Braiding method for stent, and stent
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SHANGHAI AOHUA PHOTOELECTRICITY ENDOSCOPE
- Filing Date
- 2024-12-31
- Publication Date
- 2026-06-04
Smart Images
Figure CN2024144531_04062026_PF_FP_ABST
Abstract
Description
Bracket weaving method and bracket Technical Field
[0001] This invention relates to the field of medical device technology, and in particular to a method for weaving a stent and the stent itself. Background Technology
[0002] In the medical field, braided stents (including vascular and non-vascular stents, such as biliary stents, respiratory stents, and digestive stents) are widely used to treat luminal stenosis or obstructive diseases. Traditional braided structures typically employ either a hook structure or a cross structure, each with its own limitations. The hook structure, through circumferential braiding with hook-like paths, offers good flexibility and is suitable for luminals with varying degrees of curvature. However, the hook structure has limitations in providing radial support, especially in complex and tortuous luminal environments, where incomplete unfolding or insufficient support may occur, leading to poor fit. In contrast, the cross structure, through cross-braiding to form a uniformly distributed support structure, can provide higher radial support and stability within the lumen. However, because stress concentration easily occurs at the cross points, under prolonged loads or high stress conditions, it may increase the risk of local fatigue and fracture.
[0003] Currently, most stents are typically woven using a single-path structure, which has limitations in multi-directional support, especially in complex luminal environments, where stents are prone to localized stress concentration and structural instability. To address these shortcomings, this invention provides a stent that is both highly flexible and provides excellent support, effectively conforming to various luminal morphologies while reducing the difficulty of operation for the surgeon. Summary of the Invention
[0004] This invention aims to address the problem of insufficient flexibility and support of existing stents in complex luminal environments by providing a stent weaving method using W-shaped and inverted W-shaped paths to improve the radial support force and flexibility of the stent.
[0005] This invention provides a braiding method for a support, using a clamp with multiple positioning pins arranged circumferentially and longitudinally to guide and fix the braiding path of the wires, including the following steps:
[0006] Step A: Fix the first wire to the main body of the clamp and weave it circumferentially from the starting point along a predetermined path. The predetermined path is W-shaped, inverted W-shaped, or at least a combination of both, forming alternating peaks and valleys. The predetermined path is distributed circumferentially under the guidance of the positioning pins, covering the surface of the current braided layer.
[0007] Step B: After the first wire completes the weaving of the current braided layer, it moves longitudinally to the next braided layer, repeating Step A to reach the predetermined number of layers, forming a multi-layered braided structure woven along the forward path.
[0008] Step C: Starting from the end of the forward path, the first wire is woven into a reverse path in the opposite direction to the forward path, which is complementary to and interspersed with the forward path, covering the entire braided layer to form multiple diamond mesh structures. The diamond mesh structures include multiple hook structures and overlapping structures.
[0009] Using a second wire, starting from any empty positioning pin, weave along the empty positioning pins until all positioning pins are filled, forming multiple diamond-shaped mesh structures. The second wire interweaves with the first wire to form the overall structure of the support. In the support weaving method provided by this invention, the adjacent peaks of the W-shaped path have different heights, and the height ratio of adjacent peaks in the same weaving layer is 2:1.
[0010] In the braiding method provided by the present invention, the predetermined path in the braided layer in step A is characterized by the fact that when the forward W-shaped path and the inverted W-shaped path are adjacent, the inverted W-shaped path shares a path with the adjacent W-shaped path.
[0011] In the bracket weaving method provided by the present invention, both the hook structure and the overlapping structure are formed at the vertices of the rhomboid mesh structure; wherein, the hook structure intersects each other and has a physical locking function, and the overlapping structure intersects vertically and does not have a physical locking function.
[0012] In the stent weaving method provided by this invention, the predetermined path in step A includes at least one of a W-shape, an inverted W-shape, or a combination of both. By intersecting the wires to form hook and overlap structures, good support and flexibility are achieved in both the radial and longitudinal directions. The hook structure provides a physical locking function, keeping the stent stable within the lumen and preventing slippage, allowing the stent to adapt to complex lumen morphologies. The overlap structure, lacking a physical locking function, effectively maintains the shape and position of the stent under external pressure. Through the stent weaving method and the resulting stent structure of this invention, the stability and load-bearing capacity of the stent are enhanced, leading to better clinical application results in medicine. Attached Figure Description
[0013] To facilitate understanding of the technical solutions in this invention, the accompanying drawings are briefly described below. These drawings illustrate different embodiments of the invention and are provided for reference by those skilled in the art.
