Segmented expansion member, delivery device and vascular implant system including same

Abstract

The present application relates to a segmented expansion member, a delivery device including the same, and a vascular implant system. The segmented expansion member has at least one segmented expansion unit, including an expandable section, a proximal end restraint section connected to the proximal end of the expandable section, and a distal end restraint section connected to the distal end of the expandable section. The segmented expansion member is obtained by cross-knitting two or more threads into a mesh tubular structure and segmenting and restraining them at predetermined intervals over a predetermined length. In the segmented expansion unit, when the expandable section is radially expanded, the ratio of the axial length of the expandable section to the axial length of the proximal end restraint section is 8:1 to 20:1, and the number of intersections per inch of the expandable section is 20 to 200. The segmented expansion member of the present application provides appropriate axial pushing force and radial support force at the distal end, ensuring compression adjustment and flattening of the inner wall of the implant, while maintaining compliance and pushability.

Description

[Technical Field]

[0001] The present application relates to the medical device technical field, and more particularly to a segmented expandable member, a delivery device and a vascular implant system including the same. [Background technology]

[0002] Self-expanding tubular implants (e.g., stents) are typically delivered from a proximal end outside the body (e.g., the radial artery or femoral artery) to a diseased blood vessel using a delivery system. The delivery system typically includes a pushing guidewire extending from the proximal end outside the body to a diseased blood vessel inside the body. Starting from the distal end of the pushing guidewire, a preventive member (e.g., a silicone pad), an auxiliary pushing guidewire, and a developing head are sequentially provided. The auxiliary pushing guidewire typically extends from the pushing guidewire, and the preventive member typically surrounds the distal end of the pushing guidewire. However, it is desirable to further improve the tracking and pushability of the auxiliary pushing guidewire designed in this manner.

[0003] CN214285319U discloses a bead-string-like member and a stent delivery system, the bead-string-like member comprising an expandable body and at least two forming assemblies, each forming assembly comprising a first member and a second member, the first member having an inner lumen, and some segments of the expandable body converging into the lumen to form contracted segments of the bead-string-like member, or the first member having an outer surface, and some segments of the expandable body being fixedly connected to the outer surface to form contracted segments of the bead-string-like member. The second member is a tubular member, and the contracted segments are fitted into the second member, forming expanded segments of the bead-string-like member between two adjacent contracted segments. The bead-string-like member allows for smooth release of the stent, contributing to smoother stent delivery, and is simple in structure, easy to manufacture, and highly reliable.

[0004] The bead string-like members of the prior art smoothly release the stent and tightly fit it to the diseased blood vessel, and by providing a contraction segment, reduce the contact area between the expandable body and the inner wall of other devices or the inner wall of the blood vessel, thereby reducing damage to the vascular endothelium.In addition, the expansion segment of the expandable body deforms according to the course and shape of the blood vessel, reducing resistance to stent delivery and improving the smoothness of stent delivery.

[0005] In conventional procedures, after releasing a self-expanding tubular implant, the tubular implant is further compressed and adjusted using a guidewire to flatten its inner wall and further improve its adhesion to the blood vessel. After releasing the tubular implant, the inner wall of the tubular implant is directly compressed and adjusted without removing the beaded string-like member from the body. However, when using the beaded string-like member in the conventional technology, the process of compressing and adjusting the inner wall was not considered. Further exploration is needed to determine how to flatten the inner wall of the distal end of the tubular implant to improve adhesion, while maintaining the tracking ability of the distal end and improving the safety of the distal end when compressing and adjusting the inner wall of the tubular implant.

[0006] Therefore, there is an expectation in the art to develop a delivery member for a tubular implant, including a segmented expansion member and a delivery system including the same, that has excellent trackability and pushability, as well as excellent control over the distal end. Summary of the Invention

[0007] In view of the deficiencies of the prior art, a first object of the present application is to provide a segmented inflatable member, the segmented inflatable member having at least one segmented inflatable unit, the segmented inflatable unit including an inflatable section, a proximal end restraint section connected to a proximal end of the inflatable section, and a distal end restraint section connected to a distal end of the inflatable section, the segmented inflatable member being obtained by cross-knitting two or more wires into a mesh tubular structure, and segmenting and restraining the wires at predetermined intervals over a predetermined length; In the segment type expansion unit, when the expandable portion is radially expanded, the ratio of the axial length of the expandable portion to the axial length of the proximal end restraint portion is 8:1 to 20:1 (e.g., 8.4:1, 8.8:1, 9.5:1, 10.2:1, 10.7:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, etc.).

[0008] The expandable portion has 20 to 200 crossing points per inch of length, for example, 25, 30, 35, 50, 70, 90, 120, 150, 170, 180, 190, etc., and preferably 50 to 120.

[0009] The segmented expansion member of the present application is made of integrally braided threads, and is braided according to a predetermined length ratio. By selecting the ratio between the axial length of the expandable section and the axial length of the proximal end restraint section and limiting the braid density (the number of intersections within one inch of the length of the expandable section), it is possible to ensure that the segmented expansion member has appropriate compliance and pushability during the pushing process, and has an appropriate and relatively small axial pressing force at the distal end and an appropriate and relatively large radial supporting force after release. This is because, as the length of the expandable section increases, the compliance of the segmented expansion unit increases, but the pushing force decreases, and the radial supporting force of the segmented expansion unit is too small, resulting in a poor compression adjustment effect on the inner wall of the implant. On the other hand, as the length of the restraint section increases, the axial pressing force at the distal end of the segmented expansion unit is too large, which is likely to lead to damage to the blood vessel. Furthermore, the more intersections per inch of length of the inflatable section, the higher the braid density, and with the appropriate braid density, the segmented inflatable member can have adequate radial support and axial compression.

