(i),(i+1)=L,(i)-L,(i+1)-L,(i,1) (1)

[0141] ③Wire feeding structure

[0142] In order to reduce the stiffness difference between the suture sleeve 7 and the deformation control unit 5, improve the synchronous coordination of the deformation between the suture sleeve 7 and the deformation control unit 5, reduce the difference in spatial position between the head end of the suture sleeve 7 and the head end of the first deformation control unit 5, improve the deformation control accuracy, and at the same time reduce the gap area between the outer edge of the head end of the suture sleeve 7 and the head end of the film sleeve 4 in the first deformation control unit to improve the sealing reliability of the needle sleeve 9, the length l of the suture sleeve 7 inserted into the minimally invasive surgical incision should satisfy formula (2),

[0143] |lL,(1)|×10≤L,(1) (2)

[0144] ④Sealing measures

[0145] The needle sleeve 9 is made of an antibacterial elastic material, and wraps the deformation control unit 5 and the wire feeding unit 8 inserted into the body of the surgical object, so as to isolate the deformation control unit 5 and the wire feeding unit 8 from the organs and tissues in the body of the surgical object.

[0146] The head end of the needle cannula 9 is fixedly sealed and connected to the outer edge of the head end of the suture cannula 7. The parts of each deformation control unit 5 extending into the wound are isolated from the organs and tissues in the body of the surgical subject by the needle cannula 9. The liquid during the operation cannot penetrate into the inner side of the needle cannula 9. During the operation, the head end of the needle cannula 9 extends into the minimally invasive surgical wound. In order to ensure that the needle cannula 9 effectively isolates the organs and tissues in the body of the surgical subject from the deformation control unit and the wire feeding unit, the length of the needle cannula 9 should ensure that the tail end of the needle cannula 9 is always located outside the minimally invasive surgical wound during the operation.

[0147] The electric circuit wire 15 is located inside the needle sleeve 9 and outside the suture sleeve 7.

[0148] The lengths of the memory wire 1, the conductive wire 2, and the electric loop wire 15 should ensure that the tail end of the conductive wire 2 and the head end of the electric loop wire 15 are always located outside the minimally invasive surgical incision during the operation.

[0149] Step 2: Constructing a modular deformable suture needle for minimally invasive surgery

[0150] The modular deformable suture needle for minimally invasive surgery comprises a short needle, a differential parallel flexible deformable needle body, and a heating unit or a power supply unit;

[0151] The short needle is a curved needle 10 or a straight needle 11.

[0152] The leading ends of the curved needle 10 and the straight needle 11 are both needle tips, and the trailing ends of the curved needle 10 and the straight needle 11 are connected to the suture thread 6.

[0153] The heat source and the switch are connected in series to form a heating unit of a single deformation control unit 5,

[0154] The power supply is connected in series with the switch to form a power supply unit for a single deformation control unit 5.

[0155] Any one of the positive and negative poles of the power supply is electrically connected to the tail end of the conductive metal wire 2 through a switch, and the other pole is electrically connected to the head end of the electric loop metal wire 15, so as to realize the series connection between the power supply unit of the single deformation control unit 5 and the single deformation control unit 5.

[0156] The heat source is connected to the tail end of the conductive metal wire 2 through a switch to realize the series connection between the heating unit of the single deformation control unit 5 and the single deformation control unit 5. Step 3: Quantitative expression of bending deformation characteristics

[0157] This step is aimed at the situation where a single deformation control unit 5 is always out of contact with other deformation control units.

[0158] like Figures 4 to 5 As shown, the spatial rectangular coordinate system oi-xiyizi and the spherical coordinate system of the i-th deformation control unit are defined as The transformation relationship between the two coordinate systems is: let the coordinates of point A in the rectangular coordinate system be (xi, yi, zi), and the spherical coordinates of point A be (ri, θi), the coordinate ri is the distance from point A to the origin oi, is the angle formed by the half plane passing through the zi axis and point A and the coordinate plane zi-oi-xi; θi is the angle between the line segment oiA and the positive direction of the zi axis,

[0159] The central axis of the i-th deformation control unit 5 is divided into a deformation section and a non-deformable section by the boundary between the memory metal wire 1 and the conductive metal wire 2.

