CN113855991A

CN113855991A - A catheter

Info

Publication number: CN113855991A
Application number: CN202010622643.5A
Authority: CN
Inventors: 刘丰洋; 刘云云; 林冠宇
Original assignee: Microport Neurotech Shanghai Co Ltd
Current assignee: Microport Neurotech Shanghai Co Ltd
Priority date: 2020-06-30
Filing date: 2020-06-30
Publication date: 2021-12-31
Also published as: WO2022002280A1

Abstract

The invention provides a catheter which comprises a sheath and a lining, wherein the sheath and the lining are arranged from outside to inside along the radial direction of the catheter, the sheath is sleeved outside the lining, the lining is formed by axially splicing at least two materials with different hardness, and the materials of the lining are sequentially reduced from a near end to a far end. The splicing structure of the inner lining in the axial direction improves the mechanical property of the catheter, meets the in-place capability of the catheter, ensures that the catheter is not easy to bend or deform in the radial direction in the use process, and can pass through a tortuous blood vessel without causing damage to a biological lumen.

Description

A catheter

Technical Field

The invention relates to the technical field of medical instruments, in particular to a catheter for intracranial vascular interventional therapy.

Background

A catheter is a key instrument in the field of interventional therapy, and is generally used for being inserted into a biological lumen such as a blood vessel and reaching a lesion to be treated or diagnosed through the biological lumen.

Based on the mode of action of the catheter, it must meet the delivery performance in the biological lumen and not cause injury to the biological lumen during delivery. Once the pipe is bent or radially deformed in the conveying process, the transmission of the force of the pipe can be influenced, and the conveying performance is influenced. And the reduction of the lumen of the catheter or the reduction of the inner diameter of a partial region also affects the transportation of other instruments inside the catheter, and if the catheter is used for the aspiration of thrombus, the reduction of the lumen also affects the aspiration efficiency of thrombus. Catheters are commonly used for accessing blood vessels of the human body from the radial or femoral artery, and in some fields of treatment, particularly intracranial vascular treatment, it is desirable that the catheter be able to reach more tortuous or more distant blood vessels. In order to reach a distant lesion site, the catheter needs to satisfy certain mechanical properties, such as force transmission performance, distal over-bending capability, and the like.

In order to meet the in-place capability of the catheter, the catheter body needs to have good mechanical properties, so that the catheter body can better transmit force values during conveying, cannot be bent or radially deformed, and can pass through tortuous blood vessels without causing damage to biological lumens.

Disclosure of Invention

The invention aims to provide a catheter, which solves the problem of poor in-place capability caused by poor mechanical property in the existing catheter.

To solve the above technical problem, the present invention provides a catheter, comprising:

sheath and inside lining, the sheath with the inside lining is followed the radial outside-in setting of pipe, the sheath cover is located the outside of inside lining, the inside lining is formed by the axial concatenation of the different material of at least two kinds of hardness, the material hardness of inside lining reduces by near-end to distal end in proper order.

Optionally, the catheter further comprises a reinforcing component located between the sheath and the liner.

Optionally, in the catheter, the liner is divided into a first liner section and a second liner section from the proximal end to the distal end, the first liner section is made of a first polymer material, the second liner section is made of a second polymer material, and the hardness of the first polymer material is greater than that of the second polymer material.

Optionally, in the catheter, the first polymer material has a hardness of 40D-70D and the second polymer material has a hardness of 30A-55D.

Optionally, in the catheter, a ratio of the hardness of the first polymer material to the hardness of the second polymer material is 3:1 to 1.1: 1.

Optionally, in the catheter, the first polymer material is polytetrafluoroethylene, and the second polymer material is any one of or a combination of any several of polyolefin, polyether block polyamide and polyurethane.

Optionally, in the conduit, the second polymeric material is a linear low density polyethylene or a polyolefin elastomer or a mixture of both.

Optionally, in the catheter, the second polymer material is one or a combination of two of polyether block polyamide and polyurethane added with a lubricant.

Optionally, in the conduit, the length of the first lining segment is 1000-.

Optionally, in the catheter, the distal end of the first liner segment comprises a first head portion and the proximal end of the second liner segment comprises a second head portion, the first head portion and the second head portion axially abutting to form the splice.

Optionally, in the catheter, the distal end of the first liner segment comprises a first head, the proximal end of the second liner segment comprises a second head, the first head and the second head form a coincident segment, and the material of the coincident segment comprises a first polymeric material and a second polymeric material.

Optionally, in the catheter, the length of the overlapping section is 0-20 mm.

Optionally, in the conduit, the most distal end of the first and/or second head forms a ramp angled with respect to the conduit axis, the angle of the ramp being 5-90 °.

Optionally, in the conduit, the head-most ends of the first and/or second heads form a rectangular wave structure or a triangular wave structure.

Optionally, in the catheter, the overlapping section has a decreasing volume ratio of the first polymeric material to the second polymeric material from the proximal end to the distal end.

Optionally, in the catheter. The thickness of the first head portion decreases from the proximal end to the distal end and/or the thickness of the second head portion decreases from the distal end to the proximal end.

