Guide wire

Abstract

The purpose of the present invention is to provide a guidewire which, even when a hydrophilic coating layer is in contact with a liquid such as a bodily fluid, is capable of suppressing an increase in frictional resistance with a co-use device that accompanies swelling of the hydrophilic coating layer, and which is capable of improving the rotational response of the guidewire. A guidewire (1) is provided with a core shaft (11), a coil body (21) in which a wire (w) is wound so as to cover the outer periphery of the tip of the core shaft (11), a first portion (41) formed from a hydrophilic coating layer (411) disposed on the radially outer surface of the outer peripheral surface of the wire (w) and a hydrophobic coating layer (412) formed on the hydrophilic coating layer (411), and a second portion (51) formed from a hydrophilic coating layer (411) disposed on the radially outer surface of the hydrophobic coating layer (412). And a hydrophilic coating layer (511) that is formed on the outside in the radial direction with respect to the axial center of the wire (w) and that is disposed so as to fill a recess between adjacent wires (w, w) in the long-axis direction, the hydrophilic coating layer (511) being formed on the outer side in the radial direction with respect to the axial center of the wire (w).

Description

Technical Field

[0001] This invention relates to a guidewire. Background Technology

[0002] For example, when a therapeutic device such as a catheter (or other device) is inserted into a body cavity such as a blood vessel, a guidewire is inserted into the body cavity beforehand in order to guide the device to the treatment site.

[0003] For example, after pre-shaping the tip into a roughly J-shape, the guidewire is inserted into the body cavity. At the site where the body cavity branches, the guidewire is rotated appropriately so that the tip of the guidewire faces the desired branch lumen, and the tip of the guidewire is advanced to the treatment site.

[0004] To enable such guidewires to quickly reach the treatment site, the following techniques have been proposed. For example, techniques to reduce frictional resistance with the device by reducing the contact area between the guidewire and the wall surface (e.g., see Patent Document 1), or techniques to reduce frictional resistance with the device by providing a hydrophilic coating on the surface of the guidewire in contact with the wall, absorbing moisture upon contact with body fluids, and forming a liquid film on the outermost surface (e.g., see Patent Document 2).

[0005] Existing technical documents Patent documents Patent document 1: Japanese Patent Application Publication No. 2011-152211.

[0006] Patent Document 2: Japanese Patent Application Publication No. 2012-70979. Summary of the Invention

[0007] The problem that the invention aims to solve However, even when a hydrophilic coating forms a liquid film on the outermost surface, if the hydrophilic coating swells excessively due to water absorption, the gap between the hydrophilic coating and the co-operated device abutting the outer peripheral surface will decrease. Consequently, the frictional resistance with the co-operated device increases, sometimes leading to a poorer rotational response of the guidewire when the tip of the guidewire is rotated via a near-hand rotational operation.

[0008] The present invention is made based on the above circumstances, and its purpose is to provide a guidewire that can suppress the increase in frictional resistance with the device caused by the swelling of the hydrophilic coating even when the hydrophilic coating comes into contact with liquids such as body fluids, and can improve the rotational response of the guidewire.

[0009] Solution to the problem Some embodiments of this disclosure are shown below: (1) A guidewire, comprising: mandrel; A coil body, the threads of which are wound in such a way that they cover the outer periphery of the front end of the mandrel; The first part is formed by a hydrophilic coating and a hydrophobic coating. The hydrophilic coating is disposed on the radially outer surface of the outer peripheral surface of the filament, and the hydrophobic coating is formed on the outer peripheral surface of the hydrophilic coating. The second part, which is a part that is radially outward compared to the axis of the thread, is formed by a hydrophilic coating configured to fill the recess between adjacent threads along the long axis.

[0010] (2) The guide wire according to embodiment (1) wherein, when the hydrophilic coating dries, the distance between the outer peripheral surface of the second part and the central axis of the mandrel is less than the distance between the outer peripheral surface of the first part and the central axis of the mandrel.

