Intraspinal anesthesia catheter device with temperature compensation function

Abstract

The invention discloses an intra-spinal anesthesia catheter device with a temperature compensation function, and relates to the technical field of medical instruments. The intra-spinal anesthesia catheter device comprises an anesthesia catheter body, the anesthesia catheter body comprises a thermoplastic elastomer and a shape memory polymer, and the thermoplastic elastomer wraps the outer side of the shape memory polymer. The intraspinal anesthesia catheter has the beneficial effects that through combination of an innovative intelligent material system and an active closed-loop control technology, the traditional contradiction that the rigid requirement and the soft safety of the catheter cannot be achieved at the same time in intraspinal anesthesia is fundamentally solved. The method has the primary advantage that the dynamic programmable adjustment of the mechanical property of the catheter is realized.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a spinal anesthesia catheter device with temperature compensation function. Background Technology

[0002] Spinal anesthesia (including epidural and subarachnoid anesthesia) is a key technology in surgical procedures and analgesia, and its success and safety highly depend on the precise placement and stable indwelling of the anesthesia catheter. However, traditional anesthesia catheters, limited by the passive nature of their materials and structure, have long faced a series of unresolved technical contradictions and clinical challenges.

[0003] Most existing spinal anesthesia catheters are made of a single polymer material (such as polyurethane or silicone), and their mechanical properties remain unchanged before and after insertion. This fixed characteristic leads to a fundamental dilemma in clinical practice: to overcome tissue resistance and be successfully advanced to the target location, the catheter needs to have sufficient rigidity and stiffness. However, this characteristic also increases the risk of perforating the dura mater, damaging blood vessels or nerve roots, and is one of the main causes of complications such as headache and hematoma after dural perforation. Conversely, if a softer material is used to improve biocompatibility and safety, the catheter is more likely to bend, twist, or become difficult to insert when passing through the narrow and tortuous epidural space, leading to insertion failure or poor positioning, and affecting the anesthetic effect.

[0004] To address the rigidity issue, the industry has made several attempts. For example, composite materials or metal wires added to the catheter can enhance guidance; however, this typically only improves rigidity in the initial placement phase and does not solve the long-term tissue irritation problem caused by maintaining rigidity after placement. Other studies have explored the use of temperature-responsive materials, such as certain thermoplastic polymers, whose rigidity changes with body temperature. However, this passive change dependent on ambient temperature is uncontrollable, irreversible, and slow-responding, failing to meet the dynamic and precise requirements of catheter performance at different stages of the procedure. For example, it is impossible to actively increase rigidity during placement or actively soften it after placement.

[0005] Regarding catheter positioning and safety, traditional catheters have a fixed tip shape, making their direction of advancement unpredictable when encountering resistance or anatomical variations, potentially leading to accidental entry into blood vessels or side cavities. While there are catheters with pre-formed bends, their bending direction is fixed before insertion, making it impossible to actively avoid obstacles or adjust them within the body. Furthermore, during catheter placement, micro-movements caused by respiration and changes in body position can cause continuous friction and pressure on sensitive tissues from the edges of traditional rigid catheters.

[0006] In terms of temperature management, although there are concepts proposing to heat the catheter to change its performance, existing ideas are mostly limited to a single heating element, lacking precise spatial control and real-time feedback adjustment of the temperature field. This can easily lead to local overheating that damages tissue or uneven heating that results in inconsistent performance changes. At the same time, there is also a lack of collaborative design to effectively isolate the thermal stimulation that may be caused by active heating. In view of this, in-depth research was conducted to address the above problems, which led to this case. Summary of the Invention

