Medical catheter

Abstract

The present application provides a medical catheter, which comprises an outer layer and a reinforcing layer; the reinforcing layer has apertures, the outer layer penetrates through the apertures and wraps the reinforcing layer to be mutually embedded, and the radial position of the reinforcing layer is defined by the outer layer. In this configuration, by defining the radial position of the reinforcing layer in the outer layer, the stability of the catheter in the processing process is improved; at the same time, on the basis of not affecting the physical performance and clinical safety of the catheter, the wall thickness of the catheter is reduced, and the design of large cavity and thin wall is achieved.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a medical catheter. Background Technology

[0002] Interventional therapy, due to its fewer side effects compared to traditional surgery, has become a popular treatment option for many diseases. In all interventional procedures, medical catheters are the cornerstone of successful execution. They act as a channel during the procedure, allowing doctors to deliver specific medical instruments to designated locations and treat the patient.

[0003] Taking intracranial neurointerventional therapy as an example, the characteristics of intracranial blood vessels dictate that the medical catheters serving them need to have flexible tips to avoid damaging intracranial blood vessels. Existing catheters typically have a three-layer structure: an inner layer, a reinforcing layer, and an outer layer. Factors affecting the flexibility of the catheter include: 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 existing clinical feedback analysis, doctors prefer to use catheters with large inner lumens and thin walls in interventional procedures. This allows doctors to deliver large-sized medical devices for treatment using the catheter lumen, even when the outer diameter of the catheter is limited by the size of the patient's blood vessels. In addition, the design of a large inner lumen can also optimize the delivery performance of medical devices within the catheter.

[0004] In summary, medical catheters need to possess the following characteristics: (1) a flexible tip; and (2) a large lumen and thin walls. Currently available catheters are designed to meet clinical needs by having a very large lumen space and extremely thin walls within the constraints of vascular specifications. However, this extremely thin wall thickness results in poor physical support, making the catheter highly susceptible to bending. Furthermore, the reinforcing layer of the coil structure leads to low peak tensile strength test values, resulting in a large number of distal fracture incidents in clinical practice. This poses a significant challenge to the product's manufacturing process and the quality of the finished product. Summary of the Invention

[0005] The purpose of this invention is to provide a medical catheter that solves the problem that existing catheters cannot simultaneously meet the requirements of a large lumen and thin wall structure and good physical properties, while also solving the problem of instability in the processing technology of the prior art, which affects the quality of the finished product.

[0006] To achieve the above objectives, the present invention provides a medical catheter, comprising: an outer layer and a reinforcing layer;

[0007] The reinforcing layer has pores, the outer layer penetrates through the pores and wraps around the reinforcing layer to fit together, and the radial position of the reinforcing layer is defined by the outer layer.

[0008] Optionally, the ratio of the first radial thickness of the reinforcing layer to the second radial thickness of the outer layer is 0.2 to 0.9.

[0009] Optionally, the ratio of the first radial thickness of the reinforcing layer to the second radial thickness of the outer layer is 0.35 to 0.9.

[0010] Optionally, the ratio of the first radial thickness of the reinforcing layer to the second radial thickness of the outer layer is 0.5 to 0.75.

[0011] Optionally, the inner edge of the reinforcing layer is flush with the inner surface of the outer layer.

[0012] Optionally, the radial distance between the inner edge of the reinforcing layer and the inner surface of the outer layer is greater than 0.

[0013] Optionally, the radial distance between the centerline of the thickness of the reinforcing 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 first thickness of the reinforcing layer in the radial direction is 2D, then D / L≤Y / L<0.86.

[0014] Optional, 0.35≤Y / L≤0.65.

[0015] Optional, 0.49≤Y / L≤0.51.

[0016] Optionally, the outer layer is heat-melted, penetrates the pores, and wraps around the reinforcing layer.

[0017] Optionally, the reinforcing layer may include any one of a braided structure, a coil, or a cut tube.

[0018] Optionally, the medical catheter further includes an inner layer, the outer surface of which abuts against the inner surface of the outer layer.

[0019] Optionally, the medical catheter further includes a membrane layer that covers the outer surface of the outer layer and applies an inward compressive force to the outer layer so that the inner surface of the outer layer adheres to the outer surface of the inner layer.

