WO2024022041A1

WO2024022041A1 - Medical catheter

Info

Publication number: WO2024022041A1
Application number: PCT/CN2023/105470
Authority: WO
Inventors: 梁韬; 寸雨曦; 罗雪莉; 刘云云; 王翠
Original assignee: 微创神通医疗科技（上海）有限公司
Priority date: 2022-07-28
Filing date: 2023-07-03
Publication date: 2024-02-01
Also published as: CN117504089A

Abstract

A medical catheter, comprising an outer layer (11) and a reinforcing layer (12). The reinforcing layer (12) has pores, and the outer layer (11) penetrates through the pores and wraps the reinforcing layer (12) to be embedded with each other. Moreover, the radial position of the reinforcing layer (12) is limited by the outer layer (11). Such configuration improves the stability of the catheter in processing technology by means of limiting the radial position of the reinforcing layer (12) in the outer layer (11). Meanwhile, on the basis of not affecting the physical properties and clinical safety of the catheter, the wall thickness of the catheter is reduced, thereby achieving a design with a large cavity and thin walls.

Description

medical catheter

Technical field

The present invention relates to the technical field of medical devices, in particular to a medical catheter.

Background technique

Interventional therapy has become a popular treatment option for many diseases because it has fewer side effects than traditional surgical treatments. In all interventional surgeries, medical catheters are the cornerstone of successful surgery. It serves as a channel during surgery, allowing doctors to deliver specific medical instruments to designated locations and treat patients.

Taking intracranial neurointerventional treatment as an example, the characteristics of intracranial blood vessels determine that the medical catheters that serve them need to have a soft tip to avoid damaging the intracranial blood vessels; existing catheters usually have an inner layer, a reinforced layer, and an outer layer. Three-layer structure, and the factors that affect the softness of the catheter are: the hardness of the inner layer, the strength and coverage density of the reinforcing layer wire, and the strength of the outer layer; at the same time, according to the existing clinical feedback analysis, doctors prefer to use large inner lumens during interventional surgeries. The small wall thickness of the catheter allows doctors to use the inner lumen of the catheter to transport large-sized medical devices for treatment during clinical operations when the outer diameter of the catheter is limited by the size of the patient's blood vessels. In addition, large-sized medical devices The design of the lumen can also optimize the delivery performance of medical devices within the catheter.

In summary, medical catheters need to have the following characteristics: (1) have a soft tip; (2) have a large cavity and thin walls. Catheters currently on the market are designed to have a large lumen space and extremely thin wall thickness within the limitations of blood vessel specifications in order to meet the clinical needs of doctors. The extremely thin wall thickness causes the catheter itself to have poor physical support and is easily bent. At the same time, the reinforcement layer of the coil structure causes the catheter itself to have a low peak tensile force test value, which in turn leads to a large number of distal fracture events in clinical practice. This poses a huge challenge to product processing technology and finished product quality.

Contents of the invention

The purpose of the present invention is to provide a medical catheter to solve the problem that existing catheters cannot simultaneously meet the needs of a large cavity and thin wall structure and good physical properties, and at the same time solve the instability of the processing technology in the existing technology, thereby affecting the quality of the finished product. The problem.

In order to achieve the above object, the present invention provides a medical catheter, including: an outer layer and a reinforcing layer;

The reinforcing layer has pores, the outer layer penetrates through the pores and wraps the reinforcing layer to fit with each other, and the radial position of the reinforcing layer is defined by the outer layer.

Optionally, the ratio of the first thickness of the reinforcement layer in the radial direction to the second thickness of the outer layer in the radial direction is 0.2 to 0.9.

Optionally, the ratio of the first thickness of the reinforcement layer in the radial direction to the second thickness of the outer layer in the radial direction is 0.35 to 0.9.

Optionally, the ratio of the first thickness of the reinforcement layer in the radial direction to the second thickness of the outer layer in the radial direction is 0.5 to 0.75.

