An anti-bending intracranial double-lumen guiding catheter

Abstract

The present invention relates to the technical field of medical catheters, and specifically discloses an anti-bending intracranial double-tube guiding catheter, which includes a tube body formed by an outer catheter and an inner catheter inserted inside the outer catheter. At least two anti-bending sections are arranged at intervals in the axial direction of the tube body, and an anti-bending support mechanism is arranged in the anti-bending section; the anti-bending support mechanism includes an annular cavity and a shape memory alloy helical wire. The annular cavity is arranged in the wall layer of the outer catheter. There are multiple shape memory alloy helical wires and they are arranged in a circumferential array in the annular cavity. A temperature control tube is arranged in the annular cavity and between the multiple shape memory alloy helical wires. The temperature control tube is in an S shape in the annular cavity and is communicated with the outside through a circulation pipeline penetrating through the wall layer of the outer catheter; a temperature medium is injected into the temperature control tube through the circulation pipeline to activate the shape memory effect of the shape memory alloy helical wire through temperature; thereby realizing the dynamic adjustment of the anti-bending stiffness of the catheter.

Description

Technical Field

[0001] The present invention relates to the technical field of medical catheters, and specifically discloses an anti-bending intracranial double-tube guiding catheter. Background Art

[0002] In neurointerventional surgery, the performance of intracranial guiding catheters has a significant impact on the surgical effect. Therefore, the anti-bending performance and manipulation stability of intracranial guiding catheters will directly affect the surgical safety. Intracranial guiding catheters need to have excellent anti-bending performance and controllable stiffness characteristics to cope with the complex three-dimensional tortuous anatomical structure of intracranial blood vessels. Currently, most of the double-lumen guiding catheters used clinically are made of braided layers or polymer composite layers, and their stiffness characteristics are solidified at the design stage and are difficult to adapt to the complex tortuous morphology of intracranial blood vessels. Even though the mechanical properties of the catheters in the prior art have been improved through material compounding and structural optimization (including the design of stiffness gradient from proximal to distal), they still have the following key defects:

[0003] The stiffness characteristics of existing catheters are solidified at the manufacturing stage. For example, the elastic modulus of metal braided layers or polymer materials cannot be adjusted in real time according to the intraoperative blood vessel morphology. Although some catheters adopt a stiffness decreasing design with a hard proximal end and a soft distal end to balance the pushing force and blood vessel compliance, their gradient changes are based on a preset static material distribution (such as gradually thinning wall thickness or sparse metal mesh), and it is difficult to dynamically adjust the stiffness of specific sections according to the actual degree of blood vessel tortuosity encountered during the operation. Moreover, although the catheter reduces the risk of bending and damaging blood vessels through the stiffness decreasing design (such as distal flexibility), it sacrifices the anti-radial compression ability. Especially in tortuous blood vessels, the low-stiffness section at the distal end is prone to catheter collapse and folding due to the compression of the blood vessel wall, while the high-stiffness section at the proximal end can resist compression but may scratch the intima of the blood vessel when passing through the curved section due to excessive rigidity. Summary of the Invention

[0004] The purpose of the present invention is to provide an anti-bending intracranial double-tube guiding catheter to solve one of the above technical problems existing in the prior art.

[0005] Specifically, the present invention is realized through the following technical solutions:

[0006] An anti-bending intracranial double-tube guiding catheter includes a tube body formed by an outer catheter and an inner catheter inserted inside the outer catheter. At least two anti-bending sections are arranged at intervals in the axial direction of the tube body, and an anti-bending support mechanism is provided inside the anti-bending sections;

[0007] The anti-bending support mechanism includes an annular cavity and shape memory alloy helical wires. The annular cavity is provided in the wall layer of the outer catheter. A plurality of shape memory alloy helical wires are provided and arranged in a circumferential array in the annular cavity. A temperature control tube is provided in the annular cavity and in the gap between the plurality of shape memory alloy helical wires. The temperature control tube is in an S shape in the annular cavity and is communicated with the outside through a circulation pipeline penetrating through the wall layer of the outer catheter.

[0008] A temperature medium is injected into the temperature control tube through the circulation pipeline to activate the shape memory effect of the shape memory alloy helical wires through temperature.

[0009] Based on the above technical solution, by setting the anti-bending support mechanism in the pipeline, it cleverly utilizes the temperature-sensitive characteristics and phase change state of the shape memory alloy helical wires to realize the dynamic adjustment of the anti-bending stiffness of the pipe body. The core lies in injecting the corresponding temperature medium into the temperature control tube in the annular cavity of the anti-bending support mechanism through the circulation pipeline, so that the temperature medium flows in the temperature control tube, thereby conducting heat to the shape memory alloy helical wires therein. When the shape memory alloy helical wires receive the appropriate temperature, they will produce a shape memory effect and trigger the hardening phase of the shape memory alloy helical wires, that is, a transformation from the martensite phase to the austenite phase, so that the shape memory alloy helical wires restore the preset high-stiffness geometric shape, thereby enhancing the anti-bending stiffness of this section. Moreover, the shape memory alloy helical wires are arranged in a circumferential array, which can further enhance the anti-radial compression ability of the outer catheter of the pipe body, resist vascular compression or external loads, and evenly disperse the stress loads received outside the pipe body to avoid the pipe body from being squeezed and collapsed.

[0010] Furthermore, the anti-bending support mechanism further includes an elastic support layer attached to the outer wall of the inner catheter. The elastic support layer is correspondingly arranged and adapted to the annular cavity.

[0011] In this solution, the introduction of the elastic support layer further enhances the dynamic stiffness cooperative regulation ability of the inner catheter. The elastic support layer is attached to the outer wall of the inner catheter and aligned with the annular cavity. When the shape memory alloy helical wires are not activated (low-temperature martensite state), the elastic support layer provides the basic bending resistance support for the inner catheter through its inherent elastic modulus to prevent the inner catheter from collapsing in the low-stiffness state. When the shape memory alloy helical wires restore the austenite rigidity, the outer catheter can form a composite support structure with the elastic support layer of the inner catheter in the radial direction. It not only buffers the sudden rigidity change of the outer catheter due to the shape memory alloy helical wires through its own elastic deformation to avoid squeezing the inner catheter, but also strengthens the uniformity of the radial support of the circumferential array of the shape memory alloy helical wires based on its own resilience. In this way, the anti-bending stiffness of the inner catheter and the outer catheter is improved through their cooperation.

[0012] Specifically, a plurality of mounting grooves for fitting the memory alloy spiral wire are provided inside the annular cavity, the two ends of the memory alloy spiral wire are anchored to the mounting grooves through limiting protrusions, and the middle section of the memory alloy spiral wire is a free deformation zone, the mounting grooves force the annular cavity to bulge outward in an arc shape toward the side of the inner conduit, and a buffer positioning groove is formed between adjacent arc-shaped protrusions;

[0013] A plurality of buffer pad layers matching the buffer positioning grooves are arranged outside the elastic supporting layer.

