Double-lumen catheter

Abstract

The invention provides a double-cavity catheter which comprises a catheter body, the catheter body comprises a hollow outer catheter and an inner catheter arranged in the outer catheter, the outer catheter and the inner catheter are arranged in a spaced mode, the inner catheter comprises an inner bonding layer, a metal braid layer and an inner high polymer material layer from inside to outside in the radial direction, and the inner bonding layer is arranged between the metal braid layer and the inner high polymer material layer. The metal braid layer is formed by weaving metal flat filaments, the thickness range of the metal flat filaments is 0.015-0.02 mm, and the width range of the metal flat filaments is 0.1-0.15 mm. According to the double-cavity catheter, the metal woven layer of the inner tube is formed by weaving the metal flat wires with the thickness of 0.015-0.02 mm and the width of 0.1-0.15 mm, under the limiting condition that the wall thickness of the inner tube is strictly controlled to be within 0.25 mm, excellent radial supporting force and bursting resistance can still be provided, the functional requirement for high-pressure injection of a contrast agent in an interventional operation is met, and the function of high-pressure injection of the contrast agent in the interventional operation is achieved. And the whole catheter is ultrathin and small, so that the catheter can pass through a 5Fr catheter sheath.

Description

Technical Field

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

[0002] In interventional medicine, double-lumen catheters are a key instrument, often used in complex surgeries requiring multiple procedures to be performed simultaneously, such as providing a delivery channel for microcatheters or guidewires while simultaneously injecting contrast agents or administering drugs. To adapt to the winding and narrow blood vessels within the human body and minimize damage to the vessel walls, an ideal catheter needs to have an extremely fine outer diameter, excellent flexibility, and the ability to maintain patency when navigating through tortuous blood vessels.

[0003] Traditional double-lumen catheters face significant challenges in achieving the aforementioned comprehensive performance. First, there is a trade-off between size and pressure resistance: to ensure that the catheter can withstand the high-pressure injections required during surgery (such as up to 1000 psi), it is usually necessary to increase the wall thickness or use a robust support structure. However, this inevitably leads to an increase in the overall outer diameter of the catheter, making it difficult to pass through thinner guiding sheaths or narrow lesion sites, thus limiting its application range.

[0004] Secondly, catheter collapse or wall wrinkling is prone to occur when passing through tortuous blood vessels: When the catheter tip needs to be bent to selectively enter the target blood vessel, the traditional outer tube structure is easily crushed or wrinkled at the bend due to insufficient radial support. This not only hinders the smooth flow of contrast agents or drugs through the outer lumen, affecting the surgical outcome, but the wrinkles may also damage the inner wall of the blood vessel or impede the advancement and retreat of the catheter itself. Although some techniques have attempted to reinforce the tube wall by adding metal wires, if the structural design or material selection is inappropriate, it is still difficult to achieve excellent resistance to bending deformation while maintaining an ultra-thin wall thickness (e.g., outer tube wall thickness less than 0.1 mm).

[0005] In view of this, it is necessary to improve the existing double-lumen catheters to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a dual-lumen catheter to solve the problem that existing catheters cannot simultaneously meet the requirements of ultra-thin wall thickness and resistance to bending deformation.

[0007] To achieve the above objectives, the present invention provides a double-lumen catheter, characterized in that: the double-lumen catheter includes a tube body, the tube body includes a hollow outer tube and an inner tube disposed inside the outer tube, the outer tube and the inner tube are spaced apart, the inner tube includes an inner bonding layer, a metal braided layer and an inner polymer material layer arranged radially from the inside to the outside, the metal braided layer is formed by braiding metal flat wires, the thickness of the metal flat wires ranges from 0.015 to 0.02 mm, and the width ranges from 0.1 to 0.15 mm.

[0008] As a further improvement of the present invention, the thickness of the metal flat wire is 0.02 mm and the width of the metal flat wire is 0.1 mm.

[0009] As a further improvement of the present invention, the material of the metal flat wire is stainless steel.

[0010] As a further improvement of the present invention, the metal flat wire is fused with the inner polymer material layer through a rheological process.

[0011] As a further improvement of the present invention, the outer tube includes an outer bonding layer, a metal winding layer and an outer polymer material layer arranged radially from the inside out, wherein the metal winding layer is formed by wrapping metal wires around the outer bonding layer in the form of a spring.

[0012] As a further improvement of the present invention, the metal wire is fused with the outer polymer material layer through a rheological process.

[0013] As a further improvement of the present invention, the metal wire is a tungsten wire.

[0014] As a further improvement of the present invention, the outer side of the outer tube is coated with a hydrophilic material.

[0015] As a further improvement of the present invention, the dual-lumen catheter further includes a Y-shaped connector and a stress diffusion tube connected to the Y-shaped connector, wherein the tube body is inserted into the stress diffusion tube and the Y-shaped connector and extends from the end of the stress diffusion tube away from the Y-shaped connector.

