Filter screen and method of processing a filter screen

Abstract

The application provides a filter screen and a filter screen processing method, and relates to the technical field of medical devices.The filter screen comprises a plurality of wires, each of which is wound to form a curved portion for connecting a vascular stent and to form a first end head and a second end head extending away from the vascular stent; the first end head of any wire at least intersects with the second end head of another wire, and the second end head of any wire at least intersects with the first end head of another wire. Moreover, a special processing die is provided for the filter screen processing method, which can ensure that the filter screen is stably formed and the wires are not excessively bent, and is especially suitable for processing a degradable filter screen, so that the technical problem that the excessively bent portion is first broken during the biodegradation process can be avoided, and the medical safety is improved.

Description

Technical Field

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

[0002] Vascular stent implantation carries a significant risk of thrombus dislodging from the vessel wall, potentially leading to unintended embolism in downstream vessels. Such embolism can lead to serious complications, such as stroke or pulmonary embolism. Protective devices are currently available on the market that can be deployed before stent implantation to prevent this complication. However, these stents are non-biodegradable and, long-term implantation can cause vascular blockage, necessitating post-operative removal.

[0003] A filter woven from a biodegradable material is placed at the downstream end of the stent to intercept dislodged thrombi, preventing them from migrating to downstream vessels. It then degrades after the peak of thrombus shedding. However, the filter can break first at the sharp bends in the wire, allowing fragments to break off and migrate to downstream vessels, potentially causing serious complications. Summary of the Invention

[0004] The object of the present invention is to provide a filter screen and a filter screen processing method to alleviate the technical problems of excessive bending parts and easy breakage of the filter screen.

[0005] In a first aspect, the present invention provides a filter screen comprising a plurality of wires, each of which is wound to form a curved portion for connecting to a vascular stent and forming a first end and a second end extending away from the vascular stent;

[0006] The first end of any one of the wires crosses at least the second end of another one of the wires, and the second end of any one of the wires crosses at least the first end of another one of the wires.

[0007] In combination with the first aspect, the present invention provides a first possible implementation manner of the first aspect, wherein the filter has a conical structure, and its diameter gradually decreases from one end connected to the vascular stent to one end away from the vascular stent.

[0008] In combination with the first possible implementation manner of the first aspect, the present invention provides a second possible implementation manner of the first aspect, wherein the first ends and the second ends of the plurality of wires intersect at the tip of the tapered structure and are melt-welded.

[0009] In combination with the first aspect, the present invention provides a third possible implementation of the first aspect, wherein the intersecting first end head and the second end head are jointly arranged to form a strip-shaped filter hole area;

[0010] The first end and the second end located on both sides of the strip-shaped filter hole area are nearly parallel.

[0011] In combination with the first aspect, the present invention provides a fourth possible implementation of the first aspect, wherein the material of the wire is at least one of polybutylene carbonate, polylactic acid, polylactic acid-glycolic acid copolymer, polycaprolactone, magnesium alloy and zinc alloy.

[0012] In a second aspect, the filter screen processing method provided by the present invention adopts a processing mold for forming and preparing, wherein the processing mold includes: a cone portion, a plurality of cylindrical portions, a plurality of first limiting posts, and a plurality of second limiting posts;

[0013] The plurality of cylindrical portions are spaced apart around the conical surface of the cone portion, and the plurality of cylindrical portions are respectively connected to the bottom of the conical surface of the cone portion;

[0014] The cylindrical portion, the first limiting pillars and the second limiting pillars are spaced apart from bottom to top along the conical surface of the cone portion, and a plurality of the first limiting pillars and a plurality of the second limiting pillars are spaced apart around the cone portion respectively;

[0015] On a projection plane perpendicular to the axis of the cone portion, there are flush first limiting posts and second limiting posts between any two adjacent cylindrical portions;

[0016] The filter screen processing method comprises the following steps:

[0017] Winding wires one by one on the plurality of cylindrical portions along the circumference of the cone portion, and folding each wire in half through the cylindrical portion to form a curved portion with a first end and a second end extending toward the tip of the cone portion;

[0018] The first end of any one of the wires is crossed with at least the second end of another one of the wires, the second end of any one of the wires is crossed with at least the first end of another one of the wires, and the first limiting column and the second limiting column are supported between adjacent first ends and second ends;

[0019] The first ends and the second ends of the plurality of wires are intersected at the tip of the cone portion and connected.

