Medical device

Abstract

A guidewire (10) (medical device) is provided with: a long core (1); a cylindrical body (2) provided on the outside of the core body (1); a hydrophilic coating layer (61) that is formed from a first coating material and that is disposed on the outer peripheral surface of the cylindrical body (2); and a hydrophobic coating layer (62) that is formed from a second coating material and is disposed on the outside in the radial direction of the hydrophilic coating layer (61), the hydrophilic coating layer (61) being configured so as to be capable of absorbing water. In the presence of a liquid, the hydrophilic coating layer (61) swells on the outer surface of the hydrophobic coating layer (62) and is exposed. The guide wire 10 is simple in structure and good in operability.

Description

Technical Field

[0001] This disclosure relates to a medical device. Background Technology

[0002] Traditionally, guidewires and other medical devices are used to guide catheter-like medical devices inserted into tubular organs such as blood vessels and digestive organs to target sites. The guidewire is inserted from the external surface into the lumen of the body to reach the target site, guiding the catheter or indwelling device to that target site within the lumen. Because the lumen from the external surface to the target site is often curved or branched, the guidewire must have the ability to slide smoothly within the lumen. Furthermore, the guidewire must be able to respond sensitively to the operator's rotational movements during surgery.

[0003] It is known that guide wires improve sliding properties and ensure rotational following properties by coating the outer surface of the guide wire with a hydrophilic resin that reduces the coefficient of kinetic friction. For example, Patent Document 1 discloses a guide wire having a hydrophilic coating formed on its outer surface, which comprises a metal core wire and a coil body.

[0004] Existing technical documents Patent documents Patent Document 1: Japanese Patent Publication No. 2003-500116 Summary of the Invention The problem that the invention aims to solve If, as described in Patent Document 1, a hydrophilic coating is formed on the outer surface of the guidewire, the outer surface of the guidewire may become sticky, for example, in areas where moisture is reduced, such as bends in blood vessels, when used in conjunction with therapeutic devices such as catheters or indwelling intravenous devices. This stickiness of the outer surface may affect operability, therefore a simpler structure is needed to achieve surface properties with better operability.

[0005] This disclosure is made in view of the above circumstances, and its purpose is to provide a medical device that is simple in structure and easy to operate.

[0006] Methods for solving problems To achieve the above objectives, this disclosure provides a medical device comprising: an elongated core; a cylindrical body disposed on the outer side of the core; a hydrophilic coating formed of a first coating material and disposed on the outer peripheral surface of the cylindrical body; and a hydrophobic coating formed of a second coating material and disposed radially outside the hydrophilic coating, the hydrophilic coating being configured to absorb water (Disclosure 1).

[0007] According to this disclosure (Disclosure 1), since a hydrophobic coating is disposed on the outside of the hydrophilic coating, even when the surrounding moisture is reduced in the presence of a device or similar device, the stickiness of the outer surface of the medical device can be suppressed, and the static friction coefficient can be reduced. On the other hand, by constructing the hydrophilic coating to absorb water, liquid reaches the inner side of the hydrophobic coating from the outer surface, and the hydrophilic coating swells to increase the hydrophilicity of the outer surface of the medical device, thus realizing a medical device with a simple structure and good operability.

[0008] In the above disclosure (Disclosure 1), an opening communicating with the outer surface of the hydrophilic coating may also be formed on the hydrophobic coating (Disclosure 6).

[0009] According to the disclosure (Disclosure 2), liquid is supplied to the hydrophilic coating through an opening, causing the hydrophilic coating to swell. Furthermore, the hydrophilic coating, swollen by the supplied liquid, is exposed to the outside of the hydrophobic coating through the opening, thereby improving the hydrophilicity of the outer surface of the medical device.

[0010] In the above disclosures (Disclosures 1 and 2), it is preferable that, in the presence of a liquid, the hydrophilic coating swells and is exposed on the outer surface of the hydrophobic coating (Disclosure 3).

[0011] In the above disclosure (Disclosure 1), an intermediate layer formed by the first coating material and the second coating material may also be included between the hydrophilic coating and the hydrophobic coating (Disclosure 4).

[0012] According to the disclosure (Disclosure 4), a hydrophilic coating is constructed to absorb water, allowing liquid to reach the inner side of the hydrophobic coating from the outer surface. An intermediate layer containing components of a hydrophilic coating material, i.e., a first coating material, and a hydrophilic coating that swells to improve the hydrophilicity of the outer surface of the medical device are also included, thus achieving a medical device with a simple structure and good operability.