[0016] As a further improvement of the present invention, the portion of the tube body protruding from the stress diffusion tube is divided into a first segment, a second segment, and a third segment connected in sequence. The first segment is close to the stress diffusion tube. The outer polymer material layer of the outer tube corresponding to the first and second segments is made of Pebax 7233, the outer polymer material layer of the outer tube corresponding to the third segment is made of Pebax 5333, the inner polymer material layer of the inner tube corresponding to the first segment is made of a mixture of PA12 and Tr55, the inner polymer material layer of the inner tube corresponding to the second segment is made of Pebax 7233, and the inner polymer material layer of the inner tube corresponding to the third segment is made of Pebax 5333.

[0017] The beneficial effects of the present invention are as follows: The double-lumen catheter of the present invention uses metal flat wires with a thickness of 0.015-0.02 mm and a width of 0.1-0.15 mm to form the metal braided layer of the inner tube. Under the extreme condition of strictly controlling the inner tube wall thickness within 0.25 mm, it can still provide excellent radial support and burst resistance. It not only meets the functional requirements of high-pressure injection of contrast agents in interventional surgery, but also ensures the overall ultra-thin and miniaturized design of the catheter, enabling it to pass through a 5Fr catheter sheath. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0019] Figure 1 This is a schematic diagram of the structure of the double-lumen catheter of the present invention; Figure 2 yes Figure 1 Schematic diagram of the cross-sectional structure of AA; Figure 3 This is a partial cross-sectional schematic diagram of the tube body of the double-lumen catheter of the present invention; Figure 4 yes Figure 3 A magnified structural diagram of the extracted region.

[0020] Reference numerals: 100, double-lumen catheter; 1, tube body; 11, outer tube; 111, outer bonding layer; 112, metal wrapping layer; 113, outer polymer material layer; 12, inner tube; 121, inner bonding layer; 122, metal braided layer; 123, inner polymer material layer; 12, stress diffusion tube; 13, Y-type connector. Detailed Implementation

[0021] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, the technical features involved in the different embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0024] like Figures 1 to 4 As shown, the present invention provides a double-lumen catheter 100 including a tube body 1, the tube body 1 including a hollow outer tube 11 and an inner tube 12 disposed inside the outer tube 11, the outer tube 11 and the inner tube 12 being spaced apart, the inner tube 12 including an inner bonding layer 121, a metal braided layer 122 and an inner polymer material layer 123 arranged radially from the inside to the outside, the metal braided layer 122 being formed by braiding metal flat wires, the thickness of the metal flat wires being in the range of 0.015 to 0.02 mm and the width being in the range of 0.1 to 0.15 mm.

[0025] In this embodiment, the outer tube 11 and the inner tube 12 are spaced apart, meaning that there is at least a radial gap between them to form a cavity between them, and that they do not necessarily have to be coaxial.

[0026] In addition, the double-lumen catheter 100 in this embodiment is preferably intended for use when the inner wall thickness is 0.25 mm.

[0027] Compared to existing 0.025mm thick metal flat wires, this thickness of metal flat wire allows for a reduction in the thickness of the inner tube 12, combined with a width range of 0.1–0.15mm. This provides stronger radial support, ensuring that the inner tube 12 can withstand burst pressures up to 1000 psi even with the wall thickness strictly controlled within 0.25mm, meeting the functional requirements for high-pressure injection of contrast agents in interventional procedures. Metal wires with a thickness less than 0.015mm are difficult to mass-produce, and the cost of 0.015mm thick metal wires is significantly higher than that of 0.02mm thick metal wires. Metal flat wires with a width greater than 0.15mm have poor flexibility and are prone to breakage.

[0028] The present invention tests the strength of the inner tube 12 through experiments.

[0029] The test method is as follows: Cut a 40cm length of inner tube 12 and place it on two support points 20cm apart. Apply downward pressure to the middle of the inner tube 12 to bend the inner tube 12 downward to a position of 5cm. Record the applied force value. In this embodiment, the inner polymer material layer 123 of the inner tube 12 is selected as PA12+TR55 mixture.

[0030] The test results are as follows:

[0031] The test result must be at least 15N or higher, and the corresponding inner tube 12 can meet the usage requirements.

[0032] By comparing test data from different size combinations, it was determined that a metal flat wire with a thickness of 0.02 mm and a width of 0.1 mm is the optimal choice considering the overall processing difficulty, cost, and support strength, while meeting the performance requirement (15 N). This indicates that the technical solution not only boasts excellent performance but also takes into account the feasibility and economy of actual production, giving the product commercial value. Therefore, in this embodiment, the thickness of the metal flat wire is 0.02 mm, and the width of the metal flat wire is 0.1 mm. The metal flat wire of the preferred size allows the inner tube 12 to withstand a pressure of 19 N while only bending to the designated position, far exceeding the minimum requirement of 15 N. This strong support force ensures that the catheter will not collapse or twist when advanced through the winding blood vessels in the body, ensuring unobstructed access and smooth delivery of the instrument.