[0007] The technical solution of the present invention to achieve the above objectives is as follows: a spinal anesthesia catheter device with temperature compensation function, comprising an anesthesia catheter body, the anesthesia catheter body comprising a thermoplastic elastomer and a shape memory polymer, the thermoplastic elastomer wrapping the outer side of the shape memory polymer, the thermoplastic elastomer and the shape memory polymer being interconnected by co-extrusion molding, the thickness of the thermoplastic elastomer sheath layer accounting for 60%-80% of the total thickness of the catheter wall; on the inner side of the shape memory polymer core layer, a plurality of conical hole-shaped limiting rubber blocks are distributed axially at intervals; the conical hole-shaped limiting rubber blocks are made of polyurethane material and are cured integrally with the inner surface of the shape memory polymer core layer and the inner side of the thermoplastic elastomer sheath layer through a secondary injection molding process; the bottom surface of the conical hole-shaped limiting rubber block is connected to the shape memory polymer core layer, its conical tip protruding towards the inner side of the catheter lumen, the conical hole structure being axially continuous along the rubber block, forming a microchannel for drug flow; The thermoplastic elastomer sheath, the shape memory polymer core, and the conical hole-shaped limiting rubber block together constitute a triple collaborative intelligent structure of "active stiffness adjustment - programmed deformation - flexible mechanical limiting". The thermoplastic elastomer sheath provides adjustable active stiffness compensation for the catheter through its characteristic that the hardness changes continuously and reversibly with temperature. The shape memory polymer core layer provides the catheter tip with a safe deformation capability for active avoidance through its characteristic of triggering a preset deformation when heated; The conical hole-shaped limiting adhesive block, through its connection with the two polymer layers, the conical tip protruding into the lumen, and the axially penetrating microchannel structure, provides flexible, non-rigid physical constraints and stress dispersion when the shape memory polymer core layer is heated and expanded or bent, thereby precisely guiding it to deform along a preset path while ensuring the unobstructed flow of the liquid medicine. Through the synergistic effect of the above three structures, the anesthesia catheter body can dynamically and reliably adapt to the complex anatomical environment within the spinal canal at different stages of operation. While achieving the combined functions of "adjustable rigidity for easy insertion" and "bendable tip for active obstacle avoidance", it fundamentally overcomes the technical contradictions of traditional rigid catheters being prone to tissue damage and flexible catheters being difficult to insert and having uncontrollable deformation.

[0008] Preferably, an embedded temperature control layer is installed on the inner side of the thermoplastic elastomer. The embedded temperature control layer includes micro-metal temperature regulating wires, which are arranged in a spiral shape and pre-placed in the thermoplastic elastomer during co-extrusion molding. The micro-metal temperature regulating wires include nickel-titanium alloy and copper alloy. The embedded temperature control layer also includes a micro-temperature sensor and a flexible circuit. The micro-temperature sensor is a thin-film thermistor, which is precisely mounted on the flexible circuit. The flexible circuit is a platinum metal thin-film wire.

[0009] Preferably, the outer side of the anesthesia catheter body is coated with a medical porous aerogel coating.

[0010] Preferably, phase change material microcapsules are uniformly dispersed in the substrates of the thermoplastic elastomer and the shape memory polymer, wherein the capsule wall is a polymer material and the core material is paraffin or inorganic salt phase change material.

[0011] Preferably, the embedded sensing temperature control layer further includes a positive temperature coefficient thermistor material, which is connected to the flexible circuit as an independent heating element.

[0012] Preferably, the outer side of the medical porous aerogel coating is further composited with a biocompatible hollow fiber braided reinforcement layer, which is bonded to the catheter body by a medical adhesive.

[0013] Preferably, the thin-film thermistor, the platinum metal thin-film wire and its connecting nodes are completely encapsulated and cured into one piece by the thermoplastic elastomer material through a micro-injection molding process, and an insulating gap is provided between them and the spirally arranged micro metal temperature-regulating wires.

[0014] Preferably, the pitch of the spirally arranged micro-metal temperature-regulating wires varies in a gradient from the proximal to the distal end of the anesthesia catheter body, wherein the distal pitch is smaller than the proximal pitch, so as to form a higher heat flux density at the distal end and achieve precise and rapid temperature regulation in the catheter tip region.

[0015] Preferably, the shape memory polymer core layer has a preset deformation program; when the gradient-changing micro-metal temperature-regulating wire precisely and rapidly heats the area at the tip of the conduit, it can first trigger the shape memory polymer in that area to reach its transformation temperature, causing it to change from a preset straight shape to a set safe curved shape according to the program.