[0010] The smaller the number of intersections per inch of the length of the expandable section in its expanded state, the better the tracking ability of the segmented expansion unit and the smaller the radial support force. Therefore, by setting an appropriate ratio (8:1 to 20:1) between the axial length of the expandable section and the axial length of the proximal end restraint section and the appropriate number of intersections per inch of the length, the segmented expansion unit can have sufficient tracking ability and pushability during the pushing process, and can also obtain sufficient radial support force and small axial pushing force at the distal end after release, thereby achieving an excellent stent flattening effect.

[0011] In many cases, the smaller the wire diameter, the larger the PPI can be selected. For example, when the wire diameter is 0.040-0.050 mm, the PPI can be selected in the range of 50-120, which provides excellent followability and pushability for pushing the segmented expansion element, and also provides adequate axial pushing force and radial supporting force at the distal end.

[0012] The total length of the segmented expansion member described herein is determined by the length of the tubular implant, and preferably the segmented expansion member extends through the entire implant. Preferably, the total length of the segmented expansion member described herein is in the range of ≦70 mm. A segmented expansion member within the 70 mm range satisfies the influence of the ratio of the axial length of the expandable portion to the axial length of the proximal end restraint portion and the braid density on the radial support force and the axial compressive force of the distal end.

[0013] Preferably, when the expandable portion is in an expanded state, the projection point of the center point of the axial length of the expandable portion onto the inside of the cavity wall of the expandable portion along the same axial cross section is defined as point A, and the intersection point between the proximal end restraint portion and the inside of the cavity wall of the expandable portion is defined as point B. The angle between the line connecting points A and B and the axial direction is 10 to 30°, for example, 12°, 18°, 22°, 28°, etc.

[0014] Preferably, if the intersection point between the distal end restraint portion of the expandable portion and the inside of the cavity wall of the expandable portion is point B', the angle between the line connecting point A and point B' and the axial direction is 10 to 30°, for example, 12°, 18°, 22°, 28°, etc.

[0015] Preferably, the angle formed by the line connecting points A and B and the axial direction is the same as the angle formed by the line connecting points A and B' and the axial direction. Generally, when only one mesh tube is restrained and directional differential heat setting is not performed, a solution can be obtained in which the angle formed by the line connecting points A and B and the axial direction is the same as the angle formed by the line connecting points A and B' and the axial direction.

[0016] If the angle between the line connecting points A and B and the axial direction is too large, the degree of expansion of the expandable part will be high, the force conduction by the segmented expansion element may be weak, and the tubular implant may jump up during release, preventing smooth release and posing a risk to the safety of the surgery.If the angle between the line connecting points A and B and the axial direction is too small, the degree of expansion of the expandable part will be low, the compliance of the segmented expansion element will decrease, and the contact area with the inner wall of the tubular implant will be small, resulting in an insignificant effect on flattening the inner wall of the tubular implant.

[0017] The dimensions of the expandable portion and the restraining portion of the segmented expansion member should match the inner diameter of the tubular implant (e.g., equal to or slightly smaller than the inner diameter of the tubular implant). The present application does not specifically limit the absolute dimensions of the segmented expansion member, and those skilled in the art may select them according to the actual situation. For example, when the segmented expansion member is used in neurovascular interventional surgery, the inner diameter of the expandable portion in an expanded state is preferably 1.32 mm to 2.82 mm (e.g., 1.35 mm, 1.4 mm, 1.5 mm, 1.7 mm, 1.9 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, etc.), and the inner diameter of the restraining portion is preferably ≦0.27 mm (e.g., 0.26 mm, 0.23 mm, 0.20 mm, 0.16 mm, 0.14 mm, 0.12 mm, 0.05 mm, 0.03 mm, etc.).

[0018] The present application does not specifically limit the material of the knitting yarn, as long as the mesh tubular structure after knitting the yarn satisfies the above-mentioned structural limitations of the segmented expansion unit. For example, the knitting yarn can be made of superelastic, shape-memory, or piezoelectric materials such as Nitinol alloy material or other alternative metals, alloys, or polymers.

[0019] Preferably, the segmented inflation member has two or more segmented inflation units, and the segmented inflation units are connected end to end, and in adjacent segmented inflation units, the distal end restraint portion of the proximal end segmented inflation unit and the proximal end restraint portion of the distal end segmented inflation unit are the same restraint portion.

[0020] It should be noted that the segmented inflation member described herein may have only one segmented inflation unit, or may have two or more segmented inflation units. When two or more segmented inflation units are used, the segmented inflation units are connected end to end, and the distal end restraint of the proximal segmented inflation unit and the proximal end restraint of the distal segmented inflation unit of adjacent segmented inflation units are the same restraint. That is, the connection manner of the segmented inflation member (taking three segmented inflation units as an example) may be from proximal to distal, exemplarily, "proximal end restraint of the first segmented inflation unit - inflatable portion of the first segmented inflation unit - proximal end restraint of the second segmented inflation unit - inflatable portion of the second segmented inflation unit - proximal end restraint of the third segmented inflation unit - inflatable portion of the third segmented inflation unit."

[0021] Preferably, the segmented inflation unit is a mesh tubular structure that is constrained at both ends.

[0022] The mesh tubular structure has a certain degree of expandability, and the manufacturing method may be, for example, as follows: A mesh tube is formed by cross-knitting metal threads, and then the mesh tube is expanded to a certain degree and set. For example, a cylindrical structure is used as a central axis, and two or more metal threads are cross-knitted around the central axis to form a mesh tubular structure. The knitted mesh tube is then subjected to a setting temperature, heat-set, and then removed from the central axis to obtain the mesh tubular structure. The setting temperature may be determined depending on the material of the metal threads.

