Dynamic stiffness adjustable guide catheter based on temperature response memory alloy

Abstract

The invention discloses a dynamic stiffness adjustable guide catheter based on a temperature response memory alloy, and relates to the technical field of medical instruments, the guide catheter comprises a main body tube and a tube seat, the main body tube is installed on the right side of the outer wall of the tube seat, the main body tube is composed of a pushing tube, a steering tube and an attaching tube, and the pushing tube, the steering tube and the attaching tube are each composed of an outer tube and an inner tube; the pushing pipe and the attaching pipe are connected with the steering pipe through linkage shafts, a sliding ring is arranged in an interlayer formed by the outer pipe and the inner pipe, and an elastic piece is arranged on the side, close to the inner pipe, of the outer wall of the sliding ring. By installing the main body tube, the universal driving shaft and the tube base, the function of automatically adjusting the rigidity in a segmented mode is achieved, the problems that the rigidity is manually adjusted, catheter supporting is insufficient and flexibility is poor are solved, the rigidity of the catheter can be automatically adjusted according to the temperature, the stability and reliability of the guide catheter are improved, and the operation complexity of medical staff is reduced.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a dynamically stiff adjustable guide tube based on a temperature-responsive memory alloy. Background Technology

[0002] Guided catheters are specifically designed to establish vascular access, providing a channel for therapeutic devices such as balloon catheters, stents, and guidewires to enter the coronary arteries and peripheral blood vessels, ensuring precise delivery of devices to the lesion site. The materials of guided catheters have evolved from early single-layer polymers to a three-layer composite structure consisting of a polytetrafluoroethylene inner layer, a stainless steel braided middle layer, and a polymer outer layer, improving the pushing force and torsional control of the guided catheter. To dynamically adapt to the complexity of vascular anatomy, the stiffness of the guided catheter needs to be dynamically adjusted. For example, by combining a rigid magnetic helical structure with a flexible microstructure, remote non-destructive stiffness adjustment and independent active steering control of the microcatheter can be achieved under a single magnetic field. Existing guiding catheters mostly use non-temperature-responsive materials, such as ordinary metals or polymers, which cannot automatically adjust their performance according to body temperature. They rely on manual operation by medical staff or fixed design, which increases the complexity of operation for medical staff during surgery. Furthermore, guiding catheters with fixed stiffness designs are prone to causing the high-stiffness section to scratch the vascular intima and the low-stiffness section to collapse due to pressure from the vascular wall during surgery, leading to surgical failure.

[0003] Patent CN114082086B discloses a balloon guiding catheter. The above patent reduces the difficulty and complexity of operation during the operation, and reduces the operation time and risk.

[0004] The aforementioned patent involves placing a first balloon made of non-compliant material inside a second cannula made of compliant material, and pre-filling the second balloon with contrast agent. When the catheter passes through a stenotic area of ​​a blood vessel, the first balloon expands at the stenosis, causing the second balloon to be compressed and expand along with the first balloon. The second balloon is used to characterize the expansion effect of the stenosis, allowing the catheter to be advanced smoothly. At the same time, it can reduce the risk of puncture of the first balloon and has room for optimization in terms of the controllability of the stiffness adjustment of the guiding catheter.

[0005] Therefore, this application proposes a dynamically stiffened adjustable guide tube based on a temperature-responsive memory alloy with segmented automatic stiffness adjustment. Summary of the Invention

[0006] The purpose of this invention is to provide a dynamically stiffened guide tube based on a temperature-responsive memory alloy, so as to solve the technical problem mentioned in the background art that guide tubes with single fixed parameters or those that rely on manual adjustment cannot adapt to the dynamic vascular environment.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a dynamically stiff adjustable guide tube based on temperature-responsive memory alloy, comprising a main tube and a tube seat. The main tube is installed on the right side of the outer wall of the tube seat. The main tube is composed of a push tube, a steering tube, and a fitting tube. Each of the push tube, steering tube, and fitting tube is composed of an outer tube and an inner tube. The push tube, fitting tube, and steering tube are all connected by a linkage shaft. A sliding ring is provided in the interlayer formed by the outer tube and the inner tube. A spring piece is provided on the outer wall of the sliding ring near the inner tube. The inner tube is composed of four bushing pieces. Each bushing piece has a support piece on the outer wall near the outer tube. The bushing pieces are connected to each other by hinges and connecting edges. A hinge is installed on the outer wall of the bushing piece near the outer tube, and a connecting edge is provided on the outer wall of the bushing piece away from the outer tube.

[0008] Preferably, the sliding ring is composed of a sleeve, an outer slider, locking teeth, and a connector. A sleeve is provided on the outer wall of the spring piece near the outer tube, and locking teeth are provided on the outer wall of the sleeve near the spring piece. The outer slider and the connector are alternately arranged on the outer wall of the sleeve near the outer tube. The outer slider matches the groove provided on the inner wall of the outer tube near the sliding ring.

[0009] Preferably, the outer tube is made of braided mesh tube, and positioning platforms are provided at both ends of the outer wall of the braided mesh tube. An adjustment tube is provided on the inner wall of the outer tube. The braiding density of the push tube, the turning tube and the bonding tube decreases in sequence, and the braiding angle of the outer tube of the push tube, the turning tube and the bonding tube increases in sequence.

