A medical catheter

Abstract

The present invention provides a medical catheter, which relates to the technical field of medical devices. The medical catheter comprises a hypotube, a nickel-titanium tube, a welding piece and a sealing shell, wherein the interior of the sealing shell is provided with a first pipeline hole and a second pipeline hole which are mutually interpenetrating; the second end of the hypotube is provided at the second pipeline hole, the nickel-titanium tube is penetrated in the hypotube, the first end of the nickel-titanium tube extends out of the first end of the hypotube, and the second end of the nickel-titanium tube extends out of the second end of the hypotube; the first end of the welding piece is provided inside the second end of the hypotube, and the first end of the welding piece is fixedly connected to the second end of the hypotube; the second end of the welding piece is provided outside the nickel-titanium tube, and the second end of the welding piece is fixedly connected to the nickel-titanium tube. The present invention can reduce the breakage of the medical catheter.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a medical catheter. Background Art

[0002] Transcatheter aortic valve implantation has the advantages of no need for thoracotomy, less trauma and quick recovery after surgery, and the use of this surgery to treat aortic valve stenosis has gradually been promoted. Transcatheter aortic valve implantation surgery needs to be completed through a delivery system, which mainly includes three parts: inner tube, outer tube and handle. Among them, the inner tube part is mainly composed of metal components, and the metal parts are usually connected by welding.

[0003] At present, after the stainless steel hypotube and the nickel-titanium tube of the inner tube are welded, a brittle layer will be generated during the welding, and the brittle layer will be easily broken under the action of external force. It can be seen that the current medical catheter is prone to breakage. Summary of the invention

[0004] The embodiment of the present invention provides a medical catheter to solve the problem that the medical catheter is prone to breakage.

[0005] In a first aspect, an embodiment of the present invention provides a medical catheter, comprising a hypotube, a nickel-titanium tube, a welding piece, and a sealing shell, wherein a first pipeline hole and a second pipeline hole that penetrate each other are arranged inside the sealing shell;

[0006] The second end of the hypotube is disposed in the second pipe hole, the nickel-titanium tube is passed through the hypotube, the first end of the nickel-titanium tube extends out of the first end of the hypotube, and the second end of the nickel-titanium tube extends out of the second end of the hypotube;

[0007] The first end of the welding piece is disposed inside the second end of the hypotube, and the first end of the welding piece is fixedly connected to the second end of the hypotube;

[0008] The second end of the welding piece is arranged outside the nickel-titanium tube, and the second end of the welding piece is fixedly connected to the nickel-titanium tube.

[0009] Optionally, the medical catheter further comprises a first sealing ring and a second sealing ring, and both sides of the sealing housing are provided with a first groove and a second groove;

[0010] The outer wall of the first sealing ring abuts against the first groove of the sealing housing, and the hypotube abuts against the inner wall of the first sealing ring;

[0011] The outer wall of the second sealing ring abuts against the second groove of the sealing housing, and the second end of the nickel-titanium tube abuts against the inner wall of the second sealing ring;

[0012] The fixed connection between the welding piece and the second end of the hypotube has a gap.

[0013] Optionally, the welded part is a three-quarter cylindrical structure.

[0014] Optionally, it further includes a metal ring, the outer wall of the metal ring is fixedly connected to the inner wall of the sealing shell, the hypotube is passed through the metal ring, and the outer wall of the hypotube is fixedly connected to the inner wall of the metal ring.

[0015] Optionally, the second end of the hypotube is disposed at a point where the second pipe hole and the first pipe hole pass through.

[0016] Optionally, a diameter of a first end of the first pipe hole is greater than a diameter of a second end of the first pipe hole.

[0017] Optionally, the first end of the first conduit hole is adapted to be adapted to a Luer connector.

[0018] Optionally, the first sealing ring is made of medical silicone.

[0019] Optionally, the second sealing ring is made of medical silicone.