[0020] Optionally, the medical catheter uses a membrane layer during the manufacturing process. The membrane layer covers the outer surface of the outer layer and applies an inward pressing force to the outer layer so that the inner surface of the outer layer adheres to the outer surface of the inner layer. After the manufacturing process is completed, the membrane layer is removed.

[0021] Optionally, the outer layer is made of a hot-melt material; the film layer is made of a heat-shrinkable material.

[0022] In summary, the present invention provides a medical catheter comprising: an outer layer and a reinforcing layer; the reinforcing layer having pores, the outer layer penetrating through the pores and wrapping the reinforcing layer to interlock with each other, and the radial position of the reinforcing layer being defined by the outer layer.

[0023] This configuration, by limiting the radial position of the reinforcing layer in the outer layer, improves the stability of the catheter in terms of manufacturing process; at the same time, without affecting the physical properties and clinical safety of the catheter, it reduces the wall thickness of the catheter, achieving a design with a large lumen and thin walls. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a medical catheter according to an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of another structure of the medical catheter according to an embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram illustrating a scenario where the ratio of the thickness of the reinforcing layer to the thickness of the outer layer exceeds the range of thickness ratios in an embodiment of the present invention.

[0027] Figure 4 This is a schematic diagram illustrating the situation where the Y / L ratio exceeds the position ratio range according to an embodiment of the present invention;

[0028] Figure 5 This is a schematic diagram of a Y / L ratio below the position ratio range in an embodiment of the present invention.

[0029] The labels in the attached figures are explained as follows:

[0030] 11-Outer layer; 12-Reinforcing layer; 13-Inner layer. Detailed Implementation

[0031] To make the objectives, advantages, and features of this invention clearer, the 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 all in a very simplified form and are not drawn to scale, and are only used to facilitate and clarify the explanation of the embodiments of this invention. Furthermore, the structures shown in the drawings are often part of the actual structures. In particular, different figures may emphasize different aspects and may sometimes use different scales.

[0032] As used herein, the singular forms “a,” “an,” and “the” include plural objects; the term “or” is generally used to mean “and / or”; the term “a number” is generally used to mean “at least one”; and the term “at least two” is generally used to mean “two or more”. Furthermore, the terms “first,” “second,” and “third” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as “first,” “second,” or “third” may explicitly or implicitly include one or at least two of that feature. “One end” and “the other end,” and “proximal end” and “distal end” generally refer to two corresponding parts, including not only endpoints. “Proximal end” generally represents the direction closer to the surgeon during surgery, and “distal end” generally represents the direction closer to the lesion during surgery. The terms “installed,” “connected,” and “joined” should be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral part; as a direct connection or an indirect connection through an intermediate medium; or as a connection within two components or an interaction between two components. Furthermore, as used in this specification, the phrase "one element is disposed on another element" generally only indicates that there is a connection, coupling, cooperation, or transmission relationship between the two elements, and the connection, coupling, cooperation, or transmission between the two elements can be direct or indirect through an intermediate element. It should not be construed as indicating or implying a spatial positional relationship between the two elements, i.e., one element can be located arbitrarily inside, outside, above, below, or to the side of another element, unless otherwise explicitly stated. The terms "above," "below," "top," and "bottom" generally refer to relative positional relationships arranged according to the direction of gravity; the terms "vertical" or "vertical direction" generally refer to the direction of gravity, which is generally perpendicular to the ground; "horizontal" or "horizontal plane direction" generally refers to a direction parallel to the ground. Those skilled in the art can understand the specific meaning of the above terms in this specification according to the specific circumstances.

[0033] The purpose of this invention is to provide a medical catheter that solves the problem that existing catheters cannot simultaneously meet the requirements of a large lumen and thin wall structure and good physical properties, while also solving the problem of instability in the processing technology of the prior art, which affects the quality of the finished product.

[0034] The following description refers to the accompanying drawings.