[0010] Preferably, the regulating tube is provided with a traction wire inside. The diameter of the traction wire in the pushing tube is 0.18-0.2 mm, the diameter of the traction wire in the turning tube is 0.15-0.17 mm, and the diameter of the traction wire in the fitting tube is 0.12-0.14 mm. A knob is installed on the outer wall of the tube seat. The front side of the outer wall of the knob is provided with a scale close to the outer wall of the tube seat. The knob is connected to the connector through the traction wire.

[0011] Preferably, an anti-bending tube is installed at the connection between the main tube and the tube seat. The anti-bending tube consists of a sheath, an adjusting tube II, a spacer, a support ring, and a sealing ring. A sheath is installed on the right side of the outer wall of the tube seat. A spacer is provided on the inner wall of the sheath. An adjusting tube II is provided in the interlayer formed by the sheath and the spacer. The adjusting tube II is connected to the adjusting tube I. A support ring is provided on the outer wall of the spacer away from the sheath. A sealing ring is provided on the outer wall of the support ring away from the spacer.

[0012] Preferably, limit blocks are provided on both the left and right sides of the outer wall of the knob, a buckle is installed on the lower side of the outer wall of the tube seat, and a sealing cap is installed at the connection between the tube seat and the anti-bending tube.

[0013] Preferably, a cap is installed on the outer wall of the bonding tube away from the turning tube, a developing ring is embedded in the right side of the inner wall of the cap, a support core is installed on the left side of the outer wall of the developing ring, and the cap is connected to the bonding tube through the support core.

[0014] Preferably, the outer wall of the inner tube is coated on the side away from the outer tube.

[0015] Preferably, a second latch is provided on the outer wall of the spring piece near the locking tooth, and the second latch engages with the locking tooth.

[0016] Preferably, the inner wall of the regulating tube is provided with a guide groove, the traction wire is fitted into the guide groove, and the guide groove is parallel to the slide groove.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention, by installing a main tube, a linkage shaft, and a tube seat, achieves the function of segmented automatic stiffness adjustment, solving the problems of relying on manual stiffness adjustment, insufficient catheter support, and poor flexibility. It can automatically adjust the catheter stiffness according to temperature, improving the stability and reliability of the catheter and reducing the operational complexity for medical staff. 2. This invention achieves automatic locking by installing a sliding ring, an outer tube, and an inner tube, thus solving the problems of stiffness adjustment rebound, mechanical jamming, and structural deformation. It can automatically lock the sliding ring after the stiffness of the guide tube is adjusted, thereby improving the stability of the guide tube. 3. This invention achieves stable delivery of instruments by installing structures such as bushings, hinges, and connecting edges, solving the problems of difficult instrument pre-assembly, poor catheter passability, and the risk of collapse and leakage. It can avoid instrument jamming or damage and improve the deformation resistance and cross-sectional stability of the guide tube. 4. This invention, by incorporating a knob, an adjustment tube, a guide groove, and a traction wire, enables manual fine-tuning of the guide tube parameters. It solves the problems of single catheter stiffness, easy perforation and blockage in curved blood vessels, and inaccurate positioning. It allows for manual adjustment of the guide tube's stiffness and position, improving the accuracy and stability of guide tube delivery. Attached Figure Description

[0018] Figure 1 This is a front view structural diagram of the present invention; Figure 2 This is a side view of the present invention; Figure 3 This is a schematic diagram of the side structure of the inner tube and outer tube of the present invention; Figure 4 This is a schematic diagram of the front structure of the inner tube and outer tube of the present invention; Figure 5 This is a schematic diagram of the braided mesh tube and positioning block structure of the present invention; Figure 6 This is a schematic diagram of the anti-bending tube structure of the present invention; Figure 7This is a schematic diagram of the knob and limiting block structure of the present invention; Figure 8 This is a schematic diagram of the locking teeth and buckle structure of the present invention.

[0019] In the diagram: 1. Main tube; 2. Tube seat; 3. Push tube; 4. Turning tube; 5. Fitting tube; 6. Outer tube; 7. Inner tube; 8. Linkage shaft; 9. Sliding ring; 10. Spring piece; 11. Bushing piece; 12. Support piece one; 13. Hinge; 14. Connecting edge; 15. Sleeve; 16. Outer slider; 17. Locking tooth; 18. Joint; 19. Slide groove; 20. Braided mesh tube; 21. Positioning platform; 22. Adjusting tube one; 23. Traction wire; 24. Knob; 25. Anti-bending tube; 26. Sheath; 27. Adjusting tube two; 28. Spacer; 29. ​​Support ring; 30. Sealing ring; 31. Limiting block; 32. Buckle one; 33. Sealing cover; 34. Head cap; 35. Developing ring; 36. Support core; 37. Coating; 38. Buckle two; 39. Guide groove. Detailed Implementation