Optionally, in the conduit, the coincident segments of the first and second polymeric materials form a polymeric blend.

Optionally, in the catheter, the liner has a thickness of 0.0002-0.0015inch and the sheath has a thickness of 0.001-0.089 inch.

Optionally, in the catheter, the sheath comprises at least one material from the group consisting of polyamide, polyether block polyamide, polyurethane, polyolefin, the sheath gradually decreasing in hardness from the proximal end to the distal end.

Optionally, in the catheter, the sheath is spliced from 3-20 sections of materials with different hardness from the proximal end to the distal end, and the hardness of the material of the sheath is 25A-80D.

Optionally, in the catheter, the sheath is formed by splicing 8 sections of materials with different hardness from the proximal end to the distal end, and the hardness from the proximal end to the distal end is 79-68D, 65-60D, 60-50D, 50-38D, 40-30D, 30-20D, 65-40A and 40-25A respectively.

Optionally, in the catheter, the sheath is formed by splicing 11 sections of materials with different hardness from the proximal end to the distal end, and the hardness from the proximal end to the distal end is 79-71D, 75-68D, 65-60D, 60-50D, 50-40D, 42-38D, 40-30D, 30-20D, 65-50A, 50-40A and 40-25A respectively.

Optionally, in the catheter, the reinforcement member includes a structure in which a wire material is spirally wound or/and braided, the wire material being at least one of a metal wire and a polymer wire.

Optionally, in the catheter, the reinforcement member comprises a braided structure braided from two strands of wire in parallel.

Optionally, in the catheter, the reinforcing member comprises a cutting structure cut from a metal tube or a polymer tube.

Optionally, in the catheter, the reinforcing member further comprises a cutting structure, and the cutting structure is formed by cutting a metal pipe or a polymer pipe.

Optionally, in the catheter, the three-point bending of any point on the catheter at a position near the proximal end is measured as A1, the three-point bending at a position near the distal end is measured as A2, and the difference between A1 and A2 is not more than 2N, the position near the proximal end is a position at the proximal end of any point but not more than 1.5cm away, and the position near the distal end is a position at the distal end of any point but not more than 1.5cm away.

According to the catheter provided by the invention, the mechanical property of the catheter is improved by the splicing structure of the inner lining in the axial direction, the in-place capability of the catheter is met, the catheter is not easy to bend or deform in the radial direction in the use process, and the catheter can pass through a tortuous blood vessel without causing damage to a biological lumen.

Drawings

FIG. 1 is a cross-sectional view of a catheter provided in accordance with a preferred embodiment of the present invention;

FIG. 2 is a schematic view of the inner liner of a catheter provided in accordance with a preferred embodiment of the present invention;

FIG. 3 is a schematic view of a tip (tip) of a catheter provided in accordance with a preferred embodiment of the present invention;

FIG. 4 is a schematic view of a catheter segment provided in accordance with a preferred embodiment of the present invention;

FIG. 5 is a schematic view of a catheter segment provided in accordance with a preferred embodiment of the present invention;

FIG. 6 is a schematic view of a reinforcing member of a catheter according to a preferred embodiment of the present invention;

FIG. 7 is a schematic view of a sheath of a catheter provided in accordance with a preferred embodiment of the present invention;

FIG. 8 is a schematic view of a first liner section and a second liner section of a conduit according to a preferred embodiment of the present invention;

FIG. 9 is a schematic view of the inner liner of a catheter provided in accordance with a preferred embodiment of the present invention;

FIG. 10 is a schematic view of the inner liner of a catheter provided in accordance with a preferred embodiment of the present invention;

FIG. 11 is a schematic illustration of a first liner section and a second liner section of a conduit according to a preferred embodiment of the present invention;

fig. 12 is a schematic view of the inner liner of a catheter according to a preferred embodiment of the present invention.

[ reference numerals are described below ]:

1-a sheath; 101-a first sheath segment; 102-a second sheath segment; 103-a third sheath segment; 2-a reinforcing component; 201-a first reinforcing component section; 202-a second strength member segment; 203-a third strength member section; 2101-round wire 1; 2102-round filaments 2; 2201-round filaments 3; 2301-flat wire 1; 3-lining; 301-a first inner liner section; 302-a second liner section; 3011-a first head; 3021-a second header; 3001-a superposition section; 4-catheter lumen; 5-developing the structure; 6-tip (head end).

Detailed Description

To further clarify the objects, advantages and features of the present invention, a more particular description of the invention will be rendered by reference to the appended drawings. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention.

As used in this specification, the singular forms "a", "an" and "the" include plural referents, and the plural forms "a plurality" includes more than two referents unless the content clearly dictates otherwise. As used in this specification, the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise, and the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either fixedly connected, detachably connected, or integrally connected. Either mechanically or electrically. Either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations. The same or similar reference numbers in the drawings identify the same or similar elements.