[0023] In one preferred technical solution, the segmented inflation unit further includes a first auxiliary force transmission member, and the distal end of the first auxiliary force transmission member and the proximal end of the most proximal segmented inflation unit are coaxially extended and connected; the first force transmission auxiliary member is a mesh tubular expandable structure having one to three end-to-end constrained mesh tubular structures, and the distal end constrained portion of the first force transmission auxiliary member and the proximal end constrained portion of the adjacent segment type expansion unit are the same constrained portion; When the mesh tubular expandable structure of the first auxiliary force transmission member is expanded, the projection point of the center point of the axial length of the mesh tubular expandable structure onto the cavity wall of the mesh tubular expandable structure along the same axial cross section is defined as point C, and the intersection point of the proximal end restraint portion of the mesh tubular expandable structure and the mesh tubular expandable structure is defined as point D. The angle formed by the line connecting points C and D and the axial direction is the transition angle of the proximal end of the mesh tubular expandable structure of the first auxiliary force transmission member, and the transition angle of the proximal end of the mesh tubular expandable structure is 0 to 10°.

[0024] Preferably, in the first force transmission auxiliary member, if the intersection point between the distal end restraint portion of the mesh tubular expandable structure and the mesh tubular expandable structure is point D', the angle formed by the line connecting point C and point D' and the axial direction is the transition angle of the distal end of the mesh tubular expandable structure of the first force transmission auxiliary member.

[0025] Preferably, in the mesh tubular expandable structure of the first force transmission auxiliary member, the transition angle of the proximal end is the same as the transition angle of the distal end. Generally, if only one mesh tube is restrained and no directional differential heat setting is performed, a solution in which the transition angle of the proximal end is the same as the transition angle of the distal end can be obtained.

[0026] The first auxiliary force transmission member serves to improve the control of the segmented inflation member from the proximal end (especially from outside the body) without reducing the outer diameter and radial support force of the segmented inflation member, because the transition angle of the proximal end (and the transition angle of the distal end) of the first auxiliary force transmission member is smaller, making it easier to transmit force to the inflatable portion and the distal end when performing operations such as rotating, tilting, and pushing at the proximal end.

[0027] Preferably, in the first force transmission auxiliary member, the transition angle of the proximal end of the mesh tubular expandable structure gradually increases from the proximal to the distal end.

[0028] The magnitude of the transition angle of the proximal end of the mesh tubular expandable structure of the first force-transmitting auxiliary member can be set by adjusting the length of the expandable portion, and generally, the transition angle decreases as the length of the expandable portion decreases, or when the length is constant, the transition angle may be decreased by presetting.

[0029] Preferably, the segmented expansion member further includes a second force transmission auxiliary member; The proximal end of the second force transmission auxiliary member and the distal end of the most distal segment type expansion unit extend coaxially and are connected to each other; the second force transmission auxiliary member is a mesh tubular expandable structure having one to three end-to-end connections and both ends restrained, and the distal end restraint portion of the second force transmission auxiliary member and the distal end restraint portion of the adjacent segment-type expansion unit are the same restraint portion; When the mesh tubular expandable structure of the second auxiliary force transmission member is expanded, the projection point of the center point of the axial length of the mesh tubular expandable structure onto the cavity wall of the mesh tubular expandable structure along the same axial cross section is defined as Point E, and the intersection point of the proximal end restraint portion of the mesh tubular expandable structure and the mesh tubular expandable structure is defined as Point F. The angle between the line connecting Points E and F and the axial direction is the transition angle of the proximal end of the mesh tubular expandable structure of the second auxiliary force transmission member, and the transition angle of the proximal end of the mesh tubular expandable structure is 0 to 10°.

[0030] Preferably, in the second force transmission auxiliary member, if the intersection point between the distal end restraint portion of the mesh tubular expandable structure and the mesh tubular expandable structure is point F', the angle formed by the line connecting E and the given point F' and the axial direction is the transition angle of the distal end of the mesh tubular expandable structure of the second force transmission auxiliary member.

[0031] Preferably, in the mesh tubular expandable structure of the second force-transmitting auxiliary member, the transition angle at the proximal end and the transition angle at the distal end are the same.

[0032] The role of the second auxiliary force transmission member is as follows: it makes it easy to control the axial force of the distal end within an appropriate range; after the force is transmitted to the expandable part, the force is dispersed due to the large expansion diameter, and the axial force is too small; the second auxiliary force transmission member re-concentrates the dispersed force, making it possible to control the axial force within an appropriate range; and the distal end of the tubular implant is attached to the expandable structure of the second auxiliary force transmission member, and the relatively small transition angle of the second auxiliary force transmission member allows the distal end of the tubular implant to be released gently, eliminating the problem of the distal end of the implant jumping up during the release process.

[0033] Preferably, in said second force transmission auxiliary member, the transition angle of the mesh tubular expandable structure gradually decreases from the proximal to the distal end.

[0034] The magnitude of the transition angle of the proximal end of the mesh tubular expandable structure of the second force-transmitting auxiliary member can be achieved by adjusting the length of the expandable portion, and generally, the transition angle is reduced by shortening the length of the expandable portion, or, if the length is constant, the transition angle may be reduced by presetting.

[0035] Preferably, the restraining portions have the same length.

[0036] The lengths of the restraints are the same, making it easier to adjust the structure of the segmented inflatable member.

[0037] Preferably, the method of segmenting and restraining at predetermined intervals includes any one or a combination of at least two of connecting to the base by presetting, gluing, welding or heat welding, connecting an extended thread by direct gluing, welding or heat welding, or fitting a restraining body on the outside.

[0038] The present application is not specifically limited to a method of segmenting and restraining at predetermined intervals, and any restraining method that can form a neck portion is applicable to the present application.

[0039] In addition, to allow the segmented expansion member to be visualized within the body, the restraint portion may optionally be made of a radiopaque material, including, but not limited to, platinum, tantalum, palladium, or other radiopaque materials.

