Automatic resistance-avoiding guidewire and preparation method thereof

Abstract

The present application provides an automatic resistance avoidance guidewire and a preparation method thereof. The automatic resistance avoidance guidewire comprises a rigid proximal core wire and a flexible distal core wire that are fixedly connected; the distal core wire comprises a straight section and a pre-shaped curved section, and the proximal end of the straight section is fixedly connected to the distal end of the proximal core wire; the straight section, the proximal core wire and the curved section are all located in the same plane. The preparation method of the automatic resistance avoidance guidewire comprises: separately making a rigid proximal core wire and a flexible distal core wire, and fixing the distal end of the proximal core wire to the proximal end of the distal core wire to obtain a straight automatic resistance avoidance guidewire core wire; shaping the distal end of the distal core wire into a curved section, and the curved section and the straight section and the proximal core wire of the distal core wire are all located in the same plane to obtain an automatic resistance avoidance guidewire. The automatic resistance avoidance guidewire has good controllability and can avoid entering the mesh of the bare stent; and has the advantages of simple preparation method, low cost and high stability.

Description

Technical Field

[0001] The present application relates to the technical field of medical devices, and in particular to an automatic resistance-avoiding guidewire and a preparation method thereof. Background Art

[0002] Cardiovascular and cerebrovascular diseases are the leading cause of death in modern society, with a high number of deaths worldwide each year. Interventional therapy is currently the primary method for treating coronary atherosclerotic heart disease. Using balloon catheters to dilate stenosis or deploying stents can effectively treat stenosis, restore normal blood flow, and ensure blood supply.

[0003] Guidewires are an indispensable accessory for interventional medical devices and have been widely used in medical interventional surgeries, serving as guides and positioning for various interventional medical catheters and implantable devices to enter human organs. Currently, during surgical procedures, there are often multiple lesions. When treatment of a lesion at one site is completed and the next lesion needs to be treated, the guidewire often needs to pass through the stent at the previous lesion. During this process, the guidewire is prone to the following situations: 1. When passing through the stent, it is easy for the guidewire to pass through the stent mesh and enter the branch, causing surgical delays. In severe cases, the guidewire may become stuck in the stent, further damaging the stent or the guidewire. 2. After passing through the stent mesh, the guidewire may pass through the stent mesh and then into the stent. This may easily cause the stent to shift or subsequent treatment products, such as balloons and stents, to be unable to pass through the guidewire to reach the lesion. In severe cases, this may lead to stent damage or guidewire breakage. 3. The guidewire may easily enter the channel between the outside of the stent and the blood vessel wall, which may easily lead to the guidewire being trapped. When the balloon is used to withdraw the guidewire, the stent may be damaged or the guidewire may break. Summary of the Invention

[0004] In view of this, the purpose of this application is to propose an automatic resistance avoidance guidewire and a preparation method thereof.

[0005] Based on the above purpose, the present application provides an automatic resistance avoidance guidewire, comprising: a rigid proximal core wire and a flexible distal core wire that are fixedly connected;

[0006] The distal core wire includes a fixedly connected straight section and a pre-shaped curved section, the proximal end of the straight section is fixedly connected to the distal end of the proximal core wire; the distal end of the straight section is fixedly connected to the curved section, and the straight section, the proximal core wire and the curved section are all located in the same plane.

[0007] In some embodiments, the curved section includes a circular structure with a notch, the circular structure is connected to the straight section, and the diameter of the circular structure is larger than the mesh diameter of the bare stent to be inserted.

[0008] In some embodiments, the diameter of the circular structure is 1 mm to 5 mm, and the bending length of the circular structure is 3 mm to 20 mm.

[0009] In some embodiments, a preset angle is formed between the proximal end of the curved section and the straight section.

[0010] In some embodiments, the preset angle is 0.1-50°.

[0011] In some embodiments, the proximal end of the straight section is welded to the distal end of the proximal core wire; and further comprises a metal tube sleeved on the proximal end of the straight section and the distal end of the proximal core wire, the metal tube being bonded and fixed to the proximal end of the straight section and the distal end of the proximal core wire.

[0012] In some embodiments, the invention further comprises a safety net provided on the distal core wire, wherein the safety net is sleeved on the distal core wire, and both ends of the safety net are respectively fixed on the distal core wire; and / or

[0013] It also includes a wire wrapping sheath sleeved on the distal core wire; the head end of the wire wrapping sheath is used for development.

[0014] In some embodiments, the safety net and the wire sheath are included, the safety net is sleeved on the distal core wire, the wire sheath is sleeved on the safety net, and the distal end of the safety net is welded to the distal end of the curved section; and / or the unfolded length of the safety net is 20 to 50 mm; and / or

[0015] The wire-wound sheath is a spring, the wire-wound diameter is 0.001″-0.004″, and the total length of the spring is 1-30 cm.

[0016] In some embodiments, the safety net is coaxially arranged with the curved section, and / or the wire wrapping sheath is coaxially arranged with the safety net; and / or

[0017] It also includes a hydrophilic coating and a polymer sheath fixedly mounted on the distal end of the straight section. The hydrophilic coating is at least arranged on the surface of the proximal end of the curved section, the surface of the straight section and the surface of the wire-wound sheath.

