Nerve intervention guide wire with adjustable far-end hardness

Abstract

The invention relates to the technical field of intracranial treatment instruments, and discloses a far-end hardness adjustable nerve intervention guide wire which comprises a near-end adjusting device and a guide wire assembly, the near end of the guide wire assembly is installed in the near-end adjusting device, and an adjusting display sheet is arranged at the far end of the guide wire assembly. The guide wire assembly comprises a variable-diameter core wire, a near-end supporting component and a far-end elastic component, the near-end supporting component and the far-end elastic component are arranged on the periphery of the variable-diameter core wire in a sleeving mode, the near end of the far-end elastic component is connected with the far end of the near-end supporting component, the far end of the far-end elastic component is connected with the adjusting display sheet, an axial cavity is formed in the variable-diameter core wire, and the adjusting display sheet is arranged in the axial cavity. An adjusting wire is arranged in the cavity, and the far end of the adjusting wire penetrates through a center hole of the adjusting display sheet and then is connected with the adjusting display sheet. The length of the adjusting wire is controlled through the near-end adjusting device so as to change the axial length of the far-end elastic component, and adjustment of the far-end hardness of the nerve intervention guide wire is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of intracranial therapeutic instrument, more particularly to a nerve interventional guide wire with adjustable distal stiffness. BACKGROUND

[0002] Ischemic stroke (also known as cerebral infarction) is an acute cerebrovascular disease caused by stenosis or occlusion of cerebral blood supply arteries (such as carotid artery, vertebral artery, etc.), leading to cerebral ischemia, anoxic necrosis, and further causing neurological deficits. The main causes of ischemic stroke include atherosclerotic plaque rupture, thrombosis, cardioembolic embolism (such as atrial fibrillation) and small vessel disease, etc. The disease accounts for about 80% of all stroke cases, with high incidence, high disability rate and high mortality.

[0003] At present, the treatment of ischemic stroke is divided into drug thrombolysis and interventional therapy. Considering the unstable effect of drug thrombolysis and the short treatment time, interventional therapy is often used. The interventional therapy is divided into mechanical thrombectomy, thrombus aspiration, balloon dilation and stent implantation, etc. In these treatment methods, a micro guide wire is usually used to pass through the thrombus or stenosis site to guide the micro catheter to the right position, but the conventional guide wire cannot adjust the distal stiffness. When the lesion site is far away, the guide wire with a softer specification can reach the lesion site but it is difficult to pass through the thrombus, while the guide wire with a harder specification can pass through the thrombus but it is difficult to reach the lesion site. SUMMARY

[0004] Therefore, the present application provides a nerve interventional guide wire with adjustable distal stiffness. The guide wire can adjust the distal stiffness, and the doctor can adjust the stiffness of the head end of the guide wire to an appropriate degree before use or during the operation according to the specific situation, which is convenient for the doctor to operate, shortens the operation time, increases the success rate of the operation and improves the safety of the operation.

[0005] To achieve the above-mentioned purpose, the nerve interventional guide wire with adjustable distal stiffness provided by the present application comprises a proximal end adjusting device and a guide wire assembly. The proximal end of the guide wire assembly is detachably installed in the proximal end adjusting device. An adjusting radiograph is arranged at the distal end of the guide wire assembly. The guide wire assembly comprises a variable diameter core wire, a proximal end supporting part and a distal end elastic member. The proximal end supporting part and the distal end elastic member are sleeved on the outer periphery of the variable diameter core wire along the axial direction of the variable diameter core wire. The proximal end supporting part is fixedly connected with the variable diameter core wire. The distal end elastic member is slidably connected with the variable diameter core wire. The proximal end of the distal end elastic member is connected with the distal end of the proximal end supporting part. The distal end of the distal end elastic member is connected with the adjusting radiograph. An axial cavity is arranged in the variable diameter core wire. An adjusting wire is arranged in the cavity. The distal end of the adjusting wire is connected with the adjusting radiograph after passing through the center hole of the adjusting radiograph. The length of the adjusting wire is controlled by the proximal end adjusting device to change the axial length of the distal end elastic member, so as to adjust the distal stiffness of the nerve interventional guide wire.