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

[0021] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," 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 this 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 this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0023] Example 1: Please refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 A dynamically stiffness-adjustable guide tube based on temperature-responsive memory alloy includes a main tube 1 and a tube seat 2. The main tube 1 is installed on the right side of the outer wall of the tube seat 2. The main tube 1 is composed of a push tube 3, a steering tube 4, and a fitting tube 5. The push tube 3, steering tube 4, and fitting tube 5 are all composed of an outer tube 6 and an inner tube 7. The push tube 3 and fitting tube 5 are connected to the steering tube 4 through a linkage shaft 8. A sliding ring 9 is provided in the interlayer formed by the outer tube 6 and the inner tube 7. A spring piece 10 is provided on the outer wall of the sliding ring 9 near the inner tube 7. The inner tube 7 is composed of four bushing pieces 11. A support piece 12 is provided on the outer wall of each bushing piece 11 near the outer tube 6. The bushing pieces 11 are connected to each other through a hinge 13 and a connecting edge 14. The hinge 13 is installed on the outer wall of the bushing piece 11 near the outer tube 6, and the connecting edge 14 is provided on the outer wall of the bushing piece 11 away from the outer tube 6. The sliding ring 9 is composed of a sleeve 15, an outer slider 16, a locking tooth 17, and a connector 18. A sleeve 15 is provided on the outer wall of the spring piece 10 near the outer tube 6. A locking tooth 17 is provided on the outer wall of the sleeve 15 near the spring piece 10. The outer slider 16 and the connector 18 are alternately arranged on the outer wall of the sleeve 15 near the outer tube 6. The outer slider 16 matches the groove 19 provided on the inner wall of the outer tube 6 near the sliding ring 9. The outer tube 6 is composed of a braided mesh tube 20. Positioning platforms 21 are provided at both ends of the outer wall of the braided mesh tube 20. An adjustment tube 22 is provided on the inner wall of the outer tube 6. The braiding density of the braided mesh tube 20 of the push tube 3, the turning tube 4 and the bonding tube 5 decreases in sequence, and the braiding angle of the outer tube 6 of the push tube 3, the turning tube 4 and the bonding tube 5 increases in sequence. The outer wall of the inner tube 7 is provided with a coating 37 on the side away from the outer tube 6; Furthermore, before using the guiding tube, medical staff check the integrity of the packaging to ensure it is undamaged. The guiding tube is then removed. At this point, the ambient temperature of the guiding tube is typically 25-28℃. The braided mesh tube 20 is made of a body temperature-responsive nickel-titanium alloy, with nickel comprising 55% and titanium 45%. In the push tube 3, the braided mesh tube 20 has a braiding density of 80-90 strands / inch, a braiding angle of 30°-40°, and an outer diameter of 1.7-1.8mm. In the turning tube 4, the braided mesh tube 20 has a braiding density of 60-70 strands / inch, a braiding angle of 40°-50°, and an outer diameter of 1.6-1mm. The braided mesh tube 20 in the bonding tube 5 has a braiding density of 40-50 strands / inch, a braiding angle of 50°-60°, and an outer diameter of 1.5-1.6mm. Under normal temperature conditions, the braided mesh tube 20 is in a martensitic state with a low elastic modulus. The main tube 1 is in a naturally relaxed state. Due to the differences in braiding density, braiding angle, and outer diameter of the braided mesh tube 20, the stiffness of the outer tube 6 of the push tube 3, the turning tube 4, and the bonding tube 5 decreases sequentially under normal temperature conditions and remains within the range of 5-8GPa. The sliding ring 9 is located at the end near the tube seat 2. The spring piece 10 is made of nickel-titanium alloy with a thickness of 0.03-0.7mm.0.5mm, with an elastic modulus of 20-30GPa, the spring sheet 10 naturally contracts, causing the bushing sheet 11 constituting the inner tube 7 to expand through the hinge 13. The coating 37 ensures that the internal channel of the inner tube 7 is smooth, facilitating medical personnel to insert instruments such as stents and biopsy needles into the guiding tube. During the process of medical personnel inserting the guiding tube into the patient's blood vessel, the guiding tube enters the human body's 37°C temperature environment from the normal temperature environment. The braided mesh tube 20 undergoes a phase transformation from a martensitic state to an austenitic state. The contraction of the braided mesh tube 20 causes the sliding ring 9 to move along... As the slide groove 19 slides, the sliding ring 9 moves away from the tube seat 2, pushing the spring piece 10. The spring piece 10, after being compressed, opens and compresses the bushing 11, causing the bushing 11 to contract. This reduces the inner diameter of the inner tube 7 while increasing its rigidity. After the surgery, the medical staff withdraws the guide tube, which returns from a 37°C environment to room temperature. The braided mesh tube 20 undergoes a phase transformation from austenitic to martensitic. The braided mesh tube 20 resets, causing the sliding ring 9 to move along the slide groove 19 closer to the tube seat 2. The spring piece 10 loses its external force. The function restores the original position. The bushing 11 is reset via the hinge 13, restoring the inner diameter of the inner tube 7. Medical staff can then remove the instrument. The stiffness of the guide tube changes with the ambient temperature, eliminating the need for manual adjustment by medical staff. The high stiffness of the push tube 3 provides sufficient support, preventing kinking or bending during push. The medium stiffness of the turning tube 4 allows for flexible turning when adjusting the catheter's direction, and the stiffness remains stable after turning without rebounding. The low stiffness of the fitting tube 5 allows for gentle fitting when pushing the guide tube to the target position. To prevent scratches and compression damage to the vascular endothelium, during the phase transition caused by temperature changes in the braided mesh tube 20, which leads to gradient stiffness changes in the push tube 3, turning tube 4, and fitting tube 5, the linkage shaft 8 connecting the three sections of the braided mesh tube 20 transmits the deformation force, ensuring synchronized stiffness switching and preventing disengagement. This eliminates the need for manual adjustment by medical staff, reducing operational steps and time, and minimizing operator fatigue.