[0018] The present application also provides a method for preparing a guidewire capable of automatically avoiding resistance, comprising:

[0019] A rigid proximal core wire and a flexible distal core wire are separately manufactured, and the distal end of the proximal core wire is fixedly connected to the proximal end of the distal core wire to obtain a straight core wire of the guide wire that automatically avoids resistance;

[0020] The distal end of the distal core wire is shaped into a curved section, and the curved section, the straight section of the distal core wire, and the proximal core wire are all located in the same plane.

[0021] From the above description, it can be seen that the automatic avoidance resistance guidewire provided by the present application adopts a rigid proximal core wire and a flexible distal core wire to be fixedly connected, and a pre-shaped curved section is provided at the distal end of the distal core wire, and the curved section and the straight section of the distal core wire and the proximal core wire are all located in the same plane, so that the head end of the automatic avoidance resistance guidewire has excellent anti-deformation ability and good controllability, which can prevent the automatic avoidance resistance guidewire from entering the mesh of the bare stent; it can also enable the automatic avoidance resistance guidewire to have automatic avoidance resistance ability, thereby preventing the automatic avoidance resistance guidewire from entering the channel or interlayer between the bare stent and the blood vessel wall; and it has the advantages of simple preparation method, low cost and high stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in this application or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are merely embodiments of this application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0023] Figure 1 Schematic diagram of the current guide wire entering the bare stent mesh;

[0024] Figure 2 A schematic diagram of an automatic resistance-avoiding guidewire provided in an embodiment of the present application;

[0025] Figure 3 A schematic diagram of another automatic resistance-avoiding guidewire provided in an embodiment of the present application;

[0026] Figure 4 for Figure 2 or Figure 3 Schematic diagram of the cross section at AA in FIG;

[0027] Figure 5 This is a schematic diagram of a guidewire in a bare stent according to an embodiment of the present application;

[0028] Figure 6 Schematic diagram of the process of preparing a guidewire capable of automatically avoiding resistance according to an embodiment of the present application;

[0029] Figure 7 A schematic diagram of the assembled structure of the automatic resistance avoidance guidewire provided in an embodiment of the present application;

[0030] Figure 8 This is another structural schematic diagram of the assembled automatic resistance avoidance guidewire provided in an embodiment of the present application. DETAILED DESCRIPTION

[0031] In order to make the objectives, technical solutions and advantages of this application more clear, this application is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0032] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should have the usual meanings understood by people with ordinary skills in the field to which this application belongs. The "first", "second" and similar words used in the embodiments of the present application do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0033] Stents typically include covered stents and bare stents. Covered stents are commonly used to treat aortic dissection or aortic aneurysm. During treatment, they isolate blood flow into the dissection or aneurysm, preventing further expansion and massive bleeding. Bare stents are often used to treat cardiovascular and cerebrovascular diseases. This is because these vascular diseases often involve vascular stenosis or calcification, and stents primarily provide support and maintain patency of the vessel lumen.

[0034] Currently, the tip of the guide wire is mostly straight, such as Figure 1 As shown, during the implementation of bare stent-related surgeries, there are often multiple lesion sites. When the treatment of a lesion in a certain site is completed and the next lesion needs to be treated, the guide wire often needs to pass through the bare stent at the previous lesion site. Since the guide wire diameter is very small, the head end of the guide wire is prone to get stuck in the mesh of the bare stent, which leads to delays in the operation and damage to the bare stent or the guide wire; or the guide wire passes through the mesh of the bare stent and then enters the bare stent through the mesh of the bare stent, which leads to displacement of the bare stent or inability of subsequent treatment products to reach the lesion site, damage to the bare stent or breakage of the guide wire, etc.; or the guide wire passes through the mesh of the bare stent and enters the channel or dissection between the bare stent and the blood vessel wall, which leads to the guide wire being detained, and the bare stent being damaged or the guide wire being broken when withdrawn.

[0035] Based on this, an embodiment of the present application provides an automatic resistance avoidance guide wire and a preparation method thereof, by pre-shaping a circle with a notch at the head end of the automatic resistance avoidance guide wire, the diameter of the circle is larger than the mesh of the bare stent, and the circular structure part and the non-circular structure part are in the same plane, so that when the automatic resistance avoidance guide wire moves in the bare stent during the operation, it can avoid passing through the mesh of the bare stent and entering unnecessary branches. At the same time, due to the ability of automatic resistance avoidance, the automatic resistance avoidance guide wire can be prevented from entering the channels and dissections in the blood vessels outside the bare stent, thereby shortening the operation time and improving the success rate of the operation.

[0036] The terms "proximal end" and "distal end" are defined herein as follows: "proximal end" generally refers to the end of the medical device closest to the operator during normal operation, while "distal end" generally refers to the end of the medical device that first enters the patient's body during normal operation. A core wire generally refers to the core portion of a guidewire, typically made of metal wire.