[0033] The material of the metal flat wire is stainless steel. By using hardened stainless steel as the material of the metal flat wire, the inner tube 12 is provided with excellent radial support and tensile strength, ensuring that the catheter can still withstand burst pressure of up to 1000 psi under the extreme condition of ultra-thin wall thickness (≤0.25mm), meeting the functional requirements such as high-pressure injection of contrast agents in interventional surgery.

[0034] The metal flat wires are fused to the inner polymer material layer 123 via a rheological process. This fusion achieves a strong bond between the metal braided layer 122 and the polymer layer, effectively enhancing the overall structural strength and interlayer bonding of the inner tube 12, avoiding the risk of delamination, and thus ensuring the structural integrity and reliability of the conduit under high pressure with ultra-thin walls.

[0035] The outer tube 11 includes, from the inside out, an outer bonding layer 111, a metal winding layer 112, and an outer polymer material layer 113. The metal winding layer 112 is formed by wrapping metal wire around the outer bonding layer 111 in a spring-like manner. The spring-like manner allows the metal wire to rotate and form a helical spring. It should be emphasized that although it is called the outer bonding layer 111, the outer bonding layer 111 is located at the innermost part of the outer tube 11.

[0036] By incorporating a spring-like metal wrapping layer 112 in the middle layer of the outer tube 11, the problem of wrinkling, folding, or breakage that easily occurs when the tip of a traditional thin-walled outer tube 11 is bent is fundamentally solved. The metal wrapping layer 112 structure provides excellent radial support and flexibility to the outer tube 11, ensuring that the lumen remains unobstructed and does not collapse when the catheter is bent, while also preventing wrinkles on the surface of the outer tube 11 that obstruct blood flow, thus significantly reducing the risk of thrombosis in clinical use. Simultaneously, this design, while achieving functional support, maximizes the control of the wall thickness of the outer tube 11, contributing to the goal of miniaturizing the overall outer diameter of the catheter to ≤1.80mm, allowing it to be fitted with a 5Fr catheter sheath.

[0037] The metal wire is fused with the outer polymer material layer 113 through a rheological process, achieving a firm bond between the metal winding layer 112 and the outer polymer material layer 113. This effectively enhances the overall structural integrity and interlayer bonding force of the outer tube 11, avoiding wrinkles or folds caused by interlayer peeling when bending the head end. This ensures that the conduit still has excellent bending performance and anti-wrinkle ability even with ultra-thin walls.

[0038] The metal wire is a tungsten wire. When a tungsten wire is used, the visualization of the catheter under DSA is also enhanced.

[0039] The outer side of the outer tube 11 is coated with a hydrophilic material, which provides excellent lubrication for the guidewire to pass through the inside and outside of the catheter, significantly reducing the friction between the catheter and the blood vessel wall when it travels in the blood vessel, thereby improving the smoothness of the surgical operation and reducing damage to the blood vessel tissue.

[0040] The dual-lumen catheter 100 further includes a Y-shaped connector and a stress-diffusing tube connected to the Y-shaped connector. The tube body 1 is inserted into the stress-diffusing tube and the Y-shaped connector and extends from the end of the stress-diffusing tube away from the Y-shaped connector. The proximal end of the tube body 1 is sequentially inserted into and fixed inside the stress-diffusing tube and the Y-shaped connector, and finally extends from the end of the stress-diffusing tube away from the Y-shaped connector, entering the human blood vessel. The Y-shaped connector serves as the operating end, providing an independent channel interface for the internal and external lumens.

[0041] The portion of the tube body 1 protruding from the stress diffusion tube is divided into a first section, a second section, and a third section connected in sequence. The first section is close to the stress diffusion tube. The outer polymer material layer 113 of the outer tube 11 corresponding to the first and second sections is made of Pebax 7233. The outer polymer material layer 113 of the outer tube 11 corresponding to the third section is made of Pebax 5333. The inner polymer material layer 123 of the inner tube 12 corresponding to the first section is made of a mixture of PA12 and Tr55. The inner polymer material layer 123 of the inner tube 12 corresponding to the second section is made of Pebax 7233. The inner polymer material layer 123 of the inner tube 12 corresponding to the third section is made of Pebax 5333.

[0042] Strength tests are conducted on different materials.

[0043] The test method is as follows: Cut a 40cm length of inner tube 12 and place it on two support points 20cm apart. Apply downward pressure to the middle of the inner tube 12 to bend it downward to a position of 5cm. Record the applied force value. In this embodiment, the size of the metal wire of the inner tube 12 is selected as 0.02mm×0.1mm.