[0020] Optionally, the sealing shell is made of medical polyoxymethylene.

[0021] In an embodiment of the present invention, the medical catheter includes a hypotube, a nickel-titanium tube, a welding part and a sealing shell, the first end of the welding part is arranged inside the second end of the hypotube, the first end of the welding part is fixedly connected to the second end of the hypotube, the second end of the welding part is arranged outside the nickel-titanium tube, the second end of the welding part is fixedly connected to the nickel-titanium tube, the hypotube is fixedly connected to the nickel-titanium tube by the welding part, the direct welding of the nickel-titanium tube and the hypotube to form a brittle layer can be avoided, the toughness of the nickel-titanium tube can be improved, and the breakage of the medical catheter can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a structural diagram of a medical catheter provided by an embodiment of the present invention;

[0023] Figure 2 is a structural diagram of a hypotube provided by an embodiment of the present invention;

[0024] Figure 3 is a structural diagram of a nickel-titanium tube provided in an embodiment of the present invention;

[0025] Figure 4 is a structural diagram of a sealed housing provided by an embodiment of the present invention;

[0026] Figure 5 This is one of the structural diagrams of a sealing ring provided by an embodiment of the present invention;

[0027] Figure 6 This is a second structural diagram of a sealing ring provided by an embodiment of the present invention;

[0028] Figure 7 is a structural diagram of a welding part provided by an embodiment of the present invention;

[0029] Figure 8 is a structural diagram of a metal ring provided by an embodiment of the present invention;

[0030] Fig. 9 It is a structural diagram of a Luer connector provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0032] The terms "first", "second", etc. in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances, so that the embodiments of this application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first" and "second" are generally of the same type, and the number of objects is not limited. For example, the first object can be one or more.

[0033] See also Figure 1 , Figure 1 is a structural diagram of a medical catheter provided by an embodiment of the present invention, such as Figure 1 As shown, the medical catheter includes a hypotube 1, a nickel-titanium tube 2, a welding piece 3 and a sealing shell 4, wherein the interior of the sealing shell 4 is provided with a first pipe hole 41 and a second pipe hole 42 which are mutually interpenetrating; the second end of the hypotube 1 is arranged in the second pipe hole 42, the nickel-titanium tube 2 is penetrated in the hypotube 1, the first end of the nickel-titanium tube 2 extends out of the first end of the hypotube 1, and the second end of the nickel-titanium tube 2 extends out of the second end of the hypotube 1; the first end of the welding piece 3 is arranged inside the second end of the hypotube 1, and the first end of the welding piece 3 is fixedly connected to the second end of the hypotube 1; the second end of the welding piece 3 is arranged outside the nickel-titanium tube 2, and the second end of the welding piece 3 is fixedly connected to the nickel-titanium tube 2.

[0034] Among them, Figure 2As shown, the hypotube 1 is made of stainless steel, the outer diameter OD of the hypotube 1 can be 2.1-2.5 mm, the inner diameter ID of the hypotube 1 can be 1.6 mm, and the length of the hypotube 1 can be 1300-1800 mm. When the medical catheter enters the human body, the stainless steel hypotube 1 can provide rigid support. Generally speaking, the outer diameter of the hypotube 1 is adapted to the size of the second pipe hole 42, and the second end of the hypotube 1 can be disposed in the second pipe hole 42.

[0035] like Figure 3 As shown, the nickel-titanium tube 2 is a nickel-titanium alloy, the outer diameter OD of the nickel-titanium tube 2 can be 1.0-1.04mm, the inner diameter ID of the nickel-titanium tube 2 can be 0.9-0.94mm, and the length of the nickel-titanium tube 2 can be 1500-2000mm. During the operation, the nickel-titanium tube 2 is guided by the guide wire to deliver the catheter to the designated lesion site. Generally speaking, the outer diameter of the nickel-titanium tube 2 is smaller than the inner diameter of the hypotube 1, and the length of the nickel-titanium tube 2 is greater than the length of the hypotube 1. In this way, the nickel-titanium tube 2 can be inserted into the hypotube 1, and the first end of the nickel-titanium tube 2 extends out of the first end of the hypotube 1, and the second end of the nickel-titanium tube 2 extends out of the second end of the hypotube 1.