Example one

The present embodiment provides a catheter, and fig. 1 is an axial sectional view and a radial sectional view of the catheter provided in the first embodiment of the present invention. As shown in figure 1, a sheath 1, a reinforcing component 2 and a lining 3 are sequentially arranged along the radial direction of the catheter from outside to inside, the reinforcing component 2 is sleeved outside the lining 3, the sheath 1 covers the reinforcing component 2, and the lining 3 defines an inner cavity 4 of the catheter. In other embodiments, the catheter includes only the sheath 1 and the liner 3, and no reinforcing members 2.

The sheath 1 is a polymer layer, and in the embodiment of the invention, the material of the sheath 1 is at least one selected from polyamide, polyether block polyamide, polyurethane and polyolefin; in this embodiment, the material of the sheath 1 includes polyamide, polyether block polyamide, polyurethane, and polyolefin, and the sheath 1 is formed by splicing the above materials. In the embodiment of the invention, the reinforcing component 2 is made of a metal material or a high polymer material and is used for improving the strength, the supporting performance, the anti-collapse level of the tube cavity, the force transmission performance and the torsion control transmission performance of the catheter; in this embodiment, the reinforcing member 2 is composed of a metal material; the inner lining 3 is a polymer layer, in the embodiment of the invention, the material of the inner lining 3 comprises at least two of polytetrafluoroethylene, polyolefin, polyurethane and polyether block polyamide; in this embodiment, the material of the liner 3 comprises polytetrafluoroethylene and polyolefin.

Fig. 2 is a schematic cross-sectional view of a liner 3 of a catheter according to a first embodiment of the present invention, as shown in fig. 2, the liner 3 is divided into a first liner segment 301 located at a proximal end and a second liner segment 302 located at a distal end, the first liner segment 301 is made of a first polymer material, the second liner segment 302 is made of a second polymer material, and a hardness of the first polymer material is greater than a hardness of the second polymer material. In the embodiment of the present invention, the first polymer material has a hardness of 40D to 70D, and may be, but is not limited to, teflon; in this embodiment, the first polymer material has a hardness of 60D and is made of ptfe; in other embodiments, the first polymer material may have a hardness of 40D; in other embodiments, the first polymer material may have a hardness of 70D. In the embodiment of the present invention, the hardness of the second polymer material is 30A-55D, and the material may be, but is not limited to, any one or a mixture of any several of polyolefin, polyether block polyamide, and polyurethane; in some embodiments, the second polymeric material is a linear low density polyethylene or a polyolefin elastomer; in some embodiments, the second polymeric material is a polyether block polyamide with a lubricant added thereto or a polyurethane with a lubricant added thereto; in this embodiment, the second polymeric material is a polyolefin having a hardness of 35D; in some other embodiments, the second polymer material may have a hardness of 30A; in other embodiments, the second polymer material may have a hardness of 55D. In an embodiment of the present invention, the length of the first liner segment 301 is 1000-1550mm, and the length of the second liner segment 302 is 50-600 mm; in this embodiment, the first liner section 301 has a length of 1200mm and the second liner section 302 has a length of 250 mm.

In other embodiments, the material of the first inner lining section 301 and/or the second inner lining section 302 may also be a blend of several polymer materials, or a polymer mixed with inorganic substances such as a metal powder; in other embodiments, the material of the first inner liner section 301 and/or the second inner liner section 302 is a blend of polyolefin and polyether block polyamide in a material ratio of 1: 1; in other embodiments, the material of the first inner liner section 301 and/or the second inner liner section 302 is a blend of polyolefin and polyurethane in a material ratio of 2: 1; in other embodiments, the material of the first inner liner section 301 and/or the second inner liner section 302 is a blend of polyether block polyamide and polyurethane in a ratio of 1: 2; in other embodiments, the material of the first inner liner section 301 and/or the second inner liner section 302 is a blend of polyolefin, polyether block polyamide, polyurethane in a ratio of 1:1: 1; in other embodiments, the material of the first inner liner section 301 and/or the second inner liner section 302 is a blend of linear low density polyethylene and polyolefin elastomer in a ratio of 1: 1; in other embodiments, the material of the first and/or second liner sections 301, 302 is a linear low density polyethylene mixed with tungsten powder, which polymer may provide visualization properties to the catheter body. In other embodiments, the material of first inner liner section 301 and/or second inner liner section 302 is a polyether block polyamide with added lubricant; in other embodiments, the material of first inner liner section 301 and/or second inner liner section 302 is a lubricant-loaded polyurethane; in other embodiments, the material of first inner liner section 301 and/or second inner liner section 302 is a mixture of polyether block polyamide and polyurethane with lubricant added in a ratio of 1: 1.

