Anti-bending intracranial double-tube guide catheter

Abstract

The invention relates to the technical field of medical catheters, and particularly discloses an anti-bending intracranial double-catheter guiding catheter which comprises a catheter body formed by an outer catheter and an inner catheter inserted into the outer catheter, at least two anti-bending sections are arranged in the axial direction of the catheter body at intervals, and anti-bending supporting mechanisms are arranged in the anti-bending sections; the anti-bending supporting mechanism comprises an annular cavity and memory alloy spiral wires, the annular cavity is formed in the wall layer of the outer catheter, the multiple memory alloy spiral wires are arranged in the annular cavity in a circumferential array mode, temperature control pipes are arranged in the annular cavity and located in gaps among the multiple memory alloy spiral wires, and the temperature control pipes are in an S shape in the annular cavity; the circulating pipeline penetrates through the wall layer of the outer guide pipe and is communicated with the outside; a temperature medium is injected into the temperature control tube through the circulating pipeline, so that the memory alloy spiral wire is activated through temperature to generate a shape memory effect; therefore, dynamic adjustment of the anti-bending rigidity of the guide pipe is achieved.

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 proximal-to-distal stiffness gradient design), 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 a gradually thinning wall thickness or a 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 a 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 collapse and fold due to the compression of the blood vessel wall, while the high-stiffness section at the proximal end, although able to resist compression, 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, comprising a tube body formed by an outer catheter and an inner catheter inserted inside the outer catheter, and 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 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 gap between the plurality of shape memory alloy helical wires inside the annular cavity. 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 providing an anti-bending support mechanism inside 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 a 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 inside. When the shape memory alloy helical wires receive the appropriate temperature, they will produce a shape memory effect and trigger the hardened 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 caused by 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 realize the 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 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 at the distal end of the tube body is set 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 outlet 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 outlet 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 inlet end of the second pipeline and the first medium inlet end of the return pipeline. The second medium inlet 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 outlet end of the return pipeline is communicated with the outside;

[0024] And an adjustment valve is further provided at the connection between the medium outlet 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 the 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 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 cavities at the proximal or distal end 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 wires at the distal end of the tube body are activated only under the low-temperature medium of 38 °C when in the position of the vulnerable blood vessel segment (such as the anterior cerebral artery segment), while the shape memory alloy helical wires at the proximal end of the tube body are activated only under the high-temperature medium of 40 °C when in the position of the high-resistance blood vessel segment (such as the petrous segment of the internal carotid artery). By means of 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 when 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, tightly 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 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 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 penetrates out of the distal end port of the outer catheter to form an extension section for interventional operation. A developing ring is provided at the end position of the extension section, which facilitates the operator to accurately position the extension section of the inner catheter through the developing ring during catheter interventional surgery.

[0031] More specifically, an annular fitting portion is formed between the distal end 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 a high-temperature medium, the inner catheter can still pass through the outer catheter smoothly to ensure the normal operation of the inner pipeline.

[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 in 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 circulating pipeline, so that the temperature medium flows in the temperature control tube, thereby conducting heat to the shape memory alloy helical wire therein. 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 vascular 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 cooperative 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 caused by the shape memory alloy helical wire through its own elastic deformation to avoid extrusion on the inner catheter, but also strengthens the radial support uniformity 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. The present invention forms a buffer positioning groove between adjacent arc-shaped protrusions through the arc-shaped protrusions on the inner wall of the annular cavity, which can form a convex-concave interlocking structure with the buffer pad of the elastic support layer on the outer wall of the inner catheter. 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. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0038] Figure 2 This is a schematic diagram of the internal structure of the anti-bending section of the present invention, which is intended to illustrate the specific internal state thereof;

[0039] Figure 3 It is a schematic diagram of the cross-sectional structure of the anti-bending section of the present invention, which is intended to show the internal structure of the annular cavity;

[0040] Figure 4 It is a schematic diagram of a half-section structure of the outer catheter of the present invention, which is intended to show the annular cavity structure;

[0041] Figure 5 is a schematic diagram of the structure of the memory alloy spiral wire of the present invention, Figure 5 (a) aims to show the martensite phase state of the memory alloy spiral wire. Figure 5 (b) aims to show the austenite phase state of the memory alloy spiral wire;

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

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

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

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

[0046] Figure 10 It is a partial enlarged structural schematic diagram of the present invention, which is intended to show the structure of the annular matching portion.