[0014] Based on the above scheme, when the external temperature medium enters the temperature control tube in the annular cavity to produce a shape memory effect on the memory alloy spiral wire and cause a phase change, the free deformation zone in the middle section of the memory alloy spiral wire can be restored to a preset high-rigidity geometric shape under the constraints of both ends. The preset high-rigidity geometric shape is specifically that the spiral radius of the middle section of the memory alloy spiral wire is reduced and radially contracted, thereby increasing the axial and radial stiffness of the memory alloy spiral wire itself, so as to enhance the bending resistance and radial compression resistance of the outer catheter, and significantly improve the bending resistance stiffness of the outer catheter in the target section;

[0015] At the same time, the buffer positioning grooves formed between adjacent arc-shaped protrusions through the arc-shaped protrusions on the inner wall of the annular cavity can form a convex-concave interlocking structure with the buffer pad of the elastic support layer on the outer wall of the inner catheter, so that when the outer catheter is subjected to bending force, the arc-shaped protrusion area transmits the supporting force to the inner catheter through the buffer pad layer, and the deformation space of the buffer positioning groove allows the elastic support layer to produce a certain radial compression to buffer and absorb the bending energy, thereby avoiding the inner catheter from being damaged due to excessive rigid extrusion, thereby improving the overall bending stiffness of the tube body.

[0016] Furthermore, the buffer positioning groove and the buffer cushion layer can also be used to install and position the inner catheter and the outer catheter to a certain extent, thereby preventing the inner catheter and the outer catheter from moving relative to each other when bent, which would cause inconvenience to the interventional surgery.

[0017] Preferably, the two anti-bending sections are respectively located at the proximal end and the distal end of the tube body, and the temperature of the memory alloy spiral wire in the annular cavity of the two anti-bending sections decreases along the flow direction of the temperature medium in the circulating pipeline when the shape memory effect occurs.

[0018] Furthermore, the temperature thresholds at which the two memory alloy spiral wires produce shape memory effect and undergo phase change are different, that is, the temperature at which the memory alloy spiral wire in the anti-bending section at the distal end of the tube produces shape memory effect is lower than that of the memory alloy spiral wire in the anti-bending section at the proximal end of the tube.

[0019] It should be noted that by setting shape memory alloy helical wires with different phase change temperature thresholds in the anti-bending sections at the proximal and distal ends, the shape memory alloy helical wires at the proximal or distal end of the tube body can be correspondingly adjusted by introducing temperature media at different temperatures, so as to achieve differential stiffness adjustment of the anti-bending adjustment section of the tube body for different parts of the intracranial blood vessels.

[0020] In addition, as a supplement, the distal end of the tube body serves as the interventional operation end and directly contacts the delicate and fragile distal blood vessel endothelium. If the phase change temperature is too high, the temperature medium may cause thermal damage to the blood vessel wall. Therefore, for this solution, the temperature threshold of the shape memory alloy helical wire at the distal end of the tube body is set to be lower than that of the shape memory alloy helical wire at the proximal end of the tube body, which can avoid thermal damage to the blood vessel wall to a certain extent. When operating the proximal end of the tube body, it is located in thick blood vessel segments such as the internal carotid artery, where the blood vessel wall is thicker than the distal end. Therefore, a higher temperature can be used to activate the shape memory alloy helical wire at the proximal end of the tube body to produce a shape memory effect for phase change, thereby enhancing the anti-bending stiffness of the tube body for easy support and pushing.

[0021] Specifically, the circulation pipeline includes a first pipeline, a second pipeline, and a return pipeline. The medium outflow end of the first pipeline is communicated with the inlet of the temperature control tube in the annular cavity at the proximal end of the tube body;

[0022] The second pipeline is located between the two anti-bending sections, and the medium outflow end of the second pipeline is communicated with the inlet of the temperature control tube in the annular cavity at the distal end of the tube body;

[0023] The outlet of the temperature control tube in the annular cavity at the proximal end of the tube body is simultaneously communicated with the medium inflow end of the second pipeline and the first medium inflow end of the return pipeline. The second medium inflow end of the return pipeline is communicated with the outlet of the temperature control tube in the annular cavity at the distal end of the tube body, and the medium outflow end of the return pipeline is communicated with the outside;

[0024] And an adjustment valve is further provided at the connection between the medium outflow end of the second pipeline and the inlet of the temperature control tube in the annular cavity at the distal end of the tube body. A on-off component matching the activation temperature of the shape memory alloy helical wire in the annular cavity at the proximal end of the tube body is arranged inside the adjustment valve.

[0025] That is to say, the on-off component is configured to block the second pipeline when the injected temperature medium reaches the temperature at which the shape memory alloy helical wire in the annular cavity at the proximal end of the tube body produces a shape memory effect, so as to prevent its temperature medium from entering the annular cavity at the distal end.

[0026] Based on the above solution, it realizes independent temperature control and coordinated stiffness adjustment of the anti-bending sections at the proximal and distal ends of the tube body, which improves the operation accuracy and safety of the tube body in the complex intracranial vascular environment. Specifically, through the design of the first pipeline, the second pipeline and the return pipeline, and combined with the passage control of the on-off component, during specific operations, it ensures that the temperature medium at the corresponding temperature can flow specifically into the annular cavities at the proximal or distal ends of the tube body, so as to realize the targeted activation of the shape memory alloy helical wires at the proximal and distal ends of the tube body. Thus, it ensures that the shape memory alloy helical wire at the distal end of the tube body is activated only under the low-temperature medium of 38°C when it is in a vulnerable blood vessel segment position (such as the anterior cerebral artery segment), while the shape memory alloy helical wire at the proximal end of the tube body is activated only under the high-temperature medium of 40°C when it is in a high-resistance blood vessel segment position (such as the petrous segment of the internal carotid artery). Through the differential temperature threshold design of the distal and proximal anti-bending sections and combined with the independently controllable temperature medium delivery path, it realizes the independent anti-bending stiffness adjustment of the proximal and distal ends of the tube body.

[0027] Preferably, the on-off component includes a ball valve cavity, and a shape memory alloy ball valve core is adaptively arranged in the ball valve cavity. The temperature at which the shape memory alloy ball valve core undergoes the shape memory effect is the same as the temperature of the shape memory alloy helical wire of the anti-bending section located at the proximal end of the tube body. When the temperature is suitable for the shape memory alloy helical wire of the anti-bending section located at the proximal end of the tube body, the shape memory alloy ball valve core undergoes the shape memory effect and expands, closely fitting with the spherical cavity to block the second pipeline.