[0016] Preferably, an external temperature control monitoring unit is connected to the anesthesia catheter body, and the external temperature control monitoring unit includes: The main control unit is pre-programmed with a temperature control program and deformation triggering parameters for the shape memory polymer; The temperature acquisition module receives temperature signals from multiple monitoring points of the thin-film thermistor in real time via the platinum metal thin-film wire. The power drive module outputs a controllable drive current to the miniature metal temperature-regulating wire according to the output command of the main control unit. The main control unit is configured to: based on the real-time temperature data fed back by the temperature acquisition module, dynamically adjust the current output to the miniature metal temperature-regulating wire through the power drive module, thereby forming a closed-loop control system that can independently or collaboratively execute at least one of the following control modes: Hardness adjustment mode: Controls the overall or segmented temperature of the thermoplastic elastomer sheath to change its hardness, assisting in insertion or increasing indwelling comfort; Deformation triggering mode: Precisely control the heating rate and target temperature of the catheter tip region to trigger the shape memory polymer core layer to safely deform according to a preset program.

[0017] The spinal anesthesia catheter device with temperature compensation function, manufactured using the technical solution of this invention, fundamentally solves the traditional contradiction in spinal anesthesia where "the rigidity requirement of the catheter and the softness and safety are mutually exclusive" through an innovative intelligent material system combined with active closed-loop control technology. Its primary advantage is the realization of dynamic programmable adjustment of the catheter's mechanical properties: through the "rigidity adjustment mode" of the external host, the catheter can be actively controlled to remain rigid during insertion to facilitate pushing, and quickly return to softness after placement to reduce tissue damage. This significantly reduces the risk of complications such as dural perforation while improving the success rate of first-time placement. The second major advantage is the realization of active and controllable directional safety deformation: based on the synergy of gradient heating technology and shape memory polymers, the catheter tip can precisely bend within the body according to a preset program, achieving "active obstacle avoidance" and greatly enhancing safety and passage through complex anatomical structures. Third, the entire system operates with precision, safety, and reliability: the high-precision closed-loop temperature control system ensures minute-by-minute thermal management; while the passive buffering of the phase change material, the efficient thermal insulation of the aerogel, and the mechanical reinforcement of the hollow fiber layer together constitute a multi-layered safety guarantee, preventing thermal damage and improving catheter durability. Finally, while highly integrating miniaturized sensing and actuation elements, this design fully retains the core drug delivery function of the catheter, and through biocompatible materials and surface treatments, ensures clinical feasibility and patient comfort. In summary, this device represents a paradigm shift from passive instruments to active intelligent devices, providing an unprecedented integrated solution for spinal anesthesia that combines safety, precision, and controllability. Attached Figure Description

[0018] Figure 1 This is a schematic diagram illustrating the control of a spinal anesthesia catheter device with temperature compensation function as described in this invention.

[0019] Figure 2 This is a schematic diagram of the main structure of a spinal anesthesia catheter device with temperature compensation function according to the present invention.

[0020] In the figure: 1. Thermoplastic elastomer; 2. Shape memory polymer; 3. Conical hole-shaped limiting block; 4. Miniature metal temperature regulating wire; 5. Nickel-titanium alloy; 6. Copper alloy; 7. Thin film thermistor. Detailed Implementation

[0021] Those skilled in the art should connect all electrical components and their compatible power supplies in this case via wires, and should select appropriate controllers according to actual conditions to meet control requirements. The specific connection and control sequence should refer to the working principle described below, where the electrical components are connected in sequence. The detailed connection methods are well-known in the art. The following mainly introduces the working principle and process, without explaining the electrical control.