In one embodiment, the first polymer material is polytetrafluoroethylene with a hardness of 55D, the second polymer material is a polyolefin elastomer with a hardness of 47D, and the ratio of the hardness of the first polymer material to the hardness of the second polymer material is 1.170: 1; in other embodiments, the first polymer material is polytetrafluoroethylene with a hardness of 55D, the second polymer material is polyurethane with a hardness of 28D, and the ratio of the hardness of the first polymer material to the hardness of the second polymer material is 1.964: 1; in other embodiments, the first polymer material has a hardness of 40D, the second polymer material has a hardness of 20D, and the ratio of the hardness of the first polymer material to the hardness of the second polymer material is 2: 1; in other embodiments, the first polymer material has a hardness of 70D, the second polymer material has a hardness of 55D, and the ratio of the hardness of the first polymer material to the hardness of the second polymer material is 1.273: 1. In other embodiments, the first polymer material has a hardness of 45D, the second polymer material has a hardness of 60A (≈ 15D), and the ratio of the hardness of the first polymer material to the hardness of the second polymer material is 3: 1.

In one embodiment, first liner segment 301 has a length of 1000mm and second liner segment 302 has a length of 170 mm; in other embodiments, the first liner section 301 has a length of 1550mm and the second liner section 302 has a length of 50 mm; in other embodiments, the length of first liner section 301 is 1150mm and the length of second liner section 302 is 600 mm; in other embodiments, the first liner section 301 has a length of 200mm and the second liner section 302 has a length of 1200 mm.

In an embodiment of the present invention, the thickness of the liner 3 is 0.0002-0.0015 inch; in this embodiment, the thickness of the liner 3 is 0.001 inch; in other embodiments, liner 3 has a thickness of 0.0005 inch; in other embodiments, the thickness of the liner 3 is 0.0015 inch; in other embodiments, the thickness of the liner 3 is 0.0002 inch. In the embodiment of the present invention, the thickness of the sheath 1 is 0.001-0.089 inch; in this embodiment, the thickness of the sheath 1 is 0.001 inch; in other embodiments, the sheath 1 has a thickness of 0.089 inch; in other embodiments, the thickness of the sheath 1 is 0.005 inch.

Example two

In addition to the first embodiment, the reinforcing member 2 of the catheter provided in the second embodiment has a braided structure formed by braiding wire members, and the wire members constituting the reinforcing member 2 are nickel-titanium wires. In other embodiments, the strength member 2 is a helical structure formed by helically winding a wire; in some embodiments, the reinforcing component 2 is a combination of a helical structure and a braided structure, such as a braided structure over a helical structure or a braided structure over a helical structure. In the embodiment of the invention, the wire material of the reinforcing component 2 is one or the combination of at least two of nickel-titanium wire, stainless steel wire, cobalt-chromium wire, polymer wire and other medical wire materials; in other embodiments, the wire of the strength member 2 is stainless steel wire; in other embodiments, the wire of the strength member 2 is cobalt chromium; in other embodiments, the filaments of the strength member 2 are polymeric filaments; in other embodiments, the wire material of the strength member 2 is a combination of nickel titanium wire and stainless steel wire; in other embodiments, the wire material of the strength member 2 is a combination of cobalt chromium wire and polymer wire.

As shown in fig. 3, the reinforcing member 2 is a braided structure of a braided wire material: in the embodiment of the invention, the diameter r of the wire is 0.0005-0.03inch, and 4-64 strands of wires are adopted for weaving; in this example, the wire has a diameter r of 0.0015inch and is braided using 32 strands of wire. In the embodiment of the invention, the weaving structure is one of double-strand round wire parallel weaving, single-strand round wire weaving, multi-strand round wire weaving, single-strand flat wire weaving and multi-strand flat wire weaving; in this embodiment, the braided structure is a double round wire parallel braid. In embodiments of the present invention, the weave pattern may be, but is not limited to, two over and two under, one over and one under, etc.; in this embodiment, the weave pattern is two over and two under. The braided structure shown in fig. 3 is formed by braiding two

round wires

2101 and 2102 in parallel, and the double-wire braided structure can enable the catheter to have good flexibility and collapse resistance, good torsion control transmissibility, good transmissibility of axial force and high axial strength.

In other embodiments, the wire has a diameter r of 0.0005inch and is braided using 64 strands; in other embodiments, the wire has a diameter r of 0.03inch and is braided using 8 strands; in other embodiments, the wire has a diameter r of 0.015inch and is braided using 4 strands.

In other embodiments, the strength member 2 may be a helical structure formed by helically winding the wire of a round wire 2201 as shown in FIG. 4; in some embodiments, the wire has a diameter of 0.0005 to 0.03inch and is wound at an angle of 5 ° to 89 ° from the axial direction of the catheter; in some embodiments, the wire has a diameter of 0.002inch and is wound at an angle of 45 ° to the axial direction of the catheter; in other embodiments, the wire diameter of the helical structure is 0.0005inch and the angle of winding is 89 ° from the catheter axis; in other embodiments, the wire diameter of the helical structure is 0.03inch and the angle of winding is 5 ° from the catheter axis; in other embodiments, the helical structure may be formed by winding a plurality of round wires together, the pitch of the wires wound in the axial direction of the catheter may be the same or different, and the number of the round wires may be 1-8.