[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, developing ring; 4, thermochromic ring; 5, joint; 6, Luer seat. Specific Embodiment

[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 with reference to the embodiments and the accompanying drawings. The illustrative embodiments and descriptions thereof of the present invention are only used to explain the present invention and are not intended to limit the present invention. It should be noted that the present invention has been in the actual research and development 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 arranged circumferentially in the annular cavity 21. A temperature control tube 23 is arranged in the gap between the plurality of shape memory alloy helical wires 22 inside the annular cavity 21. 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 to some extent adapts to the changes in the diameter and curvature of intracranial blood vessels from large proximal vessels to small distal vessels, which 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 interventional instruments 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 setting an anti-bending support mechanism in the pipeline, it cleverly utilizes the temperature-sensitive characteristics and phase change state of the shape memory alloy wire 22 to realize the dynamic adjustment of the anti-bending stiffness of the tube body 1. The core lies in injecting a corresponding temperature medium into the temperature control tube 23 in the annular cavity 21 of the anti-bending support mechanism through a circulating pipeline, so that the temperature medium flows in the temperature control tube 23, thereby conducting heat to the shape memory alloy wire 22 therein. When the shape memory alloy 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 wire 22, that is, it changes from the martensite phase to the austenite phase, causing the shape memory alloy wire 22 to restore to 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 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 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 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 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 the 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 material for preparing 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 shape in the 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 is injected and flows 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 transformation. 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] Furthermore, 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 most existing double-lumen catheters adopt an independent reinforcement design, and there is a lack of a synergistic mechanism for improving the stiffness of the outer catheter 11 and the inner catheter 12, which 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 synergistic regulation 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 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 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 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 wire 22 based on its own resilience, so as to improve the anti-bending stiffness of the inner catheter 12 and the outer catheter 11 through their synergy.

[0067] Specifically, as shown in Figure 2 and Figure 3 , a plurality of installation grooves for fitting and installing the shape memory alloy wire 22 are provided inside the annular cavity 21. Both ends of the shape memory alloy wire 22 are anchored to the installation grooves through limit bumps, and the middle section of the shape memory alloy 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 protrusions 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 scheme, it should be noted that when the external temperature medium enters the temperature control tube 23 in the annular cavity 21 to produce a shape memory effect on the memory alloy spiral wire 22 and a phase change occurs, the memory alloy spiral wire 22 is constrained at both ends, and the free deformation zone in the middle section can be restored to a preset high-rigidity geometric shape. The preset high-rigidity geometric shape is specifically that the spiral radius of the middle section of the memory alloy spiral wire 22 is reduced and radially contracted (that is, it is restored to a preset high-strength tight spiral shape to form a radial preload with the wall of the outer catheter 11), thereby increasing the axial and radial stiffness of the memory alloy spiral wire 22 itself, so that the memory alloy spiral wire 22 forms a higher radial support force on the inner wall of the outer catheter 11, enhances the bending resistance and radial compression resistance of the outer catheter 11, and significantly improves the bending resistance of the outer catheter 11 in the target section;

[0070] At the same time, the arc-shaped protrusions 25 on the inner wall of the annular cavity 21 and the buffer positioning grooves formed between adjacent arc-shaped protrusions 25 can form a convex-concave bite structure with the buffer pad of the elastic support layer 24 on the outer wall of the inner catheter 12, so that when the outer catheter 11 is subjected to bending force, the arc-shaped protrusion 25 area transmits the supporting force to the inner catheter 12 through the buffer pad layer 26, and the deformation space of the buffer positioning groove allows the elastic support layer 24 to produce a certain radial compression to buffer and absorb the bending energy, thereby avoiding the inner catheter 12 from being damaged due to excessive rigid extrusion, thereby improving the overall bending stiffness of the 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 and an elastic modulus of 25-35 MPa. The cushion layer 26 on its surface is porous silicone (porosity 30%) with a compression rebound rate ≥ 95%.

[0072] Furthermore, the buffer positioning groove and the buffer pad layer 26 can also be used to install and position the inner catheter 12 and the outer catheter 11 to a certain extent, thereby preventing the inner catheter 12 and the outer catheter 11 from moving relative to each other when bending, thereby preventing inconvenience to the interventional surgery.

[0073] As a preference, Figure 1 As shown in the figure, the two anti-bending sections 2 are respectively located at the proximal end and the distal end of the pipe body 1, and the temperature of the memory alloy spiral wire 22 in the annular cavity 21 of the two anti-bending sections 2 decreases along the flow direction of the temperature medium of the circulating pipeline when the shape memory effect occurs.