[0011] (3) The guide wire according to embodiment (1), wherein when the hydrophilic coating comes into contact with the liquid, the distance between the outer peripheral surface of the second part and the central axis of the mandrel is approximately equal to the distance between the outer peripheral surface of the first part and the central axis of the mandrel.

[0012] (4) A guidewire, comprising: mandrel; The coil body has its threads wound in such a way that they cover the outer periphery of the front end of the mandrel; The first part is formed by a hydrophobic coating, which is disposed on the radially outer surface of the outer peripheral surface of the filament. The second part, which is a part that is radially outward compared to the axis of the thread, is formed by a hydrophilic coating configured to fill the recess between adjacent threads along the long axis.

[0013] It should be noted that in this specification, "front end side" refers to the direction along the long axis of the guidewire, indicating insertion into the deeper (distal) part of the body cavity. "Base end side" refers to the direction along the long axis of the guidewire, the opposite direction to "front end side." "Front end" refers to the end of the front end side of any component or part, and "base end" refers to the end of the base end side of any component or part. "Anterior end portion" refers to the portion of any component or part, including its front end and extending from its front end towards the base end side to the middle of its long axis. "Base end portion" refers to the portion of any component or part, including its base end and extending from its base end towards the front end side to the middle of its long axis. Unless otherwise specified, "long axis direction" refers to the long axis direction of the mandrel. "Radial" refers to a radial direction orthogonal to the long axis direction of the mandrel.

[0014] Invention Effects The present invention provides a guidewire that can suppress the increase in frictional resistance with the device caused by the swelling of the hydrophilic coating, even when the hydrophilic coating is in contact with liquids such as body fluids, and can improve the rotational response of the guidewire. Attached Figure Description

[0015] Figure 1 This is a schematic longitudinal sectional view illustrating the first embodiment.

[0016] Figure 2 This is a schematic side view showing an enlarged portion of the first embodiment.

[0017] Figure 3 This is a schematic longitudinal sectional view enlarged to show a portion of the first embodiment, and is a diagram of the hydrophilic coating during drying.

[0018] Figure 4 This is a schematic longitudinal sectional view enlarged to show a portion of the first embodiment, and is a diagram of the hydrophilic coating in contact with a liquid; Figure 5A This is a schematic cross-sectional view illustrating an example of the state of the guide wire during the drying of the hydrophilic coating in the first embodiment.

[0019] Figure 5B This is a schematic cross-sectional view illustrating an example of the state of the guidewire when the hydrophilic coating comes into contact with the liquid in the first embodiment.

[0020] Figure 6 This is a schematic longitudinal sectional view showing a portion of the second embodiment, enlarged, and is a diagram of the hydrophilic coating during drying.

[0021] Figure 7 This is a schematic longitudinal sectional view enlarged to show a portion of the second embodiment, showing the hydrophilic coating in contact with a liquid.

[0022] Figure 8A This is a schematic longitudinal sectional view showing a modified example of the second part.

[0023] Figure 8B This is a schematic longitudinal sectional view showing a modified example of the second part.

[0024] Figure 8C This is a schematic longitudinal sectional view showing a modified example of the second part. Detailed Implementation

[0025] The guide wire disclosed herein includes: a mandrel; a coil body having a wire wound around the outer periphery of the front end of the mandrel; a first portion formed of a hydrophilic coating and a hydrophobic coating, the hydrophilic coating being disposed on a radially outer surface of the outer periphery of the wire, and the hydrophobic coating being formed on the outer periphery of the hydrophilic coating; and a second portion being a portion further radially outer than the axis of the wire, formed of a hydrophilic coating, the hydrophilic coating being disposed to fill a recess between adjacent wires along the long axis direction.

[0026] This disclosure includes a guide wire comprising: a mandrel; a coil body having a wire wound around the outer periphery of the front end of the mandrel; a first portion formed of a hydrophobic coating disposed on a radially outer surface of the outer periphery of the wire; and a second portion, which is a portion further radially outer than the axis of the wire, formed of a hydrophilic coating disposed to fill a recess between adjacent wires along the long axis.