Optionally, the inner edge of the reinforcement layer is flush with the inner surface of the outer layer.

Optionally, the radial distance between the inner edge of the reinforcement layer and the inner surface of the outer layer is greater than 0.

Optionally, the radial distance between the thickness center line of the reinforcement layer in the radial direction and the inner surface of the outer layer is Y, the second thickness of the outer layer in the radial direction is L, and the reinforcement layer is The first thickness is 2D, then D/L≤Y/L<0.86.

Optional, 0.35≤Y/L≤0.65.

Optional, 0.49≤Y/L≤0.51.

Optionally, the outer layer is heat-melted to penetrate the pores and wrap the reinforcing layer.

Optionally, the reinforcing layer includes any one of a braided structure, a coil, or a cut tube.

Optionally, the medical catheter further includes an inner layer, and the outer surface of the inner layer abuts against the inner surface of the outer layer.

Optionally, the medical catheter further includes a membrane layer covering the outer surface of the outer layer and applying an inward squeezing force to the outer layer, so that the inner surface of the outer layer The surface conforms to the outer surface of the inner layer.

Optionally, the medical catheter uses a film layer during the preparation process. The film layer covers the outer surface of the outer layer and applies an inward squeezing force to the outer layer, so that the outer layer The inner surface is attached to the outer surface of the inner layer, and after the preparation is completed, the film layer is removed.

Optionally, the outer layer is made of hot-melt material; the film layer is made of heat-shrinkable material.

To sum up, the present invention provides a medical catheter, which includes: an outer layer and a reinforcing layer; The strong layer has pores, and the outer layer penetrates through the pores and wraps the reinforcing layer to fit into each other, and the radial position of the reinforcing layer is defined by the outer layer.

Such a configuration improves the stability of the catheter in processing technology by limiting the radial position of the reinforcement layer in the outer layer; at the same time, it reduces the wall thickness of the catheter without affecting the physical properties and clinical safety of the catheter. Achieve a design with large cavity and thin wall.

Description of drawings

Figure 1 is a schematic structural diagram of a medical catheter according to an embodiment of the present invention;

Figure 2 is another structural schematic diagram of a medical catheter according to an embodiment of the present invention;

Figure 3 is a schematic diagram when the ratio of the thickness of the reinforcing layer to the thickness of the outer layer exceeds the thickness ratio range according to the embodiment of the present invention;

Figure 4 is a schematic diagram when Y/L exceeds the position ratio range according to the embodiment of the present invention;

Figure 5 is a schematic diagram when Y/L is lower than the position ratio range according to the embodiment of the present invention.

Among them, the description of each reference symbol is as follows:
11-outer layer; 12-reinforcement layer; 13-inner layer.

Detailed ways

In order to make the purpose, advantages and features of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are in a very simplified form and are not drawn to scale, and are only used to conveniently and clearly assist in explaining the embodiments of the present invention. In addition, the structures shown in the drawings are often part of the actual structure. In particular, each drawing needs to display different emphasis, and sometimes uses different proportions.

As used in this specification, the singular forms "a", "an" and "the" include plural referents, the term "or" is generally used in its sense including "and/or", and the term "several" The term "at least two" is usually used in a meaning including "at least one", and the term "at least two" is usually used in a meaning including "two or more". In addition, the terms "first" and "th "Second" and "third" are used for descriptive purposes only and cannot be understood as indicating or implying the relative importance or implicitly indicating the quantity of the technical features indicated. Therefore, the features defined as "first", "second" and "third" may explicitly or implicitly include one or at least two of these features, "one end" and "other end" and "proximal end" and "Remote" is usually Refers to the two corresponding parts, which not only include the endpoints. The "proximal end" usually represents the direction close to the doctor during the operation, and the "distal end" usually represents the direction close to the lesion during the operation. The terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be The internal connection between two elements or the interaction between two elements. In addition, as used in this specification, one element is disposed on another element, which usually only means that there is a connection, coupling, matching or transmission relationship between the two elements, and the relationship between the two elements may be direct or indirect through an intermediate element. connection, coupling, cooperation or transmission, and cannot be understood as indicating or implying the spatial positional relationship between two elements, that is, one element can be in any position inside, outside, above, below or to one side of another element, unless the content Also clearly stated. The terms "upper", "lower", "top" and "bottom" usually refer to the relative positional relationship arranged according to the direction of gravity; the terms "vertical, vertical direction" usually refer to the direction of gravity, which is generally perpendicular to the ground. , "horizontal, horizontal plane direction" usually refers to a direction parallel to the ground; for those of ordinary skill in the art, the specific meanings of the above terms in this specification can be understood according to specific circumstances.

