Radio frequency closed catheter and manufacturing method thereof

Abstract

The invention discloses a radio frequency closed catheter and a manufacturing method thereof, and relates to the technical field of medical instruments.The radio frequency closed catheter comprises an inner film, the inner film is composed of a left section and a right section, a heating wire is wound on the outer surface of the right section of the inner film, a spiral coil is wound on the outer surface of the left section of the inner film, and the outer surface of the spiral coil is wrapped with a woven mesh; and outer membranes are arranged on the outer surfaces of the woven mesh at the left section and the heating wire at the right section of the inner membrane. Due to the existence of the metal ring net, the catheter is not easy to fold to form creases in use so as to influence use, and compared with an existing catheter adopting a PI (Polyimide) or PEEK (Polyether Ether Ketone) tube design, the whole structure is smaller in bending radius, low in rigidity, easy to push in tortuous veins, large in internal aperture, and capable of supporting thrombus aspiration or passing through other required instruments such as guide wires; meanwhile, the liquid injection function can be achieved through the guide pipe, the low-impedance copper-nickel flat wire heating body is suitable for low-voltage driving equipment, and the safety performance is higher.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a radiofrequency closure catheter and its manufacturing method. Background Technology

[0002] A radiofrequency ablation catheter is a medical device used for minimally invasive treatment of varicose veins. It delivers radiofrequency energy to the affected vein through a catheter, causing the vein wall to contract and close due to heat, thus achieving the therapeutic goal. The catheter typically consists of a long, flexible catheter, a switch, a Luer adapter, and a connecting cable. It is a single-use product and is sterilized with ethylene oxide. It requires the use of a dedicated radiofrequency generator (such as a ClosureRFG radiofrequency generator). The generator controls the energy output and delivers the energy to the venous tissue through a heating element at the catheter tip, while simultaneously providing real-time temperature feedback to ensure treatment accuracy. The radiofrequency ablation catheter is primarily used for the treatment of varicose veins of the great saphenous vein in the lower extremities (limited to superficial veins). Under ultrasound guidance, the doctor inserts the catheter into the affected vein through a small incision in the skin. The heat generated by the radiofrequency energy (typically raising the local tissue temperature to 60-120 degrees Celsius) selectively destroys the vascular endothelium and collagen, leading to venous intimal damage, collagen contraction, and thrombosis, ultimately achieving permanent closure of the vein. This method is a minimally invasive treatment, causing less damage compared to traditional surgery, and is characterized by high efficiency, safety, and rapid recovery.

[0003] Currently, there are various models of radiofrequency closure catheters on the market, such as Medtronic's CF7-7-60, all of which require operation by professionals in medical institutions.

[0004] Existing products consist of PI and / or PEEK catheters, with a copper-nickel alloy wire wound around one end of the catheter to form a heating element. Current varicose vein treatments mostly use AC drives ranging from tens to 500kHz, with peak voltages often exceeding 60Vrms or even reaching 100Vrms.

[0005] The catheter body is mostly made of PI and / or PEEK materials. Its structural strength and bending characteristics are determined by these two materials, as they are relatively hard and thick, making them prone to folding during bending. The heating element is a tightly wound constantan wire with an impedance of 20–150Ω, driven by radio frequency at several hundred kHz. Both internal and external tubing support and fixation are required. The catheter has poor bending performance, and the heating element is too rigid, resulting in poor passage through tortuous veins. When the outer skin is broken during unpacking or use, there is a risk of electric shock to the patient. Furthermore, its core diameter is small and only suitable for guiding the guidewire, making it unsuitable for thrombus aspiration. Moreover, residual thrombi that move are a major cause of postoperative complications. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a radiofrequency closure catheter and its manufacturing method, thus solving the problems mentioned in the background section.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a radiofrequency closure catheter, comprising an inner membrane, the inner membrane being composed of left and right sections, a heating wire being wound around the outer surface of the right section of the inner membrane, a spiral coil being wound around the outer surface of the left section of the inner membrane, a woven mesh being wrapped around the outer surface of the spiral coil, and an outer membrane being provided on the outer surface of the woven mesh of the left section of the inner membrane and the heating wire of the right section.

[0008] Furthermore, the inner membrane is composed of PTFE and / or PEBAX materials.

[0009] Furthermore, the outer membrane is composed of PTFE and / or PEBAX materials.

[0010] Furthermore, the spiral ring is made of stainless steel or nickel-titanium alloy, making it difficult to bend.

[0011] Furthermore, the woven mesh is made of stainless steel or nickel-titanium alloy, making it difficult to bend.

[0012] Furthermore, the inner diameter of the inner membrane tube is the same as that of a conventional aspiration catheter. With the same outer diameter, the larger inner diameter can be used for thrombus aspiration, fluid injection, and other equipment access.

[0013] Furthermore, the heating wire is composed of copper-nickel alloy flat wire, with a significantly increased cross-sectional area compared to existing heating element round wires, thus also possessing better support strength.

[0014] Furthermore, the heating wire is adjusted to have a flat wire parameter so that its impedance is less than 15Ω, in conjunction with a low-voltage (<36V) drive circuit.

[0015] Furthermore, the length of the left segment of the radiofrequency closure catheter is not less than 1m, while the length of the right segment of the radiofrequency closure catheter is 3cm, 7cm, 8cm or 10cm.

[0016] A method for manufacturing a radiofrequency closed conduit involves first forming an inner membrane into a tubular shape, then winding a heating wire around the right section of the tubular inner membrane, while simultaneously winding a spiral coil around the left section of the tubular inner membrane, wrapping a braided mesh around the outer surface of the spiral coil, and finally wrapping the entire outer membrane around and covering the braided mesh and the heating wire.

