CN111888622B

CN111888622B - Stepless gradual change type catheter

Info

Publication number: CN111888622B
Application number: CN202010805636.9A
Authority: CN
Inventors: 胡伟; 张晨朝; 王越; 王君毅; 时玉楠; 程瑞; 王国辉
Original assignee: Shanghai Xinwei Medical Technology Co ltd
Current assignee: Shanghai Xinwei Medical Technology Co ltd
Priority date: 2020-08-12
Filing date: 2020-08-12
Publication date: 2022-08-26
Anticipated expiration: 2040-08-12
Also published as: CN111888622A

Abstract

The invention relates to a stepless gradual change type catheter, and belongs to the technical field of medical instruments. Comprises an inner liner, a reinforcing layer and an outer sleeve layer; the reinforcing layer is set as a single weaving section; the reinforcing layer is formed from the stem end near the operator end to the head end far from the operator end, and the shape of the braided wires of the braided section of the reinforcing layer, the braiding angle between the braided wires or the degree of mutual bending between the braided wires is set to be in a stepless gradual change form. Through the stepless gradual change of various structural forms, the stepless gradual change of the catheter structure from the catheter seat end to the head end is realized, so that the catheter seat end has excellent support and pushing performance, the head end has better flexibility, the whole bending resistance and the lumen maintenance performance of the catheter are good, and the performance defect of the part between sections caused by a multi-braided section structure of the currently adopted catheter is avoided. The stepless gradual change catheter has multiple functions, and can be used for treatment means such as internal guide wires, stents or auxiliary thrombus suction.

Description

Stepless gradual change type catheter

Technical Field

The invention relates to a stepless gradual change type catheter, and belongs to the technical field of medical instruments.

Background

With the development of social economy, the national life style also changes deeply, particularly the aging of population and the acceleration of urbanization process, the prevalence trend of cardiovascular disease risk factors in China is increasingly obvious, and the number of people suffering from cardiovascular diseases is continuously increased. At present, about 220 tens of thousands of patients suffering from chronic total occlusion lesions of coronary arteries in China exist. Clinically, when minimally invasive interventional therapy is performed on a blood vessel with chronic total occlusion or a vascular dissection, a catheter and other interventional devices are usually required to be used in cooperation for performing therapeutic operation, such as balloon dilatation, stent implantation and other technical means. In the operation process, the catheter is often required to be pushed to the pathological change position from the outside of the body, so that the catheter is required to have very strong pushing performance, bending resistance, flexibility and the like, and the micro-catheter is ensured to accurately reach the pathological change part of a patient and pass through the pathological change blood vessel in the operation process without damaging the healthy blood vessel. The existing conduit pipe body generally comprises an inner liner, a reinforcing layer and an outer sleeve layer; and the reinforcing layer includes a braided section and a helical section (as shown in figure 1). Wherein the braided section 1 is close to the tube seat at one side of the operator, and the spiral section 2 is close to the head end. This design provides the catheter tip with good compliance while providing the tip with good shape retention. However, the design of the multi-segment structure changes, which results in a large difference in performance between segments at the joint portion, and thus, the overall bending resistance and shape retention are poor. At the same time, such proximal braided structures can provide limited support and pushability.

Disclosure of Invention

The invention aims to solve the technical problem that the performance difference of the connection part between a braided section and a spiral section of the existing catheter is large, so that the overall bending resistance and the shape retention capacity of the catheter are poor.

In order to solve the above problems, the present invention provides a stepless gradual change type catheter, which comprises an inner liner, a reinforcing layer and an outer jacket; the reinforcing layer is set as a single weaving section; the reinforcing layer is formed from the stem end near the operator end to the head end far from the operator end, and the shape of the braided wires of the braided section of the reinforcing layer, the braiding angle between the braided wires or the degree of mutual bending between the braided wires is set to be in a stepless gradual change form.

