TPE-based variable stiffness medical catheter structure

Abstract

This utility model discloses a variable stiffness medical catheter structure based on TPE, including an outer tube, an inner tube, and a fixing tube. The outer tube has a linear groove on its surface, and a telescopic rod passes through the groove, connecting to a telescopic motor. The inner tube is nested inside the outer tube and contains heat-conducting fibers. The fixing tube integrates a heat-conducting wire, a heat-conducting protective plate, and a locking mechanism. When the telescopic rod extends in the straight section of the blood vessel, it enhances stiffness and ensures pushing stability. When the telescopic rod retracts in the tortuous section of the blood vessel, the heat-conducting fibers and the heat-conducting wire are energized and heated, softening the TPE material in seconds. Combined with the flexible bending state at the distal end, it can adapt to complex blood vessel morphologies. The heat-conducting protective plate isolates the surface temperature of the heat-conducting wire to prevent tissue burns. The locking mechanism enables rapid fixation during surgery. This structure, through the dual-mode coordinated control of thermal softening and mechanical reinforcement, overcomes the limitations of traditional hydraulic catheters in terms of response delay and bulky structure, significantly improving the safety and efficiency of microvascular surgeries such as cerebral vascular surgery.

Description

Technical Field

[0001] This utility model relates to the field of medical device and biomaterial interdisciplinary technology, and in particular to a variable stiffness medical catheter structure based on TPE. Background Technology

[0002] Thermoplastic elastomers (TPEs) are gradually replacing traditional PVC materials in the field of medical catheters due to their excellent biocompatibility, flexibility, and ease of processing. However, existing TPE catheters generally suffer from the defect that their stiffness cannot be dynamically adjusted. Rigid catheters are prone to damage to the intima when passing through tortuous blood vessels, while flexible catheters are prone to bending and instability, affecting surgical precision. Current variable stiffness technology mainly relies on hydraulic structures, but it has problems such as long response delay and bulky structure, making it difficult to adapt to microvascular scenarios such as cerebral blood vessels. Therefore, a variable stiffness medical catheter structure based on TPE is needed to solve the above-mentioned problems. Utility Model Content

[0003] The purpose of this utility model is to solve any of the problems in the above-mentioned technologies, thereby proposing a variable stiffness medical catheter structure based on TPE, including an outer tube, an inner tube, and a fixed tube. The outer wall surface of the outer tube is provided with grooves, which are linearly and equidistantly distributed on the outer wall of the outer tube. A telescopic rod is inserted through the grooves and is movably connected to the grooves. The telescopic rod passes through a bottom tube, which is located at the bottom of the outer tube and is fixedly connected to the outer tube. A telescopic motor is provided at the bottom of the telescopic rod and is movably connected to the telescopic rod.

[0004] Furthermore, the inner tube is located inside the outer tube, and the inner tube and the outer tube are concentric. A heat-conducting fiber is provided between the outer wall and the interior of the inner tube (2). The heat-conducting fiber penetrates the inner tube and is fixedly connected to the inner tube.

[0005] Furthermore, the fixing tube includes a heat-conducting protective plate, a heat-conducting wire, a fixing clamp, and a tightening nut. The fixing tube is located at the bottom of the outer tube and is fixedly connected to the outer tube. The heat-conducting wire is located on the outer wall surface of the fixing tube and is fixedly connected to the fixing tube. The heat-conducting plate is located around the heat-conducting wire.

[0006] Furthermore, the heat shield surrounds the heat-conducting wire, the heat shield is fixedly connected to the fixed tube, the tightening nut is disposed through both sides of the bottom of the fixed tube, the tightening nut is movably connected to the fixed tube, and the fixing clamp is disposed on both sides of the inner wall of the fixed tube and movably connected to the tightening nut.

[0007] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0008] 1. This utility model uses the linear extension and retraction of the telescopic rod within the groove to change the local stiffness of the outer tube in real time. The catheter can actively soften in tortuous vascular segments (such as coronary artery bifurcation) to significantly reduce the bending modulus, while the straight tube segment remains rigid, completely solving the response delay problem of traditional hydraulic structures. At the same time, combined with the synergistic effect of thermally conductive fibers and thermally conductive wires, a dual-mode control of "thermal softening + mechanical strengthening" is formed to avoid bending instability caused by single drive.