[0024] Example 2: Please refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 8A dynamically stiffness-adjustable guide tube based on temperature-responsive memory alloy includes a main tube 1 and a tube seat 2. The main tube 1 is installed on the right side of the outer wall of the tube seat 2. The main tube 1 is composed of a push tube 3, a steering tube 4, and a fitting tube 5. The push tube 3, steering tube 4, and fitting tube 5 are all composed of an outer tube 6 and an inner tube 7. The push tube 3 and fitting tube 5 are connected to the steering tube 4 through a linkage shaft 8. A sliding ring 9 is provided in the interlayer formed by the outer tube 6 and the inner tube 7. A spring piece 10 is provided on the outer wall of the sliding ring 9 near the inner tube 7. The inner tube 7 is composed of four bushing pieces 11. A support piece 12 is provided on the outer wall of each bushing piece 11 near the outer tube 6. The bushing pieces 11 are connected to each other through a hinge 13 and a connecting edge 14. The hinge 13 is installed on the outer wall of the bushing piece 11 near the outer tube 6, and the connecting edge 14 is provided on the outer wall of the bushing piece 11 away from the outer tube 6. The sliding ring 9 is composed of a sleeve 15, an outer slider 16, a locking tooth 17, and a connector 18. A sleeve 15 is provided on the outer wall of the spring piece 10 near the outer tube 6. A locking tooth 17 is provided on the outer wall of the sleeve 15 near the spring piece 10. The outer slider 16 and the connector 18 are alternately arranged on the outer wall of the sleeve 15 near the outer tube 6. The outer slider 16 matches the groove 19 provided on the inner wall of the outer tube 6 near the sliding ring 9. The outer wall of the spring piece 10 is provided with a second buckle 38 on the side near the locking tooth 17, and the second buckle 38 engages with the locking tooth 17; Furthermore, at room temperature, the sliding ring 9 is in its initial position near the tube seat 2, the spring 10 naturally retracts, and the second latch 38 and the locking tooth 17 are separated. When the guide tube enters the 37°C environment of the human body from the room temperature environment, the sliding ring 9 moves away from the tube seat 2 under the action of the braided mesh tube 20. The outer slider 16 on the surface of the sleeve 15 slides in the groove 19. The gap between the outer slider 16 and the groove 19 is extremely small, so there will be no shaking during the movement of the sliding ring 9, so that the locking tooth 17 and the second latch 38 on the surface of the spring 10 are accurately aligned. When the sliding ring 9 pushes the spring 10 to open, the spring 10 is squeezed. Upon compression, deformation occurs, and the second latch 38 moves closer to the locking tooth 17. During the movement of the sliding ring 9, when it reaches the preset stroke and the stiffness of the push tube 3, the steering tube 4, and the fitting tube 5 reaches the set value (e.g., the stiffness of the push tube 3 is 20 GPa, the stiffness of the steering tube 4 is 10 GPa, and the stiffness of the fitting tube 5 is 7 GPa), the second latch 38 is completely engaged in the groove of the locking tooth 17 under the compression of the spring piece 10, forming a tight mesh. Under the combined action of the elastic restoring force of the second latch 38 and the compressive force of the spring piece 10, the sliding ring 9 is firmly locked in its current position and cannot move on its own. The sliding ring 9 is completely locked. After completion, the opening angle of the spring 10 remains unchanged, and the contraction state of the inner tube 7 cannot be changed. The stiffness of the push tube 3, the turning tube 4, and the fitting tube 5 remains stable. The linkage shaft 8 connects the push tube 3, the turning tube 4, and the fitting tube 5, transmitting the deformation force of each section of the braided mesh tube 20 to ensure that the sliding ring 9 in the push tube 3, the turning tube 4, and the fitting tube 5 locks synchronously. When the medical staff withdraws the guide tube, the guide tube enters the normal temperature environment from the 37°C environment. The braided mesh tube 20 undergoes a phase change and reset, driving the sliding ring 9 to move along the slide groove 19 towards the tube seat 2. During this process, the sliding ring 9 compresses the spring 10. As the force is gradually reduced, the spring 10 rebounds elastically, causing the second latch 38 to move away from the locking tooth 17. When the sliding ring 9 returns to its initial position, the second latch 38 completely disengages from the groove of the locking tooth 17, releasing the locking state between the sliding ring 9 and the spring 10. Subsequently, the spring 10 continues to contract, the inner tube 7 returns to its original position and expands, and the stiffness of the guide tube returns to its initial state. This prevents problems such as insufficient pushing force and positioning deviation caused by rebound after stiffness adjustment during the stiffness adjustment process. This ensures that the shape and stiffness of the guide tube remain unchanged when medical staff push instruments and adjust the direction of the guide tube, thus improving the accuracy of the surgery.