[0160] Define the spatial rectangular coordinate system oi-xiyizi: the normal plane of the non-deformable segment of the axis of the i-th deformation control unit 5 at the boundary between the deformation segment and the non-deformable segment is taken as the coordinate plane zi-oi-yi, the axis of the i-th deformation control unit 5 passes through the origin oi, and the normal vector of the coordinate plane zi-oi-yi passing through the origin oi is taken as the xi axis,

[0161] The origin oi is the end point of the deformation segment of the axis of the i-th deformation control unit 5. The point on the axis of the i-th deformation control unit 5 that is farthest from the origin oi is defined as the beginning point gi of the deformation segment of the axis of the i-th deformation control unit 5. The distance between gi and oi along the axis of the i-th deformation control unit 5 is the length of the deformation segment of the axis of the i-th deformation control unit. The midpoint of the deformation segment of the axis of the i-th deformation control unit is denoted as mi.

[0162] According to the spatial rectangular coordinate system oi-xiyizi and the spherical coordinate system The conversion relationship between gi, mi, and oi in the spherical coordinate system The coordinates inside are (0,0,0),

[0163] The bending deformation characteristics of the i-th deformation control unit include arc-chord ratio αi, peak position βi, arc mouth direction,

[0164] The arc-chord ratio αi is the ratio of the length of the deformation segment Lgioi of the axis of the i-th deformation control unit 5 to the length of the deformation segment chord lgioi, which reflects the deformation degree of the memory metal. lgioi is the length of the straight line segment gioi, as shown in formula (3).

[0165]

[0166] The peak position βi reflects the relative position relationship between mi and gi, oi, as shown in formula (4), γi is the shortest distance from mi to the middle plane, the middle plane is the normal plane of the straight line segment gioi passing through the midpoint ζi of the straight line segment gioi, lmioi is the length of the straight line segment mioi, lmigi is the length of the straight line segment migi, and the bias attribute ηi is shown in formula (5),

[0167]

[0168]

[0169] The arc direction includes the first direction and the second direction θi'δiζi=θi'δiζi'v / 1rad, define the intersection of the middle surface and the deformation segment of the axis of the i-th deformation control unit 5 as the arc bottom point δi, then the spherical coordinates of the vector δiζi are

[0170] The non-deformable section of the axis of the i-th deformation control unit 5 is not unable to bend-straighten due to the infinite stiffness of the material, but does not bend-straighten due to voltage or heat when the i-th deformation control unit 5 is always out of contact with other deformation control units 5. When the non-deformable section of the i-th deformation control unit 5 is in contact with other deformation control units 5, it can be driven to bend-straighten accordingly.

[0171] Step 4: Establish a single-segment morphology control model

[0172] This step is aimed at the situation where a single deformation control unit 5 is always out of contact with other deformation control units 5.

[0173] Deformation stabilization moment: if the absolute value of the difference between the first direction of the deformation control unit 5 at the current moment and the first direction 10 seconds ago does not exceed 5% of the first direction 10 seconds ago at the current moment, then the current moment is the deformation stabilization moment.

[0174] (1) Electrically controlled deformation measurement

[0175] The j-th voltage Ui,j=j×Δui of the power supply unit connected to the i-th deformation control unit 5, j is the voltage level, and the voltage level difference Δui≥0.01V,

[0176] After applying Ui,j to the i-th deformation control unit 5, when the deformation of the deformation control unit 5 is stable, the arc-chord ratio αi,j, the peak position βi,j, and the first direction of the i-th deformation control unit bending under Ui,j are measured. and the second direction θi'δiζi,j, the measured sample of the electric control deformation is J is the highest voltage level, J≥100, Z is an integer set,

[0177] (2) Thermal control deformation measurement

[0178] The k-th level heat power Pi of the heating unit connected to the i-th deformation control unit, k=k×Δpi, k is the heat power level, and the heat power level difference Δpi≥0.1W,

[0179] After Pi,k is applied to the i-th deformation control unit 5, when the deformation of the deformation control unit is stable, the arc-chord ratio αi,k, the peak position βi,k, and the first direction of the i-th deformation control unit bending under Pi,k are measured. and the second direction θi'δiζi,k, the thermal control deformation measured sample is K is the highest thermal power level, K≥100, Z is an integer set,

[0180] (3) Deformation control model

[0181] The deformation control model includes the electric control deformation segmentation model and the thermal control deformation segmentation model.