[0044] The test results are as follows:

[0045] It is evident that different materials require different pressures to achieve the same shape. In the case of using only PA12 in the first section, the supporting force of the inner tube 12 is insufficient to achieve the desired effect. Therefore, a mixture of PA12 and TR55 is considered for the first section.

[0046] By dividing the tube body 1 extending from the stress diffusion tube, i.e. the flexible working section entering the blood vessel, into the first, second, and third sections, and matching polymer materials of different hardness to different sections, the mechanical properties of the catheter with a gradual change from rigidity to flexibility from the proximal end to the distal end are achieved.

[0047] Specifically, the proximal end of the catheter (the first segment) possesses sufficient pushing force and torque transmission efficiency to ensure stable movement within the blood vessel; while the distal end (the third segment) is exceptionally flexible, significantly reducing the risk of irritation and damage to the vessel wall from the catheter tip. This allows for safe passage through tortuous vascular pathways and adaptation to their anatomical morphology, thereby enhancing surgical safety and maneuverability. This segmented structure is a key technological solution for achieving the goal of gradually softening the catheter.

[0048] The dual-lumen catheter 100 of this invention uses a metal braided layer 122 formed by braiding metal flat wires with a thickness of 0.015-0.02 mm and a width of 0.1-0.15 mm to create the inner tube 12. Under the extreme condition of strictly controlling the wall thickness of the inner tube 12 to within 0.25 mm, it can still provide excellent radial support and burst resistance. This not only meets the functional requirements of high-pressure injection of contrast agents in interventional surgery, but also ensures the overall ultra-thin and miniaturized design of the catheter, allowing it to pass through a 5Fr catheter sheath. At the same time, the outer tube 11 is composited with a spring-loaded metal wire layer and a polymer material, which effectively avoids wrinkling, folding, or breakage problems when the tip is bent. Combined with the segmented rigid-flexible gradient design of the tube body 1 and the hydrophilic coating, the catheter's pushability, flexibility, imaging properties, and smoothness of operation are further improved. Overall, it achieves a unity of high performance, high safety, and high reliability with an extremely thin wall thickness.

[0049] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0050] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A double-lumen catheter, characterized in that: The double-lumen catheter includes a tube body, which includes a hollow outer tube and an inner tube disposed inside the outer tube. The outer tube and the inner tube are spaced apart. The inner tube includes an inner bonding layer, a metal braided layer and an inner polymer material layer arranged radially from the inside to the outside. The metal braided layer is formed by braiding metal flat wires. The thickness of the metal flat wires ranges from 0.015 to 0.02 mm and the width ranges from 0.1 to 0.15 mm.

2. The double-lumen catheter according to claim 1, characterized in that: The thickness of the metal flat wire is 0.02 mm, and the width of the metal flat wire is 0.1 mm.

3. The double-lumen catheter according to claim 1, characterized in that: The material of the metal flat wire is stainless steel.

4. The double-lumen catheter according to claim 1, characterized in that: The metal flat wire is fused to the inner polymer material layer through a rheological process.

5. The double-lumen catheter according to claim 1, characterized in that: The outer tube includes an outer bonding layer, a metal winding layer, and an outer polymer material layer arranged radially from the inside out. The metal winding layer is formed by wrapping metal wire around the outer bonding layer in the form of a spring.

6. The double-lumen catheter according to claim 5, characterized in that: The metal wire is fused to the outer polymer material layer through a rheological process.

7. The double-lumen catheter according to claim 5, characterized in that: The metal wire is a tungsten wire.

8. The double-lumen catheter according to claim 5, characterized in that: The outer side of the outer tube is coated with a hydrophilic material.

9. The double-lumen catheter according to claim 1, characterized in that: The dual-lumen catheter further includes a Y-shaped connector and a stress diffusion tube connected to the Y-shaped connector. The tube body is inserted into the stress diffusion tube and the Y-shaped connector and extends from the end of the stress diffusion tube away from the Y-shaped connector.

10. The double-lumen catheter according to claim 9, characterized in that: The portion of the tube body protruding from the stress diffusion tube is divided into a first section, a second section, and a third section connected in sequence. The first section is close to the stress diffusion tube. The outer polymer material layer of the outer tube corresponding to the first and second sections is made of Pebax 7233, and the outer polymer material layer of the outer tube corresponding to the third section is made of Pebax 5333. The inner polymer material layer of the inner tube corresponding to the first section is made of a mixture of PA12 and Tr55, the inner polymer material layer of the inner tube corresponding to the second section is made of Pebax 7233, and the inner polymer material layer of the inner tube corresponding to the third section is made of Pebax 5333.

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