In other embodiments, the stiffening member 2 may be a helical structure formed by winding a flat wire 2301 as shown in fig. 5, in some embodiments, the width of the flat wire 2301 is 0.0005inch to 0.01inch, the thickness of the flat wire 2301 is 0.0001inch to 0.008inch, and the winding angle of the flat wire 2301 is 5 ° to 89 ° from the catheter axial direction; in other embodiments, the width of ribbon wire 2301 is 0.0005inch, the thickness of ribbon wire 2301 is 0.001inch, and the angle of winding of ribbon wire 2301 is 60 ° from the catheter axis; in other embodiments, the width of ribbon wire 2301 is 0.01inch, the thickness of ribbon wire 2301 is 0.008inch, and the angle of winding of ribbon wire 2301 is 5 ° from the catheter axis; in other embodiments, the ribbon wire 2301 has a width of 0.005inch, the ribbon wire 2301 has a thickness of 0.0001inch, and the ribbon wire 2301 is wound at an angle of 89 ° to the catheter axis. In other embodiments, the helical structure may be formed by winding a plurality of flat wires in parallel, the winding pitches may be the same or different, and the number of the flat wires 2301 may be 1-6.

In other embodiments, the reinforcing member 2 may be formed by co-winding one or more flat wires and one or more round wires, and the pitch of the wires wound in the axial direction of the catheter may be the same or different.

As shown in fig. 6, the reinforcement member 2 is divided into a first reinforcement member segment 201, a second reinforcement member segment 202, and a third reinforcement member segment 203 according to the order from the proximal end to the distal end, wherein the PPI or winding density of the first reinforcement member segment 201 is greater than the PPI or winding density of the second reinforcement member segment 202, and the PPI or winding density of the second reinforcement member segment 202 is greater than the PPI or winding density of the third reinforcement member segment 203. Without being limited to this embodiment, the reinforcing member 2 may be divided into 1-15 segments according to the variation of PPI or winding density, the PPI or winding density may also be changed in a gradual manner, and the PPI or pitch variation of the reinforcing member 2 may provide different physical properties at different positions of the catheter to meet the requirements of the mechanical properties at different positions.

In other embodiments, the reinforcing member 2 may further include a cutting structure, the cutting structure is made of metal or polymer tube, the metal includes stainless steel, nickel-titanium alloy, cobalt-chromium alloy, platinum-tungsten alloy, etc., the polymer includes polyimide, polytetrafluoroethylene, aramid, etc., and the thickness of the cutting structure is 0.0005-0.03 inch. In some embodiments, the cutting structure is made of metal tubing, the metal tubing being a stainless steel alloy, the metal tubing having a thickness of 0.0005 inch; in other embodiments, the cutting structure is made of metal tubing, the metal tubing is platinum tungsten alloy, and the thickness of the metal tubing is 0.03 inch; in some embodiments, the cutting structure is made of a metal tubing, the metal tubing being a nickel titanium alloy, the metal tubing having a thickness of 0.01 inch; in other embodiments, the cutting structure is made of polymer tubing, which is polytetrafluoroethylene, and has a thickness of 0.005 inch.

In other embodiments, the reinforcement member 2 may comprise a combination of two or three of a filament spiral wound structure, a filament woven structure, and a cutting structure, such as a combination of a spiral wound structure and a filament woven structure, a combination of a spiral wound structure and a woven structure and a cutting structure, or a combination of two different filament woven structures, and the like.

EXAMPLE III

On the basis of the first embodiment or the second embodiment, the sheath 1 of the catheter provided in the third embodiment is divided into several sections in the axial direction of the catheter according to different materials, and the material of the sheath 1 can be selected from several of the polyamide, polyether block polyamide, polyurethane and polyolefin categories.

As shown in fig. 7, the sheath 1 is divided proximally to distally into a first sheath segment 101, a second sheath segment 102, and a third sheath segment 103. The first sheath section 101 is made of polyurethane, and the length of the first sheath section is 1000 mm; the material of the second sheath segment 102 is polyether block polyamide, the length of which is 300 mm; the material of the third sheath segment 103 is polyamide, which has a length of 50 mm.

The section of the sheath 1 is not limited to the case shown in fig. 7, in other embodiments, the sheath 1 can be divided into 3-20 sections according to the hardness of the material, and the sheath 1 with different hardness is selected at different positions of the catheter to further optimize the mechanical property of the catheter and ensure the delivery performance and safety of the catheter. In a preferred embodiment, the material stiffness of the catheter sheath 1 decreases from the proximal end to the distal end to meet the support properties at the proximal end and the flexibility properties at the distal end of the catheter. In other embodiments, the sheath 1 has a durometer of 25A-80D.

In one embodiment, the sheath 1 is composed of materials of different hardness from the proximal end to the distal end, the materials of different hardness including different kinds of materials of different hardness, the same kind of materials but different hardness. In this embodiment, the sheath 1 has a hardness from proximal to distal of 79-71D, 75-68D, 65-60D, 60-50D, 50-40D, 42-38D, 40-30D, 30-20D, 65-50A, 50-40A, 40-25A, respectively. In another embodiment, the sheath 1 is composed of eight different durometer materials, with the durometer of the sheath 1 from proximal to distal being 79-68D, 65-60D, 60-50D, 50-38D, 40-30D, 30-20D, 65-40A, 40-25A, respectively. In other embodiments, the stiffness of the sheath 1 may vary from proximal to distal; in other embodiments, the sheath 1 is spliced from 5 sections of materials of different hardness from the proximal end to the distal end; in other embodiments, the sheath 1 is spliced from 20 segments of different durometer materials from end to distal end.