[0182] When the deformation of the memory metal wire is controlled by applying voltage, the segmented model of the electric-controlled deformation is as shown in equation (6), j'=j-1, They are αi,j, βi,j, and the predicted value of θi'δiζi,j, the voltage characteristic Ui is the ratio of the voltage value to 1V,

[0183] a'1,j, a'2,j, a'3,j, a'4,j, a'5,j are respectively Ui in the prediction model 1 / 3 、Ui 2 / 3 、Ui、Ui 4 / 3 、Ui 2 The coefficient of

[0184] b'1,j, b'2,j, b'3,j, b'4,j and b'5,j are Ui in the prediction model 1 / 3 、Ui 2 / 3 、Ui、Ui 4 / 3 、Ui 2 The coefficients of c'1,j, c'2,j, c'3,j, c'4,j and c'5,j are Ui in the prediction model 1 / 3 、Ui 2 / 3 、Ui、Ui 4 / 3 、Ui 2 The coefficients of d'1,j, d'2,j, d'3,j, d'4,j and d'5,j are Ui in the prediction model 1 / 3 、Ui 2 / 3 、Ui、Ui 4 / 3 、Ui 2 The coefficient of

[0185] When the deformation of the memory metal wire is controlled by heat conduction, the thermal control deformation segmentation model is as shown in equation (7), k'=k-1, They are αi,k, βi,k, and the predicted values ​​of θi'δiζi,k, the thermal power characteristic Pi is the ratio of thermal power to 1W,

[0186] e'1,k, e'2,k, e'3,k, e'4,k and e'5,k are respectively Pi in the prediction model 1 / 3 、Pi 2 / 3 ,Pi,Pi 4 / 3 、Pi 1.5 The coefficients of f'1,k, f'2,k, f'3,k, f'4,k and f'5,k are Pi in the prediction model 1 / 3 、Pi 2 / 3 ,Pi,Pi 4 / 3 、Pi 1.5 The coefficients of λ'1,k, λ'2,k, λ'3,k, λ'4,k, and λ'5,k are Pi in the prediction model 1 / 3 、Pi 2 / 3 ,Pi,Pi 4 / 3 、Pi 1.5 The coefficient of

[0187] τ'1,k, τ'2,k, τ'3,k, τ'4,k, τ'5,k are respectively Pi in the prediction model 1 / 3 、Pi 2 / 3 ,Pi,Pi 4 / 3 、Pi 1.5 The coefficient of

[0188] The electric control deformation measured sample and the thermal control deformation measured sample are fitted by equation (6) and equation (7) respectively: the coefficients in equation (6) and equation (7) are obtained by the least square method, so that the electric control deformation measured sample and the thermal control deformation measured sample are fitted by equation (6) and equation (7) respectively under the condition of given voltage or thermal power.

[0189] (7) Explicitly predict the arc-chord ratio, peak position, and arc mouth direction, thereby controlling the deformation of a single deformation control unit by adjusting the voltage or thermal power.

[0190] Step 5: Continuous Shape Control

[0191] When the axis deformation segment in the i+1 deformation control unit 5 undergoes bending-straightening deformation, the axis non-deformable segment in the i deformation control unit 5 undergoes deformation following the axis deformation segment in the i+1 deformation control unit 5 under the drive of the axis deformation segment in the i+1 deformation control unit 5.

[0192] When the suture site is blocked or covered by tissues or organs, the premise is that the part of the minimally invasive surgical modular deformable suture needle extending into the wound can smoothly turn, move forward, and retreat, and the workload is minimized with continuous morphological control, that is, the control target is to minimize the overall bending deformation degree ∑αi of the part of the minimally invasive surgical modular deformable suture needle extending into the wound, where ∑αi is the sum of the αi of the deformation control units of all memory wires extending into the minimally invasive surgical incision.

[0193] (1) Turning control method

[0194] By rotating the tail end of a single deformation control unit 5, a rough adjustment of the first direction of the deformation control unit 5 is achieved, and then according to step 4, by adjusting the voltage or thermal power, a fine adjustment of the first direction and the second direction of the deformation control unit 5 is completed.