[0037] like Figure 2 As shown, an embodiment of the present application provides an automatic resistance avoidance guidewire, comprising: a rigid proximal core wire 1 and a flexible distal core wire 2. The distal core wire 2 has its tip located at the distal end of the automatic resistance avoidance guidewire and extends to the tip end of the automatic resistance avoidance guidewire, while the proximal core wire 1 is located at the proximal end of the automatic resistance avoidance guidewire, and the distal end of the proximal core wire 1 is fixedly connected to the proximal end of the distal guidewire.

[0038] The distal core wire 2 includes a fixedly connected straight section and a pre-shaped unclosed curved section 7, the proximal end of the straight section is fixedly connected to the distal end of the proximal core wire 1; the distal end of the straight section is connected to the curved section 7, and the straight section, the proximal core wire 1 and the curved section 7 are all located in the same plane.

[0039] The automatic avoidance resistance guidewire of the embodiment of the present application adopts a rigid proximal core wire 1 fixedly connected with a flexible distal core wire 2, and a pre-shaped curved section 7 is provided at the distal end of the distal core wire 2, and the curved section 7 and the straight section of the distal core wire 2 and the proximal core wire 1 are all located in the same plane, so that the head end of the automatic avoidance resistance guidewire has excellent anti-deformation ability and good controllability, which can prevent the automatic avoidance resistance guidewire from entering the mesh of the bare stent 93; it can also enable the automatic avoidance resistance guidewire to have automatic avoidance resistance ability, thereby preventing the automatic avoidance resistance guidewire from entering the channel or interlayer between the bare stent 93 and the wall of the blood vessel 94; and it has the advantages of simple preparation method, low cost and high stability.

[0040] In some embodiments, the cross-sectional shape of the head end of the proximal core wire 1 can be a ground cone, parabola, streamline or any other structure, and the cross-sectional shape of the head end of the distal core wire 2 can be a ground cone, parabola, streamline or any other structure, so as to provide good flexibility and pushing performance for the automatic resistance avoidance guide wire.

[0041] In some embodiments, the proximal core wire 1 can be made of any material with good deformation resistance and suitable for use as an automatic resistance-avoiding guidewire, including but not limited to nickel-titanium alloy, Fe-Ni alloy, or Ti-Ni-X alloy. The distal core wire 2 can be made of any material with good support and high rigidity and suitable for use as an automatic resistance-avoiding guidewire, including but not limited to 304 stainless steel, 316 stainless steel, cobalt-based alloy, Fe-Mn alloy, or Cu-Zn alloy.

[0042] In some embodiments, as Figure 2 As shown, the curved section 7 comprises only a circular structure with a notch, which is connected to the straight section. The diameter of the circular structure is larger than the mesh diameter of the bare stent 93 to be inserted. The diameter of the circular structure is determined based on the diameter of the blood vessel 94 and the mesh size of the bare stent 93, and can be larger than the mesh diameter of the bare stent 93 to be inserted and smaller than the diameter of the blood vessel 94.

[0043] In some embodiments, the diameter of the circular structure is preferably 1mm to 5mm, and the bending length of the circular structure is 3mm to 20mm. That is, the length of the circular structure after being straightened is 3mm to 20mm. In this way, the shape of the curved section 7 is adapted to the shape of the mesh of the bare stent 93 to be entered, and the diameter of the curved section 7 is larger than the diameter of the mesh of the bare stent 93 to be entered, which can prevent the automatic avoidance resistance guide wire from entering the mesh of the bare stent 93. At the same time, since the head end of the automatic avoidance resistance guide wire is a circular structure, the head end of the automatic avoidance resistance guide wire can automatically avoid resistance during the pushing process, avoid entering the channel between the bare stent 93 and the wall of the blood vessel 94 or entering the interlayer, so that the automatic avoidance resistance guide wire remains in the bare stent 93 or moves in the true lumen.

[0044] In some embodiments, as Figure 3 and Figure 7 As shown, there is a preset angle between the proximal end of the curved section and the straight section. Specifically, the curved section 7 also includes a bending structure 8, that is, the curved section includes a circular structure and a bending structure, and the bending structure is located between the circular structure and the straight section, that is, there is the preset angle between the proximal end of the bending structure and the straight section. Specifically, the distal end of the bending structure 8 is connected to the proximal end of the circular structure with a notch, and the proximal end of the bending structure 8 is connected to the distal end of the straight section. It can be understood that while the head end of the automatic avoidance resistance guidewire is a circular structure, there is also a bend, A bend, at the proximal end of the circular structure. The bending structure 8 can be used for direction selection, that is, selecting the branch vessel 94 that needs to be entered. By setting the bending structure 8, the automatic avoidance resistance guidewire can be adapted to different clinical lesion requirements, such as entering branch vessels 94 at different angles.

[0045] It should be understood that since the curved section 7, the straight section and the proximal core wire 1 are all located in the same plane, and the bending structure 8 is part of the curved section 7, the bending structure 8, the circular structure with the notch, the straight section, the proximal core wire 1 and the curved section 7 are all located in the same plane.

