Knitting method of stent and stent

Abstract

The invention provides a weaving method of a stent and the stent. The method utilizes circumferential and longitudinal positioning pins on a clamp to guide a wire path, and stent weaving comprises: weaving a first wire along a predetermined path (W-shaped, inverted-W-shaped or a combined path thereof), forming alternating peak points and valley points, covering a current woven layer; then, moving to the next layer along the longitudinal direction to form a multi-layer woven structure; the first wire rod is woven along the reverse path from the end point of the forward path and is complementarily staggered with the forward path to form a rhombic net structure, and the rhombic net structure comprises a hooking structure and an overlapping structure. The hooking structure is formed at the intersection of a peak point and a valley point and has a physical locking function; the overlapping structure is formed at the upper and lower intersections and does not have a physical locking function. And the second wire rod is woven from the spare positioning pin and is interwoven with the first wire rod to form an integral structure of the bracket. The support force and flexibility of the stent can be effectively improved, and the stent is suitable for complex lumen environments and meets various medical application requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a braiding method of a stent and the stent. Background Art

[0002] In the medical field, braided stents (including vascular and non-vascular stents, such as biliary stents, respiratory stents, digestive tract stents, etc.) are widely used to treat luminal stenosis or obstructive diseases. Traditional braided structures usually adopt Hook structure or Cross structure, each of which has certain limitations. The Hook structure has good flexibility through circumferential weaving of hook-shaped paths, and is suitable for application in lumens with different degrees of curvature. However, the Hook structure is relatively limited in providing radial support, especially in complex and curved lumens. There may be problems of incomplete deployment or insufficient support, resulting in poor fit. In contrast, the Cross structure forms a uniformly distributed support structure through cross-weaving, which can provide higher radial support and stability in the lumen. However, since stress concentration is prone to occur at the intersection position, the risk of local fatigue and fracture may increase under long-term load or high stress conditions.

[0003] At present, most stents are usually woven with a single path structure, which has certain limitations in multi-directional support, especially in complex lumen environments, where stents are prone to local stress concentration and structural instability. In order to solve these shortcomings, the present invention provides a stent with both high flexibility and good support, which can effectively conform to various lumen morphologies and reduce the difficulty of operation for operators. Summary of the invention

[0004] The present invention aims to solve the problem of insufficient flexibility and support of existing stents in complex lumen environments and provide a stent weaving method using W-shaped and inverted W-shaped paths to achieve improved radial support force and flexibility of the stent.

[0005] The present invention provides a method for braiding a stent, using a clamp provided with a plurality of positioning pins arranged along the circumferential direction and the longitudinal direction to guide and fix the braiding path of the wire, comprising the following steps:

[0006] Step A: Fix the first wire on the main body of the clamp, and weave it along a predetermined path from the starting point along the circumferential direction. The predetermined path is W-shaped, inverted W-shaped, or at least one of a combination of the two to form alternating peaks and valleys. The predetermined path is distributed along the circumferential direction under the guidance of the positioning pins to cover the surface of the current braided layer.

[0007] Step B: After the first wire completes weaving the current braided layer, it moves longitudinally to the next braided layer, and repeats step A to reach a predetermined number of layers to form a multi-layer braided structure woven along a forward path.

[0008] Step C: The first wire starts from the end point of the forward path and weaves a reverse path in the opposite direction of the forward path, which is complementary to the forward path and staggered, covering all the braided layers to form a plurality of diamond mesh structures, wherein the diamond mesh structure includes a plurality of hook structures and overlapping structures.

[0009] Using a second wire, starting from any free positioning pin, weaving along the free positioning pin until all positioning pins are filled, forming multiple diamond-shaped mesh structures, the second wire is interwoven with the first wire to form the overall structure of the stent. In the stent weaving method provided by the present invention, the heights of adjacent peaks of the W-shaped path are different, and the height ratio of adjacent peaks in the same braided layer is 2:1.

[0010] In the stent weaving method provided by the present invention, the predetermined path in the weaving layer in step A is characterized by that when a forward W-shaped path and an inverted W-shaped path are adjacent, the inverted W-shaped path and the adjacent W-shaped path have a common path.

[0011] In the stent weaving method provided by the present invention, the hooking structure and the overlapping structure are both formed at the vertices of the diamond mesh structure; wherein the hooking structures cross each other and have a physical locking function, and the overlapping structures cross up and down and do not have a physical locking function.

[0012] In the stent weaving method provided by the present invention, the predetermined path in step A includes at least one of a W-shape, an inverted W-shape, or a combination of the two. By forming a hooking structure and an overlapping structure through the mutual crossing of the wires, good support force and flexibility are achieved in the radial and longitudinal directions. The hooking structure has a physical locking function, which keeps the stent stable in the lumen and prevents sliding, so that the stent can adapt to complex lumen morphology. The overlapping structure does not have a physical locking function, and can effectively maintain the shape and position of the stent when subjected to external pressure. Through the stent weaving method of the present invention and the stent structure obtained by weaving, the stability and load-bearing capacity of the stent are enhanced, and better clinical application effects are obtained in medical treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to facilitate understanding of the technical solutions in the present invention, the following briefly describes the accompanying drawings, which show different implementations of the present invention for reference by those skilled in the art.