[0040] A second object of the present application is to provide a vascular implant delivery device, the vascular implant delivery device comprising: A pushing guide wire, a segmented expansion member according to the first object connected to the distal end of the pushing guidewire; a development tip connected to a distal end of the segmented expansion member; A vascular implant placement and withdrawal assisting member is fixed to and fitted over the distal end of the pushing guide wire, the vascular implant placement and withdrawal assisting member including a fixing portion for fixing to and fitting over the distal end of the pushing guide wire, and an opening provided at the distal end of the fixing portion, the opening having a structure that gradually widens from the proximal end to the distal end.

[0041] Preferably, the opening comprises one of a horn-shaped opening, with the opening directed towards the distal end, and a splint, which radiates from the proximal end to the distal end.

[0042] Preferably, the development tip includes a core portion obtained by extending a segmented expansion member, and a development thread wound around and fixed to the core portion. The helical coil is an optional structure for the development thread, and those skilled in the art can substitute a structure equivalent in flexibility, toughness, and strength. Typically, the helical coil of the development tip can be formed of a monowire or a multiwire, but is not limited thereto.

[0043] The developing metal material of the developing tip is a radiopaque material, including but not limited to platinum, tantalum, palladium or other radiopaque materials.

[0044] Preferably, the vascular implant delivery device further includes an annular retaining portion fitted onto the proximal end of the segmented expansion member, the annular retaining portion having radial compressive elasticity.

[0045] A third object of the present application is to provide a vascular implant system, the vascular implant system comprising: a vascular implant delivery device according to the second object; and a vascular implant fitted over the outside of the segmented expansion member of the vascular implant delivery device. Or, The vascular implant system comprises: A pushing guide wire, a segmented expansion member according to the first object connected to the distal end of the pushing guidewire; a development tip connected to a distal end of the segmented expansion member; a vascular implant accommodating and releasing assisting member that is fixedly fitted onto the distal end of the pushing guidewire, the vascular implant accommodating and releasing assisting member including a fixing portion that is fixedly fitted onto the distal end of the pushing guidewire, and an opening provided at the distal end of the fixing portion, the opening having a structure that gradually widens from the proximal end to the distal end; and a vascular implant fitted over the outside of the segmented expansion member of the vascular implant delivery device.

[0046] Preferably, the vascular implant system further comprises a sheath for housing the vascular implant delivery device over which the vascular implant is fitted.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] The segmented expansion member of the present application has a segmented structure and limits the PPI of the expandable portion, so that the segmented expansion member can obtain appropriate axial pushing force and radial supporting force at the distal end, while maintaining its trackability and pushability, thereby ensuring the implant's inner wall compression and flattening effects. After the self-expanding stent is fully released, the segmented expansion member of the present application (including the ratio of the axial length of the expandable portion to the axial length of the proximal end restraint portion and the PPI) can effectively compress and adjust the self-expanding stent, allowing the operation of the proximal end (outside the body) pushing guidewire to be transmitted to the segmented expansion member, which can effectively contact the inner wall of the self-expanding stent (especially the inner wall at the distal end) without significantly protruding from the distal end of the self-expanding stent, and has a certain radial acting force, thereby achieving the effect of flattening the inner wall of the stent and improving the wall adhesion rate. The small axial pushing force at the distal end maintains the trackability of the distal end and improves the safety of the distal end. [Brief explanation of the drawings]

[0049] [Figure 1] 1 is a structural schematic diagram of a segment-type expansion member according to Example 1. FIG. [Figure 2] 2 is a structural schematic diagram of the first inflatable section 100. FIG. [Figure 3] FIG. 13 is a structural schematic diagram of a segment-type expansion member according to Example 10. DETAILED DESCRIPTION OF THE INVENTION

[0050] Hereinafter, the technical solution of the present application will be further interpreted and explained with reference to the detailed description of the invention. However, it should be noted that the detailed description of the invention is merely a specific implementation and interpretation of the substantial content of the technical solution of the present application, and should not be understood as a restriction on the scope of protection of the present application.

[0051] The present application will be described in more detail below with reference to the drawings and examples. It is to be understood that the specific examples described herein are merely used to interpret the relevant application and are not intended to limit the present application. It should be further explained that, for the sake of convenience, only parts relevant to the application are shown in the drawings.

[0052] It should be understood that in the description of this application, unless otherwise clearly specified or limited, the terms "attach," "connect," "couple," and the like should be understood in a broad sense, and may refer to, for example, fixed connection, detachable connection, integral connection, mechanical connection, electrical connection, direct connection, or indirect connection via an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to specific circumstances.

[0053] In the description of this application, it should be understood that the terms "distal end" and "proximal end" in the specification are viewed from the direction of the surgeon, with the "distal end" being the end away from the surgeon and the "proximal end" being the end closer to the surgeon. The "axial direction" should be understood as the pushing direction of the stent or the length direction of the guidewire, and the "radial direction" should be understood as the direction perpendicular to the "axial direction".

[0054] In the description of the present application, it should be noted that, unless contradictory, the embodiments and features of the embodiments in the present application can be combined with each other. Example 1

[0055] A segmented expanding member is formed by weaving 18 nitinol alloy wires with a diameter of 0.046 mm around a 3.5 mm diameter core to have a PPI of 85, with two over and two under knitting (specifically, one set of warp yarns is made up of four adjacent weft yarns crossing the warp yarn, and each set of yarns includes four knitting points, each of which is two positive knitting points and two negative knitting points, and the two positive knitting points are adjacent, or the two negative knitting points are adjacent), and is heat-set at 520°C for 5 minutes. After removing the core, a mesh tubular structure with a length of 60 mm is obtained. The mesh tubular structure (in its natural state) was divided into four segments, each 8 mm long, and the segments were restrained. The restraining method was to weld a platinum alloy cylinder (developing member) with an outer diameter of 0.41 mm and a length of 0.5 mm to the inside of the starting part of the proximal end of the segment, thereby obtaining a segmented expansion member (the ratio of the axial length of the expandable part to the axial length of the proximal end restraining part was 15:1). After expansion, the outer diameter of the expandable part was 2.5 mm, and the angle between the line connecting points A and B and the axial direction was 15.58°. Example 2

[0056] The only difference from Example 1 is that the proportion of segments in the mesh tubular structure is changed to form five segments every 6 mm (the ratio of the axial length of the expandable portion to the axial length of the proximal end restraint portion is 11:1).