[0046] In some embodiments, as Figure 3 As shown, the predetermined included angle (also known as the external included angle) α between the proximal end of the curved section (i.e., the proximal end of the bent structure 8) and the straight section is 0.1-50°, and the extended length of the bent structure 8 is 3 mm-20 mm. This means that the included angle between the proximal end of the bent structure 8 and the extended line of the distal end of the straight section is 0.1-50°. The length of the bent structure 8 after straightening is 3 mm-20 mm.

[0047] The distal end of the proximal core wire 1 is fixedly connected to the proximal end of the distal core wire 2. Specifically, the proximal end of the straight section in the distal core wire 2 is fixedly connected to the distal end of the proximal core wire 1. In some embodiments, the connection method of the proximal core wire 1 and the distal core wire 2 can be one or more of resistance welding, brazing, ultrasonic welding, laser welding, bonding, and snap fit. Preferably, as Figure 4 As shown, the proximal core wire 1 and the distal core wire 2 are fixedly connected by resistance welding, that is, the proximal end of the straight section of the distal core wire 2 is resistance-welded to the distal end of the proximal core wire 1, forming a weld 9. Resistance welding can improve torque transmission between the proximal core wire 1 and the distal core wire 2.

[0048] Furthermore, the device further includes a metal tube 91 that is sleeved between the proximal end of the straight section and the distal end of the proximal core wire 1. The metal tube 91 is bonded to the proximal end of the straight section and the distal end of the proximal core wire 1. In other words, the proximal core wire 1 and the distal core wire 2 are connected together by resistance welding and bonding. This can be understood as the metal tube 91 bonding the proximal end of the straight section to the distal end of the proximal core wire 1 with the help of an adhesive 92. This bonding method prevents misalignment or bending of the proximal and distal core wires 1 and 2 after resistance welding, as well as stress concentration at the weld 9 that can lead to breakage when the automatic resistance-avoiding guidewire is bent. This improves the torque controllability of the automatic resistance-avoiding guidewire. The high-strength proximal core wire 1 provides excellent support and pushing force for the automatic resistance-avoiding guidewire, while the highly deformable distal core wire 2 provides excellent deformation resistance and flexibility, resulting in excellent controllability of the automatic resistance-avoiding guidewire.

[0049] In some embodiments, the metal tube 91 can be made of any material with strong deformation resistance, including but not limited to nickel-titanium alloy, Fe-Ni alloy, or Ti-Ni-X alloy. The adhesive 92 can be made of any material with good connectivity, including but not limited to one or more of AB glue, purple glue, and solder.

[0050] In some embodiments, as Figure 7 and Figure 8 As shown, (where, Figure 8 It can be understood as Figure 7 The safety net 5 is obtained by cross-sectioning the area at the wire sheath 6 in the figure, so as to more clearly show the wire sheath 6 and the safety net 5) and also includes a safety net 5 arranged between the distal core wire 2 and the wire sheath 6, that is, in the radial direction, the structure from the inside to the outside is the core wire, the safety net and the wire sheath, which can be understood as the safety net being arranged on the distal core wire 2, and the wire sheath being arranged on the safety net. Among them, the safety net can be arranged only on the entire curved section 7, or can be arranged on the entire curved section and part of the straight section, or can be arranged on the entire distal core wire. In some embodiments, the safety net 5 is arranged on the curved section 7 and is fixedly connected to the curved section 7. The safety net 5 can be understood as a metal wire mesh structure, a mesh structure woven by interlacing metal wires with each other through a special braiding machine. Specifically, the safety net 5 can be fixedly connected to any position of the automatic resistance avoidance guide wire head end (that is, the curved section 7) according to actual needs. By setting the safety net 5 on the head end of the automatic resistance avoidance guide wire (i.e. the curved section 7), the automatic resistance avoidance guide wire can have a soft head end and a higher breaking force, which can better avoid the breakage of the head end of the automatic resistance avoidance guide wire (i.e. the curved section 7). Figure 2 and Figure 3 In the figure, the safety net is a cross-sectional view at 5 locations.

[0051] In some embodiments, the distal end of the safety net 5 is welded to the distal end of the curved section 7, for example, in parallel. Preferably, the safety net 5 can be made of 6-20 metal wires. And the safety net 5 can be made of different mesh densities (PPI) or different metal wire sizes according to the different hardness requirements of the automatic avoidance resistance guide wire head. Preferably, the length of the safety net 5 ranges from 20 to 50 mm. It can be understood that the unfolded length of the safety net 5 (that is, the length after being straightened) can be 20 to 50 mm.

[0052] Furthermore, the safety net 5 is coaxially arranged with the curved section 7. That is, the safety net 5 is sleeved on the curved section 7 and coaxially nested with the curved section 7. This can further improve the connection stability between the safety net 5 and the curved section 7 and further enhance the flexibility of the automatic resistance avoidance guide wire tip.