[0195] (2) Forward coherent morphology control method

[0196] Under the premise of ensuring that the modular deformable suture needle for minimally invasive surgery passes through the passable gap of the organ tissue in the body of the surgical object, the arc-chord ratio and the peak position of each deformation control unit are finely adjusted by adjusting the voltage or thermal power according to step 4 in the order of i increasing, and the arc mouth direction of each deformation control unit is roughly adjusted and finely adjusted according to the turning control method, so that the modular deformable suture needle for minimally invasive surgery is inserted into the wound and moves toward the suture site.

[0197] (3) Backward coherent morphology control method

[0198] Under the premise of ensuring that the modular deformable suture needle for minimally invasive surgery passes through the passable gap of the organ tissue in the body of the surgical object, the arc-chord ratio and the peak position of each deformation control unit are finely adjusted by adjusting the voltage or thermal power in the order of i in step four, and the arc mouth direction of each deformation control unit is roughly and finely adjusted according to the turning control method, so as to realize the retreat of the modular deformable suture needle for minimally invasive surgery from the suture point to the wound.

[0199] Embodiment 1

[0200] I=1, at this time, the deformation control unit and the wire feeding unit are adjacent to each other on the cross section of the needle body and are both located inside the needle body sleeve 9; the relative positions of the deformation control unit and the wire feeding unit at the maximum cross section of the differential parallel flexible deformation needle body are as follows Figure 6 shown.

[0201] Embodiment 2

[0202] I=2, two deformation control units 5 are adjacent to each other and are both adjacent to the wire feeding unit 8 on the cross section of the needle body, and each deformation control unit and wire feeding unit is located inside the needle body sleeve 9 .

[0203] Embodiment 3

[0204] I=2, two deformation control units 5 are adjacent to each other and are adjacent to the wire feeding unit 8 on the cross section of the needle body, each deformation control unit and the wire feeding unit are located inside the needle body sleeve 9, and the first deformation control unit 5 and the second deformation control unit 5 are bent and deformed. When the angle between vector δ1ζ1 and vector δ2ζ2 is an obtuse angle, the front view and side view of the modular deformable suture needle for minimally invasive surgery are Fig.10 , Fig.11 .

[0205] Embodiment 4

[0206] I=3, the first deformation control unit, the second deformation control unit, and the third deformation control unit are all bent and deformed. When the angle between vector δ1ζ1 and vector δ2ζ2 is an obtuse angle, and the angle between vector δ3ζ3 and vector δ2ζ2 is an obtuse angle, the front view and side view of the modular deformable suture needle for minimally invasive surgery are Fig.12 , Fig.13 The relative positions of the deformation control unit and the wire feeding unit at the maximum cross section of the differential parallel flexible deformation needle body are as follows: Fig.14 As shown,

[0207] Embodiment 5

[0208] like Fig.15 ,I>3, each deformation control unit in the needle body sleeve 9 is bent and deformed, and the non-deformable section of the axis of the i-th deformation control unit is driven by the deformation section of the axis of the i+1 deformation control unit to follow the deformation of the deformation section of the axis of the i+1 deformation control unit.

[0209] The relative positions of the deformation control unit and the wire feeding unit at the maximum cross section of the differential parallel flexible deformation needle body are as follows: Fig.16 As shown,