[0028] Further preferably, the wall layer of the outer catheter includes, from the inside to the outside, a co-extruded inner lining layer, a heat insulation layer and a softening and compatible layer. The annular cavity, the first pipeline and the second pipeline are located in the inner lining layer, the return pipeline is located in the heat insulation layer, and the heat insulation layer forms a thickened heat insulation buffer section corresponding to the position of the anti-bending section.

[0029] Furthermore, the setting of the inner lining layer is mainly used as the bearing layer of the annular cavity and the circulation pipeline, while the heat insulation layer can isolate the annular cavity from the outside of the tube body, avoiding heat conduction through the tube body, so as to isolate the intracranial body temperature from the heat exchange generated in the annular cavity inside the tube body and avoid the mutual influence of heat. And setting a heat insulation buffer section at the position corresponding to the anti-bending section can further isolate the heat conduction between the tube body and the tissue body temperature, so as to ensure the normal excitation of the shape memory alloy helical wire, which is only affected by the temperature medium. In addition, the softening and compatible layer is arranged on the outermost layer of the outer catheter, which can ensure the affinity with the intracranial blood vessels during interventional operations and avoid damage to the intracranial blood vessels.

[0030] Furthermore, the length of the inner catheter is greater than that of the outer catheter, and the distal end of the inner catheter passes through the distal port of the outer catheter to form an extension section for interventional operations. A radiopaque ring is provided at the end position of the extension section. This facilitates the operator to accurately position the extension section of the inner catheter through the radiopaque ring during catheter interventional surgery.

[0031] More specifically, an annular fitting portion is formed between the distal port of the outer catheter and the outer wall of the inner catheter, and an anti-friction coating is provided on the annular fitting portion. Through the cooperation of the annular fitting portion and the anti-friction coating, it is ensured that when the distal anti-bending section of the tube body is activated by the high-temperature medium, the inner catheter can still pass through the outer catheter smoothly to ensure the normal operation of the inner tube.

[0032] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0033] 1. By providing an anti-bending support mechanism inside the pipeline, the present invention cleverly utilizes the temperature-sensitive characteristics and phase change state of the shape memory alloy helical wire to dynamically adjust the anti-bending stiffness of the tube body. The core lies in injecting a corresponding temperature medium into the temperature control tube in the annular cavity of the anti-bending support mechanism through a circulation pipeline, so that the temperature medium flows in the temperature control tube, thereby conducting heat to the shape memory alloy helical wire inside. When the shape memory alloy helical wire receives the appropriate temperature, it will produce a shape memory effect and trigger the hardening phase of the shape memory alloy helical wire, that is, it changes from the martensite phase to the austenite phase, so that the shape memory alloy helical wire restores the preset high-stiffness geometric shape, thereby enhancing the anti-bending stiffness of this section. Moreover, the shape memory alloy helical wires are circumferentially arrayed, which can further enhance the anti-radial compression ability of the outer catheter of the tube body, resist blood vessel compression or external loads, and evenly disperse the stress loads received outside the tube body to avoid extrusion and collapse of the tube body.

[0034] 2. The present invention introduces an elastic support layer, which further enhances the dynamic stiffness co-regulation ability of the inner catheter. The elastic support layer adheres to the outer wall of the inner catheter and is aligned with the annular cavity. When the shape memory alloy helical wire is not activated (low-temperature martensite state), the elastic support layer provides the basic bending resistance support for the inner catheter through its inherent elastic modulus to prevent the inner catheter from collapsing in the low-stiffness state. When the shape memory alloy helical wire restores the austenite rigidity, the outer catheter can form a composite support structure with the elastic support layer of the inner catheter in the radial direction. It not only buffers the sudden rigidity change of the outer catheter due to the shape memory alloy helical wire through its own elastic deformation to avoid extrusion on the inner catheter, but also strengthens the uniformity of the radial support of the circumferential array of the shape memory alloy helical wire based on its own resilience. In this way, the anti-bending stiffness of the inner catheter and the outer catheter is improved through their cooperation.

[0035] 3. Through the arc-shaped protrusions on the inner wall of the annular cavity of the present invention, a buffer positioning groove formed between adjacent arc-shaped protrusions can form a convex-concave engagement structure with the buffer pads of the elastic support layer on the outer wall of the inner catheter. When the outer catheter is subjected to a bending force, the arc-shaped protrusion area transmits a supporting force to the inner catheter through the buffer layer, and the deformation space of the buffer positioning groove allows the elastic support layer to generate a certain radial compression to buffer and absorb the bending energy, avoiding damage to the inner catheter due to excessive rigid extrusion, thereby improving the overall anti-bending stiffness of the tube body. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, form a part of this application, and do not limit the embodiments of the present invention. In the drawings:

[0037] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0038] Figure 2 is a schematic diagram of the internal structure of the anti-bending section of the present invention, aiming at its specific internal state;

[0039] Figure 3 is a schematic diagram of the cross-sectional structure of the anti-bending section of the present invention, aiming at showing the internal structure of the annular cavity;

[0040] Figure 4 is a schematic diagram of the semi-sectional structure of the outer catheter of the present invention, aiming at showing the annular cavity structure;

[0041] Figure 5 is a schematic diagram of the structure of the shape memory alloy helical wire of the present invention, Figure 5 (a) aims at showing the martensite phase state of the shape memory alloy helical wire, Figure 5 (b) aims at showing the austenite phase state of the shape memory alloy helical wire;

[0042] Figure 6 is a schematic diagram of the flow state of the circulation pipeline of the present invention, specifically when the regulating valve is in the closed state;

[0043] Figure 7 is a schematic diagram of the flow state of the circulation pipeline of the present invention, specifically when the regulating valve is in the open state;

[0044] Figure 8 is a schematic diagram of the internal structure of the regulating valve of the present invention, specifically when the shape memory alloy ball valve core is in the open state;

[0045] Figure 9 is a schematic diagram of the internal structure of the regulating valve of the present invention, specifically when the shape memory alloy ball valve core is in the closed state;

[0046] Figure 10 is a schematic diagram of the partial enlarged structure of the present invention, aiming at showing the annular mating part structure.

[0047] The components represented by the reference numerals are as follows: 1, tube body; 11, outer catheter; 111, inner lining layer; 112, heat insulation layer; 113, softening and compatible layer; 12, inner catheter; 13, annular fitting portion; 2, anti-bending section; 21, annular cavity; 22, shape memory alloy helical wire; 23, temperature control tube; 24, elastic support layer; 25, arc-shaped protrusion; 26, buffer cushion layer; 271, first pipeline; 272, second pipeline; 273, return pipeline; 28, regulating valve; 281, ball valve cavity; 282, shape memory alloy ball valve core; 3, imaging ring; 4, thermochromic ring; 5, joint; 6, Luer seat. Detailed implementation manners

[0048] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with embodiments and the accompanying drawings. The illustrative implementation manners of the present invention and their descriptions are only used to explain the present invention and shall not be construed as a limitation to the present invention. It should be noted that the present invention has been in the actual R & D and use stage.