Description will be made below with reference to the drawings.

Please refer to Figures 1 to 2. The present invention provides a medical catheter, including: an outer layer 11 and a reinforcing layer 12; the reinforcing layer 12 has pores, and the outer layer 11 penetrates through the pores and wraps the The reinforcing layers 12 are fitted with each other, and the radial position of the reinforcing layers 12 is defined by the outer layer 11 . It should be noted that in the exemplary examples shown in FIGS. 1 to 5 , the radial direction is the up-down direction, and the axial direction is the left-right direction. The outer layer 11 penetrates through the pores and wraps the reinforcing layer 12 to form a mutually fitting structure. In the same conduit, the inner edge of the reinforcing layer 12 can be flush with the inner surface of the outer layer 11, or can be flush with the inner surface of the outer layer 11. The surface forms a certain radial distance, and the radial position of the reinforcing layer 12 is limited by the embedded structure formed by the outer layer 11 penetrating the pores and wrapping it. The wires in the reinforcing layer 12 are not along the axis of the outer layer 11 in the outer layer 11 extends in a direction that is at an angle with the axial direction of the outer layer 11 . This embodiment solves problems such as wire leakage during the production process of the catheter by controlling the position ratio of the reinforcement layer 12 in the outer layer 11 and the thickness ratio of the reinforcement layer 12 to the outer layer 11 in the radial direction, thereby improving the catheter The stability of the production process, while not affecting the physical properties and clinical safety of the catheter, can meet the design effect of a large and thin-walled catheter lumen, so that the catheter can simultaneously meet the requirements of a large-lumen, thin-walled and good physical properties.

As an optional implementation, the ratio of the first thickness of the reinforcement layer 12 in the radial direction to the second thickness of the outer layer 11 in the radial direction is 0.2 to 0.9, where the first thickness refers to the thickness of the reinforcement layer 12 The distance between the outer surface and the inner surface, the second thickness refers to the distance between the outer surface and the inner surface of the outer layer 11 . Furthermore, when the first thickness of the reinforcing layer 12 in the radial direction and the second thickness of the outer layer 11 in the radial direction are both small, the thickness ratio range can be adjusted to 0.35˜0.9. Furthermore, when both the first thickness in the radial direction of the reinforcing layer 12 and the second thickness in the radial direction of the outer layer 11 are larger, the thickness ratio range can be adjusted to 0.5 to 0.75. It should be noted that the thickness ratio range is affected by the materials of the outer layer 11 and the reinforcement layer 12. Different materials are suitable for different thickness ratio ranges, but what needs to be satisfied is that when it is within the above thickness ratio range, the reinforcement layer 12 is not easy to appear. It has no leakage and can better balance softness and support.