[0053] In some embodiments, it also includes a wire wrapping sheath 6 that is sleeved on the distal core wire. The wire wrapping sheath 6 can be set only on the entire curved section 7, or can be set on the entire curved section and part of the straight section, or can be set on the entire distal core wire. The length of the wire wrapping sheath 6 can be adapted to the length of the safety net, and the proximal end of the wire wrapping sheath 6 can be fixedly connected to the distal end of the straight section. The wire wrapping sheath 6 is mainly used for development to achieve the visibility of the automatic resistance avoidance guide wire under X-rays. The wire wrapping sheath 6 can be understood as a metal wire spiral structure, a spiral structure formed by winding the metal wire side by side through a special spring machine.

[0054] Furthermore, the wire sheath 6 can also be set on the bending structure 8 to better achieve the visibility of the automatic resistance avoidance guide wire tip under X-ray.

[0055] Preferably, the wire sheath 6 may be a developing spring, which may be any one of a platinum-tungsten spring, a platinum-nickel spring, a platinum-iridium spring, a gold spring, or a stainless steel spring, or a combination of any two. The developing spring has excellent developing properties and can enhance the visibility of the automatic resistance-avoiding guidewire under X-rays.

[0056] In some embodiments, the wires are all wound by a spring machine. Preferably, the wire diameter is 0.001" to 0.004", the pitch is 0.01 to 0.05 mm, and the total length of the spring is 1 to 30 cm.

[0057] In some embodiments, the wire wrapping sheath 6 is coaxially arranged with the safety net 5. Thus, the circular structure with the notch, the safety net 5, and the wire wrapping sheath 6 are coaxially arranged. It should be understood that when the curved section 7 further includes a bending structure 8, the circular structure with the notch and the bending structure 8 are both coaxially arranged with the safety net 5 and the wire wrapping sheath 6. Because the curved section 7, the safety net 5, and the wire wrapping sheath 6 are coaxially arranged, the proximal core wire 1 and the distal core wire 2 are coaxially arranged with the safety net 5 and the wire wrapping sheath 6, thereby providing the safety net 5 and the wire wrapping sheath 6 with good stability.

[0058] In some embodiments, a polymer sheath 3 may be provided at the distal end of the straight section. The polymer sheath 3 may be made of a polymer material with excellent lubricity, and its main function is to provide excellent lubricity to facilitate the automatic resistance-avoiding guidewire to pass through the tortuous and complex blood vessels 94.

[0059] In some embodiments, a hydrophilic coating 4 may be further included to improve the lubricity of the automatic resistance avoidance guidewire, so that the automatic resistance avoidance guidewire has good lubricity, thereby reducing the passage resistance of the automatic resistance avoidance guidewire in the blood vessel 94, making the automatic resistance avoidance guidewire easy to push. The hydrophilic coating 4 can be provided at least on the surface of the bending structure 8, the surface of the straight section, and the surface of the wire sheath 6. Preferably, the hydrophilic coating 4 can be provided on the surface of all areas of the proximal core wire 1 and the distal core wire 2, so that the automatic resistance avoidance guidewire has good lubricity.

[0060] In some embodiments, the hydrophilic coating 4 is one of a polyvinyl pyrrolidone coating, a polyethylene oxide coating, a transparent ester acrylic coating or a polymethyl vinyl ether-maleic anhydride coating. The hydrophilic coating 4 can be coated on the surface of all areas of the proximal core wire 1 and the distal core wire 2.

[0061] In some embodiments, the proximal end of the proximal core wire 1 may be larger than the distal end for better grip during operation. Preferably, the proximal end of the proximal core wire 1 may be provided with anti-slip protrusions to increase friction and facilitate better grip.

[0062] like Figure 5 As shown, the automatic avoidance resistance guidewire provided in the embodiment of the present application can avoid entering the mesh of the bare stent 93, and is soft and does not damage the blood vessel 94; the automatic avoidance resistance guidewire has the ability to automatically avoid resistance, which can avoid the automatic avoidance resistance guidewire from entering the channel between the outside of the bare stent 93 and the wall of the blood vessel 94 or entering the interlayer; the circular structure head end and the non-circular structure part of the automatic avoidance resistance guidewire are in the same plane, thereby improving the controllability of the automatic avoidance resistance guidewire; the distal core wire 2 (that is, the distal guidewire) is made of a material with strong deformation resistance and good flexibility, so that the automatic avoidance resistance guidewire has excellent bending retention ability; the proximal core wire 1 (that is, the proximal guidewire) is made of a material with good support and strong rigidity, so that the automatic avoidance resistance guidewire has good support and pushing properties. The distal guide wire and the proximal guide wire are connected together by welding and bonding. The welding method can keep the automatic avoidance resistance guide wire coaxial after connection, thereby improving the torque transmission of the automatic avoidance resistance guide wire. Bonding can avoid stress concentration at the welding point 9 when the automatic avoidance resistance guide wire is bent, which may cause the automatic avoidance resistance guide wire to break. At the same time, bonding can also correct the guide wire that is not coaxial or bent at the welding position, so that the distal guide wire and the proximal guide wire remain coaxial, thereby improving the torque control and safety of the automatic avoidance resistance guide wire.