[0014] Figure 1 It is a partial enlarged view of the hook structure and the overlapping structure in the present invention;

[0015] Figure 2 is a schematic diagram of the support structure in the first embodiment;

[0016] Figure 3 is a schematic diagram of a clamp structure in a sixth embodiment;

[0017] Figures 4 to 9 The braiding process of the stent in the first embodiment is shown;

[0018] Figures 10 to 12 The braiding process of the second wire of the stent in the fourth embodiment is shown;

[0019] Figures 13 to 15 The braiding process of the second wire of the stent in the fifth embodiment is shown;

[0020] Figures 16 to 23 This is the braiding process of the head and tail expansion parts of the stent in the sixth embodiment;

[0021] Fig.24 This is a front view of a stent woven in accordance with a sixth embodiment of the present invention.

[0022] Description of Reference Numerals

[0023] Stent 100, head expansion portion 101, tail expansion portion 102,

[0024] The main body 103, the first main body 1031, the second main body 1032,

[0025] The coating portion 104,

[0026] A first wire 10, a second wire 11,

[0027] Clamp 200, head end expansion part clamp 201, main body clamp 203, tail expansion part clamp 202,

[0028] Positioning pin P, hooking structures 31a, 31b, overlapping structures 32a, 32b. DETAILED DESCRIPTION

[0029] The orientation terms used in this specification (such as "center", "longitudinal", "lateral", "upper", "lower", "front", "back", etc.) are only based on the orientation description of the drawings, for the convenience of description rather than limiting the specific device, and do not specifically refer to the actual orientation of the device. The terms "first", "second", etc. are only used to distinguish similar elements and do not represent relative importance. Unless explicitly stated, "upper" or "lower" in the description can refer to direct contact between elements or indirect contact through other structures.

[0030] In the description of the present invention, the terms "one embodiment", "some embodiments", etc. mean that the features described in conjunction with the example are included in at least one embodiment of the present invention. Those skilled in the art can combine the features of different embodiments as needed to meet specific application requirements.

[0031] The stent weaving method of the present invention is described in detail in Figures 4 to 22 The diagrams illustrate the braiding paths and structures of different embodiments. Figure 2 and Fig.23 A schematic structural diagram of a stent obtained by the weaving method of the present invention is shown.

[0032] In the attached figure, the dotted line represents the completed wire movement path, the solid line represents the wire path in the current step, and the hollow dots indicate the arrangement of the positioning pins on the fixture. The wire path is only an example and does not represent the material and size of the specific wire.

[0033] In this embodiment, a clamp provided with a plurality of positioning pins P arranged circumferentially and longitudinally is used to guide and fix the braiding path of the wire for braiding the stent structure. The braided wire includes a first wire 10 and a second wire 11, both of which are preferably metal wires of the same material and diameter to ensure uniform overall strength of the stent structure. In a preferred embodiment, nickel-titanium alloy is selected as the wire material to provide excellent flexibility and memory, so that the stent maintains a stable structure in a complex luminal environment. In other embodiments, metal wires of different materials and diameters may also be selected to achieve balanced or differentiated support forces under specific application requirements.

[0034] The first wire 10 is used to weave the first main body 1031 of the stent, and the second wire 11 is used to weave the second main body 1032 of the stent to form a diamond mesh structure. Both are composed of a plurality of mesh structures arranged circumferentially. In order to ensure the structural independence and overall integrity during the weaving process, the first wire 10 and the second wire 11 are each woven through different positioning pins P, and do not share positioning pins. After the first wire 10 is woven, the second wire 11 uses the remaining positioning pins to fill the gap to avoid path overlap and form a complete stent structure.

[0035] The grid structures of the first wire 10 and the second wire 11 are arranged in sequence in the longitudinal direction of the stent to form adjacent support structures. The weaving layers of the two are independent and complement each other to ensure the stability of the stent structure.

[0036] In a specific embodiment, the weaving of the first wire 10 and the second wire 11 can be performed simultaneously or alternately. There is no fixed requirement for the start order of the two. The second wire 11 can be started after the weaving of the first wire 10 is completed, or it can be started at the same time as the first wire 10, and work independently of each other. For the sake of distinction, the "first wire 10" and "second wire 11" in the following description are only used to distinguish the weaving order, and do not mean that there is an inevitable causal relationship between the two.

[0037] In a specific embodiment, the fixture 200 is designed as a standard cylinder, which is evenly divided into a plurality of dividing points in the circumferential and longitudinal directions. The circumferential dividing lines x1, x2, …, x14 represent the equally spaced dividing positions of the fixture in the circumferential direction, and the longitudinal dividing lines y1, y2, …, y7 represent the dividing positions of the fixture in the length direction. The coordinates of each dividing point are represented by (x, y). For example, (x1, y2) represents the position of the positioning pin corresponding to the first dividing point in the circumferential direction and the second dividing point in the longitudinal direction. The wire passes through these positioning pins in sequence to complete the weaving path. In other embodiments, the fixture 200 can also be set to a non-cylindrical shape, and the spacing between the dividing lines is not limited, preferably equally spaced. The shape of the fixture is modified according to the clinical requirements of the required stent.

[0038] Define the distance between adjacent dividing points of the fixture 200 as the unit distance. During the weaving process, when the wire moves 1 or 2 unit distances simultaneously in the circumferential and longitudinal directions, the path lengths passed can be L or 2L respectively. By controlling the unit distance, the accuracy of the weaving path and the symmetry of the grid are ensured.