[0006] Preferably, the distal elastic member comprises a head end outer layer adjusting spring, a distal end of the head end outer layer adjusting spring being connected with the adjusting film, and a proximal end of the head end outer layer adjusting spring being connected with the proximal end supporting part.

[0007] Preferably, the head end outer layer adjusting spring is internally provided with a head end inner layer developing spring movably sleeved on an outer periphery of the variable diameter core wire.

[0008] Preferably, a softness calculation formula of the head end outer layer adjusting spring is as follows: Softness = 1 / k, wherein k is a stiffness coefficient of the head end outer layer adjusting spring. A stiffness coefficient k calculation formula of the head end outer layer adjusting spring is as follows:

[0009] wherein G is a shear modulus of the head end outer layer adjusting spring, d is a wire diameter of the head end outer layer adjusting spring, D is a mean diameter of the head end outer layer adjusting spring, and n is a coil number of the head end outer layer adjusting spring.

[0010] Preferably, the distal end elastic member is provided with a developing ring at a connection position with the proximal end supporting part.

[0011] Preferably, the proximal end supporting part is internally provided with a proximal end inner layer developing spring sleeved on an outer periphery of the variable diameter core wire.

[0012] Preferably, a distal end of the proximal end inner layer developing spring is connected with a distal end of the proximal end supporting part, and a length of the proximal end inner layer developing spring is equal to or less than a length of the proximal end supporting part.

[0013] Preferably, the proximal end supporting part is a metal tube with a cutting structure or a spring wound by a metal wire.

[0014] Preferably, an inner part of the variable diameter core wire is coated with a PTFE coating layer.

[0015] Preferably, an outer layer of the guide wire assembly is coated with a hydrophilic coating layer.

[0016] According to the above technical solution, compared with the prior art, the distal end hardness adjustable nerve intervention guide wire provided by the present application has the following beneficial effects: 1. Precise adjustment of distal stiffness to adapt to complex lesions: The length of the adjustment wire can be controlled by the proximal adjustment device to change the axial compression degree of the distal elastic member (such as the outer adjustment spring at the head end) in real time, thereby linearly adjusting the distal stiffness of the guide wire. When it is necessary to pass through a thrombus or a narrow part, the length of the distal elastic member is shortened to increase the stiffness and improve the penetration ability. When it is necessary to enter a distal tortuous blood vessel, the length of the distal elastic member is lengthened to reduce the stiffness, improve the flexibility and compliance, and solve the contradiction between the traditional guide wire "hard to reach the position and soft to penetrate" to reduce the operation time and significantly improve the success rate of operation; 2. Multiple imaging design to improve the accuracy of intraoperative visualization: The distal adjustment film is provided, the proximal support member is connected with the distal elastic member, the proximal inner layer development spring and the distal inner layer development spring are provided, and multiple development marks are formed. The position of the distal end of the guide wire and the compression state of the distal elastic member can be clearly observed by X-ray during operation, which facilitates the doctor to accurately control the adjustment degree, avoids the damage to the blood vessel caused by excessive adjustment, and improves the operation safety; 3. Optimized structure design to enhance overall performance: The variable diameter core wire considers the proximal support force and the distal flexibility, cooperates with the internal PTFE coating to reduce the sliding resistance of the adjustment wire, ensures the smooth and stable adjustment process, the proximal support member adopts a cutting metal pipe or a spring structure, is fixedly connected with the variable diameter core wire, provides reliable proximal rigid support, and avoids the influence of the proximal deformation on the control of the distal stiffness during adjustment; 4. Surface coating treatment to improve biocompatibility and operation experience: The guide wire assembly is coated with a hydrophilic coating, which significantly reduces the frictional resistance between the guide wire and the blood vessel wall, facilitates smooth pushing in the blood vessel, and can safely and quickly reach the lesion site in a soft state in narrow cases or thrombectomy surgery. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without creating any inventive labor on the basis of the provided drawings.