[0025] Example 3: Please refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 8A dynamically stiffness-adjustable guide tube based on temperature-responsive memory alloy includes a main tube 1 and a tube seat 2. The main tube 1 is installed on the right side of the outer wall of the tube seat 2. The main tube 1 is composed of a push tube 3, a steering tube 4, and a fitting tube 5. The push tube 3, steering tube 4, and fitting tube 5 are all composed of an outer tube 6 and an inner tube 7. The push tube 3 and fitting tube 5 are connected to the steering tube 4 through a linkage shaft 8. A sliding ring 9 is provided in the interlayer formed by the outer tube 6 and the inner tube 7. A spring piece 10 is provided on the outer wall of the sliding ring 9 near the inner tube 7. The inner tube 7 is composed of four bushing pieces 11. A support piece 12 is provided on the outer wall of each bushing piece 11 near the outer tube 6. The bushing pieces 11 are connected to each other through a hinge 13 and a connecting edge 14. The hinge 13 is installed on the outer wall of the bushing piece 11 near the outer tube 6, and the connecting edge 14 is provided on the outer wall of the bushing piece 11 away from the outer tube 6. The sliding ring 9 is composed of a sleeve 15, an outer slider 16, a locking tooth 17, and a connector 18. A sleeve 15 is provided on the outer wall of the spring piece 10 near the outer tube 6. A locking tooth 17 is provided on the outer wall of the sleeve 15 near the spring piece 10. The outer slider 16 and the connector 18 are alternately arranged on the outer wall of the sleeve 15 near the outer tube 6. The outer slider 16 matches the groove 19 provided on the inner wall of the outer tube 6 near the sliding ring 9. The outer wall of the inner tube 7 is provided with a coating 37 on the side away from the outer tube 6; Furthermore, in a normal temperature environment, the braided mesh tube 20 is in a martensitic state, the main tube 1 is naturally relaxed, the sliding ring 9 is in its initial position near the tube seat 2, the spring plate 10 naturally contracts, and there is no significant compressive force on the support plate 12 on the surface of the bushing plate 11. With its own elasticity and the assistance of the support plate 12, the bushing plate 11 fully expands through the hinge 13, the connecting edge 14 naturally extends, and completely fills the gap between adjacent bushing plates 11. The initial inner diameter of the inner tube 7 reaches 1.5 mm, and the coating 37 covers the inner wall of the inner tube 7, making... The inner tube 7 has a smooth surface, allowing medical staff to easily pre-install instruments such as stents and biopsy needles into its channel. When the guide tube enters a 37°C environment, the braided mesh tube 20 undergoes a phase change, causing the sliding ring 9 to move along the slide groove 19. During the movement of the sliding ring 9, the spring 10 is compressed, causing it to open at an angle of 5°-10°. The opened spring 10 exerts a uniform compressive force on the support plate 12 on the surface of the bushing 11. Under the compressive force of the spring 10, the bushing 11 rotates inward synchronously around the hinge 13 and contracts, reducing the inner diameter of the inner tube 7 to 1. 2-1.3mm, the connecting edge 14, under the pressure of the bushing 11, tightly fits the edge of the adjacent bushing 11, completely filling the gap of the bushing 11. The support piece 12 maintains the circular cross-section of the inner tube 7 during the shrinkage of the bushing 11. At this time, the sliding ring 9 is locked in the current position to avoid an elliptical cross-section. The linkage shaft 8 connects the push tube 3, the turning tube 4, and the bonding tube 5, transmitting the deformation force of each section of the braided mesh tube 20, ensuring that the sliding ring 9 in the push tube 3, the turning tube 4, and the bonding tube 5 moves synchronously and the spring piece 10 opens synchronously. To achieve synchronous contraction of the three sections of inner tube 7, during the retraction of the guide tube, the guide tube changes from a 37°C environment to a normal temperature environment, the braided mesh tube 20 undergoes a phase change, causing the sliding ring 9 to move closer to the tube seat 2. After the sliding ring 9 resets, the spring piece 10 loses its compressive force and contracts naturally, and the support force on the bushing piece 11 disappears. With its own elasticity and the assistance of the support piece 12, the bushing piece 11 is fully reset and expanded through the hinge 13, and the connecting edge 14 naturally extends again, ensuring that there is no gap between adjacent bushing pieces 11, and the inner diameter of the inner tube 7 is restored to 1.5mm.