[0039] In this embodiment, the stent weaving layer (hereinafter referred to as "layer") refers to a set of complete weaving paths within the longitudinal height range. Each layer spans 3 rows of positioning pins, and adjacent layers are tightly connected by sharing the middle row of positioning pins to ensure the stability and continuity of the interlayer structure. If the number of weaving layers is set as n (where n is a positive integer and n≥1), the total number of rows of positioning pins is 2n + 1, so that each layer is effectively connected to the adjacent upper and lower layers to form a stable support structure.

[0040] Each layer of weaving covers a certain longitudinal height range, and this range can be adjusted according to the arrangement of the positioning pins and the parameters of the fixture design. Preferably, the height of each layer is kept consistent to ensure the regularity and overall stability of the weaving structure. For example, when the height of each layer is fixed at 5 mm, the total height of the stent can be precisely controlled by adjusting the number of layers n. When the stent needs to increase the longitudinal length to meet the requirements of a specific lumen or lesion position, it can be achieved by increasing the number of weaving layers n. The design of the fixture will be adjusted according to the number of layers of the target stent to match the total number of rows of positioning pins and ensure the effective connection between each layer.

[0041] In the first specific embodiment of the present invention, the weaving process of the stent main body is as follows:

[0042] (1. Single-layer forward path weaving <Step A>)

[0043] In step A, the first wire 10 is fixed on the main body of the fixture, and any positioning pin is selected as the initial position, and the wire is woven along the circumferential direction according to a predetermined path, wherein the path is W-shaped, inverted W-shaped, or at least one of the two, forming alternating peaks and valleys. The path is distributed along the circumferential direction under the guidance of the positioning pin, covering the surface of the current braided layer. The end position of the path is the starting position of the next path. Specific implementation method 1

[0045] In the specific implementation mode 1, the predetermined path in step A is designed as a W-shaped path, such as Figure 4 As shown, specifically including:

[0046] Step A-1: ​​The first wire 10 starts from the initial position A1 (x1, y2), moves 2L downward in the diagonal direction, forms the first descending section of the W-shaped path, and reaches the first valley point M1 (x3, y4); then, the first wire 10 moves L upward in the diagonal direction from the valley point M1 (x3, y4), forms the first ascending section, and reaches the first peak point M2 (x4, y3); then, the first wire 10 moves L downward in the diagonal direction from the first peak point M2 (x4, y3), forms the second descending section, and reaches the second valley point M3 (x5, y4); finally, the first wire 10 moves 2L upward in the diagonal direction from the second valley point M3 (x5, y4), forms the second ascending section, and the end point is the end point M4 (x7, y2) of the W-shaped path, and the end point M4 of the previous W-shaped path is symmetrical with the starting point A1 in the circumferential direction, completing a complete W-shaped path.

[0047] Step A-2: The first wire 10 uses the end point M4 (x7, y2) of the previous W-shaped path as the starting point of the next path, and weaves step by step according to step A-1 until the surface of the entire braided layer is covered to form a closed-loop structure within the layer. In a specific embodiment, the braiding path passes through the valley point M5 (x9, y4), the peak point M6 (x10, y3), the valley point M7 (x11, y4) and the peak point M8 (x13, y3) in sequence, and finally achieves coverage of the surface of the current braided layer. After completing the braiding of the current layer, the first wire 10 moves longitudinally to the next braided layer and starts braiding a new braided layer.

[0048] Step A-3: If the positioning pins in the current braided layer can be completely covered by the continuous arrangement of the W-shaped path, that is, the entire braided layer surface is covered, the wire moves directly along the longitudinal direction to the starting point of the next braided layer to achieve a rapid transition of the path.

[0049] If the remaining area of ​​the locating pins in the current braid layer is not enough to accommodate a complete W-shaped path (called an uncovered row), the following procedures are followed:

[0050] If the uncovered rows are not enough to accommodate the complete W-shaped path and the number of rows is small (for example, only 1-2 rows are left), the wire directly moves in the longitudinal direction to the starting point of the next braiding layer to achieve a rapid transition of the path.

[0051] If the number of uncovered rows is large, to avoid too large a path span, a bent path can be braided within the remaining row area to fill the empty area, ensuring path continuity and uniform distribution. After filling, the wire moves from the end point of the bent path in the longitudinal direction to the starting point of the next braiding layer to achieve a smooth transition between layers.

[0052] In single-layer braiding, the termination position of each W-shaped path is the starting point of the next path, and it is gradually braided circumferentially until the entire braiding layer is covered. The height of adjacent peak points of the W-shaped path is preferably 2:1, and this height difference enhances the radial and longitudinal support forces and flexibility of the stent, so as to adapt to the deformation in a complex lumen environment.

[0053] (2. Braiding of multi-layer forward paths <Step B>)

[0054] After the first wire 10 completes the path of the current braiding layer, it moves longitudinally to the next braiding layer, and repeats layer by layer according to the braiding structure of Step A until the predetermined number of layers is reached, forming a forward multi-layer braiding structure of the stent main body.

[0055] Step B-1: The first wire 10 moves from the end position of the last path of the current braiding layer in the longitudinal direction to the starting position of the next braiding layer, and starts a new layer of braiding. Under the guidance of the positioning pins, repeat the predetermined path of Step A, and distribute circumferentially to cover the surface of the current braiding layer until a complete single-layer closed-loop structure is formed.