[0049] Embodiment

[0050] Please refer to Figures 1 to 10 As shown, this embodiment discloses an anti-bending intracranial double-tube guiding catheter, which includes a tube body 1 formed by an outer catheter 11 and an inner catheter 12 inserted inside the outer catheter 11. At least two anti-bending sections 2 are arranged at intervals in the axial direction of the tube body 1, and an anti-bending support mechanism is provided inside the anti-bending section 2;

[0051] The anti-bending support mechanism includes an annular cavity 21 and a shape memory alloy helical wire 22. The annular cavity 21 is arranged in the wall layer of the outer catheter 11. A plurality of shape memory alloy helical wires 22 are provided and circumferentially arranged in an array in the annular cavity 21. A temperature control tube 23 is arranged inside the annular cavity 21 and in the gaps between the plurality of shape memory alloy helical wires 22. The temperature control tube 23 is in an S shape in the annular cavity 21 and is communicated with the outside through a circulation pipeline passing through the wall layer of the outer catheter 11;

[0052] A temperature medium is injected into the temperature control tube 23 through the circulation pipeline to activate the shape memory effect of the shape memory alloy helical wire 22 through temperature.

[0053] It should be noted that although certain progress has been made in traditional intracranial guiding catheter technology, there are still many deficiencies. This is because in the existing technology, the stiffness of these catheters is mostly designed to decrease from the proximal end to the distal end. Although this method adapts to the changes in the diameter and curvature of intracranial blood vessels from large proximal vessels to small distal vessels to a certain extent and helps the catheter to advance in the blood vessel, there are still certain defects in actual use. Since the anti-bending stiffness of the entire catheter is predetermined and cannot be adjusted autonomously, it is difficult to cope when the blood vessel morphology differs greatly from the preset situation. For example, in some areas where the degree of blood vessel stenosis or tortuosity far exceeds expectations, the already low anti-bending stiffness at the distal end makes the catheter extremely prone to excessive bending or even twisting, resulting in the inability of the inner catheter 12 and the interventional device to pass smoothly, seriously affecting the surgical process. In the proximal blood vessel segment where a large pushing force is required, if the resistance of the blood vessel wall increases abnormally, the fixed stiffness cannot be increased according to actual needs, making it difficult for the operator to stably push the catheter to the target position, thus greatly limiting the use effect of the catheter.

[0054] Therefore, the applicant specifically proposes an anti-bending intracranial double-tube guiding catheter disclosed in the above embodiments. By means of an anti-bending support mechanism arranged in the pipeline, it cleverly utilizes the temperature-sensitive characteristics and phase change state of the shape memory alloy helical wire 22 to realize the dynamic adjustment of the anti-bending stiffness of the tube body 1. The core lies in that by adding a corresponding temperature medium to the temperature control tube 23 in the annular cavity 21 of the anti-bending support mechanism through a circulation pipeline, so that the temperature medium flows in the temperature control tube 23, thereby conducting heat to the shape memory alloy helical wire 22 therein. When the shape memory alloy helical wire 22 receives the appropriate phase change temperature, it will produce a shape memory effect and trigger the hardening phase of the shape memory alloy helical wire 22, that is, it changes from the martensite phase to the austenite phase, so that the shape memory alloy helical wire 22 restores the preset high-stiffness geometric shape, thereby improving and adjusting the anti-bending stiffness of the anti-bending section 2. Moreover, the shape memory alloy helical wires 22 are circumferentially arrayed, which can further improve the anti-radial compression ability of the outer catheter 11 of the tube body 1, resist blood vessel compression or external loads, and evenly disperse the stress loads received outside the tube body 1 to avoid the extrusion and collapse of the tube body 1.

[0055] Furthermore, this solution utilizes the shape memory alloy helical wire 22 to produce a shape memory effect and restore to the initial high-stiffness shape at the appropriate temperature, thereby adjusting the mechanical properties of the corresponding anti-bending section 2 to achieve the dynamic adjustment of the anti-bending stiffness of the tube body 1. Specifically, 6-8 shape memory alloy helical wires 22 are evenly distributed circumferentially in the annular cavity 21. As Figure 3 shown in, in this embodiment, 6 are preferably used, and the material of the shape memory alloy helical wire 22 is nitinol alloy, which has two crystal forms, martensite and austenite (as Figure 5As shown in the figure, at low temperatures, it is in the martensite phase, with good flexibility. Its crystal structure presents an orthorhombic lattice that is prone to deformation, enabling the shape memory alloy helical wire 22 to bend naturally with the tube body 1 in the blood vessel, facilitating transportation. When the temperature rises above the phase transition temperature, the shape memory alloy helical wire 22 absorbs heat, and the lattice structure is reconstructed, transforming into the austenite phase with a regular face-centered cubic lattice. At this time, the shape memory alloy helical wire 22 returns to the pre-set high-rigidity helical shape, and its ability to resist external force bending is significantly enhanced. Thus, by injecting different temperature media into the temperature control tube 23 through a circulation pipeline, the conversion of the shape memory alloy helical wire 22 between the two forms can be precisely controlled, thereby realizing the dynamic adjustment of the anti-bending rigidity of the tube body 1.

[0056] As a further example, the preparation material of the shape memory alloy helical wire 22 is Nitinol (NiTi), and its phase transition temperature can be precisely regulated by the alloy composition ratio. Specifically:

[0057] During the preparation process, by precisely increasing the nickel (Ni) content, the phase transition temperature can be reduced. Its typical ratio is:

[0058] For the shape memory alloy helical wire 22 at the proximal end (high-temperature threshold): the nickel (Ni) content is 50.6% - 50.8%, and the phase transition temperature is 40°C;

[0059] For the shape memory alloy helical wire 22 at the distal end (low-temperature threshold): the nickel (Ni) content is 50.9% - 51.1%, and the phase transition temperature is 38°C;

[0060] Regarding the addition of trace elements: adding ≤0.5% of tantalum (Ta) or copper (Cu) can improve the phase transition temperature stability and cycle life.