[0027] It should be noted that rotational response refers to the ease with which the tip of the guidewire can initiate a rotational action relative to the base of the guidewire, while torque transmittance refers to the ability to transmit the rotational force applied to the base of the guidewire to the tip of the guidewire.

[0028] Hereinafter, the first and second embodiments of the present invention will be described with reference to the accompanying drawings, but the present invention is not limited to the embodiments described in the drawings. Furthermore, the dimensions of the parts shown in the drawings are for ease of understanding and do not necessarily correspond to actual dimensions.

[0029] exist Figures 1 to 8C In the diagram, the left side shows the anterior end (distal side) of the insertion into the deeper (distal) part of the body cavity, while the right side shows the basal end (proximal hand side, proximal side).

[0030] [First Implementation Method] Figures 1 to 4 This is a schematic diagram illustrating the first embodiment. (For example...) Figure 1 , Figure 2 As shown, the guide wire 1 is roughly composed of a mandrel 11, a coil body 21, a front end fixing part 31, a first part 41, and a second part 51. It should be noted that... Figure 3 This indicates that guidewire 1 is not in contact with the liquid (the state when the hydrophilic coatings 411 and 511 are dry). Figure 4 This indicates the state of guidewire 1 in contact with the liquid (the state of hydrophilic coatings 411 and 511 in contact with the liquid).

[0031] The mandrel 11 is an elongated component that forms the axis of the guide wire 1. The mandrel 11 is formed, for example, from a flexible material, and its front end is configured to taper in diameter toward the front end.

[0032] In this embodiment, the front end of the mandrel 11 is configured to have: a small-diameter portion 111 with a constant outer diameter, a large-diameter portion 113 located closer to the base end than the small-diameter portion 111 and having a larger constant outer diameter than the small-diameter portion 111, and a tapered portion 112 arranged to be continuous with the small-diameter portion 111 and the large-diameter portion 113 and gradually expanding in diameter from the small-diameter portion 111 toward the large-diameter portion 113. That is, when the mandrel 11 extends in a straight line, the small-diameter portion 111 and the large-diameter portion 113 are both cylindrical with a constant outer diameter, and the tapered portion 112 is a frustum-shaped cone that gradually expands in diameter toward the base end.

[0033] It should be noted that, although not shown in the figure, the mandrel 11 also has: a frustum-shaped connecting part, the front end of which is continuous with the base end of the large-diameter part 113; and a cylindrical main body part, the front end of which is continuous with the base end of the connecting part, and the outer diameter is constant.

[0034] The material constituting the mandrel 11 is preferably flexible and possesses antithrombotic and biocompatibility properties. Examples of such materials include stainless steel such as SUS304 and superelastic alloys such as Ni-Ti alloys.

[0035] The coil body 21 is a helical (coil-shaped) component, with its threads wound around the outer periphery of the front end of the mandrel 11. Specifically, the coil body 21 can be formed by winding one or more threads w around the mandrel 11 in a manner that covers at least a portion of it. The coil body 21 can be a loose winding with gaps between the threads along its long axis, or a tight winding with the threads in contact with each other.

[0036] The wire w constituting the coil body 21 can be one or more single wires, or one or more stranded wires. However, a single wire refers to a single wire, while stranded wire refers to a bundle of wires formed by twisting multiple single wires together beforehand.

[0037] From the viewpoint of ensuring the flexibility of the guidewire 1 and imparting antithrombotic and biocompatibility, the wire constituting the coil body 21 can be made of stainless steel such as SUS316, super-elastic alloys such as Ni-Ti alloy, or radiation-impermeable metals such as platinum and tungsten.