[0057] The outer diameter of the expandable portion of the segmented expandable member obtained in Example 2 after expansion was 2.3 mm, and the angle formed by the line connecting points A and B and the axial direction was 18.97°. Example 3

[0058] The only difference from Example 1 is that the proportion of segments in the mesh tubular structure is changed to form three segments every 10.5 mm (the ratio of the axial length of the expandable portion to the axial length of the proximal end restraint portion is 20:1).

[0059] The segmented expansion member obtained in Example 3 had an outer diameter of 2.7 mm after expansion of the expandable portion, and the angle formed by the line connecting points A and B and the axial direction was 12.90°. Examples 4 to 6

[0060] The only difference from Example 1 is that the braid density PPI of the mesh tubular structure was changed to 50 (Example 4), 120 (Example 5), and 200 (Example 6). Example 7

[0061] A segmented expanding member is formed by weaving 18 nitinol alloy wires with a diameter of 0.046 mm around a 3.5 mm diameter core to have a PPI of 85, with two over and two under knitting (specifically, one set of warp yarns is made up of four adjacent weft yarns crossing the warp yarn, and each set of yarns includes four knitting points, each of which is two positive knitting points and two negative knitting points, and the two positive knitting points are adjacent, or the two negative knitting points are adjacent), and is heat-set at 520°C for 5 minutes. After removing the core, a mesh tubular structure with a length of 80 mm is obtained. The mesh tubular structure (in its natural state) was formed into six segments, each 8 mm long, and the segments were restrained. The restraining method involved welding a platinum alloy cylinder with an outer diameter of 0.41 mm and a length of 0.5 mm to the inside of the starting part of the proximal end of the segment, resulting in a segmented expansion element (the ratio of the axial length of the expandable part to the axial length of the proximal end restraint part was 15:1). After expansion, the outer diameter of the expandable part was 2.5 mm, and the angle between the line connecting points A and B and the axial direction was 15.58°. Example 8

[0062] The differences from Example 1 are as follows: a segmented expanding member, in which 16 nitinol alloy wires with a diameter of 0.09 mm are used as knitting yarns, knitted around a core with a diameter of 4.5 mm to a PPI of 30, knitted in a two-over-two-under knitting manner (specifically, one warp yarn and four adjacent weft yarns crossing the warp yarn constitute one set of knitting yarns, and each set of knitting yarns includes four knitting points, each of which is two positive knitting points and two negative knitting points, and the two positive knitting points are adjacent or the two negative knitting points are adjacent), is kept at 530°C for 6 minutes for heat setting, and after removing the core, a mesh tubular structure with a length of 80 mm is obtained; The mesh tubular structure (in its natural state) was formed into four segments, each 12 mm apart, and the segments were restrained. The restraint method involved welding a platinum alloy cylinder with an outer diameter of 0.5 mm and a length of 0.6 mm to the inside of the starting part of the proximal end of the segment, resulting in a segmented expansion element (the ratio of the axial length of the expandable part to the axial length of the proximal end restraint part was 19:1). After expansion, the outer diameter of the expandable part was 3.7 mm, and the angle between the line connecting points A and B and the axial direction was 15.69°. Example 9

[0063] The differences from Example 1 are as follows: a segmented expanding member, in which 16 nitinol alloy wires with a diameter of 0.09 mm were used as knitting yarns, knitted around a core with a diameter of 4.5 mm to a PPI of 30, and the knitting method was two over and two under (specifically, one set of knitting yarns consisted of one warp yarn and four adjacent weft yarns crossing the warp yarn, and each set of knitting yarns included four knitting points, two positive knitting points and two negative knitting points, and the two positive knitting points were adjacent, or the two negative knitting points were adjacent), and after heat setting at 530°C for 6 minutes and removing the core, a mesh tubular structure with a length of 80 mm was obtained; The mesh tubular structure (in its natural state) was divided into nine segments, each 5.5 mm long, and the segments were restrained. The restraining method was to weld a platinum alloy cylinder with an outer diameter of 0.5 mm and a length of 0.6 mm to the inside of the starting part of the proximal end of the segment, resulting in a segmented expansion element (the ratio of the axial length of the expandable part to the axial length of the proximal end restraint part was 8:1). After expansion, the outer diameter of the expandable part was 3.5 mm, and the angle between the line connecting points A and B and the axial direction was 28.62°.

[0064] Examples 1 to 9 have similar structures, and taking Example 1 as an example, the specific structure of the obtained segment-type expanding member is shown in Figure 1 (Figure 1 is a structural schematic diagram of the segment-type expanding member according to Example 1). The airbag includes four segmented inflation units, wherein a first segmented inflation unit 100 includes a first inflatable section 110 and a first proximal end restraint 111 connected to a proximal end of the first inflatable section 110; a second segmented inflation unit 200 includes a second inflatable section 210 and a second proximal end restraint 211 connected to a proximal end of the second inflatable section 210; a third segmented inflation unit 300 includes a third inflatable section 310 and a third proximal end restraint 311 connected to a proximal end of the third inflatable section 310; a fourth segmented inflation unit 400 includes a fourth inflatable section 410 and a fourth proximal end restraint 411 connected to a proximal end of the fourth inflatable section 410; and the distal end restraint of the fourth segmented inflation unit 400 is a first distal end restraint 412; The distal end restraint portion of the first segmented expansion unit 100 is the second proximal end restraint portion 211, the distal end restraint portion of the second segmented expansion unit 200 is the third proximal end restraint portion 311, and the distal end restraint portion of the third segmented expansion unit 300 is the fourth proximal end restraint portion 411.