Example four

As shown in fig. 8, the distal end of the first liner section 301 of the splicing location of the liner 3 includes a first head 3011, the proximal end of the second liner section 302 includes a second head 3021, and the first head 3011 and the second head 3021 are ends formed by cutting tubing. In some embodiments, the first and

second heads

3011, 3021 may be butted to form a splice as shown in fig. 2, with the two end faces butted and then heat shrunk; in other embodiments, the first head portion 3011 and the second head portion 3021 may overlap with each other to form a overlapping section 3001 as shown in fig. 9, the overlapping section 3001 may be formed by inserting the first head portion 3011 into the second head portion 3021 or inserting the second head portion 3021 into the first head portion 3011, the first head portion 3011 and the second head portion 3021 may be heat-shrunk after overlapping, and the material of the overlapping section 3001 may include a first polymer material and a second polymer material. In some embodiments, the length of coincident segment 3001 is 1 mm; in other embodiments, the length of the coincident segment 3001 is 10 mm; in other embodiments, the length of coincident segment 3001 is 20 mm. In other embodiments, the first head portion 3011 and the second head portion 3021 are subjected to a heat shrinking process after being overlapped, and when the heat shrinking temperature is higher than the melting points of the first polymer material and the second polymer material, the first polymer material and the second polymer material may be melted with each other to form a blended material. In other embodiments, the first and

second heads

3011, 3021 may be stretched prior to overlapping such that the thickness of the first head 3011 decreases from the proximal end to the distal end and/or the thickness of the second head 3021 decreases from the distal end to the proximal end. In some embodiments, the overlapping section 3001 is gradually reduced from the proximal end to the distal end by changing the shapes, thicknesses and the like of the first head portion 3011 and the second head portion 3021, and the performance of the splicing position can be gradually changed by gradually reducing the volume ratio of the first polymer material to the second polymer material in the overlapping section 3001, so that the change of the performance of the catheter is smoother and more natural, stress concentration points are not easily generated at the splicing position, the catheter has better force transmission performance in the use process, and radial deformation is not easily generated during bending.

In some embodiments, the most distal ends of the first and/or

second heads

3011, 3021 may form a slope with an angle of inclination to the axial direction of the catheter of 5-89 °. In some embodiments, the angle of inclination is 5 °; in some embodiments, the angle of inclination is 45 °; in some embodiments, the angle of inclination is 89 °. The first head portion 3011 and the second head portion 3021 may be inclined at the same angle or different angles with respect to the axial direction, or one of the head portions may be inclined at an angle with respect to the axial direction, and the other head portion may be perpendicular to the axial direction. The bending resistance of the conduit in a bending state can be further improved by adopting a non-vertical splicing mode. In this embodiment, the first head 3011 and the second head 3021 form a coincident section 3001, and in other embodiments, the first head 3011 and the second head 3021 may also form a butt joint structure as shown in fig. 10.

In other embodiments, the most distal ends of the first and/or

second heads

3011, 3021 form a rectangular wave structure as shown in fig. 11 or a triangular wave structure as shown in fig. 12. In some embodiments, the first head 3011 and the second head 3021 may form a coincident segment 3001, and in other embodiments, the first head 3011 and the second head 3021 may also form a butt joint structure.

EXAMPLE five

As shown in fig. 3, the catheter may further include a developing structure 5in addition to the sheath 1, the reinforcing member 2, and the lining 3, and in the embodiment of the present invention, the developing structure 5 is selected from, but not limited to, a developing ring, a developing belt, a developing spring, and the like. In this embodiment, the development structure 5 is a development ring; in other embodiments, the development structure 5 may be a development belt; in other embodiments, the development structure 5 may be a development spring; in other embodiments, the development structure 5 may be a combination of a development ring and a development spring; in other embodiments, the development structure 5 may be a combination of a development ring and a development belt. The visualization structure 5 provides a visual effect of the catheter in the human body, preferably at the distal end of the catheter. In the embodiment of the present invention, the material of the developing structure 5 is selected from developing metals such as platinum, gold, iridium, tungsten, etc., or their alloys or their composites with macromolecules; in this embodiment, the material of the development structure 5 is platinum-iridium alloy.

In this embodiment, the catheter may also include a tip 6, tip 6 being located at the distal-most end of the catheter, tip 6 being generally flexible to prevent damage to the vessel during delivery.