[0038] The front end fixing part 31 is the part where the front end of the spindle 11 is integrally fixed to the front end of the coil body 21. Specifically, for example, the front end fixing part 31 can be formed into a generally hemispherical shape with the front end bent into a convex shape towards the front end. In this way, the resistance when the guide wire 1 advances in the body cavity can be reduced, and the guide wire 1 can be inserted smoothly.

[0039] As a method for forming the front-end fixing part 31, for example, it can be formed by melting and molding a part of the components constituting the mandrel 11 and / or coil body 21, or by joining the mandrel 11 and coil body 21 with solder and molding the solder. As solder, for example, examples include metal solders such as Sn-Pb alloy, Pb-Ag alloy, Sn-Ag alloy and Au-Sn alloy.

[0040] The base end of the coil body 21 can be engaged with the mandrel 11. Specifically, for example, the base end of the coil body 21 can be engaged with the outer peripheral surface of the mandrel 11 (e.g., the outer peripheral surface of the large diameter portion 113, etc.) using a solder. As a solder for engaging the base end of the coil body 21, examples include solders similar to those used to form the front end fixing portion.

[0041] The first part 41 is a part formed by a hydrophilic coating and a hydrophobic coating. The hydrophilic coating is disposed on the radially outer surface of the outer peripheral surface of the filament w, and the hydrophobic coating is formed on the outer peripheral surface of the hydrophilic coating. Specifically, as Figure 2 and Figure 3 As shown, the first part 41 is disposed on the outer peripheral surface of the coil body 21, that is, on the surface of the wire w located radially outward from the center of the wire w. A hydrophilic coating 411 and a hydrophobic coating 412 are sequentially layered on the first part 41 from the wire w side. It should be noted that the static friction coefficients of each surface when in contact with the liquid increase in the following order: hydrophilic coating < hydrophobic coating < wire.

[0042] For example, when the guidewire 1 is inserted into the body cavity, the hydrophilic coating 411 can improve the smoothness between the surface of the guidewire 1 and the surface of the body cavity wall, as well as the smoothness between the surface of the guidewire 1 and the concomitant device (not shown) through which the guidewire 1 is inserted (reducing frictional resistance).

[0043] Materials constituting the hydrophilic coating 411 may include, for example, polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol, polyacrylamide, polyacrylic acid, sodium polyacrylate, poly(2-hydroxyethyl) methacrylate, maleic anhydride copolymers, ethylene-vinyl alcohol copolymers, 2-methacryloyloxyethyl phosphocholine or copolymers thereof, (2-hydroxyethyl methacrylate)-styrene block copolymers, various synthetic peptides, collagen, hyaluronic acid, cellulose polymers, and mixtures thereof. It should be noted that the hydrophilic coating 411 may contain additives such as crosslinking agents, non-volatile solvents, volatile solvents, and surfactants.

[0044] For example, the hydrophobic coating 412 can limit the amount of liquid that penetrates deep into the first portion 41. The hydrophobic coating 412 can inhibit liquid from reaching the hydrophilic coating 411 located deep in the first portion 41, thereby reducing the possibility of the hydrophilic coating 411 becoming excessively swollen due to the penetrating liquid.

[0045] Materials constituting the hydrophobic coating 412 may include, for example, silicone, polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), and mixtures thereof. It should be noted that the hydrophobic coating 412 may contain additives such as crosslinking agents, non-volatile solvents, volatile solvents, and surfactants.

[0046] The second part 51 is a part located radially outward compared to the axis of the filament w, and is formed by a hydrophilic coating configured to fill the recesses between adjacent filaments along the long axis. Specifically, as... Figure 2 and Figure 3 As shown, the second part 51 is configured to fill the recesses (valve portions) between adjacent wires w located on the outer peripheral surface side of the coil body 21, that is, located radially outside the axis of the wire w.

[0047] It should be noted that the hydrophilic coating 511 in the second part 51 can also improve, for example, the smoothness between the surface of the guidewire 1 and the surface of the body cavity wall when the guidewire 1 is inserted into the body cavity, and improve the smoothness between the surface of the guidewire 1 and the device through which the guidewire 1 is inserted (reducing frictional resistance).