[0065] In FIG. 1, the arrow direction points from the proximal end to the distal end.

[0066] As shown in Figure 2 (Figure 2 is a structural schematic diagram of the first expandable section 100), taking the first expandable section 100 as an example, in the expanded state, along the same axial cross section, the projection point of the center point of the axial length of the expandable section 100 onto the inside of the cavity wall of the expandable section is Point A, the intersection point of the proximal end restraint section and the inside of the cavity wall of the expandable section is Point B, and the intersection point of the distal end restraint section and the inside of the cavity wall of the expandable section is Point B'. Example 10

[0067] A segmented expanding member is provided, comprising 18 nitinol alloy wires with a diameter of 0.046 mm as braided metal yarns, braided around a 3.5 mm diameter core to have a PPI of 85, and knitted in a two-over-two-under knitting manner (specifically, one warp yarn and four adjacent weft yarns crossing the warp yarn constitute one set of braided yarns, each set of braided yarns containing four knitting points, two positive knitting points and two negative knitting points, each of which is adjacent to the two positive knitting points, or the two negative knitting points are adjacent to each other). The member is kept at 520°C for 5 minutes for heat setting, and the core is removed to obtain a mesh tubular structure with a length of 60 mm. The mesh tubular structure (in its natural state) was segmented so that the first segment was 4 mm, the second segment was 8 mm, the third segment was 8 mm, the fourth segment was 8 mm, and the fifth segment was 4 mm. The segments were then constrained by welding a platinum alloy cylinder with an outer diameter of 0.41 mm and a length of 0.5 mm to the inside of the starting portion of the proximal end of the segment to obtain a segmented expansion element. The outer diameters of the first and fifth segments were 0.9 mm, and the outer diameters of the second, third, and fourth segments were 2.5 mm. The transition angle between the first and fifth segments was 7.97°, and the angle between the line connecting points A and B of the second, third, and fourth segments and the axial direction was 15.58°.

[0068] The specific structure of the segmented inflatable member obtained in Example 10 is shown in Figure 3 (Figure 3 is a structural schematic diagram of the segmented inflatable member according to Example 10). It has five segments, which are arranged from proximal to distal, in order: a first force transmission auxiliary member 500 (including a first mesh tubular inflatable structure 510 and a fifth proximal end restraint portion 511 connected to the proximal end of the mesh tubular inflatable structure 510), a first segmented inflating unit 100 (including a first inflatable portion 110 and a first proximal end restraint portion 111 connected to the proximal end of the first inflatable portion 110), a second segmented inflating unit 200 (including a second inflatable portion 210 and a fifth proximal end restraint portion 511 connected to the proximal end of the first inflatable portion 110), a third inflating unit 200 (including a second inflatable portion 210 and a fifth proximal end restraint portion 511 connected to the proximal end of the first inflatable portion 210), a fourth inflating unit 200 (including a second inflatable portion 210 and a fifth proximal end restraint portion 511 connected to the proximal end of the first inflatable portion 210), a fifth inflatable portion 210 (including a fifth ... a third segmented inflation unit 300 (including a third inflatable portion 310 and a third proximal end restraint portion 311 connected to the proximal end of the third inflatable portion 310); a second force transmission auxiliary member 600 (including a second mesh tubular inflatable structure 610 and a sixth proximal end restraint portion 611 connected to the proximal end of the mesh tubular inflatable structure 610); and the distal end restraint portion of the second force transmission auxiliary member 600 is a second distal end restraint portion 612; The distal end restraint portion of the first mesh tubular expandable structure 510 is the first proximal end restraint portion 111, the distal end restraint portion of the first segmented expansion unit 100 is the second proximal end restraint portion 211, the distal end restraint portion of the second segmented expansion unit 200 is the third proximal end restraint portion 311, and the distal end restraint portion of the third segmented expansion unit 300 is the sixth proximal end restraint portion 611.

[0069] In FIG. 3, the arrow direction points from the proximal end to the distal end. Example 11

[0070] A segmented expanding member is provided, comprising 18 nitinol alloy wires with a diameter of 0.046 mm as braided metal yarns, braided around a 3.5 mm diameter core to have a PPI of 85, and knitted in a two-over-two-under knitting manner (specifically, one warp yarn and four adjacent weft yarns crossing the warp yarn constitute one set of braided yarns, each set of braided yarns containing four knitting points, two positive knitting points and two negative knitting points, each of which is adjacent to the two positive knitting points, or the two negative knitting points are adjacent to each other). The member is kept at 520°C for 5 minutes for heat setting, and the core is removed to obtain a mesh tubular structure with a length of 60 mm. The mesh tubular structure (in its natural state) was segmented so that the first segment was 1 mm, the second segment was 3 mm, the third segment was 8 mm, the fourth segment was 8 mm, the fifth segment was 8 mm, and the sixth segment was 4 mm. The segments were then constrained by welding a platinum alloy cylinder having an outer diameter of 0.41 mm and a length of 0.5 mm to the inside of the proximal end of each segment. The outer diameter of the first segment was 0.42 mm. the outer diameter of the second segment is 0.6 mm, the outer diameters of the third, fourth, and fifth segments are 2.5 mm, the outer diameter of the sixth segment is 0.9 mm, the transition angle of the first segment is 1.14°, the transition angle of the second segment is 4.35°, the angle between the line connecting points A and B of the third, fourth, and fifth segments and the axial direction is still 15.58°, and the transition angle of the sixth segment is 7.97°. Example 12