[0013] In the above disclosures (Disclosures 1 and 4), the second coating material may contain one or more polar solvents selected from lower chain alcohols, lower alkyl ethers, acetone, halogenated solvents and lower alkylamines (Disclosure 5).

[0014] According to the disclosure (Disclosure 5), during the process of covering the outer peripheral surface of the hydrophilic coating with a hydrophobic coating after the hydrophilic coating is applied, the polar solvent contained in the hydrophobic coating can partially dissolve the outer surface of the hydrophilic coating and partially dissolve with the hydrophobic coating, thereby intentionally forming an intermediate layer.

[0015] In the above disclosures (Disclosures 4 and 5), an opening communicating with the outer surface of the intermediate layer may also be formed on the hydrophobic coating (Disclosure 6).

[0016] According to the disclosure (Disclosure 6), liquid is supplied to the intermediate layer through an opening, or to the hydrophilic coating via the intermediate layer, causing the intermediate layer and the hydrophilic coating to swell. Furthermore, the intermediate layer and the hydrophilic coating, swollen by the supplied liquid, are exposed to the outside of the hydrophobic coating through the opening, thereby increasing the hydrophilicity of the outer surface of the medical device.

[0017] In the above disclosures (Disclosures 4 and 5), it is preferable that, in the presence of a liquid, at least one of the intermediate layer and the hydrophilic coating swells and is exposed on the outer surface of the hydrophobic coating (Disclosure 7).

[0018] Invention Effects According to this disclosure, a medical device with a simple structure and good operability can be provided. Attached Figure Description

[0019] Figure 1 This is a longitudinal sectional view showing the structure of the guidewire according to an embodiment of the present disclosure.

[0020] Figure 2 This is a partially enlarged explanatory diagram showing the structure of the covering layer formed on the guidewire according to this embodiment.

[0021] Figure 3 This is a partially enlarged illustration showing a modified example of the structure of the covering layer. Detailed Implementation

[0022] The guidewire 10 according to embodiments of the present disclosure will be described below based on the accompanying drawings. The guidewire 10 is an example of a medical device of the present disclosure, used when inserting catheters or indwelling devices into blood vessels or digestive organs. The tip side of the guidewire 10 is the side inserted into the body, and the base side is the side operated by a surgeon such as a physician. This disclosure is not limited to the embodiments described below; the described embodiments are merely illustrative of the technical features of the present disclosure. The shapes and dimensions shown in the accompanying drawings are for ease of understanding of the contents of this disclosure and do not accurately reflect actual shapes and dimensions. This disclosure can also be applied to medical devices other than guidewires.

[0023] In this specification, "front end side" refers to the direction along the axis of the guidewire, and is the direction in which the guidewire travels toward the target area. "Base end side" refers to the direction along the axis of the guidewire, and is the opposite direction to the 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. "Front end portion" refers to the portion of any component or part that includes its front end and extends from the front end toward the base end side to the middle of the component, etc., and "base end portion" refers to the portion of any component or part that includes its base end and extends from the base end toward the front end side to the middle of the component, etc. Figure 1 In the diagram, the left side shows the "front end" inserted into the body, and the right side shows the "base end" operated by the surgeon.

[0024] Figure 1 This is a longitudinal sectional view showing the structure of the guide wire 10 according to this embodiment. The guide wire 10 includes a long strip-shaped core 1 and a cylindrical body 2 disposed outside the core 1. A front end tip 3 is provided at the front end of the guide wire 10 to join the core 1 and the cylindrical body 2, and a fixing part 4 is provided at the base end of the cylindrical body 2 to fix the core 1 and the cylindrical body 2.

[0025] The core 1 is an elongated component that serves as the axis of the guide wire 10. For example... Figure 1 As shown, the core 1 has a narrow diameter portion 11 at the front end and a wide diameter portion 13 at the base end. Between the narrow diameter portion 11 and the wide diameter portion 13, there is a tapered portion 12 whose outer diameter decreases from the base end to the front end. The core 1 can be formed, for example, from stainless steel alloys (SUS302, SUS304, SUS316, etc.), superelastic alloys such as Ni-Ti alloys, piano wire, nickel-chromium alloys, cobalt alloys, tungsten, etc., but is not limited to these materials. The core 1 can be formed from any known material other than those mentioned above, as long as it is a component that can prevent the core 1 from breaking and allows the front end to rotate.