[0014] Figure 1 is a partial enlarged view of the hook structure and overlapping structure in this invention;
[0015] Figure 2 is a schematic diagram of the support structure in the first embodiment;
[0016] Figure 3 is a schematic diagram of the clamp structure in the sixth embodiment;
[0017] Figures 4 to 9 illustrate the weaving process of the bracket in the first embodiment;
[0018] Figures 10 to 12 illustrate the braiding process of the second wire of the bracket in the fourth embodiment;
[0019] Figures 13 to 15 illustrate the weaving process of the second wire of the bracket in the fifth embodiment;
[0020] Figures 16 to 23 illustrate the weaving process of the head and tail expansion portions of the support in the sixth embodiment;
[0021] Figure 24 is a front view of the braided support obtained in the sixth embodiment of the present invention.
[0022] The attached drawings include: bracket 100, head expansion 101, tail expansion 102, main body 103, first main body 1031, second main body 1032, coating 104, first wire 10, second wire 11, clamp 200, head expansion clamp 201, main body clamp 203, tail expansion clamp 202, positioning pin P, hook structures 31a and 31b, and overlapping structures 32a and 32b. Detailed Implementation
[0023] The directional terms used in this specification (such as "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," etc.) are based solely on the orientation shown in the accompanying drawings and are for ease of description rather than limiting the specific device; they do not specifically refer to the actual orientation of the device. Terms such as "first," "second," etc., are used only to distinguish similar elements and do not represent relative importance. Unless explicitly stated, "upper" or "lower" in the description may refer to direct contact between elements or indirect contact through other structures.
[0024] In the description of this invention, the terms "one embodiment," "some embodiments," etc., mean that the features described in connection with the example are included in at least one embodiment of the invention. Those skilled in the art can combine features of different embodiments as needed to meet specific application requirements.
[0025] Examples of the braiding method of the present invention are shown in Figures 4 to 22. The figures illustrate the braiding paths and structures of different embodiments. Figures 2 and 23 show schematic diagrams of the structures of the braids obtained by the braiding method of the present invention.
[0026] In the attached diagram, dashed lines represent completed wire movement paths, solid lines represent the wire path in the current step, and hollow dots indicate the arrangement of locating pins on the fixture. The wire paths are for illustrative purposes only and do not represent the specific material and dimensions of the wire.
[0027] In this embodiment, a clamp with multiple locating pins P arranged circumferentially and longitudinally is used to guide and fix the braiding path of the wires for braiding the support structure. The braiding wires include a first wire 10 and a second wire 11, both preferably made of the same material and diameter to ensure uniform overall strength of the support structure. In a preferred embodiment, the wire material is selected as a nickel-titanium alloy to provide excellent flexibility and shape memory, enabling the support to maintain a stable structure in complex tubular environments. In other embodiments, wires of different materials and diameters can also be selected to achieve balanced or differentiated support forces under specific application requirements.
[0028] The first wire 10 is used to braid the first main body 1031 of the support frame, and the second wire 11 is used to braid the second main body 1032 of the support frame, forming a diamond-shaped mesh structure. Both are composed of multiple mesh structures arranged circumferentially. To ensure structural independence and overall integrity during the braiding process, the first wire 10 and the second wire 11 are braided using different positioning pins P and do not share positioning pins. After the first wire 10 is braided, the second wire 11 uses the remaining positioning pins to fill gaps to avoid path overlap and form a complete support structure.
[0029] The mesh structures of the first wire 10 and the second wire 11 are arranged sequentially along the longitudinal direction of the support, forming adjacent support structures. The weaving layers of the two are independent yet complementary, ensuring the stability of the support structure.
[0030] In specific embodiments, the weaving of the first wire 10 and the second wire 11 can be performed simultaneously or alternately. There is no fixed requirement for their starting order; the second wire 11 can begin weaving after the first wire 10 has been completed, or it can begin weaving simultaneously with the first wire 10, working independently of each other. For ease of distinction, the terms "first wire 10" and "second wire 11" in the following description are only used to differentiate the weaving order and do not imply a necessary causal relationship between them.
[0031] In a specific implementation, the clamp 200 is designed as a standard cylinder, uniformly divided into multiple division points along the circumferential and longitudinal directions. The circumferential division lines x1, x2, ..., x14 represent the equally spaced division positions of the clamp in the circumferential direction, and the longitudinal division lines y1, y2, ..., y7 represent the division positions of the clamp in the longitudinal direction. The coordinates of each division point are represented by (x, y), such as (x1, y2) representing the positions of the positioning pins corresponding to the first circumferential division point and the second longitudinal division point. The wire moves sequentially through these positioning pins to complete the braiding path. In other implementations, the clamp 200 can also be non-cylindrical, and the spacing between the division lines is not limited, but equally spaced is preferred. The shape of the clamp can be modified according to the clinical needs of the required stent.