[0071] A segmented expanding member is provided, which is made of 18 nitinol alloy wires with a diameter of 0.046 mm as braided metal yarns, braided around a 6 mm diameter core to have a PPI of 85, and knitted in a two-over-two-under knitting manner (specifically, one warp yarn and four adjacent weft yarns crossing the warp yarn constitute one set of braided yarns, and each set of braided yarns contains four knitting points, two positive knitting points and two negative knitting points, and the two positive knitting points are adjacent, or the two negative knitting points are adjacent), and is heat-set at 520°C for 5 minutes, and after removing the core, a mesh tubular structure with a length of 60 mm is obtained; The mesh tubular structure (in its natural state) was divided into four segments, each 8 mm apart, and the segments were restrained. The restraining method involved welding a platinum alloy cylinder with an outer diameter of 0.41 mm and a length of 0.5 mm to the inside of the starting part of the proximal end of the segment, resulting in a segmented expansion element (the axial length of the expandable part was 15:1 compared to the axial length of the proximal end restraint part). After expansion, the outer diameter of the expandable part was 5.3 mm, and the angle between the line connecting points A and B and the axial direction was 33.12°. Comparative Example 1

[0072] The only difference from Example 1 is that the braid density PPI of the mesh tubular structure is changed to 15. Comparative Example 2

[0073] A segmented expanding member is provided, which is made of 18 nitinol alloy wires with a diameter of 0.046 mm as braided metal yarns, braided around a 3.5 mm diameter core to have a PPI of 85, and is braided in a two-over-two-under braiding manner (specifically, one warp yarn and four adjacent weft yarns crossing the warp yarn constitute one set of braided yarns, and each set of braided yarns includes four braiding points, each of which is two positive braiding points and two negative braiding points, and the two positive braiding points are adjacent or the two negative braiding points are adjacent), and is heat-set at 520°C for 5 minutes, and after removing the core, a mesh tubular structure with a length of 60 mm is obtained; The mesh tubular structure (in its natural state) was formed into 10 segments, each 3 mm long, and the segments were restrained. The restraining method was to weld a platinum alloy cylinder with an outer diameter of 0.41 mm and a length of 0.5 mm to the inside of the starting part of the proximal end of the segment, thereby obtaining a segmented expansion element (the ratio of the axial length of the expandable part to the axial length of the proximal end restraint part was 5:1). After expansion, the outer diameter of the expandable part was 0.6 mm, and the angle between the line connecting points A and B and the axial direction was 4.35°. Comparative Example 3

[0074] A segmented expanding member is provided, comprising 18 nitinol alloy wires with a diameter of 0.046 mm as braided metal yarns, braided around a 3.5 mm diameter core to have a PPI of 85, and knitted in a two-over-two-under knitting manner (specifically, one warp yarn and four adjacent weft yarns crossing the warp yarn constitute one set of braided yarns, each set of braided yarns containing four knitting points, two positive knitting points and two negative knitting points, each of which is adjacent to the two positive knitting points, or the two negative knitting points are adjacent to each other). The member is kept at 520°C for 5 minutes for heat setting, and the core is removed to obtain a mesh tubular structure with a length of 60 mm. The mesh tubular structure (in its natural state) was divided into two segments, each 12.5 mm apart, and the segments were restrained. The restraining method involved welding a platinum alloy cylinder with an outer diameter of 0.41 mm and a length of 0.5 mm to the inside of the starting part of the proximal end of the segment, resulting in a segmented expansion element (the ratio of the axial length of the expandable part to the axial length of the proximal end restraint part was 24:1). After expansion, the outer diameter of the expandable part was 0.6 mm, and the angle between the line connecting points A and B and the axial direction was 11.73°. [Performance test]

[0075] The proximal end of each of the segmented expansion members of the examples and comparative examples was fixedly connected to the distal end of a 100 cm pushing guide wire to obtain a test sample, which was used to carry out the following performance tests.

[0076] (1) Trackability: The test sample was pushed into a trackability test fixture to record whether it could smoothly pass through the curved section. The trackability test fixture included a blood vessel model with a coplanar entry path and a curved path, and the curved path included four alternating semicircular curves with a curvature radius of 2 mm.

[0077] (2) Force value at the distal end: The test sample is placed in a straight blood vessel model, and a force of 200 mN is applied from the proximal end, and the force value at the distal end is monitored using a full-module push-pull force cage.

[0078] (3) Radial bearing capacity: Using a radial bearing capacity testing machine (MSI RS550), at a temperature of 37±2°C, the initial diameter of the fixture is set to 5.5 mm, the expandable part of the segmented expansion member is placed in the fixture, and the diameter of the fixture is gradually reduced to 0.4 mm at a speed of 0.1 mm / s, and then gradually expanded to 5.5 mm at a speed of 0.1 mm / s, and the maximum force value during the change process is recorded.

[0079] The test results are shown in Table 1. [Table 1]

[0080] As can be seen from Table 1, the segmented expansion element of the present invention can smoothly pass through a predetermined curved shape formed by four alternating semicircular curves, each with a curvature radius of 2 mm, and when a pushing force of 200 mN is applied to the proximal end, the distal end can maintain a small axial pushing force of 3 to 6 mN and maintain an appropriate radial supporting force.

[0081] In Table 1, the expandable portion in Comparative Example 1 has too few intersections per inch of length, and the axial pressing force and radial support force are too small, making it unable to pass through a blood vessel model with a curved path. In Comparative Example 2, the ratio of the axial length of the expandable portion to the axial length of the proximal end restraint portion is too small, resulting in poor tracking and making it unable to pass through a blood vessel model with a curved path. On the other hand, in Comparative Example 3, the ratio of the axial length of the expandable portion to the axial length of the proximal end restraint portion is too large, making the axial pressing force too small and making it unable to pass through a blood vessel model with a curved path.