EXAMPLE six

TABLE 1 design of liner splice short samples and comparison short samples

To illustrate the mechanical advantage of the catheter provided by the present invention, the present example provides the mechanical properties of two sets of short coupons at the liner splice location and one set of shorter coupons compared. The three groups of short reinforcing components 2 are all of stainless steel 304 double round wire braided structure, the wire diameter is 0.0015inch, and the braided PPI is 60; the sheaths 1 of the three groups of short samples are spliced by the same material with the same length from the far end to the near end: 5cm of polyurethane material (55A), 5cm of polyurethane material (62A) and 5cm of polyether-block polyamide (25D). The three groups of short samples are different in that: liner splicing liner 3 of short 1 is 9cm of PTFE material plus 6cm of polyurethane material (62A) from proximal to distal end; liner splice liner 3 of short 2 has 9cm of PTFE and 6cm of polyether block polyamide (25D) from the proximal end to the distal end; the comparative short liner 3 was 15cm of PTFE.

The experimental data for the three short runs are shown in the following table:

TABLE 2 overbending ability of liner splice short samples versus control short samples

Sample (I)	Mean two point bend/N	Rate of change of lumen
			Lining splicing short sample 1	0.0399	6.41％
Lining splicing short sample 2	0.0489	7.00％
			Comparative short sample	0.0677	9.87％

The test method of the two-point bending comprises the following steps: intercepting a sample about 2cm from a sample to be tested, loading the sample into a grabbing disc of a lower clamp (the far end is exposed at the right end), screwing the grabbing disc to expose the sample for 10-15mm, adjusting the clamp and a pressure head to press down until the pressure head just contacts with a guide pipe to be tested, adjusting the farthest end of the sample just to be attached to the pressure head, just contacting the sample with the pressure head but not generating a force value, setting the pressing distance d to be 2.5mm in the program, testing the speed to be 2.5mm/min, and recording the maximum pressing force N1. The average value of the two-point bending of the lining splicing short sample 1 and the lining splicing short sample 2 at the splicing position is smaller than that of the comparison short sample, the two-point bending test result represents the softness of the conduit, the better the softness of the conduit at the far end is, and the better the bending passing capability is. The lumen change rates at bending in the curvature radius of 2.5cm of each of the lining splicing short sample 1 and the lining splicing short sample 2 were smaller than those of the comparative short sample. The lumen rate of change is the rate at which the outer diameter of the catheter becomes smaller when bent. Therefore, the smaller the rate of change of the lumen, the better the shape retention ability of the catheter at overbending and the better the resistance to kink. Experimental data show that the over-bending capacity of the lining splicing short sample 1 and the lining splicing short sample 2 is superior to that of a comparison short sample.

EXAMPLE seven

TABLE 3 design of liner splice length and contrast length

To illustrate the mechanical advantage of the catheter provided by the present invention, the present example provides mechanical properties of a set of lined spliced filaments and a set of comparative filaments. The two groups of long-like reinforcing components 2 are all flat wire braided structures made of stainless steel 304, the wire width is 0.006inch, the wire thickness is 0.002inch, the braided PPI is 59-125, and the PPI is gradually increased from the near end to the far end; the two groups of long sheaths 1 are of splicing structures of three macromolecules, namely polyolefin, polyurethane and polyether block polyamide. The difference lies in that: liner 3 of liner splice bar 1 is 118cm of teflon material plus 17cm of low density polyethylene from proximal to distal; the control sample liner 3 was 135cm of teflon.

The data for the two sets of pilot samples are shown in the following table:

TABLE 4 overbending Capacity of Lining splice Long samples versus control Long samples

Sample (I)	Ability to be in place	Push resistance (gf)
			Lining splicing long sample 1	M1	79
Comparative sample	C7	155.9

The in-place and push resistance tests were performed on the liner spliced length 1 and the control length in a simulated vascular anatomical model to obtain the data in table 4. As can be seen from the table, the lining splicing long sample 1 can reach the intracranial M1 section (horizontal section) when pushed to the position, the contrast long sample can only reach the intracranial C7 section (traffic section), in the intracranial blood vessel, the M1 section is higher than the C7 section, and the position reaching capability of the lining splicing long sample is better than that of the contrast long sample. The pushing resistance is the maximum resistance of the catheter in the pushing to position process, the maximum resistance of the lining splicing long sample 1in the pushing process is 79gf, the maximum resistance of the comparison long sample in the pushing process is 155.9gf, and the pushing resistance of the lining splicing long sample 1 is smaller than that of the comparison long sample, so that the lining splicing long sample 1 has better pushing performance, force transmission capacity and over-bending capacity.

Example eight

In the embodiment, two points are selected from the area of 0-35cm close to the most far end surface on the catheter main body, the distance between the two points is less than or equal to 3cm, the three-point bending measurement value of one point is A1, the three-point bending measurement value of the other point is A2, and the maximum difference value between A1 and A2 is 1.15N and less than 1.5N.

In another embodiment, there are optionally two points in the catheter body in a region of 0-35cm proximal to the distal-most surface, the two points being separated by a distance of 3cm or less, wherein one point has a three-point bend measurement of A1 and the other point has a three-point bend measurement of A2, and the difference between A1 and A2 is 0.95N and less than 1.5N at maximum.