[0061] Regarding its shape memory training process as follows:

[0062] First, wind the shape memory alloy helical wire 22 into the target helical shape (i.e., a high-rigidity geometric shape with a reduced helical radius and a tight pitch) in the austenite state (high temperature), and apply a constant stress (50 - 100 MPa). Then, cool it to the martensite state and unload the stress. The shape memory alloy helical wire 22 retains the relaxed martensite state (i.e., a larger helical radius and a loose pitch); and repeat the thermo-mechanical cycle 3 - 5 times to form a stable two-way shape memory characteristic.

[0063] Preferably, when the temperature medium flows through the injection in the temperature control tube 23, its function is not limited to transferring heat to activate the shape memory alloy helical wire 22 to produce a memory effect and phase change. It can also, through the injection of the temperature medium, form a stable static pressure inside the temperature control tube 23 to promote the improvement of the anti-bending rigidity performance of the anti-bending section.

[0064] In specific implementation, the temperature control tube 23 is preferably made of a graphite-based composite material, significantly improving the efficiency and uniformity of heat conduction.

[0065] Further, please refer to Figure 3 , the anti-bending support mechanism further includes an elastic support layer 24 attached to the outer wall of the inner catheter 12, and the elastic support layer 24 is correspondingly arranged and adapted to the annular cavity 21.

[0066] It should be understood that existing double-lumen catheters mostly adopt an independent reinforcement design, and the lack of a synergy mechanism for improving the stiffness of the outer catheter 11 and the inner catheter 12 affects the normal use of the catheter during the operation. In view of this, in this embodiment, the elastic support layer 24 is introduced, which further enhances the dynamic stiffness synergy control ability of the inner catheter 12. The elastic support layer 24 is attached to the outer wall of the inner catheter 12 and aligned with the annular cavity 21. When the shape memory alloy helical wire 22 is not activated (martensite phase), the elastic support layer 24 provides the basic bending resistance support for the inner catheter 12 through its inherent elastic modulus, preventing the inner catheter 12 from collapsing in the low-stiffness state. When the shape memory alloy helical wire 22 returns to the rigid austenite phase, the outer catheter 11 can form a composite support structure with the elastic support layer 24 of the inner catheter 12 in the radial direction. It not only buffers the sudden rigid change of the outer catheter 11 caused by the shape memory alloy helical wire 22 through its own elastic deformation, avoiding extrusion on the inner catheter 12, but also strengthens the radial support uniformity of the circumferential array of the shape memory alloy helical wire 22 based on its own resilience, thereby improving the anti-bending stiffness of the inner catheter 12 and the outer catheter 11 through the synergy of the two.

[0067] Specifically, as shown in Figure 2 and Figure 3 , a plurality of installation grooves for adaptively installing the shape memory alloy helical wire 22 are provided inside the annular cavity 21. The two ends of the shape memory alloy helical wire 22 are anchored to the installation grooves through limit bumps, and the middle section of the shape memory alloy helical wire 22 is a free deformation area. The installation grooves force the side surface of the annular cavity 21 facing the inner catheter 12 to bulge outward in an arc shape 25, and a buffer positioning groove is formed between adjacent arc-shaped bulges 25;

[0068] A plurality of buffer pads 26 adapted to the buffer positioning grooves are provided outside the elastic support layer 24, as shown in Figure 3 .

[0069] Based on the above solution, it should be noted that when the external temperature medium enters the temperature control tube 23 in the annular cavity 21, causing a shape memory effect on the shape memory alloy helical wire 22 and a phase change to occur, under the constraint of both ends of the shape memory alloy helical wire 22, the free deformation region in the middle section can return to a preset high-rigidity geometric shape. The preset high-rigidity geometric shape is specifically that the middle section helical radius of the shape memory alloy helical wire 22 decreases and radially contracts (that is, it returns to a preset high-strength tight helical form to form a radial pre-tightening force with the wall of the outer catheter 11), thereby increasing the axial and radial stiffness of the shape memory alloy helical wire 22 itself, enabling the shape memory alloy helical wire 22 to form a higher radial supporting force on the inner wall of the outer catheter 11, enhancing the anti-bending ability and anti-radial compression performance of the outer catheter 11, and significantly improving the anti-bending stiffness of the outer catheter 11 in the target section;

[0070] Meanwhile, through the arc-shaped protrusions 25 on the inner wall of the annular cavity 21, a buffer positioning groove formed between adjacent arc-shaped protrusions 25 can form a convex-concave engagement structure with the buffer pads of the elastic support layer 24 on the outer wall of the inner catheter 12. When the outer catheter 11 is subjected to a bending force, the arc-shaped protrusion 25 area transmits a supporting force to the inner catheter 12 through the buffer cushion layer 26, and the deformation space of the buffer positioning groove allows the elastic support layer 24 to generate a certain amount of radial compression to buffer and absorb the bending energy, avoiding damage to the inner catheter 12 due to excessive rigid extrusion, thereby enhancing the anti-bending stiffness of the overall tube body 1.

[0071] Specifically, the elastic support layer 24 is made of a silicone rubber-polyurethane blend, with a thickness of 0.3 mm, an elastic modulus of 25 - 35 MPa, and the buffer cushion layer 26 on its surface is porous silica gel (porosity 30%), and the compression and rebound rate ≥ 95%

[0072] Furthermore, through the buffer positioning groove and the buffer cushion layer 26, to a certain extent, it also locates the installation of the inner catheter 12 and the outer catheter 11, avoiding relative movement between the inner catheter 12 and the outer catheter 11 during bending, which may cause inconvenience to the interventional surgical operation.

[0073] As preferably, as Figure 1 shown, the two anti-bending sections 2 are respectively located at the proximal end and the distal end of the tube body 1, and when the shape memory alloy helical wires 22 in the annular cavities 21 of the two anti-bending sections 2 undergo a shape memory effect, the temperature decreases along the flow direction of the temperature medium in the circulation pipeline.

[0074] Furthermore, the temperature thresholds when the two shape memory alloy helical wires 22 produce a shape memory effect and undergo a phase change are different, that is, the temperature at which the shape memory alloy helical wire 22 in the anti-bending section 2 at the distal end of the tube body 1 undergoes a shape memory effect is lower than that of the shape memory alloy helical wire 22 in the anti-bending section 2 at the proximal end of the tube body 1.

[0075] It should be noted that by setting shape memory alloy helical wires 22 with different phase change temperature thresholds in the anti-bending sections 2 at the proximal end and the distal end, the shape memory alloy helical wires 22 at the proximal end or the distal end of the tube body 1 can be correspondingly adjusted by introducing temperature media at different temperatures, so as to realize differential stiffness adjustment of the anti-bending adjustment section of the tube body 1 for different parts of the intracranial blood vessels.