[0048] As the material constituting the hydrophilic coating 511 in the second part 51, materials similar to those used in the hydrophilic coating 411 described above can be listed. It should be noted that the material constituting the hydrophilic coating 511 may be the same as or different from the material constituting the hydrophilic coating 411.

[0049] Here, the states of the first part 41 and the second part 51 when the guidewire 1 is not in contact with the liquid (the state when the hydrophilic coatings 411 and 511 are dry) and the states of the first part 41 and the second part 51 when the guidewire 1 is in contact with the liquid (the state when the hydrophilic coatings 411 and 511 are in contact with the liquid) will be described.

[0050] Figure 3 This is a schematic diagram showing the drying process of hydrophilic coatings 411 and 511. Figure 4 This is a schematic diagram showing the hydrophilic coatings 411 and 511 in contact with a liquid. For example, when the guidewire 1 is inserted into a body cavity and comes into contact with surrounding liquids such as bodily fluids, at the first location 41, the liquid permeates through the hydrophobic coating 412 on the surface to the hydrophilic coating 411. When the liquid permeates into the hydrophilic coating 411, the hydrophilic coating 411 absorbs the liquid and forms a liquid film (not shown) on the surface side (radially outward) of the hydrophilic coating 411. The formed liquid film expands in volume due to the absorbed liquid and exhibits viscosity.

[0051] At this point, when there is no hydrophobic coating and a hydrophilic coating is exposed on the surface, the gap between the guidewire and the inner wall of the connecting device becomes smaller due to the hydrophilic coating swelling from absorbing body fluids. Therefore, even if a liquid film is formed, it actually increases the frictional resistance between the guidewire and the connecting device, hindering the smooth operation of the connecting device.

[0052] However, in this embodiment, such as Figure 4 As shown, in the first portion 41, since the hydrophobic coating 412 is layered on top of the hydrophilic coating 411, the hydrophobic coating 412 limits the amount of liquid that can penetrate into the deeper portion of the hydrophilic coating 411. As a result, swelling of the hydrophilic coating 411 is suppressed, and by ensuring a gap between the guidewire 1 and the inner wall of the combined device, the frictional resistance between the guidewire 1 and the combined device can be reduced.

[0053] On the other hand, the second portion 51 lacks a hydrophobic coating, instead exhibiting a hydrophilic coating 511 on its surface. Therefore, when the guidewire 1 comes into contact with a liquid, due to the absence of a hydrophobic coating, more liquid permeates into the hydrophilic coating 511, causing it to swell according to the amount of liquid absorbed. As a result, the outer surface s2 of the second portion 51, located in the valley between adjacent wires w, bulges radially outward, and the liquid film on the bulging surface reduces the frictional resistance between the guidewire 1 and the connecting device.

[0054] There is no particular limitation on the area ratio of the first portion 41 to the second portion 51 on the outermost surface of the guidewire 1 during drying. The ratio of the surface area of ​​the first portion 41 to the surface area of ​​the second portion 51 can be set, for example, from 1:10 to 10:1.

[0055] The thickness of the hydrophilic coating 411 and the hydrophobic coating 412 of the first part 41 during drying is not particularly limited as long as it does not impair the effect of the present invention. The respective thickness of the hydrophilic coating 411 and the hydrophobic coating 412 of the first part 41 can be set, for example, from 1 μm to 300 μm.

[0056] The radial thickness of the hydrophilic coating 511 of the second part 51 during drying is not particularly limited as long as it does not impair the effect of the present invention. The thickness of the hydrophilic coating 511 of the second part 51 can be set, for example, from 1 μm to 300 μm.