Referring to FIGS. 1 and 3 , the inner edge of the reinforcement layer 12 is flush with the inner surface of the outer layer 11 and the outer surface of the inner layer 13 . In the example shown in FIG. 1 , the inner surface of the outer layer 11 abuts the outer surface of the inner layer 13 , the inner edge of the reinforcement layer 12 is flush with the inner surface of the outer layer 11 , and at the same time, the inner edge of the reinforcement layer 12 It is also on the same plane as the outer surface of the inner layer 13 , and the ratio of the first thickness of the reinforcing layer 12 in the radial direction to the second thickness of the outer layer 11 in the radial direction is within an appropriate ratio range. At this time, the reinforcing layer 12 There will be no defective phenomena such as leakage; in the example shown in Figure 3, the ratio of the first thickness of the reinforcing layer 12 in the radial direction to the second thickness of the outer layer 11 in the radial direction is 0.95, which exceeds the thickness ratio. The upper limit of the range will cause all the outer layer 11 materials to penetrate into the pores of the reinforcement layer 12 during the processing, leaving a part of the reinforcement layer 12 exposed outside the outer surface of the outer layer 11, resulting in defects such as wire leakage. At the same time, if the thickness of the reinforcing layer 12 is too large, the flexibility of the catheter is insufficient, and it is easy to puncture or scratch the blood vessels; in other embodiments, the first thickness of the reinforcing layer 12 in the radial direction is different from the radial thickness of the outer layer 11 The ratio of the second thickness is 0.1, which is lower than the lower limit of the thickness ratio range, which will lead to insufficient support and anti-collapse properties of the catheter as a whole, and it is easy to retreat or collapse during the delivery and treatment process.

Please refer to FIG. 2 , the radial distance between the inner edge of the reinforcement layer 12 and the inner surface of the outer layer 11 is greater than 0. It should be noted that whether the inner edge of the reinforcement layer 12 is flush with the inner surface of the outer layer 11 or the radial distance is greater than 0, the first thickness of the reinforcement layer 12 in the radial direction is equal to the second thickness of the outer layer 11 in the radial direction. The thickness ratios need to be in the range of 0.2 to 0.9.

Please refer to FIG. 2 and FIG. 4 to FIG. 5 . The radial distance between the center line of the thickness of the reinforcement layer 12 in the radial direction and the inner surface of the outer layer 11 is Y. The second thickness of the outer layer 11 in the radial direction is Y. is L, and the first thickness of the reinforcement layer 12 in the radial direction is 2D, then D/L≤Y/L<0.86. It should be noted that the thickness centerline of the reinforcement layer 12 in the radial direction is defined as the radial distance from a point located on the thickness centerline to the inner edge of the reinforcement layer 12 is equal to the radial distance to the outer edge of the reinforcement layer 12 . In the example shown in FIG. 1 , D/L=Y/L, that is, when the inner edge of the reinforcing layer 12 is flush with the inner surface of the outer layer 11 , the thickness centerline of the reinforcing layer 12 in the radial direction reaches the outer layer 11 The ratio of the radial distance of the inner surface to the second thickness of the outer layer 11 in the radial direction is also within a suitable position ratio range; at the same time, in the exemplary examples of FIG. 2 and FIGS. 4 to 5 , the reinforcing layer 12 is in the radial direction. The ratios of the first upward thickness and the second thickness of the outer layer 11 in the radial direction are both in the range of 0.2 to 0.9. In the example shown in Figure 4, Y/L exceeds the upper limit of the position ratio range, causing a part of the reinforcement layer 12 to be exposed outside the outer surface of the outer layer 11, resulting in unqualified phenomena such as wire leakage; in Figure 5 In the example shown, Y/L is lower than the lower limit of the position ratio range, causing the inner edge of the reinforcement layer 12 to be located outside the inner surface of the outer layer 11. Considering the influence of the fluidity of the material of the outer layer 11, resulting in The portion of the inner edge of the reinforcing layer 12 beyond the inner surface of the outer layer 11 is not filled with the material of the outer layer 11 , thereby increasing the wall thickness of the conduit and failing to achieve the design effect of a large cavity and a thin wall.