[0056] Step B-2: The first wire 10 is connected layer by layer longitudinally in each braiding layer, maintaining the consistency of the path arrangement, and gradually completing the multi-layer braiding. The path design of each layer preferably keeps the heights of each layer consistent to ensure the symmetry and stability of the overall multi-layer structure.

[0057] After the wire path completes the braiding of all predetermined layers, the end positions of each layer path and the starting positions of adjacent layers are regularly distributed longitudinally. Through the continuous connection of the paths, each layer of braiding forms a complete multi-layer closed-loop structure.

[0058] In a specific embodiment, the forward path is a W-shaped path that sequentially passes through valley point M10(x3, y6), peak point M11(x4, y5), valley point M12(x5, y6), peak point M13(x7, y4), valley point M14(x9, y6), peak point M15(x10, y5), valley point M16(x11, y6), and peak point M17(x13, y4). The entire surface of the braided layer is covered, and the first wire 10 completes the path braiding of the current layer. The end point is M18(x1, y6), and this end point is vertically symmetric with the initial position A1(x1, y2) of the first layer, forming a complete multi-layer closed-loop structure.

[0059] (3. Braiding of the reverse path <Step C>)

[0060] Step C: The first wire 10 starts from the end point of the forward path and braids the reverse path in the opposite direction to the forward path. The reverse path is complementary to and interleaved with the forward path, covering the entire braided layer and forming multiple diamond-shaped mesh structures. The diamond-shaped mesh structure includes a hooking structure and an overlapping structure. Through the interaction of the hooking structure and the overlapping structure, the radial stability and flexibility of the stent are enhanced. In a specific embodiment, when the predetermined forward path adopts a W-shaped path, the reverse path is a complementary inverted W-shaped path.

[0061] Step C-1: Take the termination position of the forward braiding path of the first wire 10 (such as M18(x1, y6)) as the starting point for braiding the reverse path, and braid a path complementary to the forward path along the reverse path direction. The path forms a hooking structure at the meeting points of the peak points and valley points, and an overlapping structure at the upper and lower intersections, covering the surface of the current braided layer to ensure the symmetry and stability of the path.

[0062] Step C-2: After the first wire 10 completes the first-layer braiding of the reverse path, move vertically to the starting point of the next braided layer and continue the braiding of the reverse path. The braiding of each layer of the reverse path maintains the consistency of path interleaving and hooking structure with the reverse path of the previous layer, forming a multi-layer closed-loop structure layer by layer. The closed-loop structure is achieved through the complete coverage of the intra-layer path and the smooth transition of the inter-layer path, and forms an overall continuous stent structure with the forward path in the logical connection of the starting point and the end point.

[0063] The specific weaving process is as follows: the first wire 10 starts from the end point (M18) of the forward path, and moves in the diagonal direction according to the weaving rules of the inverted W-shaped path, gradually forming peaks and valleys. For example, the first wire 10 moves 2L upward in the diagonal direction from M18 to reach the peak point N1 (x3, y4), and then moves L downward in the diagonal direction to reach the valley point N2 (x4, y5). The path meets the forward path at the intersection to form a hooking structure. After completing the current braided layer, the first wire 10 moves longitudinally to the starting point of the next braided layer (such as N9), and repeats the above path generation rules until the surface of all braided layers is covered. The weaving of the reverse path and the forward path realizes the establishment of the support structure.

[0064] In the multi-layer braiding path design of the present invention, the closed-loop structure forms an overall continuous grid structure by connecting the paths within the layer and transitioning the paths between the layers. The positions of the starting point and the end point of each layer of the path are reasonably arranged according to the design of the braiding path to facilitate the continuous connection of the paths between the layers. The complete coverage of the single-layer path is achieved by staggered arrangement of the forward path and the reverse path. When transitioning between layers, the wire selects an appropriate transition method based on the distance between the end point of the current layer and the starting point of the next layer: if the end point is close to the starting point, the wire moves directly in the longitudinal direction and connects quickly; if the end point is far from the starting point, the wire transitions through a braided bending path to ensure path continuity and uniform distribution.

[0065] After all the braided layers are completed, the final end of the path coincides with the starting point of the first layer, forming a multi-layer closed-loop structure. The closed-loop design enables the stent to have evenly distributed support forces in the radial and longitudinal directions.

[0066] In the stent weaving method of the present invention, the single-layer closed-loop structure is used to achieve full coverage of the path of a single braided layer; the interlayer closed-loop structure is used to achieve a smooth transition of the paths of adjacent braided layers; the multi-layer closed-loop structure is used to combine multiple braided layers into a complete whole; and finally, the forward path and the reverse path are combined to achieve a complete closed-loop structure of the stent from the starting point to the end point. The closed-loop structures at all levels complement each other, providing the stent with all-round radial support, flexibility and stability, and are suitable for medical applications in complex lumen environments.

[0067] The forward path and the reverse path form a hook point at the intersection, and the hook structure is formed by the overlap of the peak point and the valley point where they meet, such as Figure 1 As shown in the figure, it has a physical locking function, which enhances the local support force and prevents path slippage, thereby improving radial stability. At the same time, the overlapping points between the paths are formed by the wires crossing up and down between the braided paths. It does not have a physical locking function, but provides deformation space when subjected to local force, making the stent more flexible to adapt to complex lumen environments.