[0057] It should be noted that during the drying of hydrophilic coatings 411 and 511, if... Figure 5AAs shown, preferably, the distance L2 between the outer peripheral surface s2 of the second portion 51 and the central axis x of the mandrel 11 is less than the distance L1 between the outer peripheral surface s1 of the first portion 41 and the central axis x of the mandrel 11. Thus, even when the hydrophilic coating 511 of the second portion 51 is in contact with the liquid, it is possible to suppress the second portion 51 from protruding further radially outward compared to the first portion 41, and in conjunction with the formation of the liquid film, further reduce the frictional resistance between the second portion 51 and the concurrent device in contact with it.

[0058] Furthermore, when the hydrophilic coatings 411 and 511 come into contact with a liquid, preferably, as shown in the example below. Figure 5B As shown, the distance L2 between the outer peripheral surface s2 of the second part 51 and the central axis x of the mandrel 11 is approximately equal to the distance L1 between the outer peripheral surface s1 of the first part 41 and the central axis x of the mandrel 11. Therefore, when the hydrophilic coating 511 of the second part 51 comes into contact with the liquid, the difference in roughness between the outer peripheral surfaces s1 and s2 of the first part 41 and the second part 51 is small, thereby improving the smoothness between the two devices.

[0059] Next, the method of using guidewire 1 will be explained. Here, the method of inserting guidewire 1 into a blood vessel will be illustrated.

[0060] First, in order to improve blood vessel selectivity through rotation, the tip of guidewire 1 can be bent into a J shape or similar shape before inserting it into the blood vessel, as needed.

[0061] Next, guidewire 1 is inserted into the blood vessel from its tip, and the protruding base of guidewire 1 is manipulated to advance its tip. It should be noted that at the branching point of the blood vessel, a rotational operation is applied to guidewire 1 so that its tip faces the desired blood vessel. At this point, guidewire 1 can be easily rotated due to its excellent rotational response.

[0062] Next, once the tip of guidewire 1 reaches the treatment site, the base of guidewire 1 is inserted into the lumen of the concomitant device (not shown) from the tip of the catheter or other concomitant device, and the concomitant device is advanced along guidewire 1 within the blood vessel. Then, once the concomitant device reaches the treatment site, various procedures are performed using the concomitant device. After completing the above procedures, the concomitant device and guidewire 1 are withdrawn from the blood vessel to conclude the series of procedures.

[0063] As described above, since the guidewire 1 has the aforementioned structure, even when the hydrophilic coating 411 is in contact with a liquid such as bodily fluid, the increase in frictional resistance (especially the static friction coefficient) with the device caused by the swelling of the hydrophilic coating 411 can be suppressed, and the rotational response of the guidewire 1 can be improved. Furthermore, since the frictional resistance with the device is improved, torque transmission can also be improved.

[0064] It should be noted that the improvement in rotational response and torque transmission is presumably achieved for the following reasons. Specifically, in the first portion 41, the presence of the hydrophobic coating 412 restricts the penetration of bodily fluids into the surface of the first portion 41. Therefore, by utilizing bodily fluids that moderately penetrate the hydrophilic coating 411, a liquid film is formed covering a portion of the outermost surface of the first portion 41 (the surface in contact with the concurrent device), while simultaneously suppressing the swelling of the hydrophilic coating 411 located directly beneath the hydrophobic coating 412. As a result, the increase in frictional resistance with the concurrent device caused by the swelling of the hydrophilic coating 411 can be suppressed, and it is presumably that the formation of the combined liquid film improves the rotational response and torque transmission of the guidewire 1.

[0065] It should be noted that, although not in Figure 4 As shown, when the first portion 41 comes into contact with the liquid, it can be in the following state: during drying, a portion of the hydrophilic coating 411 located directly below the hydrophobic coating 412 seeps out onto the hydrophobic coating 412 and forms a liquid film on its outermost surface (the surface of the guide wire connected to the device). Alternatively, the hydrophilic coating 411 may remain directly below the hydrophobic coating 412, forming a liquid film covering a portion of the outermost surface.