[0026] Example 4: Please refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 7A dynamically stiffness-adjustable guide tube based on temperature-responsive memory alloy includes a main tube 1 and a tube seat 2. The main tube 1 is installed on the right side of the outer wall of the tube seat 2. The main tube 1 is composed of a push tube 3, a steering tube 4, and a fitting tube 5. The push tube 3, steering tube 4, and fitting tube 5 are all composed of an outer tube 6 and an inner tube 7. The push tube 3 and fitting tube 5 are connected to the steering tube 4 through a linkage shaft 8. A sliding ring 9 is provided in the interlayer formed by the outer tube 6 and the inner tube 7. A spring piece 10 is provided on the outer wall of the sliding ring 9 near the inner tube 7. The inner tube 7 is composed of four bushing pieces 11. A support piece 12 is provided on the outer wall of each bushing piece 11 near the outer tube 6. The bushing pieces 11 are connected to each other through a hinge 13 and a connecting edge 14. The hinge 13 is installed on the outer wall of the bushing piece 11 near the outer tube 6, and the connecting edge 14 is provided on the outer wall of the bushing piece 11 away from the outer tube 6. The regulating tube 22 is equipped with a traction wire 23. The diameter of the traction wire 23 in the pushing tube 3 is 0.18-0.2mm, the diameter of the traction wire 23 in the turning tube 4 is 0.15-0.17mm, and the diameter of the traction wire 23 in the fitting tube 5 is 0.12-0.14mm. A knob 24 is installed on the outer wall of the tube seat 2. The front side of the outer wall of the knob 24 is close to the outer wall of the tube seat 2 and has a scale. The knob 24 is connected to the connector 18 through the traction wire 23. A bending-resistant tube 25 is installed at the connection between the main tube 1 and the tube seat 2. The bending-resistant tube 25 is composed of a sheath 26, an adjusting tube 27, a spacer 28, a support ring 29, and a sealing ring 30. A sheath 26 is installed on the right side of the outer wall of the tube seat 2. A spacer 28 is provided on the inner wall of the sheath 26. An adjusting tube 27 is provided in the interlayer formed by the sheath 26 and the spacer 28. The adjusting tube 27 is connected to the adjusting tube 22. A support ring 29 is provided on the outer wall of the spacer 28 away from the sheath 26. A sealing ring 30 is provided on the outer wall of the support ring 29 away from the spacer 28. Limiting blocks 31 are provided on both the left and right sides of the outer wall of the knob 24, a buckle 32 is installed on the lower side of the outer wall of the tube seat 2, and a sealing cap 33 is installed at the connection between the tube seat 2 and the anti-bending tube 25. The inner wall of the regulating tube 22 is provided with a guide groove 39, and the traction wire 23 is set in contact with the guide groove 39. The guide groove 39 is parallel to the slide groove 19. Furthermore, before the guide tube enters the patient's body, medical staff fix the tube seat 2 to the operating platform using the clip 32 to prevent catheter displacement during the operation. Medical staff rotate the knob 24 back and forth to retract and extend the traction wire 23, testing that the retraction and extension of the traction wire 23 does not cause jamming or unraveling, confirming that the guide groove 39 is parallel to the slide groove 19. During the rotation of the knob 24, the limiting block 31 prevents excessive rotation by medical staff, which could cause the traction wire 23 to break or loosen. After completing the inspection, medical staff rotate the knob 24 to the initial 0 position. After the guide tube enters the patient's body, although the rigidity of the main tube 1 changes due to temperature differences... However, due to the patient's blood vessel curvature, diameter, and other morphological factors, as well as surgical requirements, the rigidity of the push tube 3, steering tube 4, and fitting tube 5 may need to be manually adjusted. Medical staff rotate knob 24 to move the traction wire 23 along the guide groove 39 inside the first adjustment tube 22. The connection between the second adjustment tube 27 and the first adjustment tube 22 allows the traction wire 23 to be transmitted to the main tube 1 through the internal channel of the anti-bend tube 25. The sheath 26 and support ring 29 of the anti-bend tube 25 ensure that the traction wire 23 moves without resistance or deviation during movement. To prevent medical staff from accidentally rotating knob 24, knob 24 can be configured with three knobs, each connected to one of the push tube 3, steering tube 4, and fitting tube 5 respectively. Corresponding to tube 5, medical staff can individually adjust the stiffness of the push tube 3, the turning tube 4, and the fitting tube 5 by rotating the corresponding knob 24. The traction wire 23 inside the push tube 3 has a diameter of 0.18-0.2mm, is high in strength, and increases the stiffness of the push tube 3 when tightened, making it suitable for pushing into superficial straight blood vessels and providing sufficient support. The traction wire 23 inside the turning tube 4 has a diameter of 0.15-0.17mm, is flexible, and has moderate stiffness when tightened, making it suitable for blood vessel bifurcation points and allowing for flexible turning without rebound. The traction wire 23 inside the fitting tube 5 has a diameter of 0.12-0.14mm, is flexible, and slightly increases in stiffness when tightened. It is suitable for deep and tortuous blood vessels, and can gently fit without damaging the vascular endothelium. During adjustment, the sheath 26 can bend slightly with the rotation of the main tube 1. The support ring 29 can prevent excessive bending at the connection between the anti-bend tube 25 and the main tube 1, which would cause the traction wire 23 to get stuck. The sealing ring 30 and the sealing cap 33 can ensure the sealing of the guide tube and prevent body fluids and impurities from entering. During withdrawal, medical staff can turn the knob 24 to the 0 mark to completely relax the traction wire 23 and reset the sliding ring 9. Medical staff can then release the buckle 32 and hold the tube seat 2 to withdraw the guide tube. The sheath 26 will naturally stretch during withdrawal to prevent the guide tube from bending.