[0035] Please refer to Figures 1 to 2 This invention provides a medical catheter, comprising: an outer layer 11 and a reinforcing layer 12; the reinforcing layer 12 has pores, the outer layer 11 penetrates through the pores and wraps around the reinforcing layer 12 for interlocking, and the radial position of the reinforcing layer 12 is defined by the outer layer 11. It should be noted that... Figures 1 to 5In the illustrated example, radial direction refers to the vertical direction, and axial direction refers to the horizontal direction. The outer layer 11 penetrates through the pores and wraps around the reinforcing layer 12, forming an interlocking structure. In the same catheter, the inner edge of the reinforcing layer 12 can be flush with the inner surface of the outer layer 11, or it can form a certain radial distance from the inner surface of the outer layer 11. The radial position of the reinforcing layer 12 is restricted by the interlocking structure formed by the penetration and wrapping of the outer layer 11. The filaments in the reinforcing layer 12 do not extend along the axial direction of the outer layer 11, but extend in a direction that makes an angle with the axial direction of the outer layer 11. This embodiment solves problems such as filament leakage that occur during catheter production by controlling the position ratio of the reinforcing layer 12 in the outer layer 11 and the radial thickness ratio of the reinforcing layer 12 to the outer layer 11, thereby improving the stability of the catheter manufacturing process. At the same time, without affecting the physical properties and clinical safety of the catheter, it meets the design effect of a large lumen and thin wall, so that the catheter simultaneously meets the requirements of a large lumen, thin wall, and good physical properties.

[0036] As an optional implementation, the ratio of the first radial thickness of the reinforcing layer 12 to the second radial thickness of the outer layer 11 is 0.2 to 0.9, where the first thickness refers to the distance between the outer surface and the inner surface of the reinforcing layer 12, and the second thickness refers to the distance between the outer surface and the inner surface of the outer layer 11. Further, when both the first radial thickness of the reinforcing layer 12 and the second radial thickness of the outer layer 11 are small, the thickness ratio range can be adjusted to 0.35 to 0.9. Even further, when both the first radial thickness of the reinforcing layer 12 and the second radial thickness of the outer layer 11 are large, 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 reinforcing layer 12; different materials are suitable for different thickness ratio ranges. However, it is necessary to ensure that when within the above-mentioned thickness ratio range, the reinforcing layer 12 is less prone to yarn leakage and can better balance flexibility and support.

[0037] Please refer to Figure 1 and Figure 3 The inner edge of the reinforcing layer 12 is flush with the inner surface of the outer layer 11 and the outer surface of the inner layer 13. Figure 1 In the illustrated example, the inner surface of the outer layer 11 and the outer surface of the inner layer 13 abut against each other, the inner edge of the reinforcing layer 12 is flush with the inner surface of the outer layer 11, and the inner edge of the reinforcing layer 12 is also on the same plane as the outer surface of the inner layer 13. Furthermore, the ratio of the first radial thickness of the reinforcing layer 12 to the second radial thickness of the outer layer 11 is within a suitable range. In this case, the reinforcing layer 12 will not exhibit defects such as missing threads. Figure 3In the illustrated example, the ratio of the first radial thickness of the reinforcing layer 12 to the second radial thickness of the outer layer 11 is 0.95, exceeding the upper limit of the thickness ratio range. This causes all the material of the outer layer 11 to penetrate the pores of the reinforcing layer 12 during processing, resulting in a portion of the reinforcing layer 12 being exposed outside the outer surface of the outer layer 11, leading to defects such as wire leakage. At the same time, an excessively high thickness ratio of the reinforcing layer 12 results in insufficient flexibility of the catheter, making it prone to puncturing or scratching blood vessels. In other embodiments, the ratio of the first radial thickness of the reinforcing layer 12 to the second radial thickness of the outer layer 11 is 0.1, which is lower than the lower limit of the thickness ratio range. This results in insufficient overall support and anti-collapse performance of the catheter, making it prone to retraction or collapse during delivery and treatment.

[0038] Please refer to Figure 2 The radial distance between the inner edge of the reinforcing layer 12 and the inner surface of the outer layer 11 is greater than 0. It should be noted that, regardless of whether the inner edge of the reinforcing layer 12 is flush with the inner surface of the outer layer 11 or the radial distance is greater than 0, the ratio of the first radial thickness of the reinforcing layer 12 to the second radial thickness of the outer layer 11 must be within the range of 0.2 to 0.9.