Preferably, the angle of the included angle formed between the tube seat end knitting wire at the end, close to the operator, of the reinforcing layer and the central axis of the catheter is larger than the angle of the included angle formed between the head end knitting wire at the end, far away from the operator, of the reinforcing layer and the central axis of the catheter.

Preferably, the reinforcing layer is formed such that the braiding angle between the braided filaments of the braided section of the reinforcing layer is set to a stepless gradual change form from the stem end close to the operator end to the head end far from the operator end.

Preferably, the cross section of the braided wire at the end of the reinforcing layer close to the tube seat at one end of the operator is square; the cross section of the braided wire at the end, away from the operator, of the reinforcing layer is circular; the cross section of the braided wire of the reinforcing layer from the tube seat end close to one end of an operator to the head end far away from the end of the operator is gradually changed from a square shape without steps to a circular shape.

Preferably, the braided wires at the end of the tube seat close to the operator of the reinforcing layer are bent mutually to a greater extent than the braided wires at the end of the head end far away from the operator.

Preferably, the diameter of the braided wire at the end of the tube seat, close to the operator, of the reinforcing layer is larger than the diameter of the braided wire at the end of the tube seat, far away from the operator.

Preferably, the reinforcing layer is arranged from the tube seat end close to one end of an operator to the head end far away from the end of the operator, and the diameter of the braided filaments of the braided section of the reinforcing layer is set to be in a stepless gradual change form from large to small.

Preferably, the braided wires of the reinforcing layer braided section are nickel titanium wires or stainless steel wires.

Compared with the prior art, the invention has the following beneficial effects:

1. the catheter adopts a single-braided-section design in structure, realizes stepless gradual change of the performance of the catheter from the tube seat end to the head end through various structural characteristics, ensures that the tube seat end of the catheter has excellent support and push performance and the head end has better flexibility, simultaneously has excellent integral bending resistance and tube cavity holding performance, and avoids performance defects between sections caused by a multi-braided-section structure.

2. The catheter realizes stepless gradual change of the structure and the performance on the performance, meets the requirements of the hardness, the supporting property and the pushing property required by the tube seat end of the catheter, the compliance property required by the head end, the integral bending resistance and the shape maintaining property of the tube cavity of the catheter, and avoids the performance defect of the section-to-section part caused by the multi-section structure design of the braided section.

3. The stepless gradual change of the performance of the catheter is realized by changing the weaving angle, the weaving camber, the size of the weaving silk and the section shape of the catheter reinforcing layer weaving net, and the performance defect of the section-to-section part caused by the multi-section structural design of the weaving section is avoided. The stepless gradual change catheter has multiple functions, and can be used for treatment means such as internal guide wires, stents or auxiliary thrombus suction.

Drawings

FIG. 1 is a schematic view of a catheter in use at present;

FIG. 2 is a schematic angle view of a braided wire mesh structure at the tube seat end of a stepless gradual change catheter according to the present invention;

FIG. 3 is a schematic angle view of a braided wire mesh structure at the tip of a catheter of the present invention;

FIG. 4 is a schematic view of the cross-sectional shape change of the braided wire of a catheter of the present invention;

FIG. 5 is a schematic structural diagram illustrating the degree of mutual bending between braid wires at the hub end of a catheter according to the present invention;

FIG. 6 is a schematic structural view illustrating the degree of mutual bending between the braided wires at the tip end of a catheter according to the present invention;

FIG. 7 is a cross-sectional view of a stepless gradual change type catheter according to the present invention;

reference numerals: 1. a weaving section; 2. a helical section; 3. a grid at the base end; 4. a grid of head ends; 5. a rectangular cross-section; 6. a circular cross-section; 7. an overcoat layer; 8. weaving layer; 9. an inner liner layer;