[0032] Define the distance between adjacent dividing points of the fixture 200 as the unit distance. During the braiding process, when the wire moves 1 or 2 unit distances simultaneously in the circumferential and longitudinal directions, the path lengths passed through can be L or 2L respectively. By controlling the unit distance, ensure the accuracy of the braiding path and the symmetry of the grid.
[0033] In this embodiment, the stent braiding layer (hereinafter referred to as "layer") refers to a set of complete braiding 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 braiding 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 can be effectively connected to the adjacent upper and lower layers to form a stable support structure.
[0034] Each layer of braiding 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 braiding structure. For example, when the height of each layer is fixed at 5 mm, the total stent height can be precisely controlled by adjusting the number of layers n. When the stent needs to increase its longitudinal length to meet the requirements of a specific lumen or lesion location, it can be achieved by increasing the number of braiding 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.
[0035] In the first specific embodiment of the present invention, the braiding process of the stent main body is as follows:
[0036] (1. Single-layer forward path braiding <Step A>)
[0037] In Step A, fix the first wire 10 on the fixture main body, select any positioning pin as the initial position, and braid along the circumferential direction according to a predetermined path, and the path is at least one of a W shape, an inverted W shape, or a combined arrangement of the two, forming alternating peak points and valley points. The path is distributed along the circumferential direction under the guidance of the positioning pins and covers the surface of the current braiding layer. The termination position of this path is the starting position of the next path.
[0038] The first specific embodiment
[0039] In the first specific embodiment, the predetermined path in Step A is designed as a W-shaped path, as shown in Figure 4, and specifically includes:
[0040] Step A-1: Starting from the initial position A1(x1,y2), the first wire 10 moves downwards by 2L along the diagonal direction, forming the first descending segment of the W-shaped path, reaching the first valley point M1(x3,y4); then, the first wire 10 moves upwards by L along the diagonal direction from the valley point M1(x3,y4), forming the first ascending segment, reaching the first peak point M2(x4,y3); subsequently, the first wire 10 moves downwards by L along the diagonal direction from the first peak point M2(x4,y3), forming the second descending segment, reaching the second valley point M3(x5,y4); finally, the first wire 10 moves upwards by 2L along the diagonal direction from the second valley point M3(x5,y4), forming the second ascending segment, ending at the end point M4(x7,y2) of the W-shaped path. The end point M4 of the previous W-shaped path is symmetrical to the starting point A1 in the circumferential direction, completing a complete W-shaped path.
[0041] Step A-2: The first wire 10 takes 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 A-1 until it covers the entire surface of the braided layer, forming a closed-loop structure within the layer. In a specific implementation, the weaving 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, finally achieving coverage of the current braided layer surface. After completing the weaving of the current layer, the first wire 10 moves longitudinally to the next braided layer to begin weaving a new layer.
[0042] 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 surface of the braided layer is covered, the wire moves directly longitudinally to the starting point of the next braided layer, realizing a rapid transition of the path.
[0043] If the remaining area of the positioning pins in the current braided layer is insufficient to accommodate a complete W-shaped path (referred to as an uncovered row), then the following steps are taken:
[0044] If the uncovered row is insufficient to accommodate a complete W-shaped path and the number of rows is small (e.g., only 1-2 rows remain), the wire moves directly along the longitudinal direction to the starting point of the next braided layer, achieving a rapid transition of the path.
[0045] If there are many rows not covered, to avoid excessively large path spans, a curved path can be woven within the remaining row area to fill the empty space, ensuring path continuity and uniform distribution. After filling, the wire moves from the end of the curved path along the longitudinal direction to the starting point of the next braided layer, achieving a smooth transition between layers.
[0046] In single-layer braiding, the termination position of each W-shaped path serves as the starting point of the next path, and braiding is gradually carried out circumferentially until the entire braiding layer is covered. The height ratio 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, thereby adapting to deformations in complex lumen environments.
[0047] (2. Braiding of multi-layer forward paths <Step B>)
[0048] After the first wire 10 completes the path of the current braiding layer, it moves longitudinally to the next braiding layer, and the braiding structure of Step A is repeated layer by layer until the predetermined number of layers is reached, forming a forward multi-layer braiding structure of the stent main body.
[0049] Step B-1: The first wire 10 moves longitudinally from the end position of the last path of the current braiding layer to the starting position of the next braiding layer and starts braiding the new layer. Under the guidance of the positioning pins, the predetermined path of Step A is repeated, and it is distributed circumferentially to cover the surface of the current braiding layer until a complete single-layer closed-loop structure is formed.