[0009] 2. The heat-conducting fiber of the inner tube, combined with the heat-conducting wire of the fixing tube, can reach the predetermined temperature within 3 seconds after being energized, which rapidly reduces the modulus of the TPE material; the heat-conducting protective plate insulates the surface temperature of the heat-conducting wire to prevent tissue burns, and the design of the tightening nut and fixing clamp supports quick one-handed assembly and disassembly, significantly shortening the surgical preparation time and reducing the operational risk. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0011] Figure 2 This is a cross-sectional structural schematic diagram of the present invention;

[0012] Figure 3 This is a schematic diagram of the structure of the distal part of the outer tube of this utility model in a flexible state when bent;

[0013] Figure 4 This is a schematic diagram of the outer tube structure of this utility model;

[0014] Figure 5 This is a top view of the structure of this utility model;

[0015] Figure 6 This is a schematic diagram of the bottom structure of this utility model.

[0016] Figure label:

[0017] Outer tube 1; Inner tube 2; Fixed tube 3; Groove 101; Telescopic rod 102; Bottom tube 103; Telescopic motor 104; Thermal conductive fiber 201; Thermal conductive protective plate 301; Thermal conductive wire 302; Fixed clamp 303; Tightening nut 304. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0019] The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of the present invention.

[0020] The following describes, with reference to the accompanying drawings, a TPE-based variable stiffness medical catheter structure according to an embodiment of the present invention, such as... Figures 1 to 6 As shown, the variable stiffness medical catheter structure based on TPE includes an outer tube 1, an inner tube 2, and a fixed tube 3. The outer wall surface of the outer tube 1 is provided with grooves 101, which are linearly and equidistantly distributed on the outer wall of the outer tube 1. A telescopic rod 102 is inserted through the grooves 101 and is movably connected to the grooves 101. The telescopic rod 102 passes through a bottom tube 103, which is located at the bottom of the outer tube 1 and is fixedly connected to the outer tube 1. A telescopic motor 104 is provided at the bottom of the telescopic rod 102 and is movably connected to the telescopic rod 102.

[0021] In a specific embodiment: After the operator percutaneously inserts the catheter into the blood vessel, the telescopic motor 104 is activated by the control system to drive the telescopic rod 102, causing the telescopic rod 102 to extend linearly within the groove 101, thereby enhancing the local stiffness of the outer tube 1 and increasing its bending modulus in real time; when the tortuous vascular segment (such as the coronary bifurcation) needs to be softened, the thermally conductive fiber 201 and the thermally conductive wire 302 are energized for 3 seconds to reach the predetermined temperature, reducing the modulus of the TPE matrix, while the telescopic rod 102 retracts to release the mechanical support; the distal bending state of the catheter is as follows: Figure 3 As shown.

[0022] Preferably, the inner tube 2 is disposed inside the outer tube 1, and the inner tube 2 and the outer tube 1 are concentric. A heat-conducting fiber 201 is disposed between the outer wall and the inner wall of the inner tube 2. The heat-conducting fiber 201 penetrates the inner tube 2 and is fixedly connected to the inner tube 2.

[0023] Preferably, the fixing tube 3 includes a heat-conducting protective plate 301, a heat-conducting wire 302, a fixing clamp 303, and a tightening nut 304. The fixing tube 3 is disposed at the bottom of the outer tube 1 and is fixedly connected to the outer tube 1. The heat-conducting wire 302 is disposed on the outer wall surface of the fixing tube 3 and is fixedly connected to the fixing tube 3. The heat-conducting plate 301 is disposed around the heat-conducting wire 302.

[0024] Preferably, the heat shield 301 surrounds the heat-conducting wire 302, the heat shield 301 is fixedly connected to the fixed tube 3, the tightening nut 304 is disposed through both sides of the bottom of the fixed tube 3, the tightening nut 304 is movably connected to the fixed tube 3, and the fixing clamp 303 is disposed on both sides of the inner wall of the fixed tube 3 and is movably connected to the tightening nut 304.