[0026] The narrow-diameter portion 11, for example, has a flat shape (with a roughly elliptical cross-section) obtained by stamping a cylindrical material. The thick-diameter portion 13 has a cylindrical shape with a constant outer diameter from the front end to the base end. The tapered portion 12 has a frustum-shaped cone that gradually widens from the front end to the base end, connecting the narrow-diameter portion 11 and the thick-diameter portion 13.

[0027] The cylindrical body 2 is wound around the core 1 in such a way that it covers a portion of the outer periphery of the narrow-diameter portion 11, the tapered portion 12, and the thick-diameter portion 13 of the core 1. The cylindrical body 2 can be a single coil formed by spirally winding a single wire with a circular cross-section into a cylindrical shape, or it can be a hollow stranded coil formed by twisting multiple wires into a cylindrical shape. The cylindrical body 2 can also be constructed by combining a single coil and a hollow stranded coil. The cylindrical body 2 can be formed from, for example, a superelastic alloy such as stainless steel alloy (SUS302, SUS304, SUS316, etc.), Ni-Ti alloy, piano wire, nickel-chromium alloy, cobalt alloy, etc., a radiation-permeable alloy, or a radiation-impermeable alloy such as gold, platinum, tungsten, or alloys containing these elements (e.g., platinum-nickel alloy), but is not limited to these. The cylindrical body 2 can also be formed from known materials other than those mentioned above. In this embodiment, the cylindrical body 2 is formed entirely from a single component of the same material, and its outer diameter is configured to be constant from the front end to the base end.

[0028] At the front end of the guide wire 10 (i.e., the front end of the core 1), a front tip 3 is formed to join the core 1 and the cylindrical body 2. The front tip 3 is formed of a metal solder such as silver solder, gold solder, zinc, Sn-Ag alloy, or Au-Sn alloy, and the front end of the core 1 and the front end of the cylindrical body 2 are fixedly connected by this metal solder. Alternatively, the front tip 3 can be formed by an adhesive such as an epoxy adhesive, and the front end of the core 1 and the front end of the cylindrical body 2 can be fixedly connected by the adhesive.

[0029] A fixing part 4 for fixing the core 1 and the cylindrical body 2 is formed at the base end of the cylindrical body 2. The fixing part 4 is formed of a metal solder such as silver solder, gold solder, zinc, Sn-Ag alloy, or Au-Sn alloy, and the base end of the cylindrical body 2 is fixedly connected to the thick-diameter part 13 of the core 1 by the metal solder. Alternatively, the fixing part 4 can be formed by an adhesive such as an epoxy adhesive, and the thick-diameter part 13 of the core 1 and the base end of the cylindrical body 2 can be fixedly connected by the adhesive.

[0030] Inside the cylindrical body 2, two joints 5a and 5b are formed to join the tapered portion 12 of the core 1 to the cylindrical body 2. Joints 5a and 5b are formed of metal solders such as silver solder, gold solder, zinc, Sn-Ag alloy, and Au-Sn alloy, which fix the tapered portion 12 of the core 1 to the cylindrical body 2. Alternatively, joints 5a and 5b can be formed using adhesives such as epoxy adhesives, which fix the tapered portion 12 of the core 1 and the cylindrical body 2 together.

[0031] A first covering layer 6 is formed on the outer peripheral surface of the guide wire 10, except for the base end of the coarse diameter portion 13 of the core 1, that is, from the tip 3 to the outer peripheral surface of the tubular body 2, the fixing portion 4, and the coarse diameter portion 13 of the core 1. A second covering layer 7, different from the first covering layer 6, is formed on the outer peripheral surface of the base end of the core 1 (coarse diameter portion 13).

[0032] The second covering layer 7 is formed of a hydrophobic resin material. Examples of hydrophobic resin materials include fluorinated resins such as polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), and fluorinated ethylene propylene copolymer (FEP), as well as silicone. By coating the outer peripheral surface of the base end of the core 1 with this hydrophobic resin material, the area in which the first covering layer 6 is formed can be reduced, and the operator's operability can be improved.

[0033] Figure 2 This is a partially enlarged illustrative diagram showing the structure of the first covering layer 6 formed on the guidewire 10, which is enlarged and shows... Figure 1 The structure of the X portion. The first covering layer 6 has a structure consisting of a hydrophilic coating 61 disposed on the outer peripheral surface of the cylindrical body 2 and a hydrophobic coating 62 disposed radially outside the hydrophilic coating 61.