[0050] Step B-2: The first wire 10 is longitudinally connected layer by layer in each braiding layer, maintaining the consistency of the path arrangement, and gradually completing 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.
[0051] After the wire path completes the braiding of all the predetermined number of 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.
[0052] In a specific embodiment, the forward path is a W-shaped path, passing through the 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), peak point M17(x13,y4) in sequence. The entire surface of the braiding layer is covered. The first wire 10 completes the path braiding of the current layer, and the end point is M18(x1,y6). This end point is symmetric in the longitudinal direction with the initial position A1(x1,y2) of the first layer, forming a complete multi-layer closed-loop structure.
[0053] (3. Braiding of reverse paths <Step C>)
[0054] Step C: Starting from the end of the forward path, the first wire 10 weaves a reverse path in the opposite direction to the forward path, complementing and interlacing the forward path, covering the entire braided layer to form multiple diamond-shaped mesh structures. This diamond-shaped mesh structure includes hook structures and overlapping structures; the interaction of the hook and overlapping structures enhances the radial stability and flexibility of the support. In a specific embodiment, when the predetermined forward path adopts a W-shaped path, the reverse path is a complementary inverted W-shaped path.
[0055] Step C-1: Take the end position of the forward braiding path of the first wire 10 (e.g., M18(x1,y6)) as the starting point of the reverse braiding path, and braid a path that is complementary to the forward path along the reverse path direction. The path forms a hook structure where the peak and valley points meet, and an overlapping structure at the upper and lower intersections, covering the surface of the current braiding layer to ensure the symmetry and stability of the path.
[0056] Step C-2: After the first layer of reverse path weaving is completed on the first wire 10, it moves longitudinally to the starting point of the next weaving layer and continues the reverse path weaving. The weaving of each layer of reverse path maintains the consistency of the path intersection and hook structure with the previous layer's reverse path, forming a multi-layer closed-loop structure layer by layer. The closed-loop structure is achieved through the complete coverage of the path within the layer and the smooth transition of the path between layers, and forms an integral and continuous support structure with the forward path in the logical connection between the start and end points.
[0057] The specific weaving process is as follows: The first wire 10 starts from the end point (M18) of the forward path and moves diagonally according to the inverted W-shaped weaving rule, gradually forming peaks and valleys. For example, the first wire 10 moves upward 2L diagonally from M18 to reach peak N1 (x3, y4), and then moves downward L diagonally to reach valley N2 (x4, y5). The paths intersect with the forward path at the intersection, forming a hook structure. After completing the current weaving layer, the first wire 10 moves longitudinally to the starting point of the next weaving layer (e.g., N9), repeating the above path generation rule until the surface of all weaving layers is covered. The weaving of the reverse and forward paths establishes the support structure.
[0058] In the multi-layer braided path design of this invention, the closed-loop structure forms a continuous mesh structure through the connection of paths within each layer and the transition of paths between layers. The starting and ending points of each layer's path are rationally arranged according to the braided path design to facilitate the continuous connection of paths between layers. Complete coverage of a single layer's path is achieved through the alternating arrangement of forward and reverse paths. During interlayer transitions, 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 and starting point are close, the wire moves directly longitudinally for quick connection; if the end point and starting point are far apart, the wire transitions through a braided, bent path to ensure path continuity and uniform distribution.
[0059] After all the braided layers are completed, the final endpoint of the path coincides with the starting point of the first layer, forming a multi-layered closed-loop structure. The closed-loop design ensures that the support structure has a uniformly distributed support force in both the radial and longitudinal directions.
[0060] In the stent braiding method of this invention, a single-layer closed-loop structure achieves full path coverage of a single braided layer; an interlayer closed-loop structure achieves smooth path transition between adjacent braided layers; a multi-layer closed-loop structure combines multiple braided layers into a complete whole; and finally, a complete closed-loop structure of the stent from start to finish is achieved through the combination of forward and reverse paths. The various levels of closed-loop structures complement each other, providing the stent with comprehensive radial support, flexibility, and stability, making it suitable for medical applications in complex luminal environments.
[0061] The forward and reverse paths intersect to form hook points. The hook structure is formed by the coincidence of the meeting peaks and valleys, as shown in Figure 1. This provides a physical locking function, enhances local support, prevents path slippage, and improves radial stability. Meanwhile, the overlapping points between paths are formed by the vertical crossing of the wires within the braided paths. While they do not have a physical locking function, they provide deformation space under localized stress, giving the support greater flexibility to adapt to complex tubular environments.
[0062] Through the synergistic effect of closed-loop paths, hook points, and overlapping points, the overall structural stability, compressive strength, and flexibility of the support are significantly improved.