[0027] Example 5: Please refer to Figure 1 , Figure 2 , Figure 4 , Figure 6 and Figure 7A dynamically stiffness-adjustable guide tube based on temperature-responsive memory alloy includes a main tube 1 and a tube seat 2. The main tube 1 is installed on the right side of the outer wall of the tube seat 2. The main tube 1 is composed of a push tube 3, a steering tube 4, and a fitting tube 5. The push tube 3, steering tube 4, and fitting tube 5 are all composed of an outer tube 6 and an inner tube 7. The push tube 3 and fitting tube 5 are connected to the steering tube 4 through a linkage shaft 8. A sliding ring 9 is provided in the interlayer formed by the outer tube 6 and the inner tube 7. A spring piece 10 is provided on the outer wall of the sliding ring 9 near the inner tube 7. The inner tube 7 is composed of four bushing pieces 11. A support piece 12 is provided on the outer wall of each bushing piece 11 near the outer tube 6. The bushing pieces 11 are connected to each other through a hinge 13 and a connecting edge 14. The hinge 13 is installed on the outer wall of the bushing piece 11 near the outer tube 6, and the connecting edge 14 is provided on the outer wall of the bushing piece 11 away from the outer tube 6. The sliding ring 9 is composed of a sleeve 15, an outer slider 16, a locking tooth 17, and a connector 18. A sleeve 15 is provided on the outer wall of the spring piece 10 near the outer tube 6. A locking tooth 17 is provided on the outer wall of the sleeve 15 near the spring piece 10. The outer slider 16 and the connector 18 are alternately arranged on the outer wall of the sleeve 15 near the outer tube 6. The outer slider 16 matches the groove 19 provided on the inner wall of the outer tube 6 near the sliding ring 9. The regulating tube 22 is equipped with a traction wire 23. The diameter of the traction wire 23 in the pushing tube 3 is 0.18-0.2mm, the diameter of the traction wire 23 in the turning tube 4 is 0.15-0.17mm, and the diameter of the traction wire 23 in the fitting tube 5 is 0.12-0.14mm. A knob 24 is installed on the outer wall of the tube seat 2. The front side of the outer wall of the knob 24 is close to the outer wall of the tube seat 2 and has a scale. The knob 24 is connected to the connector 18 through the traction wire 23. A cap 34 is installed on the outer wall of the bonding tube 5 away from the turning tube 4. A developing ring 35 is embedded in the right side of the inner wall of the cap 34. A support core 36 is installed on the left side of the outer wall of the developing ring 35. The cap 34 is connected to the bonding tube 5 through the support core 36. Furthermore, after removing the guiding tube, medical staff check whether the cap 34 is damaged or deformed. They can gently press the flexible silicone cap 34; if it quickly rebounds without wrinkles, the cap 34's protective function is intact. During the insertion of the guiding tube into the patient, as the cap 34 at the front end of the adhesive tube 5 deepens, the platinum-iridium alloy imaging ring 35 is visualized using DSA angiography equipment. Medical staff determine the specific position of the cap 34 by observing the position of the imaging spot. When the imaging spot deviates from the target position, medical staff can adjust the rigidity of the adhesive tube 5 by rotating the tube seat 2 or by turning the knob 24, thus adjusting the direction of the guiding tube. Until the imaging spot is precisely aligned with the target position and the cap 34 is confirmed to be in contact with the target vessel wall, the medical staff then pushes the instrument pre-placed in the guiding tube. The instrument moves along the inner tube 7 and eventually passes through the support core 36 and the imaging ring 35, exiting from the side of the cap 34 away from the contact tube 5. The support core 36 can prevent the cap 34 from collapsing due to vessel compression and instrument pushing force during the delivery of the guiding tube. During the withdrawal of the guiding tube, the flexible material of the cap 34 can avoid scratching the vascular intima. After the guiding tube is completely withdrawn from the patient's body, the medical staff need to check the integrity of the cap 34, the position of the imaging ring 35, and the connection stability of the support core 36 for reuse.

[0028] Working principle: Before using the guide tube, medical staff check the integrity of the guide tube packaging to ensure that the packaging is undamaged. The medical staff take out the guide tube and rotate the knob 24 back and forth to drive the traction wire 23 to retract and extend. The traction wire 23 is tested to ensure that there is no jamming or fraying. The guide groove 39 is confirmed to be parallel to the slide groove 19. The cap 34 is checked for damage and deformation. After confirming that the guide tube is intact, the medical staff delivers the guide tube into the patient's body. The guide tube enters the human body environment of 37°C from the 25-28°C room temperature environment. The temperature change causes the braided mesh tube 20 of nickel-titanium alloy to undergo a phase transformation, changing from a martensitic state to an austenitic state. The contraction of the braided mesh tube 20 drives the sliding ring 9 to move away from the tube seat 2 along the slide groove 19. During the movement of the sliding ring 9, it pushes the spring 10. After being squeezed, the spring 10 opens and squeezes the bushing 11, which in turn causes the bushing 11 to contract, reducing the inner diameter of the inner tube 7 while increasing its rigidity. During the sliding process of the outer slider 16 on the surface of the sleeve 15 within the slide groove 19, when the sliding ring 9 pushes the spring 10 to open, the spring 10 deforms after being squeezed, and the second buckle 38 moves closer to the locking tooth 17. The sliding ring 9 moves to the preset stroke, and the stiffness of the push tube 3, the turning tube 4, and the fitting tube 5 reaches the set value. Under the compression of the spring 10, the second buckle 38 is completely inserted into the groove of the locking tooth 17, forming a tight engagement. Under the combined action of the elastic restoring force of the second buckle 38 and the squeezing force of the spring 10, the sliding ring 9 is firmly locked in the current position and cannot move on its own. After the sliding ring 9 is locked, the opening angle of the spring 10 remains unchanged, and the contraction state of the inner tube 7 cannot be changed. The stiffness of the push tube 3, the turning tube 4, and the fitting tube 5 remains stable. After the guiding tube is inserted into the patient's body, medical staff observe the position of the imaging ring 35 using DSA angiography equipment. When the head cap 34 shifts position, medical staff manually adjust the stiffness of the pushing tube 3, the turning tube 4, and the fitting tube 5 by rotating the knob 24. The knob 24 drives the traction wire 23 to move in the first adjustment tube 22 and the second adjustment tube 27, so that the sliding ring 9 moves with the extension and retraction of the traction wire 23, thereby completing the individual adjustment of the stiffness of the pushing tube 3, the turning tube 4, and the fitting tube 5, so that the head cap 34 reaches the target position, which is convenient for medical staff to operate. After the surgery, the medical staff removed the guiding tube from the patient's body. The ambient temperature of the guiding tube gradually decreased from 37℃ to 25-28℃. The braided mesh tube 20 underwent a phase transformation, changing from an austenitic state to a martensitic state. The braided mesh tube 20 reset, causing the sliding ring 9 to move along the groove 19 towards the tube seat 2. The spring 10 returned to its original position after losing external force. The second latch 38 moved away from the locking tooth 17. When the sliding ring 9 returned to its initial position, the second latch 38 completely disengaged from the groove of the locking tooth 17, releasing the locking state between the sliding ring 9 and the spring 10. Subsequently, the spring 10 continued to contract, the inner tube 7 reset and expanded, and the stiffness of the guiding tube returned to its initial state. The bushing 11 reset through the hinge 13, restoring the inner diameter of the inner tube 7. The medical staff then removed the instruments.