[0018] Figure 1 It is the overall structure diagram of the distal stiffness adjustable neurointerventional guide wire of the present application; Figure 2 It is the structure diagram of the natural state of the distal stiffness adjustable neurointerventional guide wire of the present application; Figure 3 It is the structure diagram of the distal stiffness adjustable neurointerventional guide wire of the present application; Figure 2 Figure 4 It is the structure diagram of the distal stiffness adjustable neurointerventional guide wire of the present application; ​Figure 5 A cross-sectional view of the proximal adjustment device of the present application. Figure 4 A cross-sectional view of the proximal adjustment device of the present application. Figure 6 A cross-sectional view of the proximal adjustment device of the present application. Figure 7 A cross-sectional view of the proximal adjustment device of the present application.

[0019] Explanation of reference numerals: 1 - adjustment wire, 2 - variable diameter core wire, 3 - proximal support component, 4 - head end outer layer adjustment spring, 5 - adjustment film, 6 - head end inner layer development spring, 7 - proximal inner layer development spring, 8 - development ring, 9 - adjustment slider rack, 10 - gear, 100 - guide wire assembly, 200 - proximal adjustment device. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. The description of one exemplary embodiment below is actually only illustrative, but not as any limitation on the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0021] Please refer to the drawings in the embodiments of the present application. Figures 1-7 The present application discloses a guide wire with adjustable distal stiffness for neurointervention, which is applied to the establishment of a passage in the process of neurointervention treatment and helps a microcatheter to reach a lesion position.

[0022] As shown in FIG. 1, the present application provides a guide wire with adjustable distal stiffness for neurointervention, which comprises a proximal adjustment device 200 and a guide wire assembly 100. Figure 1 The proximal end of the guide wire assembly 100 is installed in the proximal adjustment device 200, and the length of the guide wire assembly 100 is adjusted by the proximal adjustment device 200 to change the stiffness of the distal part of the guide wire assembly 100. The proximal adjustment device 200 and the guide wire assembly 100 can be disassembled or connected at any time. When adjustment is needed during the operation, the proximal adjustment device 200 and the guide wire assembly 100 are installed, and after the adjustment is completed, they can be disassembled, which does not affect subsequent other surgical operations, such as the placement of a microcatheter. The outer layer of the guide wire for neurointervention is coated with a hydrophilic coating, and the hydrophilic coating can be polyvinylpyrrolidone.

[0023] As shown in FIG. 2, the present application provides a guide wire with adjustable distal stiffness for neurointervention, which comprises a proximal adjustment device 200 and a guide wire assembly 100. Figures 2-6As shown, the guide wire assembly 100 comprises an adjusting wire 1, a variable diameter core wire 2, a proximal end support component 3, a distal end elastic member, an adjusting film 5, the adjusting wire 1 is arranged inside the variable diameter core wire 2, the proximal end support component 3 and the distal end elastic member are sleeved on the outer periphery of the variable diameter core wire 2 along the axial direction of the variable diameter core wire 2, and the distal end elastic member is located on the distal end side of the proximal end support component 3, the adjusting film 5 is arranged at the distal end of the guide wire assembly 100, and the connecting position of the distal end elastic member and the proximal end support component 3 is provided with a developing ring 8.

[0024] The adjusting wire 1 is a solid wire material, which can be selected from stainless steel, can not be ground, or can be ground to have one-step variable diameter, two-step variable diameter or multi-step variable diameter, can reduce the weight of the distal end, and can avoid the hardness control deviation caused by inertia during adjustment. The adjusting wire 1 needs to pass through the center hole of the adjusting film 5, the distal end of the adjusting wire 1 can be processed into a flat wire shape, the flat wire-shaped distal end is matched with the center hole of the adjusting film 5 to enhance the connection stability, prevent falling off or slipping during the adjustment process, and the proximal end of the adjusting wire 1 is connected with the proximal end adjusting device 200, the length of the adjusting wire 1 is adjusted through the proximal end adjusting device 200, so as to change the hardness of the distal end elastic member.