[0063] The second wire 11 is braided to form the second main body 1032:
[0064] The second wire 11 begins to weave from any empty positioning pin (such as x1, y1) in the main body that is not covered by the first wire 10, and weaves along the empty positioning pin until all positioning pins are filled, forming multiple diamond-shaped mesh structures. The second wire 11 interweaves with the first wire 10 to form the overall structure of the main body of the bracket, enhancing the overall rigidity and stability of the bracket.
[0065] Specifically, the braiding path of the second wire 11 can be the same as or different from that of the first wire 10. In this embodiment, as shown in Figures 7 to 9, the second wire 11 adopts the same W-shaped path as in step A of the first wire 10, covering the remaining positioning pins of the main body layer by layer, and finally reaching the other end of the main body (e.g., x14, y4). After completing the forward path braiding, the second wire 11 returns from the braiding endpoint of the forward path to the initial position of the main body braiding along the reverse path, braiding a complementary inverted W-shaped path and forming a closed loop structure.
[0066] During the multi-wire interlacing process, the interlacing paths of the first wire 10 and the second wire 11 form a hook structure at the meeting points of the peaks and valleys in the same layer; simultaneously, paths in the same layer or different layers form overlapping points at their vertical intersections. The closed-loop structure is achieved through the connection of the beginning and end of the paths within a layer and the smooth transition between paths between layers. During the transition between layers, the second wire 11, based on the positional relationship between the weaving end point of the current layer and the starting point of the next layer, adopts a direct longitudinal movement or a bending path to ensure path continuity and uniform distribution.
[0067] Second Implementation Method
[0068] In the second specific implementation method, the predetermined path in step A is designed as an inverted W-shaped path, specifically including:
[0069] Step A-1: The first wire 10 is woven from the initial position into an ascending segment (to the peak), a descending segment (to the valley), another ascending segment (to the peak), and a final descending segment (to the valley), forming an inverted W-shaped path. The end point of the previous W-shaped path is circumferentially symmetrical to the initial position.
[0070] Step A-2: Repeat step A-1 above, knitting continuously in the circumferential direction.
[0071] Step A-3: If there are uncovered rows, transition can be achieved through a direct or detour path.
[0072] Third Implementation Method
[0073] In the third specific implementation method, the predetermined path in step A is designed as an alternating combination of W-shaped and inverted W-shaped paths, and path segments can be shared. Specifically, it includes:
[0074] Step A-1: Weave a W-shaped path;
[0075] Step A-2: Continue weaving the inverted W-shaped path, sharing some path segments with the previous W-shaped path;
[0076] Step A-3: Repeat steps A-1 to A-2, knitting continuously in the circumferential direction;
[0077] Step A-4: If there are uncovered rows within the braided layer, and the uncovered rows are insufficient to accommodate a complete combination path, then move directly or through a bend to the next braided layer.
[0078] In specific embodiments, the predetermined path is preferably a W-shaped path, an inverted W-shaped path, or a combination of alternating paths of the two. The three path designs mentioned in the above specific embodiments one, two, and three are merely exemplary embodiments. In actual applications, the path type can be dynamically adjusted according to the application scenario of the stent, the shape of the lumen, and the requirements of the braiding process. For example, it can be combined with spiral paths, V-shaped paths, or other geometric paths to further optimize the radial support force and flexibility of the stent and meet the diverse requirements in complex environments.
[0079] Fourth Implementation Method
[0080] In this embodiment, the weaving method of the first wire 10 is the same as that in the first embodiment, and will not be described again here.
[0081] Figures 10 to 12 illustrate the braiding path of the second wire, which moves alternately along the diagonal in a V-shaped path, forming upper and lower segments layer by layer and covering a designated area (e.g., a semicircle or the entire circumference) of the current braided layer. The bending points (peaks and valleys) of each layer's path are formed at the desired angles by changing the direction of the wire.
[0082] 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:
[0083] The second wire 11 starts from the starting point (x2, y2) and moves alternately along the diagonal direction in a V-shape, 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 peaks are located at the upward bends of the path, while the valleys are located at the downward bends of the path, and the height difference and bend angle of the path can be optimized according to actual needs.
[0084] After each layer completes its current coverage, the second wire 11 moves longitudinally to the starting point of the next braided layer, maintaining consistency in the path shape and weaving pattern, thus forming a multi-layer structure layer by layer. The transition between layers can be achieved through straight or curved paths to ensure continuity and uniformity between braided layers, until the second wire 11 reaches the endpoint (x2, y6) at the other end of the main body.
[0085] After the forward path weaving is completed, the second wire 11 begins to weave in the reverse direction from the weaving end point (x2, y6) of the forward path, returning layer by layer to the starting point (x2, y2) in the opposite direction. The paths are staggered at the peaks and valleys, forming a hook structure. The reverse path and the forward path are staggered in the circumferential direction, forming a symmetrical interwoven mesh structure, which evenly distributes the radial stress of the support.