[0068] Through the synergistic effect of closed-loop paths, hooking points and overlapping points, the overall structural stability, compressive resistance and flexibility of the bracket are significantly improved.

[0069] The second wire 11 is woven to form a second main body 1032:

[0070] The second wire 11 is woven from any free positioning pin (such as x1, y1) in the main body that is not covered by the first wire 10, and is woven along the free positioning pins until all the positioning pins are filled, forming a plurality of diamond mesh structures. The second wire 11 is interwoven with the first wire 10 to form the overall structure of the stent main body, thereby enhancing the overall rigidity and stability of the stent.

[0071] Specifically, the braiding path of the second wire 11 can be selected to be the same as or different from that of the first wire 10. Figures 7 to 9 As shown, the second wire 11 adopts the same W-shaped path as the first wire 10 in step A, covers the remaining positioning pins of the main body layer by layer, and finally reaches the other end of the main body (such as x14, y4). After completing the forward path weaving, the second wire 11 returns from the weaving end point of the forward path along the reverse path to the initial position of the main body weaving, weaving a complementary inverted W-shaped path and forming a closed loop structure.

[0072] During the interweaving of multiple wires, the interweaving paths of the first wire 10 and the second wire 11 form a hooking structure at the intersection of the peak and valley points of the same layer; at the same time, the paths in the same layer or in different layers form overlapping points at the upper and lower intersections. The closed-loop structure is achieved by connecting the end of the path within the layer and the smooth transition of the path between layers. When transitioning between layers, the second wire 11 uses direct longitudinal movement or bending path according to the positional relationship between the weaving end point of the current layer and the starting point of the next layer to ensure path continuity and uniform distribution.

[0073] Second embodiment

[0074] In the second specific implementation mode, the predetermined path in step A is designed as an inverted W-shaped path, specifically including:

[0075] Step A-1: ​​The first wire 10 is woven from the initial position in sequence into an ascending section (to a peak point), a descending section (to a valley point), a rising section (to a peak point) and a final descending section (to a valley point) to form an inverted W-shaped path, wherein the end point of the previous W-shaped path is circumferentially symmetrical with the initial position.

[0076] Step A-2: Repeat the above step A-1 and weave continuously in the circumferential direction.

[0077] A-3 step: If there is an uncovered row, the transition is achieved through a direct or tortuous path.

[0078] Third embodiment

[0079] In the third specific implementation, the predetermined path in step A is designed as a W-shaped path and an inverted W-shaped path alternately arranged in combination, and the path segments can be shared. Specifically, it includes:

[0080] A-1 step: weave a W-shaped path;

[0081] Step A-2: Continue weaving the inverted W-shaped path, sharing some path segments with the previous W-shaped path;

[0082] Step A-3: Repeat steps A-1 to A-2, weaving continuously in the circumferential direction;

[0083] Step A-4: If there are uncovered rows in the braided layer and the uncovered rows are not enough to accommodate a complete combined arrangement path, move to the next braided layer directly or through a bending path.

[0084] In a specific embodiment, the predetermined path is preferably a W-shaped path, an inverted W-shaped path, or a combination of the two alternately arranged. The three path designs mentioned in the above specific embodiments 1, 2, and 3 are only exemplary embodiments. In actual applications, the path type can be dynamically adjusted according to the application scenario of the stent, the lumen morphology, and the braiding process requirements. For example, a spiral path, a V-shaped path, or other geometric paths can be combined to further optimize the radial support force and flexibility of the stent to meet the diverse requirements in complex environments.

[0085] Fourth embodiment

[0086] In this embodiment, the braiding method of the first wire 10 is the same as that of the first embodiment, and will not be described again.

[0087] Figures 10 to 12 The braiding path of the second wire is shown, which moves alternately along the diagonal direction according to the V-shaped path, forming the upper and lower segments layer by layer, and covering the specified area of ​​the current braided layer (such as half a circle or the entire circumference). The bending points (peaks and valleys) of each layer of the path form the required angles through the direction changes of the wire.

[0088] In this embodiment, the layer height of the second wire 11 is the same as the W-shaped path of the first wire, and the layer height ratio is 1:1. The specific process is as follows:

[0089] The second wire 11 starts from the starting point (x2, y2) and moves alternately along the diagonal direction along the V-shaped path, forming upper and lower segment structures in sequence, covering the area of ​​the current braided layer. Specifically, the positions of the peaks and valleys are determined by the alternating movement of the path. For example, the peak is located at the upward bend of the path, while the valley is located at the downward bend of the path, and the height difference and bending angle of the path can be optimized according to actual needs.

[0090] After each layer of the path completes the current coverage, the second wire 11 moves to the starting point of the next braided layer along the longitudinal direction, maintaining the consistency of the path shape and the braiding rule, and forming a multi-layer structure layer by layer. The interlayer transition between paths can be achieved through a straight line or a curved path to ensure the continuity and uniformity between the braided layers until the second wire 11 reaches the end point (x2, y6) at the other end of the main body.

[0091] After the forward path is braided, the second wire 11 starts to braid in the reverse direction from the braiding end point (x2, y6) of the forward path, and returns layer by layer to the starting point (x2, y2) in the opposite direction. The paths are staggered at the peaks and valleys to form a hooking structure. The reverse path and the forward path are staggered in the circumferential direction to form a symmetrical interwoven mesh structure, which evenly disperses the radial stress of the stent.