[0025] The variable diameter core wire 2 can be a solid wire material, and the inner cavity after grinding is used to place the adjusting wire 1. The inside of the variable diameter core wire 2 can be coated with a PTFE coating to reduce the friction coefficient, reduce the resistance of the adjusting wire movement, ensure the linear response of the adjustment operation, and avoid jamming.

[0026] The variable diameter core wire 2 can be ground from a hollow hypotube. The inner diameter of the hypotube can be selected according to the size of the adjusting wire. According to the size design, the hypotube is processed into different diameter sections through grinding process. Preferably, the distal end is ground more than the proximal end, that is, the diameter of the variable diameter core wire 2 gradually decreases from the proximal end to the distal end. The variable diameter core wire 2 can be one-step variable diameter, two-step variable diameter or multi-step variable diameter. The multi-step variable diameter structure makes the guide wire gradually change in rigidity from the proximal end to the distal end, meets the dual requirements of "strong support-high flexibility" for nerve intervention, and the ground pipe material of the variable diameter core wire 2 can be selected from stainless steel, nickel-titanium alloy and the like. The inner cavity of the variable diameter core wire 2 can accommodate the adjusting wire 1.

[0027] The proximal end support component 3 is fixedly connected with the variable diameter core wire 2. The proximal end support component 3 can be a variable diameter and pitch metal tube with a cutting structure as shown in Figure 2 The cutting structure is spiral, square groove or grid. The cutting structure can be consistent throughout, or can be regularly changed. The proximal end support component 3 can also be a spring wound with metal wire. The metal tube with a cutting structure and the spring wound with metal wire can provide stable proximal end support. The cutting structure is suitable for scenarios requiring high rigidity. The spring structure is suitable for proximal end transition sections requiring certain flexibility, and meets the needs of different surgical paths. The material of the proximal end support component 3 can be selected from nickel-titanium, stainless steel and the like. The inside of the proximal end support component 3 is provided with a proximal end inner layer developing spring 7 sleeved on the outer periphery of the variable diameter core wire 2.

[0028] The distal elastic member comprises a head end outer layer adjusting spring 4 which can contract with the adjusting wire 1, and a head end inner layer developing spring 6 which is located inside the head end outer layer adjusting spring 4 and movably sleeved on the outer periphery of the variable diameter core wire 2.

[0029] The head end outer layer adjusting spring 4 can be made of nickel-titanium material or stainless steel material, and can be single-strand, double-strand or multi-strand wound spring, and can be full-wound, head end-wound near end-wound or head end-wound near end-wound.

[0030] It should be noted that the hardness of the head end outer layer adjusting spring 4 is negatively correlated with its length, that is, the longer the head end outer layer adjusting spring 4 is, the lower its hardness is, and the shorter the head end outer layer adjusting spring 4 is, the higher its hardness is, and the stiffness coefficient k of the head end outer layer adjusting spring 4 can be calculated by the following formula:

[0031] wherein G is the shear modulus of the head end outer layer adjusting spring 4, d is the wire diameter of the head end outer layer adjusting spring 4, D is the mean diameter of the head end outer layer adjusting spring 4, and n is the number of turns of the head end outer layer adjusting spring 4, and the softness of the head end outer layer adjusting spring 4 is calculated by the formula: softness = 1 / k, wherein k is the stiffness coefficient of the head end outer layer adjusting spring 4; the initial hardness of the guide wire head end can be designed according to the actual design requirements of the wire diameter and pitch of the adjusting wire 1, when the guide wire head end is tightened to half of the initial length, the hardness of the guide wire head end will be doubled, and corresponding scale marks can be added on the operation proximal end adjusting device for benchmark control.

[0032] The head end outer layer adjusting spring 4 is responsible for hardness adjustment, and the head end inner layer developing spring 6 provides developing marks, both of which independently move but coaxially cooperate to avoid radial deviation during adjustment and ensure that the distal end of the guide wire still maintains the straight pushing ability when the hardness changes.