[0086] Fifth Implementation Method
[0087] In this embodiment, the weaving method of the first wire 10 is the same as that in the first embodiment, and will not be described in detail here.
[0088] Figures 13 to 15 show the weaving path of the second wire 11, which is weaved alternately in a V-shape. The layer height is half that of the W-shaped path of the first wire 10, making the layer height ratio 1:2 and forming a denser support structure.
[0089] Specifically, the second wire 11 starts from a starting point (e.g., x2, y2), and each layer of the path moves alternately along the diagonal direction, using a V-shaped path for weaving, covering half of the circumference of the current woven layer. Each layer of the path is staggered with the adjacent layer in the circumferential direction to avoid wire overlap and enhance the strength of the support structure. For example, the first layer of the path covers half of the circumference, the second layer of the path covers the other half of the circumference, and 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 sequence, and maintaining the staggered pattern during longitudinal movement.
[0090] After the second thread 11 is completed in the forward weaving, it switches to the reverse path from the other end of the main body (e.g., x1, y5). The reverse weaving path starts from the end of the forward path and moves in the opposite direction along the diagonal, covering the other half of the circumference of each weaving layer layer by layer. The forward and reverse paths form a hook structure with physical locking function at the intersection of peaks and valleys, effectively preventing thread slippage and providing all-round support.
[0091] In this embodiment, each path layer covers only half a circumference, and the paths are staggered in half-circumference units along the circumference, forming an overall structure where the braided paths intersect vertically. The overlapping structure is formed at the spatial intersection of the upper and lower paths. While it does not have a physical locking function, it provides flexibility to adapt to complex tubular environments. The hook structure is formed at the point where the peaks and valleys of the forward and reverse paths meet at the locating pin. It has a physical locking function, enhancing radial support through the interlocking effect of the paths and preventing the wire from slipping after expansion.
[0092] This embodiment combines forward and reverse paths, forming a multi-layered staggered cross structure between the first wire 10 and the second wire 11. This structure evenly distributes overlapping points and hook points, improving the radial and longitudinal support force of the support and enabling the support to exhibit good flexibility and stability in complex tubular environments.
[0093] Sixth Implementation Method
[0094] In the sixth embodiment, to further improve the fixation effect of the bracket, expansion portions are added to the head and tail ends in addition to the multi-layer W-shaped braided structure of the main body. The braiding of the main body can adopt the braiding method in the aforementioned embodiments (such as embodiments 1-5 and their variations), which will not be described in detail here.
[0095] As shown in Figure 3, the head end expansion part clamp 201 and the tail end expansion part clamp 203 are respectively located at both ends of the clamp. In this embodiment, they are designed as a tapered structure that gradually expands. The shapes of the clamps 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, horn-shaped, conical, double ellipsoidal or asymmetric structures. At the same time, the arrangement density and angle of the positioning pins of the clamp can be set according to the shape of the expansion part and the requirements of the radial supporting force, meeting the mechanical property requirements in different clinical environments.
[0096] 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 braiding. The ratio of the main body part of the clamp to the expansion part and the length of the connecting part can be flexibly changed to meet the development requirements of special stent structures. Through this clamp design, the braiding paths of the main body part and the head and tail expansion parts maintain consistent symmetry and uniformity, forming a stable stent mesh structure, which is suitable for the implantation requirements of various lumen environments.
[0097] Weaving of the head end expansion part <Step D>
[0098] In this step (Step D), as shown in Figures 16 to 17, the first wire 10 starts from the selected starting point of the head end expansion part and is woven through a plurality of circumferential and longitudinal broken line segments. The starting point of the path coincides with the end point of the current weaving layer, and then 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 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 shown in Figure 18.
[0099] The specific process is as follows:
[0100] Step D-1: The first wire 10 moves diagonally upward 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 segment of the broken line path.
[0101] Step D-2: The first wire 10 moves diagonally downward from the peak point to the valley point, forming the descending segment of the broken line path.
[0102] 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.
[0103] Weaving of the tail end expansion part <Step E>
[0104] The weaving method for the tail expansion section is similar to that for the head expansion section, maintaining a consistent path structure to ensure overall structural symmetry and continuity. The specific weaving process is as follows:
[0105] Step E-1: As shown in Figure 19, the first wire 10 moves diagonally downward from the starting point of the tail expansion section to the first valley point (e.g., x4, y7), that is, it crosses 3 positioning pins circumferentially and 1 positioning pin longitudinally, forming the descending segment of the broken line path.