[0066] [Second Implementation] Figure 6 , Figure 7 A schematic longitudinal sectional view showing a portion (part of the coil body) of the second embodiment is provided for enlargement. The guide wire 2 is generally composed of a first part 42, a mandrel 11 (not shown), a coil body 21, a front end fixing part 31 (not shown), and a second part 51. Figure 6 The diagram shows the state of guidewire 2 not in contact with the liquid (the state when the hydrophilic coating 511 is dry). Figure 7 The diagram shows the state of the guide wire 2 in contact with the liquid (the state when the hydrophilic coating 511 is in contact with the liquid). The structure of the first part 42 of the guide wire 2 differs from that of the first embodiment. It should be noted that since the structures of the spindle 11, coil body 21, front end fixing part 31, and second part 51, and even the structures other than the first part 42 shown below, are similar to those in the first embodiment, the same reference numerals are used for the same parts, and detailed descriptions are omitted. Furthermore, the method of using the guide wire 2 is also illustrated in a manner similar to that of the first embodiment.

[0067] The first part 42 is a part composed of a hydrophobic coating, which is disposed on the radially outer surface of the outer peripheral surface of the thread w. Specifically, as... Figure 6 As shown, the first part 42 is located on the outer peripheral surface of the coil body 21, that is, on the surface of the wire radially outward from the center of the wire w.

[0068] In the first part 42 of this embodiment, only a hydrophobic coating 422 is disposed on the radially outer surface of the wire w. For example, compared to the case where the wire w is in direct contact with the parallel device, this hydrophobic coating 422 reduces the frictional resistance with the parallel device. That is, the relationship between the static friction coefficients of each surface when in contact with the liquid is that the static friction coefficient of the hydrophobic coating is less than the static friction coefficient of the wire.

[0069] As the material constituting the hydrophobic coating 422, for example, materials similar to the material of the hydrophobic coating 412 illustrated in the first embodiment can be listed.

[0070] Here, we will describe the state of the first part 42 and the second part 51 when the guidewire 2 is not in contact with the liquid (the state when the hydrophilic coating 511 is dry), and the state of the first part 42 and the second part 51 when the guidewire 2 is in contact with the liquid (the state when the hydrophilic coating 511 is in contact with the liquid).

[0071] For example, when the guidewire 2 is inserted into the body cavity and comes into contact with surrounding fluids such as bodily fluids, the hydrophobic coating 422 comes into contact with the bodily fluids at the first location 42. This hydrophobic coating 422 is difficult to absorb bodily fluids, and the swelling of the hydrophobic coating 422 itself can be so small as to be negligible. Therefore, the gap between the guidewire 2 and the inner wall of the concurrent device can be maintained, and the increase in frictional resistance between the guidewire 2 and the concurrent device can be suppressed.

[0072] On the other hand, the second portion 51 does not have a hydrophobic coating, but has a hydrophilic coating 511 disposed on its surface. Therefore, when the hydrophilic coating 511 of the second portion 51 comes into contact with a liquid, the liquid can penetrate into the hydrophilic coating 511 without hindrance, such as... Figure 7 As shown, the hydrophilic coating 511 swells due to the absorption of a large amount of liquid. As a result, the outer peripheral surface s2 of the second portion 51 bulges outward in a radial direction, thereby reducing the unevenness between it and the outer peripheral surface s1. Furthermore, due to the liquid film formed on the surface of the second portion 51, a reduction in frictional resistance between the guide wire 2 and the device can be achieved. The second portion 51 is formed by the hydrophilic coating 511, which is configured to fill the gaps between adjacent wires w along the long axis.

[0073] As described above, because the guidewire 2 has the aforementioned structure, even when the hydrophilic coating 511 comes into contact with a liquid such as bodily fluid, the first portion 42 will not swell excessively because there is no hydrophilic coating directly beneath the hydrophobic coating 422. Furthermore, since the surface friction coefficient of the hydrophobic coating 422 is smaller than that of the wire w, the rotational response of the guidewire 2 can be improved. Moreover, since the frictional resistance with the connected device is improved, torque transmission performance can also be enhanced.