[0036] The material of the welding piece 3 is nickel-titanium alloy, and the fixed connection between the sea wave tube 1 and the nickel-titanium tube 2 is realized by welding with the sea wave tube 1 and the nickel-titanium tube 2. Because the materials of the sea wave tube 1 and the nickel-titanium tube 2 are different, and the wall thickness of the stainless steel sea wave tube is thicker, if the sea wave tube 1 and the nickel-titanium tube 2 are directly welded, the melting requires a large amount of energy, and the nickel-titanium tube 2 is greatly affected by heat and is prone to breakage under the action of external force. Because the material of the welding piece 3 and the nickel-titanium tube 2 is the same, the energy required for melting welding is small. Therefore, the welding piece 3 can be a transition medium for welding the sea wave tube 1 and the nickel-titanium tube 2, which can avoid the formation of a brittle layer at the welding point of the nickel-titanium tube 2 and improve the toughness of the nickel-titanium tube 2. The first end of the welding piece 3 is arranged inside the second end of the sea wave tube 1, and the first end of the welding piece 3 is fixedly connected to the second end of the sea wave tube 1. At the same time, the second end of the welding piece 3 is arranged outside the nickel-titanium tube 2, and the second end of the welding piece 3 is fixedly connected to the nickel-titanium tube 2. In this way, the sea wave tube 1 is fixedly connected to the nickel-titanium tube 2 through the welding piece 3.

[0037] In addition, during the welding process between the hypotube 1 and the weldment 3, the hypotube 1 is first assembled on the left welding chuck of the laser welding machine and tightened, and then the weldment 3 is inserted into the port of the second end of the hypotube 1 by about 2mm, and the hypotube 1 and the weldment 3 are welded at 1mm from the port of the second end of the hypotube 1. Spot welding can be used, the power of circumferential welding can be 0.3-0.5KW, the welding frequency can be 4HZ, and the welding speed can be 8r / min. During the welding process between the nickel-titanium tube 2 and the weldment 3, the outer wall of the nickel-titanium tube 2 is contacted with the weldment 3, and the distance between the second end of the weldment 3 and the second end of the nickel-titanium tube 2 is 200-260mm. The right side of the nickel-titanium tube 2 is clamped on the right chuck of the laser welding machine. Spot welding can be used, the maximum power of welding can be 0.2-0.3KW, the welding frequency can be 2HZ, and the welding speed can be 1-3r / min.

[0038] Since the nickel-titanium tube 2 and the welding piece 3 are both made of nickel-titanium alloy, welding between the same materials is relatively easy. By using spot welding, the nickel-titanium tube 2 can be minimally affected by the heat, so that it will hardly be affected by the bending stress. Through the welding of the hypotube 1 and the welding piece 3 and the welding of the nickel-titanium tube 2 and the welding piece 3, the hypotube 1, the welding piece 3 and the nickel-titanium tube 2 become a welded whole. Although the hypotube 1 and the nickel-titanium tube 2 are welded with dissimilar materials, the hypotube 1, the welding piece 3 and the nickel-titanium tube 2 are a rigid connection, so they can withstand changes in the overall bending performance.

[0039] like Figure 4 As shown, the sealing shell 4 is made of medical polyoxymethylene, and is generally a sealing structure. The sealing shell 4 is provided with a first pipeline hole 41 and a second pipeline hole 42 that are interpenetrating with each other. The first pipeline hole 41 is an injection channel for physiological saline. Since the first pipeline hole 41 and the second pipeline hole 42 are interpenetrating with each other, the physiological saline will flow into the second pipeline hole 42 after being injected from the first pipeline hole 41.