[0029] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A dynamically stiffness-adjustable conductive tube based on temperature-responsive shape memory alloy, characterized in that: Includes a main tube (1) and a tube seat (2). The main tube (1) is installed on the right side of the outer wall of the tube seat (2). The main tube (1) is composed of a push tube (3), a steering tube (4), and a fitting tube (5). The push tube (3), steering tube (4), and fitting tube (5) are all composed of an outer tube (6) and an inner tube (7). The push tube (3) and fitting tube (5) are connected to the steering tube (4) through a linkage shaft (8). A sliding ring (9) is provided in the interlayer formed by the outer tube (6) and the inner tube (7). (9) A spring piece (10) is provided on the outer wall near the inner tube (7). The inner tube (7) is composed of 4 bushing pieces (11). A support piece (12) is provided on the outer wall of each bushing piece (11) near the outer tube (6). The bushing pieces (11) are connected to each other by a hinge (13) and a connecting edge (14). A hinge (13) is installed on the outer wall of the bushing piece (11) near the outer tube (6). A connecting edge (14) is provided on the outer wall of the bushing piece (11) away from the outer tube (6).

2. The dynamically stiffness-adjustable guide tube based on temperature-responsive memory alloy according to claim 1, characterized in that: The sliding ring (9) is composed of a sleeve (15), an outer slider (16), a locking tooth (17), and a connector (18). The outer wall of the spring piece (10) is provided with a sleeve (15) on the side near the outer tube (6). The outer wall of the sleeve (15) is provided with a locking tooth (17) on the side near the spring piece (10). The outer slider (16) and the connector (18) are alternately arranged on the side of the outer wall of the sleeve (15) near the outer tube (6). The outer slider (16) matches the groove (19) provided on the side of the inner wall of the outer tube (6) near the sliding ring (9).

3. The dynamically stiffness-adjustable guide tube based on temperature-responsive memory alloy according to claim 2, characterized in that: The outer tube (6) is composed of a braided mesh tube (20). Positioning platforms (21) are provided at both ends of the outer wall of the braided mesh tube (20). An adjustment tube (22) is provided on the inner wall of the outer tube (6). The braiding density of the braided mesh tube (20) of the push tube (3), the turning tube (4) and the bonding tube (5) decreases in sequence. The braiding angle of the outer tube (6) of the push tube (3), the turning tube (4) and the bonding tube (5) increases in sequence.

4. The dynamically stiffness-adjustable guide tube based on temperature-responsive memory alloy according to claim 3, characterized in that: The regulating tube (22) is equipped with a traction wire (23). The diameter of the traction wire (23) in the pushing tube (3) is 0.18-0.2 mm. The diameter of the traction wire (23) in the turning tube (4) is 0.15-0.17 mm. The diameter of the traction wire (23) in the fitting tube (5) is 0.12-0.14 mm. A knob (24) is installed on the outer wall of the tube seat (2). The front side of the outer wall of the knob (24) is close to the outer wall of the tube seat (2). The knob (24) is connected to the connector (18) through the traction wire (23).

5. The dynamically stiffness-adjustable guide tube based on temperature-responsive memory alloy according to claim 4, characterized in that: A bending-resistant tube (25) is installed at the connection between the main tube (1) and the tube seat (2). The bending-resistant tube (25) is composed of a sheath (26), an adjusting tube (27), a spacer (28), a support ring (29), and a sealing ring (30). A sheath (26) is installed on the right side of the outer wall of the tube seat (2). A spacer (28) is provided on the inner wall of the sheath (26). An adjusting tube (27) is provided in the interlayer formed by the sheath (26) and the spacer (28). The adjusting tube (27) is connected to the adjusting tube (22). A support ring (29) is provided on the side of the outer wall of the spacer (28) away from the sheath (26). A sealing ring (30) is provided on the side of the outer wall of the support ring (29) away from the spacer (28).

6. The dynamically stiffness-adjustable guide tube based on temperature-responsive memory alloy according to claim 5, characterized in that: Limit blocks (31) are provided on both the left and right sides of the outer wall of the knob (24), a buckle (32) is installed on the lower side of the outer wall of the tube seat (2), and a sealing cap (33) is installed at the connection between the tube seat (2) and the anti-bending tube (25).

7. The dynamically stiffness-adjustable guide tube based on temperature-responsive memory alloy according to claim 1, characterized in that: A cap (34) is installed on the outer wall of the fitting tube (5) away from the turning tube (4). A developing ring (35) is embedded on the right side of the inner wall of the cap (34). A support core (36) is installed on the left side of the outer wall of the developing ring (35). The cap (34) is connected to the fitting tube (5) through the support core (36).

8. The dynamically stiffness-adjustable guide tube based on temperature-responsive memory alloy according to claim 1, characterized in that: The outer wall of the inner tube (7) is provided with a coating (37) on the side away from the outer tube (6).

9. The dynamically stiffness-adjustable guide tube based on temperature-responsive memory alloy according to claim 2, characterized in that: The outer wall of the spring piece (10) is provided with a second buckle (38) near the locking tooth (17), and the second buckle (38) engages with the locking tooth (17).

10. The dynamically stiffness-adjustable guide tube based on temperature-responsive memory alloy according to claim 4, characterized in that: The inner wall of the regulating tube (22) is provided with a guide groove (39), and the traction wire (23) is set in accordance with the guide groove (39). The guide groove (39) is parallel to the slide groove (19).

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