[0106] Step E-2: The first wire 10 moves from the valley point to the peak point along the diagonal direction, forming the rising segment of the broken line path.
[0107] Step E-3: Repeat steps E-1 and E-2, gradually covering the circumference of the tail expansion section, and smoothly transitioning to the reverse weaving path of the main body section.
[0108] When transitioning between the head and tail expansion sections and the main body, the path is smoothly connected to ensure continuity. For example, the end point of the path in the head expansion section is directly connected to the starting point of the forward braiding path (e.g., a W-shaped path) in the main body. After the braiding of the tail expansion section is completed, the wire transitions from the path in the tail expansion section to the starting point of the reverse braiding path (e.g., an inverted W-shaped path) in the main body, and returns layer by layer along the reverse path to the starting position A1 of the main body, as shown in Figures 20 to 23, ultimately forming a complete closed-loop structure.
[0109] Seventh Implementation Method
[0110] The present invention also provides two bracket products, which are made by the above-mentioned weaving method and have good support and positioning effects.
[0111] The first type of support product, as shown in Figure 2, consists only of a main body 103, which is a hollow tubular structure manufactured using the aforementioned weaving method. It is used for support within cavities. This main body can adapt to the inner diameter of the cavity, providing uniform support to prevent deformation or blockage of the cavity.
[0112] The second type of stent product, as shown in Figure 24, comprises a main body and expansion sections, suitable for cavities requiring additional positioning and anti-displacement effects. Its structure includes a main body 103, located in the middle of the stent, which provides the primary support function; at both ends of the main body are head expansion sections 101 and tail expansion sections 102. The diameter of the head and tail expansion sections is larger than that of the main body, forming cup-shaped, spherical, trumpet-shaped, conical, ellipsoidal, or asymmetrical expansion areas that conform to the cavity wall.
[0113] The head and tail expanders are designed for the inlet and outlet regions of the cavity, enhancing stent fixation through radial expansion and preventing longitudinal displacement or rotation of the stent after implantation. The expanders can be positioned symmetrically or asymmetrically according to the anatomical structure of the cavity to adapt to specific anatomical needs.
[0114] Seventh Implementation Method
[0115] In some embodiments, the scaffold may be provided with a covering portion 104, which may cover all or part of the scaffold area to provide additional protection and functionality. The covering portion material may be polyester, polyurethane, silicone, PE, PP, HDPE, PTFE, etc., which have good biocompatibility and mechanical properties and can effectively prevent tissue embedding or excessive proliferation.
[0116] The overlay can be placed on the outer, middle, or inner side of the stent. An outer overlay reduces friction between the stent and surrounding tissue, suitable for applications requiring reduced frictional damage. An inner overlay protects the inner wall of the cavity, preventing tissue damage, suitable for stents requiring protection of the internal luminal structure. A middle overlay enhances the mechanical strength of the stent; a full overlay design provides higher pressure resistance, suitable for high-pressure environments; a partial overlay design retains flexibility and provides localized support.
[0117] In a preferred embodiment, the covering portion 104 covers the entire outer surface of the stent, forming a fully covered 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.
[0118] In another embodiment, the covering portion 104 covers only a portion of the scaffold, forming a semi-covered structure that allows partial scaffold contact with tissue, providing both support and promoting tissue growth. It can selectively cover the outer or inner side to achieve physiological functions during scaffold fixation.
[0119] In addition, the stent may have a contrast-enhancing ring to clearly show the stent's position and status in medical imaging. The contrast-enhancing ring can be a circular ring, a spiral, or multiple small metal dots evenly distributed around the stent's outer periphery, and is made of high-density materials such as platinum, tungsten, or iridium. The contrast-enhancing ring can be installed by welding, mechanical fixation, or localized plating. It effectively enhances the imaging effect after stent implantation, improving the safety and accuracy of the procedure.
Claims
1. A method for weaving a support frame, characterized in that, A clamp with multiple locating pins arranged circumferentially and longitudinally is used to guide and fix the braiding path of the wire, which includes a first wire and a second wire. The weaving method includes the following steps: Step A: Fix the first wire to the main body of the clamp and weave it circumferentially from the initial position along a predetermined path. The predetermined path is at least one of a W shape, an inverted W shape, or a combination of both, forming alternating peaks and valleys. The predetermined path is distributed circumferentially under the guidance of the positioning pins, covering 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 the predetermined number of layers, forming a multi-layered braided structure woven along the forward path; Step C: The first wire starts from the end of the forward path and weaves a reverse path in the opposite direction to the forward path, which is complementary to and interspersed with the forward path, covering the entire braided layer to form multiple diamond mesh structures, the diamond mesh structures including hook structures and overlapping structures; Using a second wire, starting from any empty positioning pin, weave along the empty positioning pins until all positioning pins are filled, forming multiple diamond-shaped mesh structures. The second wire interweaves with the first wire to form the overall structure of the bracket.