[0076] For example, for the outer catheter 11 and the inner catheter 12, during the interventional operation, they are rotationally connected through the joint 5 at the end of the inner catheter 12 and the Luer seat 6 at the end of the outer catheter 11 and then fixed together. Therefore, in this solution, the proximal end of the tube body 1 is close to the Luer seat 6 and the joint 5 and is at the position of the first 1 / 3 section of the total length of the tube body 1 (for example, when the total length of the catheter is 1500 mm, the proximal range is 100 - 500 mm); while the distal end of the tube body 1 is close to the inner tube body 1 when entering the intracranial and is at the position of the last 1 / 3 section of the total length of the tube body 1 (for example, when the total length is 1500 mm, the distal range is 1000 - 1500 mm).

[0077] Exemplarily, the temperature threshold when the shape memory alloy helical wire 22 at the proximal end of the tube body 1 undergoes the shape memory effect is set to 40 °C to avoid being accidentally activated by the normal temperature of human tissues during the interventional operation, ensure that it is only triggered when anti-bending stiffness adjustment is required, and at the same time is lower than the high temperature tolerated by human tissues (42 °C) during the interventional operation to avoid thermal damage to the intracranial blood vessel tissues.

[0078] And the temperature threshold when the shape memory alloy helical wire 22 at the distal end of the tube body 1 undergoes the shape memory effect is set to 38 °C. By using a temperature value close to and slightly higher than the human body temperature, it can also avoid being accidentally activated by the normal temperature of human tissues, and there is an obvious difference from the temperature threshold when the shape memory alloy helical wire 22 at the proximal end of the tube body 1 undergoes the shape memory effect, which can avoid the mutual influence of the two shape memory alloy helical wires 22 when injecting temperature media at corresponding temperatures.

[0079] Furthermore, the distal end of the tube body 1 is the interventional operation end and directly contacts the delicate and fragile distal vascular endothelium. If the phase change temperature is too high, the temperature medium may cause thermal damage to the blood vessel wall. Therefore, for this solution, the temperature threshold of the shape memory alloy helical wire 22 at the distal end of the tube body 1 is set lower than that of the shape memory alloy helical wire 22 at the proximal end of the tube body 1, which can, to a certain extent, avoid thermal damage to the blood vessel wall. When operating the proximal end of the tube body 1, it is located in a thick blood vessel segment such as the internal carotid artery, where the blood vessel wall is thicker than the distal end. Therefore, a higher temperature can be used to activate the shape memory alloy helical wire 22 at the proximal end of the tube body 1 to produce the shape memory effect for phase change, so as to enhance the anti-bending stiffness of the tube body 1 for easy support and pushing.

[0080] Specifically, at Figure 2As shown in [figure reference], the circulation pipeline includes a first pipeline 271, a second pipeline 272, and a reflux pipeline 273. The medium outflow end of the first pipeline 271 is connected to the inlet of the temperature control pipe 23 in the annular cavity 21 at the proximal end of the pipe body 1;

[0081] The second pipeline 272 is located between the two anti-bending sections, and the medium outflow end of the second pipeline 272 is connected to the inlet of the temperature control pipe 23 in the annular cavity 21 at the distal end of the pipe body 1;

[0082] The outlet of the temperature control pipe 23 in the annular cavity 21 at the proximal end of the pipe body 1 is simultaneously connected to the medium inflow end of the second pipeline 272 and the first medium inflow end of the reflux pipeline 273. The second medium inflow end of the reflux pipeline 273 is connected to the outlet of the temperature control pipe 23 in the annular cavity 21 at the distal end of the pipe body 1, and the medium outflow end of the reflux pipeline 273 is connected to the outside;

[0083] And at the connection between the medium outflow end of the second pipeline 272 and the inlet of the temperature control pipe 23 in the annular cavity 21 at the distal end of the pipe body 1, there is also a regulating valve 28. Inside the regulating valve 28, there is a on-off component that matches the activation temperature of the shape memory alloy helical wire 22 in the annular cavity 21 at the proximal end of the pipe body 1.

[0084] That is to say, the on-off component is configured to be in an initial open state. When the injected temperature medium reaches the temperature that generates a shape memory effect on the shape memory alloy helical wire 22 in the annular cavity 21 at the proximal end of the pipe body 1, the second pipeline 272 is blocked to prevent its temperature medium from entering the annular cavity 21 at the distal end.

[0085] Based on the above implementation, it realizes independent temperature control and coordinated stiffness adjustment of the anti-bending sections at the proximal and distal ends of the pipe body 1, which improves the operation accuracy and safety of the pipe body 1 in the complex intracranial vascular environment; specifically, through the design of the first pipeline 271, the second pipeline 272, and the reflux pipe, combined with the path control of the on-off component, during specific operations, it ensures that the temperature medium at the corresponding temperature can flow specifically into the annular cavity 21 at the proximal or distal end of the pipe body 1, so as to realize targeted activation of the shape memory alloy helical wires 22 at the proximal and distal ends of the pipe body 1. Thus, it ensures that the shape memory alloy helical wire 22 at the distal end of the pipe body 1 is only activated by the low-temperature medium at 38 °C when it is in a vulnerable blood vessel segment position (such as the anterior cerebral artery segment), and the shape memory alloy helical wire 22 at the proximal end of the pipe body 1 is only activated by the high-temperature medium at 40 °C when it is in a high-resistance blood vessel segment position (such as the petrous segment of the internal carotid artery). Through the differential temperature threshold design of the distal and proximal anti-bending sections, combined with the independently controllable temperature medium delivery path, it realizes independent anti-bending stiffness adjustment of the proximal and distal ends of the pipe body 1.

[0086] For example, Figure 6As shown in the figure, when it is necessary to adjust the anti-bending performance of the anti-bending section at the proximal end of the tube body 1, a temperature medium at a corresponding temperature (such as heparin sodium physiological saline at 40 °C) is injected through the first pipeline 271. When it enters the temperature control tube 23 in the annular cavity 21 at the proximal end of the tube body 1, its heat is conducted to the surface of the shape memory alloy helical wire 22 in the annular cavity 21. The shape memory alloy helical wire 22 can reach the phase change temperature threshold and produce a shape memory effect to undergo a phase change (that is, return to the preset high stiffness geometric shape), so as to improve the anti-bending stiffness of the anti-bending section at the proximal end of the tube body 1. At the same time, when the temperature medium flows to the regulating valve 28 of the second pipeline 272, the on-off component of the valve here also reaches the temperature threshold and blocks the second pipeline 272 to prevent the temperature medium from flowing into the annular cavity 21 at the distal end of the tube body 1 through the second pipeline 272. The used temperature medium flows into the first medium inlet end of the return pipeline 273 through the outlet of the temperature control tube 23 in the annular cavity 21 and returns to the external circulation;