Detailed Description

In order to make the invention more comprehensible, preferred embodiments accompanied with figures are described in detail below:

as shown in fig. 1-7, the present invention provides a stepless gradual change type catheter, which comprises an inner liner layer 9, a reinforcing layer and an outer jacket layer 7; the reinforcing layer is arranged into a single weaving section; the reinforcing layer is formed from the stem end near the operator end to the head end far from the operator end, and the shape of the braided wires of the braided section of the reinforcing layer, the braiding angle between the braided wires or the degree of mutual bending between the braided wires is set to be in a stepless gradual change form. The angle of the included angle formed between the tube seat end knitting wire at one end of the reinforcing layer close to the operator and the central axis of the catheter is larger than the angle of the included angle formed between the head end knitting wire at one end far away from the operator and the central axis of the catheter. The reinforcing layer is formed from a tube socket end close to one end of the operator to a head end far from the other end of the operator, and the knitting angle between the knitting yarns of the knitting section of the reinforcing layer is set to be in a stepless gradual change form. The cross section of the braided wire at the end of the tube seat, close to one end of an operator, of the reinforcing layer is square; the cross section of the braided wire at the end of the reinforcing layer far away from the operator is circular; the cross-sectional shape of the braided wire from the tube seat end close to the operator end to the head end far away from the operator end of the reinforcing layer is gradually changed from a square shape without steps to a circular shape. The mutual bending degree of the weaving wires at the end of the tube seat, close to one end of the operator, of the reinforcing layer is larger than the mutual bending degree of the weaving wires at the head end, far away from one end of the operator, of the tube seat. The diameter of the braided wire at the end of the tube seat, close to one end of an operator, of the reinforcing layer is larger than that of the braided wire at the head end, far away from one end of the operator. The reinforcing layer is arranged from the tube seat end close to one end of an operator to the head end far away from the end of the operator, and the diameter of the braided wire of the braided section of the reinforcing layer is set to be in a stepless gradual change form from large to small; the weaving wires of the reinforcing layer weaving section are nickel titanium wires or stainless steel wires.

Examples

As shown in fig. 2 and 3, the stepless transition catheter main body of the present invention is composed of a mesh which is woven by nickel titanium wires or stainless steel wires. The angle formed by the grid and the axial direction of the catheter is gradually changed, the angle formed by the grid 3 close to the end of the tube seat and the axial direction of the catheter is larger, and the angle formed by the grid 4 close to the head end and the axial direction of the catheter is smaller. The design ensures that the grid density of the tube seat end is greater than that of the head end in unit length, so that the tube seat end part of the catheter has better support and pushing performance, and the head end part of the catheter has better flexibility, thereby avoiding damaging blood vessels.

As shown in fig. 4, in the stepless tapered catheter of the present invention, the cross-sectional shape of the braided wire constituting the braided layer is gradually changed from the hub end to the tip end. The cross-sectional shape of the braid filaments at the hub end is rectangular 5, while the cross-sectional shape of the braid filaments at the head end gradually transitions to a circular 6 cross-section. The design makes the end part of the catheter tube base harder, better in support and push performance, and the end part of the catheter head more flexible and better in compliance performance.

As shown in fig. 5 and 6, the woven mesh is woven by nickel-titanium wires or stainless steel wires, the weaving strength of the woven mesh at the tube seat end is higher, and the mutual deformation and bending degree of the woven wires is higher. Correspondingly, the knitting force and the mutual deformation degree between the knitting yarns are gradually reduced from the tube seat end to the head end, and the knitting yarns at the head end part are not deformed and bent. The structural design increases the interaction force between the knitting yarns at the tube seat end, so that the knitting grid is not easy to deform, and the hardness and the support performance are higher. And the interaction force between the head end knitting yarns is smaller, and the flexibility is better. The braided wire adopted at the tube seat end has larger size, thicker diameter and higher hardness and support property. The size and diameter of the braided wire are gradually reduced from the tube seat end to the head end, so that the hardness of the braided wire is gradually reduced. This design will achieve a gradual stiffness change of the knitted net section.