[0063] The embodiment of the present application also provides a method for preparing an automatic resistance avoidance guidewire, by which the head end of the automatic resistance avoidance guidewire is pre-shaped into a circular structure through heat treatment shaping and / or laser heat shaping and / or cold shaping, so that the automatic resistance avoidance guidewire can avoid entering the mesh of the bare stent 93 and has the ability to automatically avoid resistance during the pushing process, and the circular structure part and the non-circular structure part are in the same plane, so that the automatic resistance avoidance guidewire has strong controllability.

[0064] like Figure 6 As shown, the preparation method of the automatic resistance avoidance guidewire may include:

[0065] S10, respectively making a rigid proximal core wire 1 and a flexible distal core wire 2, and fixedly connecting the distal end of the proximal core wire 1 with the proximal end of the distal core wire 2 to obtain a straight core wire of the guidewire that automatically avoids resistance.

[0066] In some embodiments, the proximal core wire 1 and the distal core wire 2 can be made by grinding processes. The cross-sectional shape of the tip end of the proximal core wire 1 can be ground into a conical, parabolic, streamlined, or any other structure, and the cross-sectional shape of the tip end of the distal core wire 2 can be ground into a conical, parabolic, streamlined, or any other structure, to provide good flexibility and pushing performance for the automatic resistance avoidance guidewire.

[0067] In some embodiments, the proximal core wire 1 can be made of any material with good deformation resistance and suitable for use as an automatic resistance-avoiding guidewire, including but not limited to nickel-titanium alloy, Fe-Ni alloy, or Ti-Ni-X alloy. The distal core wire 2 can be made of any material with good support and high rigidity and suitable for use as an automatic resistance-avoiding guidewire, including but not limited to 304 stainless steel, 316 stainless steel, cobalt-based alloy, Fe-Mn alloy, or Cu-Zn alloy.

[0068] In some embodiments, the distal core wire 2 is located at the distal end of the automatic resistance avoidance guide wire and extends to the tip end of the automatic resistance avoidance guide wire, the proximal core wire 1 is located at the proximal end of the automatic resistance avoidance guide wire, and the distal end of the proximal core wire 1 is fixedly connected to the proximal end of the distal guide wire. In some embodiments, the connection method of the proximal core wire 1 and the distal core wire 2 can be one or more of resistance welding, brazing, ultrasonic welding, laser welding, bonding, and snap fit. Preferably, as Figure 4 As shown, the proximal core wire 1 and the distal core wire 2 are fixedly connected by resistance welding, that is, the proximal end of the straight section of the distal core wire 2 is resistance-welded to the distal end of the proximal core wire 1, forming a weld 9. Resistance welding can improve torque transmission between the proximal core wire 1 and the distal core wire 2.

[0069] Preferably, the proximal core wire 1 and the distal core wire 2 are further connected together by bonding, that is, the proximal core wire 1 and the distal core wire 2 are connected together by resistance welding and bonding. Figure 4 As shown, the proximal core wire 1 and the distal core wire 2 are first directly connected together by resistance welding, and then the proximal core wire 1, the distal core wire 2 and the metal tube 91 are bonded together by a metal tube 91 under the action of an adhesive 92. By using resistance welding and bonding, the torque transmission of the automatic avoidance resistance guidewire can be improved, and the problems of misalignment or bending of the proximal core wire 1 and the distal core wire 2 after resistance welding and stress concentration at the welding point 9 when the automatic avoidance resistance guidewire is bent, which may lead to fracture, can be avoided. Thus, the torque controllability of the automatic avoidance resistance guidewire is improved, and the high-strength proximal core wire 1 can provide good support and pushing force for the automatic avoidance resistance guidewire, and the distal core wire 2 with strong deformation resistance can provide good deformation resistance and flexibility for the automatic avoidance resistance guidewire, so that the automatic avoidance resistance guidewire has excellent controllability.

[0070] In some embodiments, the metal tube 91 can be made of any material with strong deformation resistance, including but not limited to nickel-titanium alloy, Fe-Ni alloy or Ti-Ni-X alloy; the adhesive 92 can be made of any material with good connectivity, including but not limited to one or more of AB glue, ultraviolet glue, and solder.

[0071] Preferably, the length of the proximal core wire 1 and the distal core wire 2 after connection can be 100 to 400 cm. At this time, the proximal core wire 1 and the distal core wire 2 are both straight strips, and the proximal core wire 1 and the distal core wire 2 after connection are both straight strips.

[0072] In some embodiments, step S10 may further include: preparing a safety net 5 and a wire wrapping sheath 6. The safety net 5 may be understood as a metal wire mesh structure, woven by interlacing metal wires using a dedicated weaving machine. The safety net 5 is designed to be placed over the tip of the automatic resistance avoidance guidewire, i.e., the distal end of the distal core wire 2, to provide the automatic resistance avoidance guidewire with a soft tip and a high breaking strength, thereby better preventing the tip of the automatic resistance avoidance guidewire from breaking.

[0073] Preferably, the safety net 53 can be made of 6-20 metal wires. Furthermore, the safety net 5 can be manufactured with different mesh densities (PPI) or different wire sizes based on the different hardness requirements of the automatic resistance avoidance guide wire tip. Preferably, the safety net 5 has a length range of 20-50 mm. It can be understood that the unfolded length of the safety net 5 (i.e., the length after being straightened) can be 20-50 mm.