[0087] And as Figure 7 shown in the figure, when it is necessary to adjust and improve the anti-bending stiffness of the anti-bending section at the distal end of the tube body 1, a temperature medium at a corresponding temperature (such as heparin sodium physiological saline at 38 °C) can be injected through the first pipeline 271. When it first enters the temperature control tube 23 in the annular cavity 21 at the proximal end of the tube body 1 through the first pipeline 271 (at this time, since the temperature does not reach the activation temperature of the shape memory alloy helical wire 22 here, so it will not produce a shape memory effect, that is, the shape memory alloy helical wire 22 here remains flexible), and the control component does not block the second pipeline 272, so that the temperature medium enters the second pipeline 272 and finally enters the temperature control tube 23 in the annular cavity 21 at the distal end. The temperature control tube 23 conducts heat to the surface of the shape memory alloy helical wire 22 in the annular cavity 21 to trigger the shape memory alloy helical wire 22 here to produce a shape memory effect and undergo a phase change (return to the preset high stiffness geometric shape), so as to improve the anti-bending stiffness of the anti-bending section at the distal end of the tube body 1. The used temperature medium flows into the second medium inlet end of the return pipeline 273 through the outlet of the temperature control tube 23 in the annular cavity 21 at the distal end of the tube body 1 and returns to the external circulation.

[0088] In summary, it is possible to accurately and independently adjust the anti-bending stiffness of the proximal and distal ends of the tube body 1 to ensure the normal use of the catheter under the complex intracranial blood vessel path. At the same time, by using different temperatures of the injected temperature medium, it is possible to adjust the anti-bending stiffness of the proximal or distal end of the tube body 1 in different sequences.

[0089] It can be understood that during the interventional operation, for the injection of the temperature medium, it is connected to the inlet interface on the Luer seat 6 at the end of the outer catheter 11 through an external temperature control pump and the first pipeline 271, while the medium output end of the return pipeline 273 is connected to the external temperature control pump through the outlet interface on the Luer seat 6 at the end of the outer catheter 11, so as to use the temperature control pump to pump the temperature medium through the circulation pipe into the pipe body 1 for circulating flow, thereby realizing the dynamic adjustment of the anti-bending stiffness at the proximal or distal end of the pipe body 1.

[0090] It should be further noted that in order to avoid heat loss of the temperature medium during the injection process through the circulation pipeline in this embodiment, a layer of nano thermal insulation film can be further coated on the inner walls of the first pipeline 271 and the second pipeline 272 of the circulation pipeline to avoid heat dissipation and cause the temperature of the temperature medium to decrease. Regarding the specific material of the nano thermal insulation film, it is only a specific choice during actual implementation, and this application does not make specific description and further limitation here.

[0091] Preferably, as Figure 8 and Figure 9 shown, the on-off component includes a ball valve cavity 281, and a shape memory alloy ball valve core 282 is adaptively arranged in the ball valve cavity 281. The temperature at which the shape memory alloy ball valve core 282 undergoes the shape memory effect is the same as the temperature of the shape memory alloy helical wire 22 in the anti-bending section at the proximal end of the pipe body 1. When the temperature is suitable for the shape memory alloy helical wire 22 in the anti-bending section at the proximal end of the pipe body 1, the shape memory alloy ball valve core 282 undergoes the shape memory effect and expands, tightly fitting with the spherical cavity to block the second pipeline 272.

[0092] For example, the preparation material of the shape memory alloy ball valve core 282 is the same as that of the shape memory alloy helical wire 22 in the annular cavity 21 at the proximal end of the pipe body 1.

[0093] Further preferably, as Figure 2 、 Figure 3 and Figure 4 shown, the wall layer of the outer catheter 11 includes, from the inside to the outside, a co-extruded inner lining layer 111, a thermal insulation layer 112, and a softening compatibility layer 113. The annular cavity 21, the first pipeline 271, and the second pipeline 272 are located in the inner lining layer 111, the return pipe is located in the thermal insulation layer 112, and a thickened thermal insulation buffer section is formed at the position of the thermal insulation layer 112 corresponding to the anti-bending section.

[0094] Furthermore, the inner lining layer 111 is mainly used as a bearing layer for the annular cavity 21 and the circulation pipeline, preferably made of TPU material. The heat insulation layer 112 can isolate the annular cavity 21 from the outside of the pipe body 1, preventing heat conduction through the pipe body 1, thus isolating the intracranial body temperature from the heat exchange generated in the annular cavity 21 inside the pipe body 1 and avoiding the mutual influence of heat. An insulation buffer zone is provided at the position corresponding to the anti-bending section, which can further isolate the heat conduction between the pipe body 1 and the tissue body temperature, thereby ensuring the normal activation of the shape memory alloy coil 22, which is only affected by the temperature medium. In addition, the softening and compatibility layer 113 is arranged on the outermost layer of the outer catheter 11, and a hydrophilic material is coated on the outside, which can ensure the affinity with the intracranial blood vessels during the interventional operation and avoid damage to the intracranial blood vessels.

[0095] Furthermore, the heat insulation layer 112 is preferably made of a transparent polyurethane material with good heat insulation performance (thermal conductivity ≤ 0.05W / (m・K)), ensuring that when the temperature medium is not injected into the pipe body 1, its internal temperature is always stable below 34°C (lower than the temperature threshold at which the shape memory effect of the shape memory alloy coil 22 at the distal end occurs, avoiding the influence of the intracranial body temperature on the shape memory alloy coil 22).

[0096] More preferably, as Figure 1 shown, a thermochromic ring 4 is integrally formed on the inner wall of the heat insulation layer 112. A number of thermochromic microcapsules are arranged inside the thermochromic ring 4. The thermochromic microcapsules are coated with crystal violet lactone (CVL) and an acidic color developer. The color change temperature threshold is accurately configured to be 38°C, which is the same as the temperature of the shape memory alloy coil 22 at the distal end of the pipe body 1. This realizes the real-time visual monitoring of the temperature state at the distal end of the catheter during the interventional operation, avoiding the risk of overheating of the temperature medium or misactivation of the shape memory alloy coil 22, and significantly improving the surgical safety and operation convenience.

[0097] Furthermore, spiral nano-grooves (depth 50 - 200nm, width 80 - 150nm, and the distance between adjacent spiral nano-grooves is 5 - 10um, not shown in the figure) are formed on the outer surface of the softening and compatibility layer 113 along its axial direction. Through the three-dimensional structure of the nano-grooves, micron-level liquid storage units can be formed on the surface of the outer catheter 11, so that during the interventional operation, body fluid or corresponding physiological saline can be accommodated and attached. Thus, when the outer catheter 11 moves in the blood vessel, a continuously distributed lubricating liquid film is formed on the outer surface of the outer catheter 11 to further reduce the friction between the outer catheter 11 and the blood vessel and reduce the damage to the blood vessel wall.