[0040] In an embodiment of the present invention, the medical catheter includes a hypotube 1, a nickel-titanium tube 2, a welding part 3 and a sealing shell 4, the first end of the welding part 3 is arranged inside the second end of the hypotube 1, the first end of the welding part 3 is fixedly connected to the second end of the hypotube 1, the second end of the welding part 3 is arranged outside the nickel-titanium tube 2, the second end of the welding part 3 is fixedly connected to the nickel-titanium tube 2, the hypotube 1 is fixedly connected to the nickel-titanium tube 2 through the welding part 3, which can avoid the nickel-titanium tube 2 and the hypotube 1 from being directly welded to form a brittle layer, can improve the toughness of the nickel-titanium tube 2, and thus can reduce the breakage of the medical catheter.

[0041] In an optional embodiment, the medical catheter further includes a first sealing ring 5 and a second sealing ring 6, and a first groove and a second groove are provided on both sides of the sealing housing 4;

[0042] The outer wall of the first sealing ring 5 abuts against the first groove of the sealing housing 4, and the hypotube 1 abuts against the inner wall of the first sealing ring 5;

[0043] The outer wall of the second sealing ring 6 abuts against the second groove of the sealing housing 4, and the second end of the nickel-titanium tube 2 abuts against the inner wall of the second sealing ring 6;

[0044] The fixed connection between the welding piece 3 and the second end of the hypotube 1 has a gap.

[0045] Among them, Figure 5 As shown, the outer diameter OD of the first sealing ring 5 can be 2.0-2.2 mm, the wire diameter of the first sealing ring 5 can be 1 mm, and the inner diameter of the first sealing ring 5 is adapted to the outer diameter of the hypotube 1. When the hypotube 1 abuts against the inner wall of the first sealing ring 5, there is no gap at the abutting position. At the same time, the outer wall of the first sealing ring 5 abuts against the first groove of the sealing housing 4, and there is no gap at the abutting position.

[0046] like Figure 6 As shown, the outer diameter OD of the second sealing ring 6 can be 1.08-1.12 mm, the wire diameter of the second sealing ring 6 can be 1 mm, the inner diameter of the first sealing ring 6 is adapted to the outer diameter of the nickel-titanium tube 2, and when the nickel-titanium tube 2 abuts against the inner wall of the second sealing ring 6, there is no gap at the abutting position. At the same time, the outer wall of the second sealing ring 6 abuts against the second groove of the sealing housing 4, and there is no gap at the abutting position.

[0047] In addition, the fixed connection between the welding piece 3 and the second end of the hypotube 1 has a gap, which can also be understood as that the welding between the welding piece 3 and the second end of the hypotube 1 is a non-complete circumferential welding. Since there is no gap at the abutting part, the interior of the sealing shell 4 forms a relatively sealed structure. In the preparation process before surgery, physiological saline is injected from the first pipe hole 41, flows into the second pipe hole 42, and flows into the pipe interlayer between the hypotube 1 and the nickel-titanium tube 2 through the connection gap between the welding piece 3 and the hypotube 1. The pipe interlayer between the hypotube 1 and the nickel-titanium tube 2 can be flushed, and the air in the pipe interlayer can be emptied, so that the entire pipe interlayer is filled with physiological saline. Therefore, when the catheter enters the human body, the air in the pipe interlayer can be prevented from causing harm to the human body.

[0048] In this embodiment, the medical catheter also includes a first sealing ring 5 and a second sealing ring 6. The outer wall of the first sealing ring 5 abuts against the first groove of the sealing shell 4, the hypotube 1 abuts against the inner wall of the first sealing ring 5, the outer wall of the second sealing ring 6 abuts against the second groove of the sealing shell 4, and the second end of the nickel-titanium tube 2 abuts against the inner wall of the second sealing ring 6, so that a sealed space is formed inside the sealing shell 4. Since the fixed connection between the welding part 3 and the second end of the hypotube 1 has a gap, physiological saline can flow into the pipe interlayer between the hypotube 1 and the nickel-titanium tube 2 through the gap, which can evacuate the air in the pipe interlayer to prevent the air in the pipe interlayer from causing harm to the human body.