[0074] The wire wrapping sheath 6 is positioned at the distal end of the core wire 2 of the automatic resistance avoidance guidewire, for example, at the distal end of the distal core wire 2. The wire wrapping sheath 6 is primarily used for visualization, ensuring X-ray visibility of the automatic resistance avoidance guidewire. The wire wrapping sheath 6 can be understood as a spiral structure of metal wires, formed by winding the metal wires side by side using a dedicated spring machine.

[0075] Preferably, the wire sheath 6 may be a developing spring, which may be any one of a platinum-tungsten spring, a platinum-nickel spring, a platinum-iridium spring, a gold spring, or a stainless steel spring, or a combination of any two. The developing spring has excellent developing properties and can enhance the visibility of the automatic resistance-avoiding guidewire under X-rays.

[0076] In some embodiments, the wires are all wound by a spring machine. Preferably, the wire diameter is 0.001" to 0.004", the pitch is 0.01 to 0.05 mm, and the total length of the spring is 1 to 30 cm.

[0077] S20: The distal end of the distal core wire 2 is formed into a curved section 7, wherein the curved section 7 is located in the same plane as the straight section of the distal core wire 2 and the proximal core wire 1. In other words, the curved section 7 is a pre-shaped curved section 7.

[0078] In some embodiments, the shaping process can be completed by a shaping process, which can be heat treatment shaping and / or cold setting. For example, heat treatment shaping can be used, and the specific process can be a heat treatment temperature of 200° C. to 600° C. and a heat treatment time of 1 minute to 30 minutes.

[0079] In some embodiments, the curved section 7 can be a circular structure with a notch, the diameter of which is larger than the mesh diameter of the bare stent 93 to be inserted. The diameter of the circular structure is determined based on the diameter of the blood vessel 94 and the mesh size of the bare stent 93, and can be larger than the mesh diameter of the bare stent 93 to be inserted and smaller than the diameter of the blood vessel 94.

[0080] In some embodiments, the diameter of the circular structure is preferably 1 mm to 5 mm, and the expanded length of the circular structure is 3 mm to 20 mm.

[0081] In other embodiments, Figure 3As shown, the curved section 7 also includes a bending structure 8, the distal end of the bending structure 8 is connected to the proximal end of the circular structure with the notch, and the proximal end of the bending structure 8 is connected to the distal end of the straight section. It can be understood that while the head end of the automatic avoidance resistance guidewire is a circular structure, there is also a bend, A bend, at the proximal end of the circular structure. The bending structure 8 can be used for direction selection, that is, to select the branch vessel 94 that needs to be entered. By providing the bending structure 8, the automatic avoidance resistance guidewire can be adapted to different clinical lesion requirements, such as entering branch vessels 94 at different angles.

[0082] In some embodiments, the outer angle α between the bent structure 8 and the straight section is 0.1-50°, and the unfolded length of the bent structure 8 is 3 mm-20 mm.

[0083] In some embodiments, the method may further include:

[0084] After step S20, the safety net 5 is placed on the curved section 7, and then the wire wrapping sheath 6 is placed on the curved section 7, and the curved section 7, the safety net 5 and the wire wrapping sheath 6 are fixedly connected. In this way, the curved section 7, the safety net 5 and the wire wrapping sheath 6 are coaxially arranged, so that the safety net 5 and the wire wrapping sheath 6 have good stability.

[0085] This step can be understood as the following sequence: putting the safety net 5 on the connected proximal core wire 1 and distal core wire 2, then putting the wire wrapping sheath 6, and then connecting the three together.

[0086] In some embodiments, the connection can be one or more of resistance welding, brazing, ultrasonic welding, laser welding, bonding, and snap fit. For example, it can be a brazing connection, and the welding temperature can be 200°C-500°C. The welding temperature is obtained through screening. The brazing temperature cannot be too high. Too high a temperature may damage the proximal core wire 1 and the distal core wire 2, resulting in the connection stability of the proximal core wire 1 and the distal core wire 2 being affected. The brazing temperature cannot be too low either. If it is lower than the brazing temperature, it will affect the combination of the proximal core wire 1 and the distal core wire 2, and it will not be possible to obtain an automatic resistance avoidance guidewire with good connection stability.

[0087] In some embodiments, the method may further include: fixing a polymer sheath 3 on the distal end of the straight section. The polymer sheath 3 may be made of one or more of polyurethane, polylactic acid, nylon elastomer, and polyetheretherketone. Specifically, the sheath 3 may be fixed to the distal core wire 2 by a hot melt process.

[0088] In some embodiments, the method may further include: coating the hydrophilic coating 4 at least on the surface of the bending structure 8, the surface of the straight section and the surface of the wire winding sheath 6. The hydrophilic coating 4 can be one of a polyvinyl pyrrolidone coating, a polyethylene oxide coating, a transparent ester acrylic coating or a polymethyl vinyl ether-maleic anhydride coating. The coating method can be a spraying method or a smearing method, and the coating is solidified and formed by a certain method so that it is not easy to fall off. After the hydrophilic coating 4 is applied, the appearance of the surface coating of the automatic avoidance resistance guidewire is observed to see if there is any abnormality. The hydrophilic coating 4 can make the automatic avoidance resistance guidewire have very good lubricity, thereby reducing the passage resistance of the automatic avoidance resistance guidewire in the blood vessel 94, making the automatic avoidance resistance guidewire easy to push.