[0092] Fifth embodiment

[0093] In this embodiment, the braiding method of the first wire 10 is the same as that of the first embodiment, and is not described again herein.

[0094] Figures 13 to 15 The braiding path of the second wire 11 is shown, which is alternately braided in a V-shaped manner, and the layer height is half of the W-shaped path of the first wire 10, so that the layer height ratio is 1:2, forming a finer support structure.

[0095] Specifically, the second wire 11 starts from a starting point (such as x2, y2), and each layer of the path moves alternately in the diagonal direction, using a V-shaped path for weaving to cover half of the circumference of the current braided layer. Each layer of the path is staggered with the adjacent layer in the circumferential direction to avoid wire overlap and enhance the structural strength of the stent. For example, the first layer of the path covers half of the circumference, and the second layer of the path covers the other half of the circumference. The two layers are staggered to complete the coverage of the entire circumference. The path passes through multiple positioning pins, forming alternating peaks and valleys in turn, and maintains the staggered pattern when moving longitudinally.

[0096] After the forward braiding is completed, the second wire 11 switches to the reverse path from the other end point of the main body (such as x1, y5). The reverse braiding path starts from the end point of the forward path and moves in the opposite direction along the diagonal direction, covering the other half of the circumference of each braided layer layer by layer. The forward path and the reverse path form a hook structure with a physical locking function at the intersection of the peak point and the valley point, which effectively prevents the wire from slipping and provides all-round support.

[0097] In this embodiment, each layer of the path only covers half of the circumference, and the paths are staggered in the circumferential direction in units of half a week, forming an overall structure where the weaving paths cross each other vertically and horizontally. The overlapping structure is formed at the spatial intersection of the upper and lower paths. The overlapping structure does not have a physical locking function, but can provide flexibility to adapt to complex lumen environments. The hooking structure is formed at the coincidence points where the peaks and valleys of the forward path and the reverse path meet at the positioning pins, and has a physical locking function. By the interlocking action of the paths, the radial supporting force is enhanced to prevent the wire from slipping after expansion.

[0098] In this embodiment, through the combination of the forward path and the reverse path, the first wire 10 and the second wire 11 toes form a multi-layer staggered cross structure. This structure evenly distributes the overlapping points and hooking points, improving the radial and longitudinal supporting forces of the stent, and enabling the stent to exhibit good flexibility and stability in complex lumen environments.

[0099] Sixth Embodiment

[0100] In the sixth embodiment, aiming to further improve the fixing effect of the stent, expansion parts are added at the head end and the tail end outside the multi-layer W-shaped weaving structure of the main body part. The weaving of the main body part can adopt the weaving methods in the foregoing embodiments (such as the 1st - 5th embodiments and their deformation schemes), which will not be elaborated here.

[0101] As Figure 3 shown, the head end expansion part fixture 201 and the tail end expansion part fixture 203 are respectively located at both ends of the fixture. In this embodiment, they are designed as gradually expanding conical structures. The shapes of the fixtures at the head and tail expansion parts are designed according to the specific application requirements of the stent, and preferably include but are not limited to double cup-shaped, double spherical, trumpet-shaped, conical, double ellipsoidal or asymmetric-shaped structures. At the same time, the arrangement density and angle of the positioning pins of the fixture can be set according to the shape of the expansion part and the requirements of the radial supporting force to meet the mechanical property requirements in different clinical environments.

[0102] The arrangement of the positioning pins gradually adjusts the spacing according to the diameter change of the expansion part to adapt to the special requirements of path weaving. The ratio of the main body part to the expansion part of the fixture and the length of the connecting part can be flexibly changed to meet the development requirements of special stent structures. Through this fixture design, the weaving paths of the main body part and the head and tail expansion parts maintain consistent symmetry and uniformity, forming a stable stent network structure suitable for the implantation requirements of various lumen environments.

[0103] Weaving of the head end expansion part <Step D>

[0104] In this step (Step D), as Figure 16 to Figure 17As shown, the first wire 10 starts from the selected starting point of the head end expansion part and is woven through multiple circumferential and longitudinal broken line segments. The starting point of the path coincides with the end point of the current woven layer, and it transitions to the W-shaped path of the main body part. Preferably, the starting point of weaving is located at the connection between the expansion part and the main body part. In other embodiments, when transitioning between the head and tail expansion parts and the main body part, the path ensures continuity through a smooth connection. For example, the end point of the weaving path of the head end expansion part is directly connected to the starting point of the W-shaped path of the main body part, as Fig.18 shown.

[0105] The specific process is as follows:

[0106] Step D-1: The first wire 10 moves upward diagonally from the selected starting point (such as x1, y2) of the head end expansion part to the first peak point (such as x4, y1), that is, it crosses 3 positioning pins circumferentially and 1 positioning pin longitudinally, forming the rising section of the broken line path.

[0107] Step D-2: The first wire 10 moves downward diagonally from the peak point to the valley point, forming the descending section of the broken line path.

[0108] Step D-3: Repeat steps D-1 and D-2, gradually covering the circumference of the head end expansion part, and finally smoothly transitioning to the W-shaped path of the main body part.