[0210] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A modular deformable suture needle for minimally invasive surgery, characterized in that: It includes a short needle, a differential parallel flexible deformable needle body, and a heating unit or a power supply unit; The differential parallel flexible deformable needle body includes a needle body sleeve, I deformation control units, and one or more wire feeding units; wherein I≥1, the number of the deformation control unit is i, 1≤i≤I; The wire feeding unit comprises a suture and a suture sleeve, wherein the suture sleeve wraps the suture; The deformation control unit includes a memory metal wire, a conductive metal wire, aerogel particles, and a film sleeve, wherein the memory metal wire and the conductive metal wire are connected end to end in sequence to form a deformation control unit core, the film sleeve is wrapped outside the deformation control unit core, and the aerogel particles are filled between the film sleeve and the deformation control unit core; when the minimally invasive surgical modular deformable suture needle includes a power supply unit, the deformation control unit also includes an electric loop metal wire, and the tail end of the electric loop metal wire is connected to the head end of the memory metal wire; The needle body sleeve is wrapped around the deformation control unit and the wire feeding unit, the electric circuit metal wire is inside the needle body sleeve and outside the film sleeve, and the head end extends to the tail end of the needle body sleeve; The arrangement of the deformation control unit in the needle sleeve satisfies: L,(i)>L,(i+1); s,(i),(i+1)>0; ； Wherein, L,(i) represents the length of the i-th deformation control unit extending into the minimally invasive surgical wound, which is numerically equal to the sum of the length of the memory metal wire of the i-th deformation control unit extending into the minimally invasive surgical wound and the length of the conductive metal wire extending into the minimally invasive surgical wound; L,(i,1) represents the length of the memory wire of the i-th deformation control unit extending into the minimally invasive surgical incision; s,(i),(i+1) represents the distance between the tail end of the memory metal wire in the i-th deformation control unit and the head end of the memory metal wire in the i+1-th deformation control unit; The head end of the needle sleeve is fixedly and sealedly connected to the outer edge of the head end of the suture sleeve, and the parts of each deformation control unit and the wire feeding unit extending into the wound are isolated from the organs and tissues in the body of the surgical object by the needle sleeve; The tail end of the short needle is connected to the suture; The heating unit is connected to the tail end of the conductive metal wire to provide a heat source; The power supply unit is connected to the tail end of the conductive metal wire and the head end of the electric loop metal wire to provide power; The tail end of the memory metal wire is electrically connected to the head end of the conductive metal wire to form a deformation control unit core of a single deformation control unit. The head end of the deformation control unit core is the head end of the memory metal wire, and the tail end of the deformation control unit core is the tail end of the conductive metal wire. The tail end of the electric loop wire is electrically connected to the head end of the memory wire and is located outside the film sleeve. The length of the film sleeve is greater than the length of the deformation control unit core wrapped inside. The inner diameter of the film sleeve is larger than the outer diameter of the deformation control unit core. The film sleeve is made of insulating and flame-retardant materials. The elastic modulus of the memory metal wire is not lower than that of the conductive metal wire. The material of the memory metal wire is a memory metal that undergoes elastic deformation when the temperature or current changes. The curvature of the memory metal wire undergoes elastic deformation when the temperature or current changes. Aerogel particles are low-density solid insulation materials; During the operation, the front end of the needle cannula is inserted into the minimally invasive surgical wound, and the length of the needle cannula is such that the rear end of the needle cannula is always located outside the minimally invasive surgical wound. The electrical circuit wire is located inside the needle casing and outside the suture casing. The lengths of the memory metal wire, the conductive metal wire and the electric loop metal wire are such that the tail end of the conductive metal wire and the head end of the electric loop metal wire are always located outside the minimally invasive surgical incision during the operation.

2. The minimally invasive surgery modular deformable suture needle according to claim 1, characterized in that: The friction coefficient and elastic modulus of the film sleeve satisfy that when the deformation control unit core in the film sleeve is bent or stretched, the lengthwise strain of the film sleeve is less than 5% of the lengthwise strain of the deformation control unit core.

3. The modular deformable suture needle for minimally invasive surgery according to claim 1, characterized in that: The curvature of the conductive wire and the loop wire does not change when the temperature or current changes, and the side is coated with an insulating coating.

4. The minimally invasive surgery modular deformable suture needle according to claim 1, characterized in that: The Feret diameter of the aerogel particles with the largest Feret diameter is less than 0.1 mm.

5. The minimally invasive surgery modular deformable suture needle according to claim 1, characterized in that: The arrangement of the control unit and the wire feeding unit in the differential parallel flexible deformable needle body also satisfies the requirement that the cross-sectional diameter is the smallest at the location where the cross-sectional diameter of the differential parallel flexible deformable needle body is the largest.

6. The minimally invasive surgery modular deformable suture needle according to claim 5, characterized in that: When I=1 and the number of wire feeding units is 1, the deformation control unit is adjacent to the wire feeding unit on the cross section of the needle body; When I=2 and the number of wire feeding units is 1, the two deformation control units are adjacent to each other on the cross section of the needle body and are both adjacent to the wire feeding unit; When I≥3 and the number of the wire feeding units is 1, each deformation control unit is located outside the wire feeding unit on the cross section of the needle body.