As shown in fig. 7, the stepless gradual change catheter provided by the present invention is a tubular structure, and the catheter body comprises, from outside to inside, an outer jacket layer 7, a braid layer 8, and an inner liner layer 9; the material of the outer sleeve layer 7 is preferably polyether block polyamide, the polyether block polyamide has the performance of a thermoplastic elastomer due to the unique chemical structure, the polyether block polyamide is the lightest engineering thermoplastic elastomer, no mechanical property loss is caused under repeated deformation, the fatigue resistance is realized, and meanwhile, the polyether block polyamide has accurate dimensional stability and good resilience and elastic recovery capability. The inner liner 9 is preferably high-density polyethylene or polytetrafluoroethylene, and the high-density polyethylene and the high-density polytetrafluoroethylene have the characteristics of small volume and good mechanical strength. The reinforcing layer is formed by weaving stainless steel wires or nickel-titanium wires. The performance of the catheter from the catheter seat end to the head end is changed step-free by changing the knitting angle, the knitting curvature, the size of the knitting silk and the shape of the cross section of the knitting net of the reinforcing layer. The support, the pushing performance, the bending resistance, the lumen shape retention capacity and the head end compliance performance of the catheter are enhanced, and the catheter is ensured to smoothly and accurately reach the diseased part of a patient and pass through a tortuous diseased vessel in the operation process.

While the invention has been described with respect to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. Those skilled in the art can make various changes, modifications and equivalent arrangements, which are equivalent to the embodiments of the present invention, without departing from the spirit and scope of the present invention, and which may be made by utilizing the techniques disclosed above; meanwhile, any equivalent changes, modifications and evolutions of the above embodiments according to the essential technology of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A stepless gradual change type catheter comprises an inner liner, a reinforcing layer and an outer sleeve layer; it is characterized in that the reinforcing layer is set as a single weaving section; the reinforcing layer is arranged from the tube seat end close to one end of an operator to the head end far away from the end of the operator, and the bending degree of the braided wires of the braided section of the reinforcing layer is set to be in a stepless gradual change mode; the degree of mutual bending between the weaving wires at the end, close to the pipe seat, of one end of the reinforcing layer, which is far away from the operator, is greater than the degree of mutual bending between the weaving wires at the head end, which is far away from one end of the operator.

2. A stepless gradual change catheter as claimed in claim 1, wherein: the reinforcing layer is arranged from the tube seat end close to one end of an operator to the head end far away from the end of the operator, and the self shape of the knitting yarns or the knitting angle among the knitting yarns of the knitting section of the reinforcing layer is set to be in a stepless gradual change form.

3. A stepless gradual change catheter as claimed in claim 2, wherein: the angle of an included angle formed between the knitting silk at the tube seat end of the reinforcing layer close to one end of the operator and the central axis of the catheter is larger than that of an included angle formed between the knitting silk at the head end far away from one end of the operator and the central axis of the catheter.

4. A stepless graduating catheter as in claim 1, wherein: the cross section of the braided wire at the end of the reinforcing layer close to the pipe seat at one end of an operator is square; the cross section of the braided wire at the end, away from the operator, of the reinforcing layer is circular; the cross section of the braided wire of the reinforcing layer from the tube seat end close to one end of an operator to the head end far away from the end of the operator is gradually changed from a square shape without steps to a circular shape.

5. A stepless gradual change catheter as claimed in claim 1, wherein: the diameter of the braided wire at the end of the tube seat, close to one end of an operator, of the reinforcing layer is larger than that of the braided wire at the head end, far away from one end of the operator.

6. A stepless gradual change catheter as claimed in claim 1, wherein: the diameter of the braided wire of the braided section of the reinforcing layer is set to be in a stepless gradual change form from large to small from the tube seat end close to one end of an operator to the head end far away from the other end of the operator.

7. A stepless gradual change catheter as claimed in claim 1, wherein: the braided wires of the braided section of the reinforcing layer are nickel titanium wires or stainless steel wires.