[0022] Example: Please see Figure 1-2 Spinal anesthesia has long faced a fundamental clinical dilemma: for successful insertion, the catheter needs to maintain sufficient rigidity to overcome tissue resistance, but this significantly increases the risk of dura mater perforation or vascular damage; conversely, while using soft materials can improve safety, it can easily lead to catheter bending, difficulty in insertion, or inaccurate positioning in complex anatomical structures. Existing improvements, such as using composite reinforcing materials or polymers that passively soften based on body temperature, cannot achieve on-demand, dynamic, and reversible adjustment of catheter performance during the procedure; traditional pre-bent catheters also lack the ability to actively avoid obstacles within the body. In addition, simple heating concepts, due to the lack of precise temperature field control and real-time feedback, pose risks of overheating or uneven performance adjustment, and fail to effectively isolate thermal stimulation. Therefore, this application protects a spinal anesthesia catheter device with temperature compensation function, including an anesthesia catheter body. The anesthesia catheter body includes a thermoplastic elastomer 1 and a shape memory polymer 2. The thermoplastic elastomer 1 is wrapped around the outside of the shape memory polymer 2. The thermoplastic elastomer 1 and the shape memory polymer 2 are interconnected by co-extrusion molding. The thickness of the sheath layer of the thermoplastic elastomer 1 accounts for 60%-80% of the total thickness of the catheter wall. On the inner side of the core layer of the shape memory polymer 2, a plurality of conical hole-shaped limiting rubber blocks 3 are distributed axially at intervals. The conical hole-shaped limiting rubber blocks 3 are made of polyurethane material and are bonded to the inner surface of the core layer of the shape memory polymer 2 and the surrounding material through a secondary injection molding process. The inner side of the thermoplastic elastomer 1 sheath is cured into a single unit; the bottom surface of the conical hole-shaped limiting adhesive block 3 is connected to the shape memory polymer 2 core layer, and its conical tip protrudes towards the inner side of the catheter lumen. The conical hole structure is axially continuous along the adhesive block, forming a microchannel for drug flow; the thermoplastic elastomer 1 sheath layer, the shape memory polymer 2 core layer, and the conical hole-shaped limiting adhesive block 3 together constitute a triple-synergistic intelligent structure of "active stiffness adjustment - programmed deformation - flexible mechanical limiting"; wherein, the thermoplastic elastomer 1 sheath layer, through its characteristic of continuous and reversible change in hardness with temperature, provides the catheter with adjustable active stiffness compensation throughout its entire length; the shape memory polymer 2 core layer, through its characteristic of heat-triggered preset deformation, provides... The catheter tip provides active obstacle avoidance and safe deformation capability. The conical orifice-shaped limiting block 3, through its connection with the two polymer layers, the conical tip protruding into the lumen, and the axially penetrating microchannel structure, provides flexible, non-rigid physical constraints and stress dispersion when the shape memory polymer 2 core layer expands or bends due to heat, thereby precisely guiding its deformation along a preset path while ensuring unobstructed drug delivery. Through the synergistic effect of the above three structures, the anesthesia catheter body can dynamically and reliably adapt to the complex anatomical environment within the spinal canal at different stages of operation. While achieving the combined functions of "adjustable rigidity for easy insertion" and "bendable tip for active obstacle avoidance," it fundamentally overcomes the limitations of traditional rigid catheters. The technical contradiction between the potential for tissue damage and the difficulty in inserting flexible catheters, and the uncontrollable deformation, is addressed. An embedded temperature-controlled sensing layer is installed on the inner side of the thermoplastic elastomer 1. This layer includes micro-metal temperature-regulating wires 4, which are arranged in a spiral shape and pre-inserted into the thermoplastic elastomer 1 during co-extrusion molding. The micro-metal temperature-regulating wires 4 comprise nickel-titanium alloy 5 and copper alloy 6. The embedded temperature-controlled sensing layer also includes a micro-temperature sensor and a flexible circuit. The micro-temperature sensor is a thin-film thermistor 7, which is precisely mounted on the flexible circuit, which is a platinum metal thin-film wire. A medical porous aerogel coating is applied to the outer side of the anesthesia catheter body.Phase change material microcapsules are uniformly dispersed in the substrates of the thermoplastic elastomer 1 and the shape memory polymer 2. The capsule walls are made of polymer materials, and the core material is paraffin or inorganic salt phase change material. The embedded sensing temperature control layer also includes a positive temperature coefficient thermistor material, which is connected to the flexible circuit as an independent heating element. A biocompatible hollow fiber braided reinforcement layer is further laminated to the outside of the medical porous aerogel coating, and the reinforcement layer is bonded to the catheter body by a medical adhesive. The thin-film thermistor 7, the platinum metal thin-film wire, and its