[0098] Further, the length of the inner catheter 12 is greater than that of the outer catheter 11, and the distal end of the inner catheter 12 passes through the distal end port of the outer catheter 11 to form an extension section (with a length of 50 - 100 mm) for interventional operation. A visualization ring 3 is provided at the end position of the extension section. This facilitates the operator to accurately position the extension section of the inner catheter 12 through the visualization ring 3 during the catheter interventional surgery.

[0099] More specifically, as Figure 10 shown, an annular fitting portion 13 is formed between the distal end port of the outer catheter 11 and the outer wall of the inner catheter 12. An anti-friction coating is provided on the annular fitting portion 13. Preferably, for the anti-friction coating, a molybdenum disulfide layer with a thickness of 2 - 5 μm is deposited by magnetron sputtering.

[0100] During specific implementation, through the cooperation of the annular fitting portion 13 and the anti-friction coating, it is ensured that when the distal anti-bending section of the tube body 1 is activated by the high-temperature medium, the inner catheter 12 can still pass through the outer catheter 11 smoothly and maintain normal operation of the inner pipeline.

[0101] The above specific implementation manners further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific implementation manners of the present invention. The specific selection and related material process parameters are only used to explain the present invention and are not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

[0102] It should be noted that the structures, proportions, sizes, etc. shown in the drawings of this specification are all schematic diagrams, which are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the implementable conditions of the present invention. Therefore, they do not have technical essence. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope that the technical content disclosed by the present invention can cover. At the same time, the terms such as "upper", "lower", "left", "right", "middle", etc. cited in this specification are only for the convenience of clear narration and are not used to limit the implementable scope of the present invention. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the implementable scope of the present invention.

Claims

1. An intracranial double-tube guiding catheter resistant to bending, comprising a tube body (1) formed by an outer catheter (11) and an inner catheter (12) inserted inside the outer catheter (11), characterized in that, At least two anti-bending sections (2) are arranged at intervals in the axial direction of the pipe body (1), and an anti-bending support mechanism is arranged in the anti-bending section (2). The anti-bending support mechanism includes an annular cavity (21) and a shape memory alloy helical wire (22). The annular cavity (21) is arranged in the wall layer of the outer conduit (11). A plurality of shape memory alloy helical wires (22) are arranged in a circumferential array in the annular cavity (21). A temperature control pipe (23) is arranged in the gap between the plurality of shape memory alloy helical wires (22) inside the annular cavity (21). The temperature control pipe (23) is in an S shape in the annular cavity (21) and is communicated with the outside through a circulation pipe penetrating through the wall layer of the outer conduit (11). A temperature medium is injected into the temperature control pipe (23) through the circulation pipe to activate the shape memory effect of the shape memory alloy helical wire (22) through temperature. The two anti-bending sections (2) are respectively located at the proximal end and the distal end of the pipe body (1), and the temperatures at which the shape memory alloy helical wires (22) in the annular cavities (21) of the two anti-bending sections (2) have a shape memory effect decrease along the direction in which the temperature medium of the circulation pipe enters. The circulation pipe includes a first pipe (271), a second pipe (272) and a return pipe (273). The medium outflow end of the first pipe (271) is communicated with the inlet of the temperature control pipe (23) in the annular cavity (21) located at the proximal end of the pipe body (1). The second pipe (272) is located between the two anti-bending sections, and the medium outflow end of the second pipe (272) is communicated with the inlet of the temperature control pipe (23) in the annular cavity (21) located at the distal end of the pipe body (1). The outlet of the temperature control pipe (23) in the annular cavity (21) located at the proximal end of the pipe body (1) is simultaneously communicated with the medium inflow end of the second pipe (272) and the first medium inflow end of the return pipe (273). The second medium inflow end of the return pipe (273) is communicated with the outlet of the temperature control pipe (23) in the annular cavity (21) located at the distal end of the pipe body (1). The medium outflow end of the return pipe (273) is communicated with the outside. And a regulating valve (28) is also provided at the connection between the medium outflow end of the second pipe (272) and the inlet of the temperature control pipe (23) in the annular cavity (21) located at the distal end of the pipe body (1). A switching component matching the activation temperature of the shape memory alloy helical wire (22) in the annular cavity (21) located at the proximal end of the pipe body (1) is arranged inside the regulating valve (28). The switching component includes a ball valve cavity (281), and a shape memory alloy ball valve core (282) is fitted in the ball valve cavity (281). The temperature at which the shape memory alloy ball valve core (282) has a shape memory effect is the same as the temperature of the shape memory alloy helical wire (22) in the anti-bending section located at the proximal end of the pipe body (1).

2. The anti-bending intracranial double-tube guiding catheter according to claim 1, wherein The anti-bending support mechanism further includes an elastic support layer (24) attached to the outer wall of the inner conduit (12). The elastic support layer (24) is arranged corresponding to and adapted to the annular cavity (21).

3. The anti-bending intracranial double-tube guiding catheter according to claim 2, wherein The interior of the annular cavity (21) is provided with a plurality of mounting grooves for adaptively installing the shape memory alloy coil wire (22). Both ends of the shape memory alloy coil wire (22) are anchored to the mounting grooves through limit bumps, and the middle section of the shape memory alloy coil wire (22) is a free deformation area. The mounting grooves force the side surface of the annular cavity (21) facing the inner catheter (12) to bulge outward in an arc shape (25), and a buffer positioning groove is formed between adjacent arc-shaped bulges (25); A plurality of buffer pads (26) adapted to the buffer positioning grooves are provided outside the elastic support layer (24).

4. An anti-bending intracranial double-tube guiding catheter according to claim 1, characterized in that, The wall layer of the outer catheter (11) includes an inner lining layer (111), a heat insulation layer (112), and a softening compatibility layer (113) from the inside to the outside. The annular cavity (21), the first pipeline (271), and the second pipeline (272) are located in the inner lining layer (111), the return pipeline (273) is located in the heat insulation layer (112), and a thickened heat insulation buffer section is formed at the position of the heat insulation layer (112) corresponding to the anti-bending section.

5. The anti-bending intracranial double-tube guiding catheter according to claim 1, characterized in that, The length of the inner catheter (12) is greater than the length of the outer catheter (11), and the distal end of the inner catheter (12) passes out of the distal end port of the outer catheter (11) to form an extension section for interventional operation. A visualization ring (3) is provided at the end position of the extension section.

6. The anti-bending intracranial double-tube guiding catheter according to claim 5, characterized in that An annular fitting portion (13) is formed between the distal end port of the outer catheter (11) and the outer wall of the inner catheter (12), and an anti-friction coating is provided on the annular fitting portion (13).

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