Further, when 2D and L are both small, that is, when the first thickness of the reinforcement layer 12 in the radial direction and the second thickness of the outer layer 11 in the radial direction are both small, for example, when the reinforcement layer 12 with a thickness of 0.001 inches needs to be integrated into the thickness When the outer layer 11 is 0.002 inches, the ratio of the radial distance Y from the thickness centerline of the reinforcement layer 12 in the radial direction to the inner surface of the outer layer 11 and the second thickness L of the outer layer 11 in the radial direction should be controlled between 0.35 and 0.65. within the range of When the reinforcement layer 12 needs to be integrated into the outer layer 11 with a thickness of 0.005 inches, the ratio of the radial distance Y from the thickness centerline of the reinforcement layer 12 in the radial direction to the inner surface of the outer layer 11 and the second thickness L of the outer layer 11 in the radial direction It should be controlled within the range of 0.49~0.51. It should be noted that the position ratio range is affected by the material and thickness of the outer layer 11 and the reinforcement layer 12. Different materials and thicknesses are suitable for different position ratio ranges, but what needs to be satisfied is that when it is within the above position ratio range, The reinforcing layer 12 is not prone to leakage and can achieve the technical effect of a large and thin wall of the catheter lumen.

As an optional embodiment, the outer layer 11 penetrates the pores and wraps the reinforcing layer 12 after being heat-melted. In this configuration, after the outer layer 11 is heated and melted, it will flow into the pores of the reinforcing layer 12 and wrap it to form a mutually embedded structure. It should be noted that in some other embodiments, the mutually fitting structure of the outer layer 11 and the reinforcing layer 12 can also be achieved through methods such as condensation shrinkage or chemical reagent immersion. Those skilled in the art can do this according to the actual situation. Configuration, the present invention is not limited to this.

As a preferred embodiment, the reinforcing layer 12 includes any one of a braided structure, a coil, or a cut tube. The reinforcing layer 12 is a braided structure, coil or cut tube made of one or more filamentary materials such as stainless steel, nickel-titanium alloy, cobalt-chromium alloy, and polymer. Taking into account the differences in materials and structures, the reinforcing layer 12 is The first radial thickness will vary from 0.001 to 0.0045 inches. Of course, in some other examples, the material and structure of the reinforcing layer 12 can be in other reasonable forms. Those skilled in the art can select appropriate materials and structures according to actual conditions, and the present invention is not limited thereto.

Please refer to FIGS. 1 to 5 , the medical catheter further includes an inner layer 13 , and the outer surface of the inner layer 13 abuts against the inner surface of the outer layer 11 . The inner layer 13 is made of one of nylon elastomer Pebax, nylon, polyurethane PU, polytetrafluoroethylene PTFE, high-density polyethylene HDPE, nylon elastomer Pebax mixed with additives to reduce friction coefficient, or polyolefin elastomer. It can be made in several ways, and those skilled in the art can select suitable materials according to different uses of the catheter, and the present invention is not limited thereto.

Furthermore, the medical catheter further includes a film layer during the preparation process. The film layer covers the outer surface of the outer layer 11 and applies an inward squeezing force to the outer layer 11 to make the outer layer 11 . The inner surface of the outer layer 11 is in contact with the outer surface of the inner layer 13 . With this arrangement, the film covering the outer surface of the outer layer 11 shrinks when exposed to heat, and exerts an inward squeezing force on the outer layer 11 so that the inner surface of the outer layer 11 is in contact with the outer surface of the inner layer 13; at the same time , the outer layer 11 melts when exposed to heat and penetrates the pores of the reinforcing layer 12 to form a mutually embedded structure. In the exemplary examples shown in FIGS. 1 to 5 , the film layer is not shown. Those skilled in the art can understand that the film layer is a film-like structure covering the outer surface of the outer layer 11 and has the ability to shrink when exposed to heat. characteristics.

As an optional embodiment, after the medical catheter is prepared, the membrane layer can be removed; in other embodiments, after the medical catheter is prepared, the membrane layer can also be left on the outside of the medical catheter as a part of the medical catheter. surface. Those skilled in the art can configure the film layer according to actual conditions, and the present invention is not limited thereto.