connecting joints are also included. The point is completely encapsulated and cured into a single unit by the thermoplastic elastomer 1 material through a micro-injection molding process, and an insulating gap is provided between it and the spirally arranged micro-metal temperature-regulating wires 4; the pitch of the spirally arranged micro-metal temperature-regulating wires 4 varies gradually from the proximal end to the distal end of the anesthesia catheter body, with the distal pitch being smaller than the proximal pitch, which can form a higher heat flux density at the distal end, achieving precise and rapid temperature regulation in the catheter tip area; the shape memory polymer 2 core layer has a preset deformation program; when the gradient-changing micro-metal temperature-regulating wires 4 precisely and rapidly heat the catheter tip area, The shape memory polymer 2 in the affected area is first triggered to reach its transformation temperature, causing it to change from a preset straight shape to a set safe curved shape according to a program. An external temperature control monitoring host is connected to the anesthesia catheter body. The external temperature control monitoring host includes: a main control unit, which has a preset temperature control program and deformation trigger parameters for the shape memory polymer 2; a temperature acquisition module, which receives temperature signals from multiple monitoring points of the thin-film thermistor 7 in real time through the platinum metal thin-film wire; and a power drive module, which outputs controllable drive power to the miniature metal temperature-regulating wire 4 according to the output command of the main control unit. Dynamic current; the main control unit is configured to: based on the real-time temperature data fed back by the temperature acquisition module, dynamically adjust the current output to the micro metal temperature-regulating wire 4 through the power drive module, thereby forming a closed-loop control system, which can independently or collaboratively execute at least one of the following control modes: hardness adjustment mode: control the overall or segmented temperature of the thermoplastic elastomer 1 sheath layer to change its hardness, assisting in insertion or increasing indwelling comfort; deformation triggering mode: precisely control the heating rate and target temperature of the catheter tip region to trigger the shape memory polymer 2 core layer to safely deform according to a preset program; In summary, the physician first selects either "hardness adjustment" or "deformation trigger" mode via an external temperature control monitoring unit based on clinical needs. Upon receiving the command, the unit's power drive module outputs precise current to the miniature metal temperature-regulating wire 4 embedded within the catheter wall, arranged in a gradient spiral pattern (sparser at the proximal end, denser at the distal end). This unique design creates a non-uniform thermal field along the catheter axis using Joule heating, achieving targeted energy accumulation and rapid response at the catheter tip. Heat is conducted to the multi-layered material system, triggering an intelligent response: in "hardness adjustment mode," heat primarily acts on the thermoplastic elastomer 1 (TPE) sheath, causing its hardness to continuously and reversibly decrease with increasing temperature. The system dynamically maintains the catheter's rigidity during insertion and its flexibility after placement through sensor feedback. In "deformation trigger mode," heat is precisely focused on the catheter tip. When the shape memory polymer 2 (SMP) core reaches its set transition temperature, it transforms from a linear shape to a preset safe curved shape according to the program. During this process, the inner conical perforated limiting adhesive block 3 provides flexible constraint through its conical tip to guide the deformation direction, while its axially penetrating microchannels ensure unobstructed drug delivery. Throughout the active temperature control process, the phase change material microcapsules uniformly dispersed in the substrate act as "miniature thermal buffers," smoothing local temperature fluctuations; while the outermost medical porous aerogel coating and hollow fiber braided layer together form a thermal barrier and mechanical protective sleeve, preventing heat diffusion damage and enhancing catheter resistance. Closed-loop control is the cornerstone of precise operation: the thin-film thermistor 7 feeds back the real-time temperature signal to the host through platinum metal thin-film wires, and the main control unit dynamically adjusts the output current accordingly, thus forming a high-precision temperature closed-loop control system that ensures all responses strictly follow instructions. In summary, this device constructs a complete intelligent medical microsystem through the deep vertical integration of intelligent material systems, embedded micro-actuators and sensors, passive compensation protective layers, and external controllers. It fundamentally solves the clinical paradox of traditional spinal anesthesia catheters being "rigid and easily damaged" and "flexible and difficult to insert," and for the first time achieves intelligent capabilities of "flexible rigidity and flexibility as needed" and "active obstacle avoidance at the tip." It is expected to significantly reduce the risk of complications, improve the success rate of the operation, and enhance patient comfort, representing an important breakthrough in the evolution of technology in this field towards active adaptation and precise control.