[0017] This invention provides a radiofrequency closure catheter and its manufacturing method, which has the following advantages: Due to the presence of the metal mesh, the catheter is less prone to folding and forming creases during use, thus affecting its usability. Compared with existing PI or PEEK tubes, the overall structure has a smaller bending radius, lower rigidity, and is easier to push into tortuous veins. The large internal aperture supports thrombus aspiration or the passage of other necessary instruments such as guidewires. Simultaneously, fluid injection can be achieved through the catheter. The low-resistance copper-nickel flat wire heating element is suitable for low-voltage driven devices. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of a radiofrequency closure catheter and its manufacturing method according to the present invention.

[0019] In the diagram: 1. Inner membrane; 2. Heating wire; 3. Spiral coil; 4. Woven mesh; 5. Outer membrane. Detailed Implementation

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to specific embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0021] A radiofrequency closure catheter and its manufacturing method are disclosed. The catheter includes an inner membrane 1, which is composed of left and right sections. A heating wire 2 is wound around the outer surface of the right section of the inner membrane 1, and a spiral coil 3 is wound around the outer surface of the left section. A braided mesh 4 is wrapped around the outer surface of the spiral coil 3. An outer membrane 5 is disposed on the outer surface of the braided mesh 4 of the left section and the heating wire 2 of the right section. The length of the left section of the radiofrequency closure catheter is not less than 1 m, while the length of the right section is 3 cm, 7 cm, 8 cm, or 10 cm.

[0022] The inner membrane 1 is composed of PTFE and / or PEBAX materials, and the outer membrane 5 is composed of PTFE and / or PEBAX materials, which greatly improves the bending performance.

[0023] The inner diameter of the intima-1 catheter is the same as that of a conventional aspiration catheter. With the same outer diameter, the larger inner diameter can be used for thrombus aspiration, fluid injection, and access to other devices (such as guidewires).

[0024] The spiral ring 3 is made of stainless steel or nickel-titanium alloy, and the woven mesh 4 is also made of stainless steel or nickel-titanium alloy. Its structural strength is supported by the inner and outer metal rings and meshes, making it difficult to bend.

[0025] Heating wire 2 is composed of copper-nickel alloy flat wire, with a significantly increased cross-sectional area compared to existing heating element round wire, thus also having better support strength.

[0026] Heating wire 2 is adjusted with flat wire parameters, resulting in a larger cross-sectional area and fewer turns, causing its impedance to typically be below 15 ohms. Combined with a low-voltage (<36V) drive circuit, this low-voltage drive provides higher safety performance. In this embodiment, the drive is a DC low-voltage drive (<36Vdc), incorporating both pulse width modulation and voltage regulation control methods.

[0027] Manufacturing method: First, the inner membrane 1, made of PTFE and / or PEBAX material, is made into a tube shape. The inner diameter of the inner membrane 1 is the same as that of a conventional suction tube. Then, the heating wire 2, made of stainless steel or nickel-titanium alloy material, is wound around the right section of the tubular inner membrane 1. At the same time, the spiral coil 3, made of stainless steel or nickel-titanium alloy material, is wound around the left section of the tubular inner membrane 1. The braided mesh 4, made of stainless steel or nickel-titanium alloy material, is wrapped around the outer surface of the spiral coil 3. The outer membrane 5, made of PTFE and / or PEBAX material, is then completely wrapped around and covered by the braided mesh 4 and the heating wire 2.

[0028] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A radiofrequency closure catheter, characterized in that, The inner membrane (1) is composed of two sections, left and right. The outer surface of the right section of the inner membrane (1) is wound with a heating wire (2), and the outer surface of the left section of the inner membrane (1) is wound with a spiral coil (3). The outer surface of the spiral coil (3) is wrapped with a woven mesh (4). The outer surface of the woven mesh (4) of the left section of the inner membrane (1) and the heating wire (2) of the right section are provided with an outer membrane (5).

2. A radiofrequency closure catheter according to claim 1, characterized in that, The inner membrane (1) is composed of PTFE and / or PEBAX materials.

3. A radiofrequency closure catheter according to claim 1, characterized in that, The outer membrane (1) is composed of PTFE and / or PEBAX materials.

4. A radiofrequency closure catheter according to claim 1, characterized in that: The spiral ring (3) is made of stainless steel or nickel-titanium alloy.

5. A radiofrequency closure catheter according to claim 1, characterized in that: The woven mesh (4) is made of stainless steel or nickel-titanium alloy.

6. A radiofrequency closure catheter according to claim 1, characterized in that: The inner pore diameter of the inner membrane (1) is the same as that of a conventional suction catheter.

7. A radiofrequency closure catheter according to claim 1, characterized in that: The heating wire (2) is composed of copper-nickel alloy flat wire, and its cross-sectional area is significantly increased compared with the existing heating element round wire.

8. A radiofrequency closure catheter according to claim 1, characterized in that: The heating wire (2) is adjusted to have a flat wire parameter so that its impedance is less than 15Ω, and is used in conjunction with a low voltage <36V drive circuit.

9. A radiofrequency closure catheter according to claim 1, characterized in that: The left segment of the radiofrequency closure catheter is no less than 1m in length, while the right segment of the radiofrequency closure catheter is 3cm, 7cm, 8cm or 10cm in length.

10. A method for manufacturing a radiofrequency closure catheter according to any one of claims 1-9, characterized in that: First, the inner membrane (1) is made into a tube shape. Then, the heating wire (2) is wound around the right section of the tubular inner membrane (1), and the spiral coil (3) is wound around the left section of the tubular inner membrane (1). The braided mesh (4) is wrapped around the outer surface of the spiral coil (3), and the outer membrane (5) is completely wrapped around and covered by the braided mesh (4) and the heating wire (2).

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