[0049] Optionally, the welded part 3 is a three-quarter cylindrical structure.

[0050] like Figure 7 As shown, the welding piece 3 is a three-quarter cylindrical structure, the outer diameter of the cylinder is adapted to the inner diameter of the hypotube 1, and the inner diameter of the cylinder is adapted to the outer diameter of the nickel-titanium tube 2. The outer diameter of the cylindrical structure can be 1.5-1.58mm, the inner diameter of the cylinder can be 1.05-1.1mm, and the length of the cylinder can be 3-8mm. A 1 / 4 portion of the cylindrical structure is peeled off to obtain a 3 / 4 cylindrical structure as a welding piece. The peeled 1 / 4 portion of the cylindrical structure can be used as a gap between the fixed connection of the welding piece 3 and the second end of the hypotube 1. In the preparation process before surgery, physiological saline is injected from the first pipeline hole 41, flows into the second pipeline hole 42, and flows into the pipeline interlayer between the hypotube 1 and the nickel-titanium tube 2 through the peeled 1 / 4 portion of the cylindrical structure, so that the air in the pipeline interlayer between the hypotube 1 and the nickel-titanium tube 2 can be emptied, so that the entire pipeline interlayer is filled with physiological saline.

[0051] In this embodiment, the welding part 3 is a three-quarter cylindrical structure, and the 1 / 4 part of the cylindrical structure that is peeled off can be used as a gap between the welding part 3 and the fixed connection of the second end of the hypotube 1. Physiological saline can flow into the pipe interlayer between the hypotube 1 and the nickel-titanium tube 2 through the 1 / 4 part of the cylindrical structure that is peeled off. The air in the pipe interlayer between the hypotube 1 and the nickel-titanium tube 2 can be emptied, so that the entire pipe interlayer is filled with physiological saline, thereby preventing the air in the pipe interlayer from causing harm to the human body.

[0052] Optionally, the medical catheter further comprises a metal ring 7 , the outer wall of the metal ring 7 is fixedly connected to the inner wall of the sealing shell 4 , the hypotube 1 is passed through the metal ring 7 , and the outer wall of the hypotube 1 is fixedly connected to the inner wall of the metal ring 7 .

[0053] The metal ring 7 is made of stainless steel, the outer wall of the metal ring 7 is fixedly connected to the inner wall of the sealing shell, and the outer wall of the hypotube 1 is fixedly connected to the inner wall of the metal ring 7, which can support and fix the hypotube 1. Figure 8As shown, the outer diameter of the metal ring 7 can be 3-6 mm, the inner diameter of the metal ring 7 can be 2.11-2.51 mm, and the thickness of the metal ring 7 can be 2-3 mm. The metal ring 7 can be assembled in the middle position of the hypotube 1, and the butt welding of the metal ring 7 and the hypotube 1 can be completed by spot welding. When the physiological saline flows into the pipe interlayer between the hypotube 1 and the nickel-titanium tube 2, there will be an impact force on the hypotube 1. Because the outer wall of the hypotube 1 is fixedly connected to the inner wall of the metal ring 7, the metal ring 7 can buffer the impact force of the flow of the physiological saline, and can improve the stability of the hypotube 1.

[0054] In this embodiment, since the medical catheter also includes a metal ring 7, the outer wall of the metal ring 7 is fixedly connected to the inner wall of the sealing shell 4, the sea wave tube 1 is inserted into the metal ring 7, and the outer wall of the sea wave tube 1 is fixedly connected to the inner wall of the metal ring 7. Since the sea wave tube 1 is fixedly connected to the metal ring 7, the metal ring 7 can support and fix the sea wave tube 1, thereby improving the stability of the sea wave tube 1.