[0020] In combination with the second aspect, the present invention provides a first possible implementation of the second aspect, wherein the filter screen processing method further includes:

[0021] The wire material is heat-treated so as to be shaped along the processing die.

[0022] In combination with the second aspect, the present invention provides a second possible implementation manner of the second aspect, wherein the step of intersecting the first ends and the second ends of the plurality of wires at the tip of the cone portion and connecting them comprises:

[0023] A developing device is sleeved on the first end and the second end of the plurality of wires;

[0024] The first end head and the second end head are cut, and a plurality of the first end heads and a plurality of the second end heads are connected by hot-melt connection.

[0025] In combination with the second possible implementation of the second aspect, the present invention provides a third possible implementation of the second aspect, wherein, when cutting the first end head and the second end head, a length of the first end head and the second end head extending outside the developing device is reserved by 1mm to 2mm.

[0026] In combination with the second aspect, the present invention provides a fourth possible implementation manner of the second aspect, wherein the processing mold further includes a support column connected to the bottom of the cone portion;

[0027] The filter screen processing method further comprises:

[0028] The plurality of curved portions are sutured and connected to the vascular stent respectively.

[0029] The embodiments of the present invention bring the following beneficial effects: each wire is wound to form a curved portion for connecting to a vascular stent, and to form a first end and a second end extending in a direction away from the vascular stent. The first end of any wire at least crosses with the second end of another wire, and the second end of any wire at least crosses with the first end of another wire. The wire is less bent during filter forming and there are no excessive bending parts. It is particularly suitable for processing to form a degradable filter, and can avoid the technical problem of premature breakage due to the presence of excessive bending parts.

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in related technologies, the following briefly introduces the drawings required for use in the specific embodiments or related technical descriptions. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1A schematic diagram of a filter provided in an embodiment of the present invention;

[0033] Figure 2 A top view of a filter screen provided in an embodiment of the present invention;

[0034] Figure 3 A schematic diagram of a filter screen and a processing mold provided by an embodiment of the present invention;

[0035] Figure 4 Schematic diagram of the filter and vascular stent provided in an embodiment of the present invention.

[0036] Icons: 100 - wire; 101 - bending part; 102 - strip filter area; 110 - first end; 120 - second end; 200 - vascular stent; 300 - processing mold; 310 - cone part; 320 - cylindrical part; 330 - first limiting column; 340 - second limiting column; 350 - support column; 400 - developing device. DETAILED DESCRIPTION

[0037] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0038] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second" and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. Physical quantities in formulas, unless separately marked, should be understood as basic quantities of the International System of Units, or derived quantities derived from basic quantities through mathematical operations such as multiplication, division, differentiation or integration.

[0039] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0040] like Figure 1 and Figure 2 As shown, the filter provided by the embodiment of the present invention includes a plurality of wires 100, each of which is wound to form a curved portion 101 for connecting to the vascular stent 200, and forms a first end 110 and a second end 120 extending away from the vascular stent 200; the first end 110 of any wire 100 intersects with the second end 120 of at least another wire 100, and the second end 120 of any wire 100 intersects with the first end 110 of at least another wire 100.

[0041] The filter screen described in this embodiment has a minimal number of bends in the wires 100, without excessively large bends, making it suitable for processing with biodegradable materials and preventing premature breakage due to excessive bending during the biodegradation process. Furthermore, the multiple wires 100 in the filter screen are clearly arranged and easily processed and formed.

[0042] In the embodiment of the present invention, the filter has a conical structure, and its diameter gradually decreases from one end connected to the vascular stent 200 to the other end away from the vascular stent 200 .