[0089] Preferably, hydrophilic coating 4 is coated on all surfaces of the automatic avoidance resistance guide wire. Like this, the whole surface of the automatic avoidance resistance guide wire can have hydrophilic coating 4.

[0090] This preparation method is simple and easy to implement. The diameter of the circular structure can be changed as needed without affecting the overall design of the automatic avoidance resistance guidewire. The prepared automatic avoidance resistance guidewire can prevent the head end of the automatic avoidance resistance guidewire from entering the mesh of the bare stent 93, allowing the automatic avoidance resistance guidewire to enter unnecessary branches. The automatic avoidance resistance guidewire has the ability to automatically avoid resistance, which can prevent the automatic avoidance resistance guidewire from entering the channel outside the bare stent 93 and between the walls of the blood vessel 94 or entering the interlayer. The circular structure head end of the automatic avoidance resistance guidewire is in the same plane as the non-circular structure part, and has strong controllability. At the same time, the transition of the circular structure part of the automatic avoidance resistance guidewire is smooth, soft, and non-traumatic. In addition, this preparation method is low in cost.

[0091] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present disclosure (including the claims) is limited to these examples. Within the scope of the present disclosure, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the embodiments of the present disclosure as described above, which are not provided in detail for the sake of simplicity.

[0092] While the disclosure has been described in conjunction with specific embodiments thereof, many alternatives, modifications and variations of these embodiments will be apparent to those skilled in the art in light of the foregoing description.

[0093] The embodiments of the present disclosure are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. A guidewire with automatic resistance avoidance, characterized in that: include: A rigid proximal core wire and a flexible distal core wire that are fixedly connected; The distal core wire includes a connected straight section and a pre-shaped curved section, the proximal end of the straight section is fixedly connected to the distal end of the proximal core wire; and the straight section, the proximal core wire and the curved section are all located in the same plane, the curved section is pre-shaped into a circular structure with a notch, and the diameter of the circular structure is larger than the bare stent mesh to be entered.

2. The automatic resistance avoidance guidewire according to claim 1, characterized in that: The diameter of the circular structure is 1 mm to 5 mm, and the bending length of the circular structure is 3 mm to 20 mm.

3. The automatic resistance avoidance guidewire according to claim 1, characterized in that: A preset angle is formed between the proximal end of the curved section and the straight section.

4. The automatic resistance avoidance guidewire according to claim 3, characterized in that: The preset angle is 0.1-50°.

5. The automatic resistance avoidance guidewire according to claim 1, characterized in that: The proximal end of the straight section is welded to the distal end of the proximal core wire; further comprising a metal tube sleeved over the proximal end of the straight section and the distal end of the proximal core wire, the metal tube being bonded and fixed to the proximal end of the straight section and the distal end of the proximal core wire; and / or It also includes a hydrophilic coating and a polymer sheath fixedly mounted on the distal end of the straight section. The hydrophilic coating is at least arranged on the surface of the proximal end of the curved section and the surface of the straight section.

6. The automatic resistance avoidance guidewire according to claim 1 or 3, characterized in that: It also includes a safety net arranged on the distal core wire, wherein the safety net is sleeved on the distal core wire, and both ends of the safety net are respectively fixed on the distal core wire; and / or It also includes a wire wrapping sheath sleeved on the distal core wire; the head end of the wire wrapping sheath is used for development.

7. The automatic resistance-avoiding guidewire according to claim 6, characterized in that: The safety net comprises the safety net and the wire wrapping sheath, wherein the safety net is sleeved on the distal core wire, the wire wrapping sheath is sleeved on the safety net, and the distal end of the safety net is welded to the distal end of the curved section; and / or the total length of the safety net is 20 to 50 mm; and / or The wire-wound sheath is a spring, the wire diameter is 0.001″~0.010″, and the total length of the spring is 1~30cm.

8. The automatic resistance-avoiding guidewire according to claim 7, characterized in that: The safety net is coaxially arranged with the distal core wire, and / or the wire wrapping sheath is coaxially arranged with the safety net.

9. A method for preparing a guide wire that automatically avoids resistance, characterized in that: include: A rigid proximal core wire and a flexible distal core wire are separately manufactured, and the distal end of the proximal core wire is fixedly connected to the proximal end of the distal core wire to obtain a straight core wire of the guide wire that automatically avoids resistance; The distal end of the distal core wire is shaped into a curved section, and the curved section is pre-shaped into a circular structure with a notch. The diameter of the circular structure is larger than the mesh of the bare stent to be entered, and the curved section and the straight section and proximal core wire of the distal core wire are all located in the same plane, thereby obtaining a pre-shaped automatic resistance avoidance guide wire.

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