[0055] Optionally, the second end of the hypotube 1 is disposed at a point where the second pipe hole 42 and the first pipe hole 41 pass through.

[0056] The physiological saline can flow from the second end of the hypotube 1 into the pipe sandwich between the hypotube 1 and the nickel-titanium tube 2. The second end of the hypotube 1 is arranged at the through-hole of the second pipe hole 42 and the first pipe hole 41, so that during the surgical preparation, when the physiological saline flows from the first pipe hole 41, it can quickly flow into the pipe sandwich between the hypotube 1 and the nickel-titanium tube 2.

[0057] In this embodiment, since the second end of the hypotube 1 is arranged at the connection point between the second pipe hole 42 and the first pipe hole 41, when physiological saline flows in, it can quickly flow into the pipe interlayer between the hypotube 1 and the nickel-titanium tube 2, thereby improving the efficiency of surgical preparation work.

[0058] Optionally, a diameter of a first end of the first pipe hole 41 is greater than a diameter of a second end of the first pipe hole 41 .

[0059] The physiological saline flows into the second pipe hole 42 through the first end of the first pipe hole 41 and the second end of the first pipe hole 41 in sequence. Since the diameter of the first end of the first pipe hole 41 is larger than the diameter of the second end of the first pipe hole 41, the physiological saline first flows into the first end of the first pipe hole 41 and then flows into the second end of the first pipe hole 41. As the flow channel becomes narrower, the flow rate of the physiological saline will be accelerated, thereby accelerating the speed at which the physiological saline flows into the pipe interlayer between the hypotube 1 and the nickel-titanium tube 2.

[0060] In this embodiment, since the diameter of the first end of the first pipe hole 41 is greater than the diameter of the second end of the first pipe hole 41 , the speed at which the physiological saline flows into the pipe interlayer between the hypotube 1 and the nickel-titanium tube 2 can be accelerated.

[0061] Optionally, the first end of the first pipe hole 41 is adapted to be compatible with the Luer connector 8 .

[0062] like Fig. 9 As shown, the Luer connector 8 is a convenient connection device used in the medical industry, which greatly simplifies the management of liquid and gaseous medical fluids. The first end of the first pipeline hole 41 is adapted to the Luer connector 8, and a 10ml injection syringe with a Luer connector filled with saline is connected to the first pipeline hole 41, and the injection syringe is pushed, and the saline flows into the pipeline sandwich between the hypotube 1 and the nickel-titanium tube 2, which can be flushed and emptied of air, so that the entire pipeline sandwich is filled with saline.

[0063] In this embodiment, since the first end of the first pipe hole 41 is adapted to the Luer connector 8, the Luer connector can be easily connected to the injection syringe, thereby facilitating the injection of physiological saline.

[0064] Optionally, the first sealing ring 5 is made of medical silicone.

[0065] Among them, medical silicone is a new type of high molecular elastic material with excellent performance, good physiological stability, and can withstand repeated harsh and sterilization conditions and has excellent resilience. The material of the first sealing ring 5 is medical silicone. Due to the good performance of medical silicone, a better sealing space can be formed through the first sealing ring 5, so that the sealing performance of the sealing housing 4 can be improved.

[0066] In this embodiment, since the material of the first sealing ring 5 is medical silicone, the sealing performance of the sealing housing 4 can be improved.

[0067] Optionally, the second sealing ring 6 is made of medical silicone.

[0068] Advantages of medical silicone As described above, the material of the second sealing ring 6 is medical silicone. Due to the good performance of medical silicone, a better sealing space can be formed through the second sealing ring 6, so that the sealing performance of the sealing housing 4 can be improved.

[0069] In this embodiment, since the material of the second sealing ring 6 is medical silicone, the sealing performance of the sealing housing 4 can be improved.

[0070] Optionally, the sealing shell 4 is made of medical polyoxymethylene.