7. The minimally invasive surgery modular deformable suture needle according to claim 1, characterized in that: The control unit and wire feeding unit in the differential parallel flexible deformable needle body also meet the following requirements: ； Wherein, l represents the length of the suture cannula inserted into the minimally invasive surgical incision.

8. The minimally invasive surgery modular deformable suture needle according to claim 1, characterized in that: The morphology control method of the suture needle comprises the following steps: By means of a statistical learning model, a quantitative relationship between the bending deformation characteristics of the deformation control unit of each deformation control unit and the heat power provided by the corresponding heating unit or the voltage provided by the corresponding power supply unit is obtained; The turning control of the corresponding memory metal wire is achieved by rotating the tail end of the deformation control unit and adjusting the corresponding thermal power or voltage; Controlling the voltage or thermal power of the deformation control unit or rotating the tail end of the deformation control unit in the order of i increasing, so as to realize the forward coherent morphological control; The voltage or thermal power of the deformation control unit or the tail end of the rotation deformation control unit is controlled in the order of decreasing i to realize the backward coherent morphological control.

9. The minimally invasive surgery modular deformable suture needle according to claim 8, characterized in that: The statistical learning model is a nonlinear function.

10. The minimally invasive surgery modular deformable suture needle according to claim 8, characterized in that: The bending deformation characteristics of the i-th deformation control unit are: arc-chord ratio αi, offset peak position βi, arc mouth direction; wherein the arc mouth direction includes a first direction φi'δiζi and a second direction θi'δiζi; According to the boundary between the memory metal wire and the conductive metal wire of the i-th deformation control unit, the central axis of the i-th deformation control unit is divided into a deformation section and a non-deformable section. Define the spatial rectangular coordinate system oi-xiyizi: the normal plane of the non-deformable segment of the axis of the i-th deformation control unit at the boundary between the deformation segment and the non-deformable segment is taken as the coordinate plane zi-oi-yi, the axis of the i-th deformation control unit passes through the origin oi, and the normal vector of the coordinate plane zi-oi-yi passing through the origin oi is taken as the xi axis; Define the spherical coordinate system oi-riφiθi. The conversion relationship between the two coordinate systems is: let the coordinates of point A in the rectangular coordinate system be (xi, yi, zi), and the spherical coordinates of point A be (ri, φi, θi). Coordinate ri is the distance from point A to the origin oi, φi is the angle formed by the half plane through the zi axis and point A and the coordinate plane zi-oi-xi; θi is the angle between the line segment oiA and the positive direction of the zi axis. The origin oi is the end point of the deformation segment of the axis of the i-th deformation control unit. The point on the axis of the i-th deformation control unit that is farthest from the origin oi is defined as the beginning point gi of the deformation segment of the axis of the i-th deformation control unit. The distance between gi and oi along the axis of the i-th deformation control unit is the length of the deformation segment of the axis of the i-th deformation control unit. The midpoint of the deformation segment of the axis of the i-th deformation control unit is denoted as mi. ； Wherein, Lgioi represents the length of the deformation section of the axis of the i-th deformation control unit; lgioi is the length of the straight line segment gioi; ； ； Among them, γi is the shortest distance from mi to the middle surface; The middle plane is the normal plane of the straight line segment gioi passing through ζi; ζi is the midpoint of the straight line segment gioi; ηi is the bias attribute; lmioi is the length of the straight line segment mioi; lmigi is the length of the straight line segment migi; φi'δiζi=φi'δiζi'v / 1rad θi'δiζi=θi'δiζi'v / 1rad Among them, the spherical coordinates of the vector δiζi are (ri'δiζi'v, φi'δiζi'v, θi'δiζi'v); δi is the arc bottom point, specifically the intersection of the middle surface and the deformation segment of the axis of the i-th deformation control unit; In minimally invasive surgery, it is assumed that the part of the modular deformable suture needle of minimally invasive surgery that is inserted into the wound can smoothly turn, move forward, and move backward, and the workload of continuous morphological control is minimized, that is, the control target is to minimize the overall bending deformation degree ∑αi of the part of the modular deformable suture needle of minimally invasive surgery that is inserted into the wound, where ∑αi is the sum of the αi of the deformation control units of all memory wires inserted into the minimally invasive surgery wound.

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