[0039] Please refer to Figure 2 as well as Figures 4 to 5 The radial distance between the centerline of the thickness of the reinforcing layer 12 and the inner surface of the outer layer 11 is Y. The second radial thickness of the outer layer 11 is L, and the first radial thickness of the reinforcing layer 12 is 2D. Therefore, D / L ≤ Y / L < 0.86. It should be noted that the radial thickness centerline of the reinforcing layer 12 is defined as the point located on the centerline whose radial distance to the inner edge of the reinforcing layer 12 is equal to its radial distance to the outer edge of the reinforcing layer 12. Figure 1 In the illustrated example, D / L = Y / L, meaning that when the inner edge of the reinforcing layer 12 is flush with the inner surface of the outer layer 11, the ratio of the radial distance from the radial thickness centerline of the reinforcing layer 12 to the inner surface of the outer layer 11 to the radial second thickness of the outer layer 11 is also within a suitable positional ratio range; simultaneously, in Figure 2 as well as Figures 4 to 5 In the exemplary case, the ratio of the first radial thickness of the reinforcing layer 12 to the second radial thickness of the outer layer 11 is in the range of 0.2 to 0.9. Figure 4 In the example shown, Y / L exceeded the upper limit of the position ratio range, causing a portion of the reinforcing layer 12 to be exposed outside the outer surface of the outer layer 11, resulting in defects such as wire leakage; Figure 5In the example shown, Y / L is below the lower limit of the position ratio range, causing the inner edge of the reinforcing layer 12 to be outside the inner surface of the outer layer 11. Considering the influence of the fluidity of the outer layer 11 material, the portion of the inner edge of the reinforcing layer 12 that extends beyond the inner surface of the outer layer 11 is not filled with the outer layer 11 material, thereby increasing the wall thickness of the catheter and failing to achieve the design effect of a large lumen and thin wall.

[0040] Furthermore, when both 2D and L are small, i.e., when the first radial thickness of the reinforcing layer 12 and the second radial thickness of the outer layer 11 are both small, for example, when a reinforcing layer 12 with a thickness of 0.001 inches needs to be integrated into an outer layer 11 with a thickness of 0.002 inches, the ratio of the radial distance Y from the centerline of the thickness of the reinforcing layer 12 to the inner surface of the outer layer 11 to the second radial thickness L of the outer layer 11 should be controlled within the range of 0.35 to 0.65. Even further, when both 2D and L are large, i.e., when the first radial thickness of the reinforcing layer 12 and the second radial thickness of the outer layer 11 are both large, for example, when a reinforcing layer 12 with a thickness of 0.0045 inches needs to be integrated into an outer layer 11 with a thickness of 0.005 inches, the ratio of the radial distance Y from the centerline of the thickness of the reinforcing layer 12 to the inner surface of the outer layer 11 to the second radial thickness L of the outer layer 11 should be controlled within the range of 0.49 to 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 reinforcing layer 12. Different materials and thicknesses are suitable for different position ratio ranges. However, it is necessary to ensure that when the position ratio is within the above range, the reinforcing layer 12 is less likely to leak and can achieve the technical effect of a large catheter lumen and thin wall.

[0041] As an optional embodiment, the outer layer 11, after being heated and melted, penetrates the pores and wraps around the reinforcing layer 12. With this configuration, after the outer layer 11 is heated and melted, it flows into the pores of the reinforcing layer 12 and wraps around it to form an interlocking structure. It should be noted that in some other embodiments, the interlocking structure of the outer layer 11 and the reinforcing layer 12 can also be achieved through methods such as condensation shrinkage or chemical reagent soaking. Those skilled in the art can configure it according to the actual situation, and the present invention is not limited thereto.

[0042] In a preferred embodiment, the reinforcing layer 12 comprises any one of a braided structure, a coil, or a cut tube. The reinforcing layer 12 is made of one or more filamentary materials selected from stainless steel, nickel-titanium alloy, cobalt-chromium alloy, and polymers. Considering the different materials and structures, the initial radial thickness of the reinforcing layer 12 may vary within the range of 0.001 to 0.0045 inches. Of course, in other examples, the material and structure of the reinforcing layer 12 may be other reasonable forms. Those skilled in the art can select appropriate materials and structures according to the actual situation, and the present invention is not limited thereto.

[0043] Please refer to Figures 1 to 5 The medical catheter further includes an inner layer 13, the outer surface of which abuts against the inner surface of the outer layer 11. The inner layer 13 is made of one or more materials selected from Pebax nylon elastomer, nylon, polyurethane PU, polytetrafluoroethylene PTFE, high-density polyethylene HDPE, Pebax nylon elastomer mixed with additives to reduce the coefficient of friction, or polyolefin elastomer. Those skilled in the art can select appropriate materials according to the different uses of the catheter, and the present invention is not limited thereto.