[0074] Furthermore, the temperature thresholds at which the two memory alloy spiral wires 22 produce shape memory effect and undergo phase change are different, that is, the temperature at which the shape memory effect occurs in the memory alloy spiral wire 22 in the anti-bending section 2 at the distal end of the tube body 1 is lower than that of the memory alloy spiral 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 full 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 full 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 has a shape memory effect is set to 40 °C, so as 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 tissue.

[0078] The temperature threshold when the shape memory alloy helical wire 22 at the distal end of the tube body 1 has a 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 has a 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 avoid thermal damage to the blood vessel wall to a certain extent. When operating the proximal end of the tube body 1, 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 22 at the proximal end of the tube body 1 to produce a 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 the figure, the circulation pipeline includes a first pipeline 271, a second pipeline 272, and a return 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 return pipeline 273. The second medium inflow end of the return 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 return pipeline 273 is connected to the outside;

[0083] And a regulating valve 28 is further provided 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. An on-off component matching 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 is arranged inside the regulating valve 28.

[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 embodiments, independent temperature control and coordinated stiffness adjustment of the anti-bending sections at the proximal and distal ends of the pipe body 1 are achieved, 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 return pipe, and combined with the path control of the on-off component, during specific operations, it is ensured 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 achieve targeted activation of the shape memory alloy helical wires 22 at the proximal and distal ends of the pipe body 1. Thus, it is ensured that the shape memory alloy helical wire 22 at the distal end of the pipe body 1 is only activated by a low-temperature medium of 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 a 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, independent anti-bending stiffness adjustment of the proximal and distal ends of the pipe body 1 is achieved.

[0086] For example, Figure 6As shown, when it is necessary to perform anti-bending enhancement adjustment on the anti-bending section at the proximal end of the tube body 1, a temperature medium at a corresponding temperature (such as heparin sodium saline at 40 degrees Celsius) 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 enhance 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 converges into the first medium inflow 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, when it is necessary to enhance 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 saline at 38 degrees Celsius) 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, its shape memory effect will not occur, 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), thereby enhancing the anti-bending stiffness of the anti-bending section at the distal end of the tube body 1. The used temperature medium converges into the second medium inflow 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 the 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 sequential orders.

[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 pipe 271, while the medium output end of the return pipe 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 pipe in this embodiment, a layer of nano-insulating film can be further coated on the inner walls of the first pipe 271 and the second pipe 272 of the circulation pipe to avoid heat dissipation and cause the temperature of the temperature medium to decrease. Regarding the specific material of the nano-insulating 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 memory alloy ball valve core 282 is adaptively arranged in the ball valve cavity 281. The temperature at which the memory alloy ball valve core 282 undergoes the shape memory effect is the same as the temperature of the memory alloy helical wire 22 in the anti-bending section at the proximal end of the pipe body 1. When the temperature is adapted to the 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 pipe 272.

[0092] For example, the preparation material of the memory alloy ball valve core 282 is the same as the preparation material of the 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 an inner lining layer 111, a heat insulation layer 112 and a softening and compatible layer 113 which are co-extruded from the inside to the outside. The annular cavity 21, the first pipe 271 and the second pipe 272 are located in the inner lining layer 111, the return pipe is located in the heat insulation layer 112, and a thickened heat insulation and buffer section is formed at the position of the heat insulation layer 112 corresponding to the anti-bending section.

[0094] Furthermore, the inner liner 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, thereby 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 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 intervention 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 ≤ 0.05 W / (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, to avoid 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 provided 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, so as to realize real-time visual monitoring of the temperature state at the distal end of the catheter during the intervention operation, avoid the risk of overheating of the temperature medium or misactivation of the shape memory alloy coil 22, and significantly improve the safety and operation convenience of the operation.

[0097] Furthermore, spiral nano-grooves (depth 50 - 200 nm, width 80 - 150 nm, and the distance between adjacent spiral nano-grooves is 5 - 10 μm, not shown in the figure) are formed on the outer surface of the softening compatibility layer 113 along its axial direction. The three-dimensional structure of the nano-grooves can form a micro-scale liquid storage unit on the surface of the outer catheter 11, so that during the intervention 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] Furthermore, 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 operations. A radiopaque 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 radiopaque ring 3 during catheter interventional surgery.

[0099] More specifically, as Figure 10 shown, an annular mating 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 mating 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 mating 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 a 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, and the specific selection and related material process parameters are only used to explain the present invention and do not limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within 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 only serve 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 implementation conditions of the present invention. Therefore, they do not have technical substance significance. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the efficacy and purpose that the present invention can achieve, 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 do not limit the implementation scope of the present invention. Any change or adjustment of their relative relationship, without substantial change in the technical content, should also be regarded as the implementable scope of the present invention.