[0033] The proximal end support member 3 is internally provided with a proximal end inner layer developing spring 7 which is sleeved on the outer periphery of the variable diameter core wire 2, the distal end of the proximal end inner layer developing spring 7 is connected with the distal end of the proximal end support member, and the length of the proximal end inner layer developing spring 7 is equal to or less than the length of the proximal end support member 3.

[0034] The head end inner layer developing spring 6 and the proximal end inner layer developing spring 7 are made of noble metal material, and the material can be platinum-tungsten material, platinum-iridium material, platinum-nickel material or pure gold; the head end inner layer developing spring 6 can be full-wound, head end-wound near end-wound or head end-wound near end-wound; the head end inner layer developing spring 6 can be single-strand, double-strand or multi-strand wound spring; and the proximal end inner layer developing spring 7 is a densely wound spring which can be single-strand, double-strand or multi-strand wound spring. The head end inner layer developing spring 6 and the proximal end inner layer developing spring 7 are wound by developing wires with different diameters, and different developing images can be obtained in surgery.

[0035] The adjusting film 5 is a circular sheet with a hole in the center. The head end of the adjusting film 5 can be treated as a ball head to prevent injury to blood vessels. The material of the adjusting film 5 can be selected from platinum tungsten material, platinum iridium material, platinum nickel material, pure gold, etc. The adjusting film 5 can provide development.

[0036] The distal end of the adjusting wire 1 is connected to the adjusting film 5. The adjusting film 5 is connected to the distal end of the head end outer adjusting spring 4 and the head end inner developing spring 6. The connection mode of the adjusting film 5 and the head end outer adjusting spring 4 and the head end inner developing spring 6 includes glue, laser welding, soldering and other connection modes. By tightening the proximal adjusting wire 1, the pitch of the head end outer adjusting spring 4 can be reduced to achieve the purpose of increasing the hardness of the head end of the nerve interventional guide wire.

[0037] It should be noted that the connection mode of all the above components can be one of laser welding, soldering or glue bonding to ensure the connection strength and the axial tension transmission efficiency during adjustment.

[0038] In this embodiment, the proximal adjusting device 200 includes a housing, a scale disc, an adjusting wire fixing device and an adjusting wire adjusting device. The scale disc, the adjusting wire fixing device and the adjusting wire adjusting device are installed on the housing to form a handle. The adjusting wire fixing device can be fixedly connected with the proximal end of the adjusting wire 1 in a detachable manner by means of but not limited to compression fixing, clamping fixing and the like. The adjusting wire adjusting device can be in a mode of but not limited to gear and rack slider mechanism, gear knob mechanism and the like to tighten or release the adjusting wire 1 fixed by the adjusting wire fixing device.

[0039] As Figure 7 described, the proximal end of the adjusting wire 1 is connected to the rotating shaft of the gear 10. The adjusting slider rack 9 engaged with the gear 10 includes a rack and a slider. By means of the slider fixed to the rack or the knob fixed to the gear 10, the gear 10 is driven to rotate to tighten the adjusting wire 1, so as to adjust the hardness of the head end outer adjusting spring 4.

[0040] In use, the proximal adjusting device 200 tightens the adjusting wire 1 to move the adjusting film 5 to the proximal end. The proximal outer support component 3 has strong rigidity and cannot be compressed. At this time, the head end outer adjusting spring 4 and the head end inner developing spring 6 are compressed, thereby adjusting the hardness of the distal end of the nerve interventional guide wire. Meanwhile, the head end outer adjusting spring 4 has two developing points on the distal and proximal sides, i.e. the adjusting film 5 and the developing ring 8 (both form clear proximal and distal mark points under X-ray. The doctor can directly judge the compression amount (i.e. the hardness adjustment degree) of the distal elastic member according to the distance between the two points, and realize quantitative adjustment by combining with the scale disc reading to avoid the error of experience-based operation), which can be used for real-time evaluation of the adjusting length during the operation to facilitate the doctor's operation and judgment.