[0082] It should be noted that the above embodiments are merely for the purpose of illustrating the technical solutions of the present application and are not intended to limit the present application. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art will understand that the technical solutions described in the above embodiments may still be modified, or some or all of the technical features therein may be equivalently replaced. Such modifications and replacements shall not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A segmented inflatable member comprising: The segmented inflation member has at least one segmented inflation unit, the segmented inflation unit including an inflatable section, a proximal end restraint section connected to a proximal end of the inflatable section, and a distal end restraint section connected to a distal end of the inflatable section, and the segmented inflation member is obtained by cross-knitting two or more threads into a mesh tubular structure, and segmenting and restraining the threads at predetermined intervals over a predetermined length; In the segment-type expansion unit, when the expandable portion is in a radially expanded state, the ratio of the axial length of the expandable portion to the axial length of the proximal end restraint portion is 8:1 to 20:1; The inflatable section is a segmented inflatable member having 20 to 200 crossover points per inch of length.

2. 2. The segmented inflation member of claim 1, wherein, when the inflatable portion is inflated, the projection point of the center point of the axial length of the inflatable portion onto the inside of the cavity wall of the inflatable portion along the same axial cross section is defined as point A, and the intersection point of the proximal end restraint portion and the inside of the cavity wall of the inflatable portion is defined as point B, and the angle formed by the line connecting points A and B and the axial direction is 10 to 30 degrees.

3. 2. The segmented inflation member of claim 1, wherein the segmented inflation member has two or more segmented inflation units, and the segmented inflation units are connected end to end, and in adjacent segmented inflation units, the distal end restraint portion of the proximal end segmented inflation unit and the proximal end restraint portion of the distal end segmented inflation unit are the same restraint portion.

4. The segmented expansion member further includes a first auxiliary force transmission member; a distal end of the first force transmission auxiliary member and a proximal end of the most proximal segment type expansion unit extend coaxially and are connected to each other; the first force transmission auxiliary member is a mesh tubular expandable structure having one to three end-to-end constrained mesh tubular structures, and the distal end constrained portion of the first force transmission auxiliary member and the proximal end constrained portion of the adjacent segment type expansion unit are the same constrained portion; 2. The segmented inflation member of claim 1, wherein when the mesh tubular expandable structure of the first auxiliary force transmission member is expanded, the projection point of the center point of the axial length of the mesh tubular expandable structure onto the cavity wall of the mesh tubular expandable structure along the same axial cross section is defined as point C, and the intersection point of the proximal end restraint portion of the mesh tubular expandable structure and the mesh tubular expandable structure is defined as point D. The angle formed by the line connecting points C and D and the axial direction is the proximal end transition angle of the mesh tubular expandable structure of the first auxiliary force transmission member, and the proximal end transition angle of the mesh tubular expandable structure is 0 to 10 degrees.

5. The segmented inflatable member according to claim 4 , wherein the proximal end transition angle of the mesh tubular expandable structure gradually increases from the proximal to the distal end of the first force-transmitting auxiliary member.

6. The segmented expansion member further includes a second auxiliary force transmission member; The proximal end of the second force transmission auxiliary member and the distal end of the most distal segment type expansion unit extend coaxially and are connected to each other; the second force transmission auxiliary member is a mesh tubular expandable structure having one to three end-to-end constrained mesh tubular structures, and the distal end constrained portion of the second force transmission auxiliary member and the distal end constrained portion of the adjacent segment type expansion unit are the same constrained portion; 2. The segmented inflation member of claim 1, wherein when the mesh tubular expandable structure of the second auxiliary force transmission member is expanded, the projection point of the center point of the axial length of the mesh tubular expandable structure onto the cavity wall of the mesh tubular expandable structure along the same axial cross section is defined as point E, and the intersection point of the proximal end restraint portion of the mesh tubular expandable structure and the mesh tubular expandable structure is defined as point F, the angle formed by the line connecting points E and F and the axial direction is the proximal end transition angle of the mesh tubular expandable structure of the second auxiliary force transmission member, and the proximal end transition angle of the mesh tubular expandable structure is 0 to 10 degrees.

7. The segmented inflatable member of claim 6 , wherein the transition angle of the mesh tubular expandable structure gradually decreases from the proximal to the distal end of the second force-transmitting auxiliary member.

8. The segmented inflatable member of claim 1 , wherein the restraints have the same length.

9. 2. The segmented inflatable member of claim 1, wherein the method of segmenting and restraining at predetermined intervals includes any one or a combination of at least two of connecting to the base by presetting, gluing, welding, or heat welding, connecting an extended thread by direct gluing, welding, or heat welding, or fitting a restraining body on the outside.

10. 1. A vascular implant delivery device comprising: A pushing guide wire, A segmented expansion member according to any one of claims 1 to 9, connected to a distal end of the pushing guide wire; a development tip connected to a distal end of the segmented expansion member; a vascular implant accommodating and release assisting member that is fixed to and fitted over the distal end of the pushing guide wire, the vascular implant accommodating and release assisting member including a fixing portion for fixing to and fitting over the distal end of the pushing guide wire, and an opening provided at the distal end of the fixing portion, the opening having a structure that gradually widens from the proximal end to the distal end.

11. 1. A vascular implant system comprising:

11. A vascular implant delivery device according to claim 10; a vascular implant fitted over the outside of the segmented expansion member of the vascular implant delivery device; Or, The vascular implant system comprises: A pushing guide wire, A segmented expansion member according to any one of claims 1 to 9, connected to a distal end of the pushing guide wire; a development tip connected to a distal end of the segmented expansion member; a vascular implant accommodating and releasing assisting member that is fixed to and fitted over the distal end of the pushing guidewire, the vascular implant accommodating and releasing assisting member including a fixing portion for fixing to and fitting over the distal end of the pushing guidewire, and an opening provided at the distal end of the fixing portion, the opening having a structure that gradually widens from the proximal end to the distal end; a vascular implant fitted over the outside of the segmented expansion member of the vascular implant delivery device.

12. The vascular implant system of claim 11 , further comprising a sheath for housing the vascular implant delivery device over which the vascular implant is fitted.

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