2. The weaving method according to claim 1, characterized in that, The adjacent peaks of the W-shaped path and the inverted W-shaped path have different heights, and the height ratio of adjacent peaks is 2:
1.
3. The bracing method according to claim 1, characterized in that, The predetermined path in step A is characterized by the fact that when a W-shaped path and an inverted W-shaped path are adjacent, the inverted W-shaped path shares a path with the adjacent W-shaped path.
4. The weaving method according to claim 1, characterized in that, Both the hook structure and the overlapping structure are formed at the vertices of the rhomboid mesh structure; The hook structures intersect each other and have a physical locking function, while the overlapping structures intersect vertically 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, including the following steps: Step A-1: The first wire moves from the initial position along the diagonal direction, forming the descending and ascending segments of the W-shaped path in sequence, forming valley points and peak points, until a W-shaped path is completed. The end point of the W-shaped path is symmetrical to the initial position in the circumferential direction. Step A-2: Repeat step A-1 to continuously weave multiple W-shaped paths along the circumference; Step A-3: If there are uncovered rows within the braided layer, and the uncovered rows are insufficient to accommodate a complete W-shaped path, then transition directly or through a bend in the path to the next braided layer.
6. The weaving method according to claim 1, characterized in that, The predetermined path in step A is an inverted W-shaped path, including the following steps: Step A-1: The first wire moves from the initial position along the diagonal direction, forming the rising and falling segments of the inverted W-shaped path in sequence, forming peaks and valleys, and completing an inverted W-shaped path. The end point of the W-shaped path is symmetrical to the initial position in the circumferential direction. Step A-2: Repeat step A-1, weaving continuously in the circumferential direction; A-3: If there is an uncovered row within the braided layer, and the uncovered row is insufficient to accommodate a complete inverted W-shaped path, then the transition to the next braided layer is direct or via a bend path.
7. The weaving method according to claim 4, characterized in that, The predetermined path in step A is an alternating combination of W-shaped and inverted W-shaped paths, including the following steps: Step A-1: The first wire moves from the initial position along the diagonal direction, forming the descending and ascending segments of the W-shaped path in sequence, forming peaks and valleys, and completing a W-shaped path. The endpoint of the W-shaped path is symmetrical to the initial position in the circumferential direction. Step A-2: The first wire continues to weave an inverted W-shaped path, sharing the last rising segment with the W-shaped path, and then forming a falling segment and a rising segment in sequence to complete an inverted W-shaped path; Step A-3: Repeat steps A-1 to A-2, knitting continuously in the circumferential direction; Step A-4: If there are uncovered rows within the braided layer, and the uncovered rows are insufficient to accommodate a complete combination arrangement path, then move directly or via a bend path to the next braided layer.
8. The weaving method according to claim 1, characterized in that, Step C includes the following steps: Step C-1: Take the end position of the forward braiding of the first wire as the starting point of the reverse path braiding, and braid a path that is complementary to the forward path along the reverse path direction. When the path meets at the peak and valley points, a hook structure is formed; when the path intersects at the top and bottom, an overlapping structure is formed, covering the surface of the braided layer. Step C-2: After completing the first layer of braiding in the reverse path, the first wire moves longitudinally to the next braiding layer and continues the braiding 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 wire is interwoven along the same path as the first wire, so that the main body forms a diamond-shaped 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 its weaving layer height is equal to the W-shaped path height of the first wire, with a layer height ratio of 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 its weaving layer height is half the height of the W-shaped path of the first wire, with a layer height ratio of 1:
2.
12. A stent, characterized in that, It is woven using the bracing method described in any one of claims 1 to 11.
13. A method for weaving a stent, comprising a stent body, a head expansion portion, and a tail expansion portion, wherein the weaving of the stent body is achieved based on the method described in any one of claims 1-11, characterized in that, The weaving method further includes: Step D: Select any positioning pin as the end starting point of the head end expansion section, and continuously weave the first wire along multiple circumferential and longitudinal zigzag segments, with the end point of the path coinciding with the end starting point; Step E: Starting from the weaving endpoint of the main body of the support in the forward path, the tail expansion section continuously weaves the thread along multiple circumferential and longitudinal zigzag segments, with the endpoint of the path coinciding with the weaving endpoint of the main body.
14. A support, characterized in that, The support is woven using the bracing method described in any one of claims 1-11 or 13. The support includes a head expansion portion, a main body portion, and a tail expansion portion in sequence, and the diameters of the head expansion portion and the tail expansion portion are both larger than the main body portion.