[0041] The foregoing description of the disclosed embodiments enables a person skilled in the art to make or use the application. Modifications of these embodiments will occur to persons of skill in the art, and that the appended claims are intended to cover all such modifications that do not depart from the true spirit and scope of the application. Therefore, the application is not limited to the embodiments shown but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A neurointervention guidewire with adjustable distal hardness, characterized in that: The invention comprises a proximal adjustment device (200) and a guide wire assembly (100), wherein the proximal end of the guide wire assembly (100) is detachably mounted in the proximal adjustment device (200), and an adjustment display film (5) is provided at the distal end of the guide wire assembly (100), and the guide wire assembly (100) comprises a variable diameter core wire (2), a proximal support component (3) and a distal elastic component, wherein the proximal support component (3) and the distal elastic component are sleeved on the outer periphery of the variable diameter core wire (2) along the axial direction of the variable diameter core wire (2), the proximal support component (3) is fixedly connected to the variable diameter core wire (2), and the distal elastic component is fixedly connected to the proximal support component (3) ...). The elastic member is slidably connected to the variable diameter core wire (2), the proximal end of the distal elastic member is connected to the distal end of the proximal support component (3), and the distal end of the distal elastic member is connected to the adjustment display film (5). An axial cavity is provided inside the variable diameter core wire (2), and an adjustment wire (1) is provided in the cavity. The distal end of the adjustment wire (1) passes through the central hole of the adjustment display film (5) and is connected to the adjustment display film (5). The length of the adjustment wire (1) is controlled by the proximal adjustment device (200) to change the axial length of the distal elastic member, thereby achieving adjustment of the distal hardness of the neurointervention guide wire.

2. The neurointervention guidewire with adjustable distal hardness according to claim 1, characterized in that: The distal elastic component comprises a head end outer layer regulating spring (4), the distal end of the head end outer layer regulating spring (4) is connected to the regulating display film (5), and the proximal end of the head end outer layer regulating spring (4) is connected to the proximal support component (3).

3. The neurointervention guidewire with adjustable distal hardness according to claim 2, characterized in that: The head end outer layer regulating spring (4) is provided inside with a head end inner layer developing spring (6) which is movably sleeved on the outer periphery of the diameter-changing core wire (2).

4. The neurointervention guidewire with adjustable distal hardness according to claim 2 or 3, characterized in that: The calculation formula for the softness of the head end outer layer adjustment spring (4) is: Softness = 1 / k, Where k is the spring constant of the outer layer adjustment spring (4) at the head end; The calculation formula of the stiffness coefficient k of the head end outer layer regulating spring (4) is: ； Wherein G is the shear modulus of the head end outer layer adjusting spring (4), d is the wire diameter of the head end outer layer adjusting spring (4), D is the median diameter of the head end outer layer adjusting spring (4), and n is the number of turns of the head end outer layer adjusting spring (4).

5. The neurointervention guidewire with adjustable distal hardness according to claim 1, characterized in that: A developing ring (8) is provided at the connection between the distal elastic component and the proximal supporting component (3).

6. The neurointervention guidewire with adjustable distal hardness according to claim 1, characterized in that: The interior of the proximal support component (3) is provided with a proximal inner layer developing spring (7) sleeved on the outer periphery of the variable diameter core wire (2).

7. The neurointervention guidewire with adjustable distal hardness according to claim 6, characterized in that: The distal end of the proximal inner layer developing spring (7) is connected to the distal end of the proximal support component (3), and the length of the proximal inner layer developing spring (7) is equal to or less than the length of the proximal support component (3).

8. The neurointervention guidewire with adjustable distal hardness according to claim 1, characterized in that: The proximal support component (3) is a metal tube with a cutting structure or a spring wound with metal wire.

9. The neurointervention guidewire with adjustable distal hardness according to claim 1, characterized in that: The interior of the reduced diameter core wire (2) is coated with a PTFE coating.

10. The neurointervention guidewire with adjustable distal hardness according to claim 1, characterized in that: The outer layer of the guidewire assembly (100) is coated with a hydrophilic coating.

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