[0109] Weaving of the tail end expansion part <Step E>

[0110] The weaving method of the tail end expansion part is similar to that of the head end expansion part, and the path structure remains the same to ensure the symmetry and continuity of the overall structure. The specific weaving process is as follows:

[0111] Step E-1: As Fig.19 shown, the first wire 10 moves downward diagonally from the starting point of the tail end expansion part to the first valley point (such as x4, y7), that is, it crosses 3 positioning pins circumferentially and 1 positioning pin longitudinally, forming the descending section of the broken line path.

[0112] Step E-2: The first wire 10 moves upward diagonally from the valley point to the peak point, forming the rising section of the broken line path.

[0113] Step E-3: Repeat steps E-1 and E-2, gradually covering the circumference of the tail end expansion part, and smoothly transitioning to the reverse weaving path of the main body part.

[0114] When the head and tail expansion parts transition to the main body, the path is connected smoothly to ensure continuity. For example, the end point of the path of the head expansion part is directly connected to the starting point of the forward braiding path (e.g., W-shaped path) of the main body. After the braiding of the tail expansion part is completed, the wire transitions from the path of the tail expansion part to the starting point of the reverse braiding path (e.g., inverted W-shaped path) of the main body, and returns to the starting position A1 of the main body layer by layer along the reverse path. Figure 20 to Figure 23 As shown, a complete closed-loop structure is finally formed.

[0115] Seventh embodiment

[0116] The present invention also provides two bracket products, which are made by the above-mentioned weaving method and have good supporting and positioning effects.

[0117] The first type of stent product: Figure 2 As shown, it only includes the main body 103, which is a hollow tubular structure made by the above-mentioned weaving method and used for supporting the cavity. The main body can adapt to the inner diameter of the cavity and provide uniform support to prevent deformation or occlusion of the cavity.

[0118] The second type of stent products: Fig.24 The stent includes a main body and an expansion part, and is suitable for cavities that require additional positioning and anti-displacement effects. Its structure includes a main body 103, which is located in the middle section of the stent and bears the main support function; a head end expansion part 101 and a tail end expansion part 102 are provided at both ends of the main body. The diameter of the head and tail expansion parts is larger than that of the main body, forming an expansion area with a cup-shaped, spherical, trumpet-shaped, conical, ellipsoidal or asymmetric structure, which fits the cavity wall.

[0119] The head and tail expansion parts are designed for the entrance and exit areas of the cavity. They enhance the fixation of the stent through radial expansion and prevent the stent from longitudinal displacement or rotation after implantation. The expansion parts can be set symmetrically or asymmetrically according to the anatomical structure of the cavity to adapt to specific anatomical requirements.

[0120] Seventh embodiment

[0121] In some embodiments, the stent may be provided with a coating 104, which may cover all or part of the stent to provide additional protection and functionality. The coating material may be polyester, polyurethane, silicone, PE, PP, HDPE, PTFE, etc. These materials have good biocompatibility and mechanical properties and can effectively prevent tissue embedding or excessive proliferation.

[0122] The coating can be configured on the outside, middle or inside of the stent. The outer coating reduces the friction between the stent and the surrounding tissue, and is suitable for applications that need to reduce friction damage. The inner coating protects the inner wall of the cavity to prevent tissue damage, and is suitable for stents that need to protect the inner cavity structure. The middle coating enhances the mechanical strength of the stent. The full coating design provides higher pressure resistance and is suitable for high-pressure environments; the half-coating design retains flexibility and provides local support.

[0123] In a preferred embodiment, the coating portion 104 covers the entire outer surface of the stent to form a full coating structure, which can effectively isolate the stent from direct contact with surrounding tissues and is particularly suitable for stent applications that require long-term implantation, such as intravascular or gastrointestinal stents.

[0124] In another embodiment, the coating portion 104 only covers a portion of the stent, forming a semi-coating structure, allowing a portion of the stent to contact the tissue, providing support and promoting tissue growth. The outer side or the inner side can be selectively covered to achieve physiological functions in stent fixation.

[0125] In addition, the stent may have a developing ring to clearly show the position and status of the stent in medical imaging. The developing ring can be a ring, a spiral or a plurality of small metal dots, evenly distributed around the periphery of the stent, and made of high-density materials (such as platinum, tungsten or iridium). The developing ring can be installed by welding, mechanical fixation or local plating. The developing ring can effectively enhance the developing effect after the stent is implanted, and improve the safety and accuracy of the operation.

Claims

1. A method for weaving a stent, characterized in that: Using a jig provided with a plurality of positioning pins arranged in the circumferential direction and the longitudinal direction, guiding and fixing a braiding path of the wires, the wires comprising a first wire and a second wire; The weaving method comprises the following steps: Step A: fix the first wire on the main body of the fixture, and weave it along a predetermined path from the initial position along the circumferential direction, wherein the predetermined path is at least one of a W shape, an inverted W shape, or a combination of the two, forming alternating peaks and valleys, and the predetermined path is distributed along the circumferential direction under the guidance of the positioning pins to cover the surface of the current braided layer; Step B: After the first wire completes the weaving of the current braided layer, it moves longitudinally to the next braided layer, and repeats step A to reach a predetermined number of layers, thereby forming a multi-layer braided structure woven along a forward path; Step C: the first wire starts from the end point of the forward path, weaves a reverse path in the opposite direction of the forward path, complements the forward path and is staggered, covers all the braided layers, and forms a plurality of diamond mesh structures, wherein the diamond mesh structures include a hooking structure and an overlapping structure; Use a second wire, start from any free positioning pin, weave along the free positioning pins until all positioning pins are filled to form a plurality of diamond-shaped mesh structures, and the second wire is interwoven with the first wire to form the overall structure of the stent.