Claims

1. A kink-resistant intracranial double-tube guide catheter, 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 tube body (1), and an anti-bending support mechanism is provided in the anti-bending section (2); The anti-bending support mechanism comprises an annular cavity (21) and a memory alloy spiral wire (22); the annular cavity (21) is arranged in the wall layer of the outer catheter (11); a plurality of the memory alloy spiral wires (22) are arranged in a circumferential 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 memory alloy spiral wires (22); the temperature control tube (23) is S-shaped in the annular cavity (21) and is connected to the outside through a circulation pipe penetrating the wall layer of the outer catheter (11); A temperature medium is injected into the temperature control tube (23) through the circulation pipe, so that the shape memory effect is generated by temperature-activated memory alloy spiral wire (22).

2. The anti-kinking intracranial double-tube guide catheter according to claim 1, characterized in that: The anti-bending support mechanism further comprises an elastic support layer (24) attached to the outer wall of the inner catheter (12), and the elastic support layer (24) is arranged correspondingly and adapted to the annular cavity (21).

3. The anti-kinking intracranial double-tube guide catheter according to claim 2, characterized in that: A plurality of mounting grooves for fitting and mounting a memory alloy spiral wire (22) are provided inside the annular cavity (21); two ends of the memory alloy spiral wire (22) are anchored to the mounting grooves via limiting protrusions, and a middle section of the memory alloy spiral wire (22) is a free deformation zone; the mounting grooves force the annular cavity (21) to form an arc-shaped protrusion (25) outwardly toward the side of the inner conduit (12), and a buffer positioning groove is formed between adjacent arc-shaped protrusions (25); A plurality of buffer pad layers (26) adapted to the buffer positioning grooves are provided outside the elastic support layer (24).

4. The anti-kinking intracranial double-tube guide catheter according to claim 1, characterized in that: The two anti-bending sections (2) are respectively located at the proximal end and the distal end of the pipe body (1), and the temperature of the memory alloy spiral wire (22) in the annular cavity (21) of the two anti-bending sections (2) decreases along the direction in which the temperature medium of the circulation pipeline enters when the shape memory effect occurs.

5. The anti-kinking intracranial double-tube guide catheter according to claim 4, characterized in that: The circulation pipeline comprises a first pipeline (271), a second pipeline (272) and a return pipeline (273); the medium outflow end of the first pipeline (271) is connected to the inlet of the temperature control tube (23) in the annular cavity (21) 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 connected to the inlet of the temperature control pipe (23) in the annular cavity (21) at the far end of the pipe body (1); The outlet of the temperature control tube (23) in the annular cavity (21) at the proximal end of the tube body (1) is simultaneously connected to the medium inflow end of the second tube (272) and the first medium inflow end of the return tube (273); the second medium inflow end of the return tube (273) is connected to the outlet of the temperature control tube (23) in the annular cavity (21) at the distal end of the tube body (1); and the medium outflow end of the return tube (273) is connected to the outside; A regulating valve (28) is also provided at the point where the medium outflow end of the second pipe (272) is connected to the inlet of the temperature control tube (23) in the annular cavity (21) at the far end of the tube body (1), and an on-off component matching the activation temperature of the memory alloy spiral wire (22) in the annular cavity (21) at the near end of the tube body (1) is provided inside the regulating valve (28).

6. The anti-kinking intracranial double-tube guide catheter according to claim 5, characterized in that: The on-off assembly comprises a ball valve cavity (281), in which a memory alloy ball valve core (282) is adapted to be arranged, and the temperature of the memory alloy ball valve core (282) when a shape memory effect occurs is consistent with the temperature of the memory alloy spiral wire (22) in the anti-bending section located at the proximal end of the tube body (1).

7. The anti-kinking intracranial double-tube guide catheter according to claim 1, characterized in that: The wall layers of the outer conduit (11) comprise, from the inside to the outside, an inner lining layer (111), a heat insulating layer (112) and a softening compatible layer (113); the annular cavity (21), the first pipe (271) and the second pipe (272) are located in the inner lining layer (111); the return pipe is located in the heat insulating layer (112); and a thickened heat insulating buffer zone is formed at the position of the heat insulating layer (112) corresponding to the anti-bending section.

8. The anti-kinking intracranial double-tube guide catheter according to claim 1, characterized in that: 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 port of the outer catheter (11) to form an extended section for interventional operations, and a developing ring (3) is provided at the end position of the extended section.

9. The anti-kinking intracranial double-tube guide catheter according to claim 8, 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).

Images