[0034] The hydrophilic coating 61 is formed from a hydrophilic coating material (the first coating material). Examples of hydrophilic coating materials include nonionic hydrophilic polymers such as polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol, polyacrylamide, polymethacrylamide, poly(2-hydroxyethyl methacrylate), and poly(N-hydroxyethyl acrylamide); anionic hydrophilic polymers such as polyacrylic acid, sodium polyacrylate, polymethacrylic acid, polymaleic acid, carboxymethyl cellulose, hyaluronic acid, and poly(2-acrylamide-2-methylpropanesulfonic acid); and solutions of cationic hydrophilic polymers such as polyethyleneimine, polyallylamine, and polyethyleneamine. The hydrophilic coating 61 can be formed by applying the above-mentioned hydrophilic coating material to the outer peripheral surface of the outer diameter portion 13 of the core body 1, from the tip 3 to the cylindrical body 2, the fixing portion 4, and the end portion 13 of the core body 1, using known coating forming methods.

[0035] The hydrophobic coating 62 is formed from a hydrophobic coating material (the second coating material). Examples of hydrophobic coating materials include silicone coating materials such as medical-grade silicone solutions, silicone, polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), and fluorinated ethylene propylene copolymer (FEP), etc. The hydrophobic coating 62 can be formed by known coating methods, such as coating the above-mentioned hydrophobic coating material onto the upper layer of the hydrophilic coating 61.

[0036] The hydrophobic coating material (second coating material) may contain one or more polar solvents selected from lower chain alcohols, lower alkyl ethers, acetone, halogen-containing solvents, and lower alkylamines. Examples of lower chain alcohols include chain alkyl alcohols having 1 to 6 carbon atoms, and examples of alkyl alcohols having 1 to 6 carbon atoms include methanol, ethanol, n-propanol, isopropanol (IPA), n-butanol, sec-butanol, tert-butanol, n-pentanol, and n-hexanol. Furthermore, examples of lower alkyl ethers include chain or cyclic alkyl ethers having 1 to 6 carbon atoms, and examples of chain or cyclic alkyl ethers having 1 to 6 carbon atoms include dimethyl ether, diethyl ether, tetrahydrofuran, and 1,4-dioxane. Furthermore, examples of halogen-containing solvents include chain alkyl groups with 1 to 6 carbon atoms containing 1 to 4 halogen atoms such as fluorine, bromine, or iodine. Examples of chain alkyl groups with 1 to 6 carbon atoms containing 1 to 4 halogen atoms such as fluorine, bromine, or iodine include chloroform, dichloromethane, and carbon tetrachloride. Examples of lower alkylamines include chain alkylamines with 1 to 6 carbon atoms, such as dimethylamine, methylamine, diethylamine, ethylamine, isopropylethylamine, and isopropylamine.

[0037] When the hydrophobic coating 62 is formed from, for example, a silicone coating material, the hydrophobic coating 62 is configured to be permeable to liquid. Specifically, the hydrophobic coating 62 is in a state where an opening is formed that communicates with the outer surface of the hydrophilic coating 61. In the presence of liquid, liquid is supplied to the hydrophilic coating 61 through the opening, causing the hydrophilic coating 61 to swell. The hydrophilic coating 61, swollen by the supplied liquid, is exposed to the outside of the hydrophobic coating 62 through the opening, thereby increasing the hydrophilicity of the outer surface of the guidewire 10.

[0038] The hydrophobic coating 62 has an open state, for example, by forming a mesh structure of the hydrophobic coating 62, or by naturally forming local gaps, cracks or perforations during the formation of the hydrophobic coating 62, or by applying a certain surface processing to the hydrophobic coating 62 after it has been formed by a known coating formation method.

[0039] According to this guidewire 10, by providing a hydrophobic coating 62 on the outside of the hydrophilic coating 61, the stickiness of the outer surface of the guidewire 10 can be suppressed and the static friction coefficient reduced even when the surrounding moisture decreases. On the other hand, by configuring the hydrophobic coating 62 to be permeable to liquid, the liquid reaches the inner side of the hydrophobic coating 62 from the outer surface, and the hydrophilic coating 61 swells to increase the hydrophilicity of the outer surface of the guidewire 10, thus realizing a guidewire 10 with a simple structure and good operability.