[0074] It should be noted that the present invention is not limited to the structure of the above-described embodiments, and aims to express that all changes equivalent to the scope of the claims and within the scope of the claims are included, as shown in the scope of the claims. A part of the structure of the above-described embodiments may be deleted, or replaced with other structures, or other structures may be added to the structure of the above-described embodiments.

[0075] For example, in the above-described embodiment, the structure in which when the guide wires 1 and 2 are in contact with the liquid, the distance L2 between the outer peripheral surface s2 of the second part 51 and the central axis x of the mandrel 11 is approximately equal to the distance L1 between the outer peripheral surfaces s1 of the first parts 41 and 42 and the central axis x of the mandrel 11 was described. However, there is no particular limitation on the degree of swelling of the second part due to contact with the liquid. For example, when the guide wire is in contact with the liquid, it may be L2 < L1 (see the second part 52A in Figure 8A ), or it may be L2 > L1 (see the second part 52B in Figure 8B ).

[0076] Moreover, when the guide wire is in contact with the liquid, the longitudinal cross-sectional shape of the outer peripheral surface of the bulged hydrophilic coating of the second part is not limited to a substantially linear shape (see Figure 4 and Figure 7 ), for example, it may be a shape with an arc (see the second part 52C in Figure 8C ).

[0077] Moreover, in the above-described embodiment, the guide wires 1 and 2 were described, in which the hydrophilic coatings 411, 511 or the hydrophobic coatings 412, 422 are provided only on the radially outer side of the outer peripheral surface of the wire w. However, a hydrophilic coating or a hydrophobic coating may also be provided on the radially inner side of the outer peripheral surface of the wire w.

[0078] Moreover, in the above-described embodiment, the guide wires 1 and 2 were described, which have a coil body 21 that is tightly wound around the wire across the entire long axis direction. However, the guide wire may also have a coil body that is loosely wound around at least a part of the long axis direction. For example, in the loosely wound coil body, in a cross-sectional view of the guide wire cut along the long axis direction, adjacent and spaced-apart wires may be connected (crosslinked) by the hydrophilic coating of the second part.

[0079] Description of Reference Numerals 1, 2, guide wire 11, mandrel 21, coil body 41, 42, first part [[ID=3-4]] 411, hydrophilic coating 412, 422, hydrophobic coating 51, second part 511. Hydrophilic coating L1, L2, Distance s1, s2, outer peripheral surface w, silk thread.

Claims

1. A guidewire, characterized in that, The guidewire includes: mandrel; A coil body, the threads of which are wound in such a way that they cover the outer periphery of the front end of the mandrel; The first part is formed by a hydrophilic coating and a hydrophobic coating, wherein the hydrophilic coating is disposed on a radially outer surface of the outer peripheral surface of the filament, and the hydrophobic coating is formed on the outer peripheral surface of the hydrophilic coating; The second portion, which is a portion further radially outward than the axis of the filament, is formed of a hydrophilic coating configured to fill the recesses between adjacent filaments along the long axis.

2. The guidewire according to claim 1, wherein, When the hydrophilic coating dries, the distance between the outer peripheral surface of the second part and the central axis of the mandrel is less than the distance between the outer peripheral surface of the first part and the central axis of the mandrel.

3. The guidewire according to claim 1, wherein, When the hydrophilic coating comes into contact with a liquid, the distance between the outer peripheral surface of the second part and the central axis of the mandrel is approximately equal to the distance between the outer peripheral surface of the first part and the central axis of the mandrel.

4. A guidewire, characterized in that, include: mandrel; A coil body, the threads of which are wound in such a way that they cover the outer periphery of the front end of the mandrel; The first part is formed by a hydrophobic coating disposed on the radially outer surface of the outer peripheral surface of the filament; The second portion, which is a portion further radially outward than the axis of the filament, is formed of a hydrophilic coating configured to fill the recesses between adjacent filaments along the long axis.

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