[0071] Among them, medical polyoxymethylene is a thermoplastic crystalline polymer with the characteristics of light weight, good rigidity, low friction coefficient, dimensional stability, good fatigue resistance, low water absorption and good biocompatibility. Medical polyoxymethylene is often used to manufacture artificial heart valve frames, human joints and other medical devices. The material of the sealing shell 4 is medical polyoxymethylene. Since medical polyoxymethylene has the characteristics of light weight and good rigidity, the sealing shell 4 can also meet the requirements of light weight and good rigidity.

[0072] In this embodiment, since the sealing shell 4 is made of medical polyoxymethylene, the sealing shell 4 can also meet the requirements of light weight and good rigidity.

[0073] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A medical catheter, characterized in that: It comprises a hypotube, a nickel-titanium tube, a welding piece and a sealing shell, wherein a first pipeline hole and a second pipeline hole which are mutually interpenetrating are arranged inside the sealing shell, and when the hypotube and the nickel-titanium tube need to be cleaned, water is injected into the first pipeline hole to clean the hypotube and the nickel-titanium tube located in the second pipeline hole; The second end of the hypotube is disposed in the second pipe hole, the nickel-titanium tube is passed through the hypotube, the first end of the nickel-titanium tube extends out of the first end of the hypotube, and the second end of the nickel-titanium tube extends out of the second end of the hypotube; The first end of the welding piece is disposed inside the second end of the hypotube, and the first end of the welding piece is fixedly connected to the second end of the hypotube; The second end of the welding piece is arranged outside the nickel-titanium tube, and the second end of the welding piece is fixedly connected to the nickel-titanium tube; The medical catheter further comprises a first sealing ring and a second sealing ring, and both sides of the sealing housing are provided with a first groove and a second groove; The outer wall of the first sealing ring abuts against the first groove of the sealing housing, and the hypotube abuts against the inner wall of the first sealing ring; The outer wall of the second sealing ring abuts against the second groove of the sealing housing, and the second end of the nickel-titanium tube abuts against the inner wall of the second sealing ring; when the hypotube and the nickel-titanium tube need to be cleaned, the first sealing ring and the second sealing ring seal the two ends of the second pipe hole so that the cleaning water will not enter other positions of the medical catheter during the cleaning process; The fixed connection between the welding piece and the second end of the hypotube has a gap, so that physiological saline flows into the pipe interlayer between the hypotube and the nickel-titanium tube through the gap between the welding piece and the hypotube, so as to flush the pipe interlayer and evacuate the air in the pipe interlayer. The pipe interlayer is filled with physiological saline, so that when the medical catheter enters the human body, the air in the pipe interlayer is prevented from causing harm to the human body; The medical catheter also includes a metal ring, the outer wall of the metal ring is fixedly connected to the inner wall of the sealing shell, the hypotube is passed through the metal ring, the outer wall of the hypotube is fixedly connected to the inner wall of the metal ring, and the metal ring supports and fixes the hypotube, so that a gap can always be maintained between the welding part and the second end of the hypotube to improve the stability of the hypotube.

2. The medical catheter according to claim 1, characterized in that The welded part is a three-quarter cylindrical structure.

3. The medical catheter according to claim 1, characterized in that: The second end of the hypotube is arranged at a penetration point between the second pipeline hole and the first pipeline hole.

4. The medical catheter according to claim 1, characterized in that: A diameter of a first end of the first conduit hole is greater than a diameter of a second end of the first conduit hole.

5. The medical catheter according to claim 4, characterized in that The first end of the first conduit hole is adapted to be fitted with a Luer connector.

6. The medical catheter according to claim 1, characterized in that: The material of the first sealing ring is medical silicone.

7. The medical catheter according to claim 1, characterized in that: The material of the second sealing ring is medical silicone.

8. The medical catheter according to claim 1, characterized in that: The sealing shell is made of medical polyoxymethylene.

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