[0043] When the filter is used to capture thrombus, the detached thrombus will be captured in the conical tip area of ​​the filter, where the blood flow is fastest, which is conducive to the rapid dissolution of the thrombus and can prevent the thrombus from adhering to the blood vessel wall and causing organization, thereby reducing the risk of vascular stenosis and blockage.

[0044] In this embodiment, the first end 110 and the second end 120 of the plurality of wires 100 intersect at the tip of the conical structure and are melt-welded. By melt-welding, a smooth connection portion can be formed between the ends of the first end 110 and the second end 120, thereby avoiding scratches on the blood vessel wall caused by sharp parts.

[0045] Furthermore, the intersecting first end 110 and the second end 120 are jointly arranged to form a strip filter area 102; the first end 110 and the second end 120 located on both sides of the strip filter area 102 are close to parallel, which on the one hand ensures smooth blood flow, and on the other hand can reduce the curvature of the first end 110 and the second end 120 to avoid breakage due to excessive bending.

[0046] The filter screen described in this embodiment is particularly suitable for manufacturing from degradable materials, wherein the material of the wire 100 is at least one of polybutylene carbonate, polylactic acid, polylactic acid-glycolic acid copolymer, polycaprolactone, magnesium alloy and zinc alloy. The diameter of the wire 100 is configured to be 0.2mm to 0.4mm. After being implanted in a blood vessel, it can be completely degraded in about six months, eliminating the need for surgical removal, thereby greatly reducing the risk of secondary surgery and related medical costs for patients.

[0047] like Figure 1 、 Figure 2 and Figure 3 As shown, the filter processing method provided by the embodiment of the present invention adopts a processing mold 300 for molding preparation, and the processing mold 300 includes: a cone portion 310, multiple cylindrical portions 320, multiple first limiting columns 330 and multiple second limiting columns 340; multiple cylindrical portions 320 are arranged at intervals around the conical surface of the cone portion 310, and multiple cylindrical portions 320 are respectively connected to the bottom of the conical surface of the cone portion 310; the cylindrical portion 320, the first limiting column 330 and the second limiting column 340 are distributed at intervals from bottom to top along the conical surface of the cone portion 310, and multiple first limiting columns 330 and multiple second limiting columns 340 are respectively arranged at intervals around the cone portion 310; on the projection surface perpendicular to the axis of the cone portion 310, there are flush first limiting columns 330 and second limiting columns 340 between any two adjacent cylindrical portions 320.

[0048] The filter screen processing method includes the following steps:

[0049] Wires 100 are wound around the plurality of cylindrical portions 320 one by one along the circumference of the cone portion 310 , and each wire 100 is folded in half through the cylindrical portion 320 to form a curved portion 101 having a first end 110 and a second end 120 extending toward the tip of the cone portion 310 ;

[0050] The first end 110 of any wire 100 is made to intersect with at least the second end 120 of another wire 100, and the second end 120 of any wire 100 is made to intersect with at least the first end 110 of another wire 100, and the first limiting post 330 and the second limiting post 340 are supported between the adjacent first end 110 and the second end 120;

[0051] The first ends 110 and the second ends 120 of the plurality of wires 100 are intersected at the tip of the cone portion 310 and connected.

[0052] Among them, the height of the cone portion 310 is about 20 mm, the bottom diameter is about 30 mm, the diameter of the cylindrical portion 320 is 7 mm, the diameters of the first limiting post 330 and the second limiting post 340 are both 1 mm, and any wire material 100 along the processing mold 300 has a smooth transition at all places, which can avoid excessive bending of the wire material 100.

[0053] In an embodiment of the present invention, the filter screen processing method further includes: heat-treating the wire 100 , heating and then cooling the wire 100 so that the wire 100 is shaped along the processing mold 300 .

[0054] Furthermore, the step of intersecting the first end 110 and the second end 120 of the plurality of wires 100 at the tip of the cone portion 310 and connecting them includes:

[0055] A developing device 400 is sleeved on the first end 110 and the second end 120 of the plurality of wires 100;

[0056] The first end pieces 110 and the second end pieces 120 are cut, and a plurality of the first end pieces 110 and a plurality of the second end pieces 120 are connected by heat-melting.