[0025] In a specific embodiment: When the operator inserts a catheter via femoral artery puncture and enters the tortuous cerebral blood vessels, the telescopic motor 104 is activated to drive the telescopic rod 102 to retract within the groove 101. Simultaneously, the heat-conducting fiber 201 and the heat-conducting wire 302 are energized and heated to 42 degrees Celsius for 3 seconds, thereby reducing the bending modulus of the distal end of the outer tube 1 (e.g., Figure 3 (As shown in the flexible state), it smoothly passes through 1 mm-level vascular bifurcation; when the straight vascular segment requires rigid support, the telescopic motor 104 pushes the telescopic rod 102 to extend, and the modulus increase ensures the stability of the push; during the operation, the heat-conducting protective plate 301 continuously isolates the surface temperature of the heat-conducting wire 302 to avoid heat damage to brain tissue above 42 degrees Celsius; the flexible segment adapts to the vascular morphology, and after the tightening nut 304 of the fixing tube 3 is tightened, it pushes the fixing clamp 303 to lock the inner tube 2. After the operation is completed and the power is cut off, the catheter restores its initial rigidity in a short time for easy removal.

[0026] Working principle: After the catheter is inserted into the blood vessel, the control system drives the telescopic rod 102 to extend and retract within the groove 101 according to the blood vessel morphology command of the telescopic motor 104. In the straight section, the telescopic rod 102 extends to strengthen the rigidity of the outer tube 1, ensuring stable pushing. In the tortuous section, the telescopic rod 102 retracts while the heat-conducting fiber 201 and heat-conducting wire 302 are energized, heating to 42 degrees Celsius within 3 seconds, reducing the modulus of the TPE material to 3 MPa (e.g., ...). Figure 3 (In a flexible state), it smoothly passes through a 1 mm-level bifurcation blood vessel. The heat-conducting protective plate 301 isolates the surface temperature of the heat-conducting wire 302 throughout the process to prevent tissue burns. After the tightening nut 304 of the fixing tube 3 is tightened, the fixing clamp 303 is pushed to mechanically lock the position of the catheter. After the operation ends and the power is cut off for 10 seconds, the material returns to its initial rigidity and the catheter is smoothly withdrawn without damage.

Claims

1. A variable stiffness medical catheter structure based on TPE, comprising an outer tube (1), an inner tube (2) and a fixed tube (3); characterized in that, The outer tube (1) has a groove (101) on its outer wall surface. The grooves (101) are linearly and equidistantly distributed on the outer wall of the outer tube (1). A telescopic rod (102) is installed through the groove (101). The telescopic rod (102) is movably connected to the groove (101). The telescopic rod (102) passes through the bottom tube (103). The bottom tube (103) is located at the bottom of the outer tube (1) and is fixedly connected to the outer tube (1). A telescopic motor (104) is installed at the bottom of the telescopic rod (102). The telescopic motor (104) is movably connected to the telescopic rod (102).

2. The TPE-based variable stiffness medical catheter structure of claim 1, wherein, The inner tube (2) is located inside the outer tube (1). The inner tube (2) and the outer tube (1) are concentric. A heat-conducting fiber (201) is provided between the outer wall and the inner wall of the inner tube (2). The heat-conducting fiber (201) penetrates the inner tube (2) and is fixedly connected to the inner tube (2).

3. The TPE-based variable stiffness medical catheter structure as described in claim 1, characterized in that, The fixed tube (3) includes a heat-conducting protective plate (301), a heat-conducting wire (302), a fixed clamp (303), and a tightening nut (304). The fixed tube (3) is located at the bottom of the outer tube (1) and is fixedly connected to the outer tube (1). The heat-conducting wire (302) is located on the outer wall surface of the fixed tube (3) and is fixedly connected to the fixed tube (3). The heat-conducting plate (301) is located around the heat-conducting wire (302).

4. The TPE-based variable stiffness medical catheter structure as described in claim 3, characterized in that, The heat shield plate (301) surrounds the heat conductor wire (302), and the heat shield plate (301) is fixedly connected to the fixed tube (3). The tightening nut (304) is disposed through both sides of the bottom of the fixed tube (3), and the tightening nut (304) is movably connected to the fixed tube (3). The fixing clamp plate (303) is disposed on both sides of the inner wall of the fixed tube (3) and is movably connected to the tightening nut (304).

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