As an optional example, the outer layer 11 is made of hot-melt material; the film layer is made of heat-shrinkable material. The outer layer 11 is made of one or more of polyether block polyamide, nylon, polytetrafluoroethylene, polyolefin, polyurethane and other materials with hot melt properties. Taking into account the difference in materials, the outer layer 11 is The second radial thickness varies between 0.002 and 0.005 inches; the film is made of tubing with heat shrink properties. In other examples, the outer layer 11 and the film layer can also be made of other materials with the same characteristics. Those skilled in the art can configure this according to actual conditions, and the present invention is not limited thereto.

In summary, the present invention provides a medical catheter, including: an outer layer and a reinforcing layer; the reinforcing layer has pores, the outer layer penetrates through the pores and wraps the reinforcing layer to fit with each other, and, The radial position of the reinforcing layer is defined by the outer layer.

The above description is only a description of the preferred embodiments of the present invention, and does not limit the scope of the present invention in any way. Any changes or modifications made by those of ordinary skill in the field of the present invention based on the above disclosure shall fall within the scope of the claims.

Claims

A medical catheter, characterized by including: an outer layer and a reinforcing layer;

The reinforcing layer has pores, the outer layer penetrates through the pores and wraps the reinforcing layer to fit with each other, and the radial position of the reinforcing layer is defined by the outer layer.
The medical catheter according to claim 1, wherein the ratio of the first thickness of the reinforcing layer in the radial direction to the second thickness of the outer layer in the radial direction is 0.2 to 0.9.
The medical catheter of claim 2, wherein the ratio of the first thickness of the reinforcing layer in the radial direction to the second thickness of the outer layer in the radial direction is 0.35 to 0.9. .
The medical catheter according to claim 2, wherein the ratio of the first thickness of the reinforcing layer in the radial direction to the second thickness of the outer layer in the radial direction is 0.5 to 0.75. .
The medical catheter of claim 1, wherein the inner edge of the reinforcement layer is flush with the inner surface of the outer layer.
The medical catheter according to claim 1, wherein the radial distance between the inner edge of the reinforcing layer and the inner surface of the outer layer is greater than 0.
The medical catheter according to claim 6, wherein the radial distance between the thickness centerline of the reinforcement layer in the radial direction and the inner surface of the outer layer is Y, and The second thickness of is L, and the first thickness of the reinforcement layer in the radial direction is 2D, then D/L≤Y/L<0.86.
The medical catheter according to claim 7, wherein 0.35≤Y/L≤0.65.
The medical catheter according to claim 7, wherein 0.49≤Y/L≤0.51.
The medical catheter according to claim 1, wherein the outer layer penetrates the pores and wraps the reinforcing layer after being heat-melted.
The medical catheter of claim 1, wherein the reinforcing layer includes any one of a braided structure, a coil, or a cut tube.
The medical catheter according to claim 1, wherein the medical catheter further includes an inner layer, and the outer surface of the inner layer abuts against the inner surface of the outer layer.
The medical catheter according to claim 12, wherein the medical catheter further includes a membrane layer, the membrane layer covers the outer surface of the outer layer and applies inward extrusion to the outer layer. force, So that the inner surface of the outer layer is in contact with the outer surface of the inner layer.
The medical catheter according to claim 12, wherein a film layer is used in the preparation process of the medical catheter, and the film layer covers the outer surface of the outer layer and applies an inward force to the outer layer. The extrusion force is used to make the inner surface of the outer layer fit with the outer surface of the inner layer. After the preparation is completed, the film layer is removed.
The medical catheter according to claim 13 or 14, wherein the outer layer is made of hot-melt material and the film layer is made of heat-shrinkable material.
The medical catheter of claim 1, wherein the first thickness of the reinforcing layer in the radial direction is in the range of 0.001 to 0.0045 inches.