[0057] When cutting the first end head 110 and the second end head 120 , 1mm to 2mm of the length of the first end head 110 and the second end head 120 extending outside the developing device 400 is reserved, so as to reserve sufficient process space for the hot melt connection operation.

[0058] See also Figure 3 and Figure 4 The processing mold 300 also includes a support column 350 connected to the bottom of the cone portion 310. The filter screen processing method also includes: suturing and connecting the multiple curved portions 101 to the vascular stent 200. During processing, after the filter screen is heat-treated and shaped, the first ends 110 and second ends 120 of the multiple wires 100 are intersected and heat-fused together. The filter screen is then removed from the cone portion 310, and the multiple curved portions 101 of the filter screen are suturing and connecting to the vascular stent 200, thereby achieving circumferential docking between the filter screen and the vascular stent 200.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A filter screen processing method, characterized in that: The filter screen processing method adopts a processing mold (300) for forming and preparing, wherein the processing mold (300) comprises: a cone portion (310), a plurality of cylindrical portions (320), a plurality of first limiting columns (330), and a plurality of second limiting columns (340); The plurality of cylindrical portions (320) are arranged at intervals around the conical surface of the cone portion (310), and the plurality of cylindrical portions (320) are respectively connected to the bottom of the conical surface of the cone portion (310); The cylindrical portion (320), the first limiting column (330) and the second limiting column (340) are spaced apart from bottom to top along the conical surface of the cone portion (310), and a plurality of the first limiting columns (330) and a plurality of the second limiting columns (340) are spaced apart around the cone portion (310); On a projection plane perpendicular to the axis of the cone portion (310), there is a flush first limiting column (330) and a flush second limiting column (340) between any two adjacent cylindrical portions (320); The filter screen processing method comprises the following steps: Wires (100) are wound around the plurality of cylindrical portions (320) one by one along the circumference of the cone portion (310), and each of the wires (100) is folded in half through the cylindrical portion (320) to form a curved portion (101) having a first end (110) and a second end (120) extending toward the tip of the cone portion (310); The first end (110) of any one of the wires (100) is crossed with at least the second end (120) of another one of the wires (100), the second end (120) of any one of the wires (100) is crossed with at least the first end (110) of another one of the wires (100), and the first limiting column (330) and the second limiting column (340) are supported between the adjacent first end (110) and the second end (120); The first end head (110) and the second end head (120) intersecting each other are jointly arranged to form a strip-shaped filter hole area (102); the first end head (110) and the second end head (120) located on both sides of the strip-shaped filter hole area (102) are approximately parallel; The first ends (110) and the second ends (120) of the plurality of wires (100) intersect at the tip of the cone portion (310) and connect them; The wire material (100) is heat-treated so that the wire material (100) is shaped along the processing mold (300).

2. The filter screen processing method according to claim 1, characterized in that: The step of intersecting and connecting the first end heads (110) and the second end heads (120) of the plurality of wires (100) at the tip of the cone portion (310) comprises: A developing device (400) is sleeved on the first end (110) and the second end (120) of the plurality of wires (100); The first end head (110) and the second end head (120) are cut, and a plurality of the first end heads (110) and a plurality of the second end heads (120) are connected by hot-melt connection.

3. The filter screen processing method according to claim 2, characterized in that: When cutting the first end head (110) and the second end head (120), a length of 1 mm to 2 mm of the first end head (110) and the second end head (120) extending outside the developing device (400) is reserved.

4. The filter screen processing method according to claim 1, characterized in that: The processing mold (300) further includes a support column (350) connected to the bottom of the cone portion (310); The filter screen processing method further comprises: The plurality of curved portions (101) are respectively sutured and connected to the vascular stent (200).

5. The filter screen processing method according to claim 1, characterized in that: The material of the wire (100) is at least one of polybutylene carbonate, polylactic acid, polylactic acid-glycolic acid copolymer, polycaprolactone, magnesium alloy and zinc alloy.

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