[0023] The above technical solutions only embody the preferred technical solutions of the present invention. Any modifications that may be made by those skilled in the art to certain parts thereof embody the principles of the present invention and fall within the protection scope of the present invention.

Claims

1. A spinal anesthesia catheter device with temperature compensation function, characterized in that, The device includes an anesthesia catheter body comprising a thermoplastic elastomer and a shape memory polymer. The thermoplastic elastomer is wrapped around the shape memory polymer, and the thermoplastic elastomer and the shape memory polymer are interconnected by co-extrusion molding. The thickness of the thermoplastic elastomer sheath layer accounts for 60%-80% of the total thickness of the catheter wall. Multiple conical hole-shaped limiting blocks are axially spaced on the inner side of the shape memory polymer core layer. These conical hole-shaped limiting blocks are made of polyurethane material and are integrally cured with the inner surface of the shape memory polymer core layer and the inner side of the thermoplastic elastomer sheath layer through a secondary injection molding process. The bottom surface of each conical hole-shaped limiting block is connected to the shape memory polymer core layer, and its conical tip protrudes towards the inner side of the catheter lumen. The conical hole structure is axially continuous along the block, forming a microchannel for drug flow.

2. The spinal anesthesia catheter device with temperature compensation function according to claim 1, characterized in that, An embedded temperature control layer is installed on the inner side of the thermoplastic elastomer. The embedded temperature control layer includes micro-metal temperature regulating wires, which are arranged in a spiral shape and pre-placed in the thermoplastic elastomer during co-extrusion molding. The micro-metal temperature regulating wires include nickel-titanium alloy and copper alloy. The embedded temperature control layer also includes a micro-temperature sensor and a flexible circuit. The micro-temperature sensor is a thin-film thermistor, which is precisely mounted on the flexible circuit. The flexible circuit is a platinum metal thin-film wire.

3. The spinal anesthesia catheter device with temperature compensation function according to claim 2, characterized in that, The outer side of the anesthesia catheter body is coated with a medical porous aerogel coating.

4. A spinal anesthesia catheter device with temperature compensation function according to claim 3, characterized in that, Phase change material microcapsules are uniformly dispersed in the substrates of the thermoplastic elastomer and the shape memory polymer. The capsule walls of the microcapsules are made of polymer materials, and the core material is paraffin or inorganic salt phase change material.

5. A spinal anesthesia catheter device with temperature compensation function according to claim 4, characterized in that, The embedded sensing temperature control layer also includes a positive temperature coefficient thermistor material, which is connected to the flexible circuit as an independent heating element.

6. A spinal anesthesia catheter device with temperature compensation function according to claim 5, characterized in that, The outer side of the medical porous aerogel coating is further composited with a biocompatible hollow fiber braided reinforcement layer, which is bonded to the catheter body by a medical adhesive.

7. A spinal anesthesia catheter device with temperature compensation function according to claim 6, characterized in that, The thin-film thermistor, the platinum metal thin-film wire and its connecting nodes are completely encapsulated and solidified into one piece by the thermoplastic elastomer material through a micro-injection molding process, and an insulating gap is provided between them and the spirally arranged micro metal temperature-regulating wires.

8. A spinal anesthesia catheter device with temperature compensation function according to claim 7, characterized in that, The pitch of the spirally arranged micro-metal temperature-regulating wires varies in a gradient from the proximal to the distal end of the anesthesia catheter body, with the distal pitch being smaller than the proximal pitch, so as to form a higher heat flux density at the distal end and achieve precise and rapid temperature regulation in the catheter tip region.

9. A spinal anesthesia catheter device with temperature compensation function according to claim 8, characterized in that, The shape memory polymer core has a preset deformation program; when the gradient-changing micro-metal temperature-regulating wire precisely and rapidly heats the area at the tip of the catheter, it can first trigger the shape memory polymer in that area to reach its transformation temperature, causing it to change from a preset straight shape to a set safe curved shape according to the program.

10. A spinal anesthesia catheter device with temperature compensation function according to claim 9, characterized in that, An external temperature monitoring unit is connected to the anesthesia catheter body, and the external temperature monitoring unit includes: The main control unit is pre-programmed with a temperature control program and deformation triggering parameters for the shape memory polymer; The temperature acquisition module receives temperature signals from multiple monitoring points of the thin-film thermistor in real time via the platinum metal thin-film wire. The power drive module outputs a controllable drive current to the miniature metal temperature-regulating wire according to the output command of the main control unit. The main control unit is configured to: based on the real-time temperature data fed back by the temperature acquisition module, dynamically adjust the current output to the miniature metal temperature-regulating wire through the power drive module, thereby forming a closed-loop control system that can independently or collaboratively execute at least one of the following control modes: Hardness adjustment mode: Controls the overall or segmented temperature of the thermoplastic elastomer sheath to change its hardness, assisting in insertion or increasing indwelling comfort; Deformation triggering mode: Precisely control the heating rate and target temperature of the catheter tip region to trigger the shape memory polymer core layer to safely deform according to a preset program.

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