[0044] Furthermore, the medical catheter also includes a membrane layer during its fabrication. This membrane layer covers the outer surface of the outer layer 11 and applies an inward compressive force to the outer layer 11, causing the inner surface of the outer layer 11 to adhere to the outer surface of the inner layer 13. With this configuration, the membrane layer covering the outer surface of the outer layer 11 shrinks upon heating, applying an inward compressive force to the outer layer 11, causing the inner surface of the outer layer 11 to adhere to the outer surface of the inner layer 13; simultaneously, the outer layer 11 melts upon heating and penetrates the pores of the reinforcing layer 12 to form an interlocking structure. Figures 1 to 5 In the illustrated example, the membrane layer is not shown. As those skilled in the art will understand, the membrane layer is a membrane-like structure covering the outer surface of the outer layer 11, which has the property of shrinking when heated.

[0045] As an optional embodiment, the membrane layer can be removed after the medical catheter is prepared; in other embodiments, the membrane layer may remain on the outer surface of the medical catheter as part of the catheter after preparation. Those skilled in the art can configure the membrane layer according to actual conditions, and the present invention is not limited thereto.

[0046] As an optional example, the outer layer 11 is made of a hot-melt material; the film layer is made of a heat-shrinkable material. The outer layer 11 is made of one or more materials with hot-melt properties, such as polyether block polyamide, nylon, polytetrafluoroethylene, polyolefin, and polyurethane. Depending on the material, the second thickness of the outer layer 11 in the radial direction varies between 0.002 and 0.005 inches. The film layer is made of a tubular material with heat-shrinkable properties. In other examples, the outer layer 11 and the film layer may also be made of other materials with the same properties. Those skilled in the art can configure them according to the actual situation, and the present invention is not limited thereto.

[0047] In summary, the present invention provides a medical catheter comprising: an outer layer and a reinforcing layer; the reinforcing layer having pores, the outer layer penetrating through the pores and wrapping the reinforcing layer to interlock with each other, and the radial position of the reinforcing layer being defined by the outer layer.

[0048] This configuration, by limiting the radial position of the reinforcing layer in the outer layer, improves the stability of the catheter in terms of manufacturing process; at the same time, without affecting the physical properties and clinical safety of the catheter, it reduces the wall thickness of the catheter, achieving a design with a large lumen and thin walls.

[0049] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A medical catheter, characterized in that, include: Outer layer and reinforcing layer; The reinforcing layer has pores, the outer layer penetrates through the pores and wraps around the reinforcing layer to fit together, and the radial position of the reinforcing layer is defined by the outer layer; The radial distance between the inner edge of the reinforcing layer and the inner surface of the outer layer is greater than 0; The radial distance between the centerline of the thickness of the reinforcing 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 first thickness of the reinforcing layer in the radial direction is 2D. Then D / L < Y / L, 0.35 ≤ Y / L < 0.

86. The medical catheter also includes an inner layer, the outer surface of which abuts against the inner surface of the outer layer; The medical catheter also includes a membrane layer that covers the outer surface of the outer layer and applies an inward compressive force to the outer layer so that the inner surface of the outer layer fits against the outer surface of the inner layer. The medical catheter uses a membrane layer during its fabrication process, which is removed after fabrication is complete.

2. The medical catheter as described in claim 1, characterized in that, The ratio of the first radial thickness of the reinforcing layer to the second radial thickness of the outer layer is 0.2 to 0.

9.

3. The medical catheter as described in claim 2, characterized in that, The ratio of the first radial thickness of the reinforcing layer to the second radial thickness of the outer layer is 0.35 to 0.

9.

4. The medical catheter as described in claim 2, characterized in that, The ratio of the first radial thickness of the reinforcing layer to the second radial thickness of the outer layer is 0.5 to 0.

75.

5. The medical catheter as described in claim 1, characterized in that, Y / L≤0.

65.

6. The medical catheter as described in claim 1, characterized in that, 0.49≤Y / L≤0.

51.

7. The medical catheter as described in claim 1, characterized in that, The outer layer penetrates the pores and wraps around the reinforcing layer after being heat-melted.

8. The medical catheter as described in claim 1, characterized in that, The reinforcing layer includes any one of a braided structure, a coil, or a cut tube.

9. The medical catheter as described in claim 1, characterized in that, The outer layer is made of a hot-melt material; the film layer is made of a heat-shrinkable material.

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