2. The weaving method according to claim 1, characterized in that: The heights of adjacent peaks of the W-shaped path and the inverted W-shaped path are different, and the height ratio of adjacent peaks is 2:

1.

3. The stent weaving method according to claim 1, characterized in that: The characteristics of the predetermined path in the step A include that when a W-shaped path and an inverted W-shaped path are adjacent to each other, the inverted W-shaped path and the adjacent W-shaped path have a common path.

4. The weaving method according to claim 1, characterized in that: The hooking structure and the overlapping structure are both formed at the vertices of the diamond-shaped mesh structure; The hook structures cross each other and have a physical locking function, and the overlapping structures cross each other up and down and do not have a physical locking function.

5. The weaving method according to claim 1, characterized in that: The predetermined path in step A is a W-shaped path, comprising the following steps: Step A-1: ​​the first wire moves from the initial position along the diagonal direction to sequentially form a descending section and an ascending section of a W-shaped path, forming a valley point and a peak point, until a W-shaped path is completed, and the end point of the W-shaped path is symmetrical with the initial position in the circumferential direction; Step A-2: Repeat step A-1 to continuously weave multiple W-shaped paths along the circumferential direction; Step A-3: If there are uncovered rows in the braided layer, and the uncovered rows are not large enough to accommodate a complete W-shaped path, then transition to the next braided layer directly or through a bent path.

6. The weaving method according to claim 1, characterized in that: The predetermined path in step A is an inverted W-shaped path, comprising the following steps: Step A-1: ​​the first wire moves from the initial position along the diagonal direction to sequentially form an ascending section and a descending section of an inverted W-shaped path, forming a peak point and a valley point, and completing an inverted W-shaped path, wherein the end point of the W-shaped path is symmetrical with the initial position in the circumferential direction; Step A-2: Repeat step A-1 and weave continuously in the circumferential direction; A-3: If there are uncovered rows in the braided layer, and the uncovered rows are not large enough to accommodate a complete inverted W-shaped path, then the next braided layer is transitioned directly or through a bent path.

7. The weaving method according to claim 4, characterized in that: The predetermined path of step A is a path that is an alternating combination of a W-shaped path and an inverted W-shaped path, and includes the following steps: Step A-1: ​​the first wire moves from the initial position along the diagonal direction to sequentially form a descending section and an ascending section of a W-shaped path, forming a peak point and a valley point, and completing a W-shaped path, wherein the end point of the W-shaped path is symmetrical with the initial position in the circumferential direction; Step A-2: the first wire continues to weave an inverted W-shaped path, shares the last ascending section with the W-shaped path, and then forms a descending section and an ascending section in sequence to complete an inverted W-shaped path; Step A-3: Repeat steps A-1 to A-2, weaving continuously in the circumferential direction; Step A-4: If there are uncovered rows in the braided layer, and the uncovered rows are not sufficient to accommodate a complete combined arrangement path, then move to the next braided layer directly or through a bending path.

8. The weaving method according to claim 1, characterized in that: The step C comprises the following steps: Step C-1: Using the end position of the forward braiding of the first wire as the starting point of the braiding of the reverse path, braiding a path complementary to the forward path along the reverse path, forming a hooking structure at the intersection of the peak and the valley of the path; and forming an overlapping structure at the intersection of the path and the upper and lower intersections, covering the surface of the braided layer; Step C-2: After completing the first layer of weaving in the reverse path, the first wire moves longitudinally to the next weaving layer and continues weaving in the reverse path to form a multi-layer closed-loop structure.

9. The weaving method according to claim 1, characterized in that: During the weaving process of the main body, the second wires are interwoven and arranged in the same path as the first wires, so that the main body forms a diamond mesh structure.

10. The weaving method according to claim 1, characterized in that: The second wire adopts a V-shaped path during the weaving process of the main body, and the height of its braided layer is equal to the height of the W-shaped path of the first wire, and the layer height ratio of the two is 1:

1.

11. The weaving method according to claim 1, characterized in that: The second wire adopts a V-shaped path during the weaving process of the main body, and the height of its braided layer is half of the height of the W-shaped path of the first wire, and the layer height ratio between the two is 1:

2.

12. A bracket, characterized in that: The stent is woven by the stent weaving method according to any one of claims 1 to 11.

13. A method for braiding a stent, comprising braiding a stent main body, a head end expansion part and a tail end expansion part, wherein the braiding of the stent main body is achieved based on the method described in any one of claims 1 to 11, characterized in that: The weaving method also includes: Step D: selecting any positioning pin at the head end expansion portion as the end starting point, using the first wire to continuously weave along multiple circumferential and longitudinal broken line segments, and the end point of the path coincides with the end starting point; Step E: Starting from the braiding end point of the stent main body in the forward path at the tail end expansion portion, the wire is used to continuously braid along multiple circumferential and longitudinal broken line segments, and the end point of the path coincides with the braiding end point of the main body.

14. A bracket, characterized in that: The stent is woven by the stent weaving method according to any one of claims 1-11 or 13, and the stent comprises a head end expansion portion, a main body portion and a tail end expansion portion in sequence, and the diameters of the head end expansion portion and the tail end expansion portion are both larger than the main body portion.

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