Although the present invention is disclosed above, it is not limited thereto. Various modifications and alterations of this invention may be made by those skilled in the art without departing from the spirit and scope of this invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. The catheter is characterized by comprising a sheath and a lining, wherein the sheath and the lining are arranged along the radial direction of the catheter from outside to inside, the sheath is sleeved on the outside of the lining, the lining is formed by axially splicing at least two materials with different hardness, and the hardness of the materials of the lining is sequentially reduced from the near end to the far end.

2. The catheter of claim 1, further comprising a reinforcing member located between the sheath and the liner.

3. The catheter of claim 1 or 2, wherein the inner liner is divided into a first inner liner section and a second inner liner section from the proximal end to the distal end, the first inner liner section is made of a first polymer material, the second inner liner section is made of a second polymer material, and the hardness of the first polymer material is greater than that of the second polymer material.

4. The catheter of claim 3, wherein the first polymeric material has a durometer of 40D-70D and the second polymeric material has a durometer of 30A-55D.

5. The catheter of claim 4, wherein the ratio of the stiffness of the first polymeric material to the stiffness of the second polymeric material is 3:1 to 1.1: 1.

6. The catheter of claim 3, wherein the first polymer material is polytetrafluoroethylene, and the second polymer material is any one or a combination of any of polyolefin, polyether block polyamide and polyurethane.

7. A catheter according to claim 6, wherein said second polymeric material is a linear low density polyethylene or a polyolefin elastomer or a mixture of both.

8. A catheter according to claim 6, wherein the second polymeric material is a mixture of either or both of polyether block polyamide or polyurethane with added lubricant.

9. The catheter of claim 3, wherein the first liner segment has a length of 1000-1550mm and the second liner segment has a length of 50-600 mm.

10. The catheter of claim 3, wherein the distal end of the first liner segment comprises a first head portion and the proximal end of the second liner segment comprises a second head portion, the first head portion and the second head portion axially abutting to form the splice.

11. The catheter of claim 3, wherein the distal end of the first liner segment comprises a first head and the proximal end of the second liner segment comprises a second head, the first head and the second head forming a coincident segment, the material of the coincident segment comprising the first polymeric material and the second polymeric material.

12. The catheter of claim 11, wherein the length of the coincident segments is 0-20 mm.

13. A catheter according to claim 10 or 11, wherein the most distal end of the first and/or second head forms a ramp inclined at an angle of 5-90 ° to the axial direction of the catheter.

14. The conduit according to claim 10 or 11, wherein the most extreme ends of the first and/or second heads form a rectangular wave structure or a triangular wave structure.

15. The catheter of claim 11, wherein the overlapping section tapers in volume ratio from the proximal end to the distal end of the first polymeric material to the second polymeric material.

16. The catheter of claim 11, wherein the thickness of the first head gradually decreases from the proximal end to the distal end, and/or the thickness of the second head gradually decreases from the distal end to the proximal end.

17. A catheter as recited in any of claims 11, 15, and 16, wherein the coincident segments of the first polymeric material and the second polymeric material form a polymeric blend.

18. The catheter of claim 1, wherein the liner has a thickness of 0.0002-0.0015inch and the sheath has a thickness of 0.001-0.089 inch.

19. The catheter of claim 1 or 2, wherein the sheath comprises at least one material from the group consisting of polyamide, polyether block polyamide, polyurethane, polyolefin, the sheath gradually decreasing in hardness from the proximal end to the distal end.

20. The catheter of claim 19, wherein the sheath is formed by splicing 3-20 sections of materials with different hardness from the proximal end to the distal end, and the hardness of the material of the sheath is 25A-80D.

21. The catheter of claim 20, wherein the sheath is formed by splicing 8 sections of materials with different hardness from the proximal end to the distal end, and the hardness from the proximal end to the distal end is 79-68D, 65-60D, 60-50D, 50-38D, 40-30D, 30-20D, 65-40A and 40-25A respectively.

22. The catheter of claim 20, wherein the sheath is formed by splicing 11 sections of materials with different hardness from the proximal end to the distal end, and the hardness from the proximal end to the distal end is 79-71D, 75-68D, 65-60D, 60-50D, 50-40D, 42-38D, 40-30D, 30-20D, 65-50A, 50-40A and 40-25A respectively.

23. A catheter according to claim 2, wherein the reinforcing member comprises a structure in which wire materials are spirally wound or/and braided, the wire materials being at least one of metal wires and polymer wires.

24. A catheter as recited in claim 23, wherein said reinforcing component comprises a braided structure of two strands of wire braided in parallel.

25. The catheter of claim 2, wherein the stiffening member comprises a cutting structure cut from a metal or polymer tube.

26. A catheter according to any of claims 23-25, wherein the reinforcing member further comprises a cutting structure cut from metal tubing or polymer tubing.

27. The catheter of claim 1, wherein there are optionally two points on the catheter body in an area of 0-35cm proximal to the distal-most end surface, wherein one point has a three-point bend measurement of a1 and the other point has a three-point bend measurement of a2, the difference between a1 and a2 being no more than 1.5N;

the distance between the optional two points is less than or equal to 3 cm.