[0040] Normally, when a hydrophilic coating is applied to the outermost layer of a medical device such as a guidewire, the dynamic friction coefficient decreases, but the static friction coefficient increases. Conversely, when a hydrophobic coating is applied to the outermost layer of a medical device such as a guidewire, the dynamic friction coefficient increases, but the static friction coefficient decreases. In the guidewire 10 of this embodiment, where a hydrophobic coating 62 is applied to the outside of the hydrophilic coating 61, the presence of the hydrophobic coating 62 on the outermost layer reduces the static friction coefficient, and the swelling of the hydrophilic coating 61 increases the hydrophilicity of the outer surface of the guidewire 10 (the hydrophilic coating 61 partially seeps out from the hydrophobic coating 62), which reduces the dynamic friction coefficient. Thus, a guidewire with both opposing properties and good operability is achieved.

[0041] The guidewire disclosed herein has been described above based on the accompanying drawings. However, this disclosure is not limited to the above embodiments and various modifications can be implemented. For example, in the above embodiments, the case in which the core 1 has a large diameter portion 13 on the base end side, a small diameter portion 11 on the front end side, and a tapered portion 12 between the large diameter portion 13 and the small diameter portion 11 has been described as an example. However, the core used in the guidewire of this disclosure can have a constant outer diameter from the base end side to the front end side, or it can have a structure in which the diameter varies in more stages.

[0042] Alternatively, an inner cylindrical body (coil body) shorter than the cylindrical body 2 can be arranged along the outer periphery of the core 1 on the inner side of the cylindrical body 2. For example, the inner cylindrical body can also be wound in such a way that it covers a portion of the outer periphery from the narrow diameter portion 11 to the tapered portion 12 of the core 1, and configured such that the cylindrical body 2 and the inner cylindrical body 8 overlap on the outer side of the core 1 only at the front end of the guide wire 10.

[0043] The first cover layer 6 can be formed to cover at least the outer side of the cylindrical body 2 of the core 1. It may or may not be disposed along the entire length of the cylindrical body 2. The first cover layer 6 may not be formed directly on the outer surface of the cylindrical body 2. For example, another cover layer may be formed between the cylindrical body 2 and the first cover layer 6. Alternatively, the second cover layer 7 may not be formed on the outer surface of the base end of the guidewire 10. For example, the entire outer surface of the guidewire 10 may be coated with the first cover layer 6.

[0044] The following will refer to Figure 3 A modified example of the first covering layer 6 of the guide wire 10 described in the above embodiment will be explained.

[0045] In this modified example, the first covering layer 6 has a structure consisting of a hydrophilic coating 61 disposed on the outer peripheral surface of the cylindrical body 2, a hydrophobic coating 62 disposed radially outward of the hydrophilic coating 61, and an intermediate layer 63 formed between the hydrophilic coating 61 and the hydrophobic coating 62. The intermediate layer 63 is formed by mixing the hydrophilic coating material (first coating material) forming the hydrophilic coating 61 and the hydrophobic coating material (second coating material) forming the hydrophobic coating 62.

[0046] The hydrophilic coating 61 can be formed by a known coating method, such as applying the aforementioned hydrophilic coating material to the outer peripheral surface of the cylindrical body 2, the fixing part 4, and the rough diameter part 13 of the core 1. The hydrophobic coating 62 can be formed by a known coating method, such as applying the aforementioned hydrophobic coating material to the upper layer of the hydrophilic coating 61. Here, when the silicone coating material used to form the hydrophobic coating 62 is applied to the upper layer of the hydrophilic coating 61, the alcohol component (IPA) contained in the silicone coating material will dissolve the hydrophilic coating material on the surface side of the hydrophilic coating 61, forming an intermediate layer 63 in which the silicone coating material and the hydrophilic coating material are mixed.

[0047] Since the hydrophobic coating 62 is formed of a silicone coating material, it is configured to be permeable to liquids. Specifically, the hydrophobic coating 62 is in a state where an opening is formed to communicate with the outer surface of the intermediate layer 63. In the presence of liquid, the liquid is supplied to the intermediate layer 63 through this opening, or to the hydrophilic coating 61 via the intermediate layer 63, causing the intermediate layer 63 and the hydrophilic coating 61 to swell. The intermediate layer 63 and the hydrophilic coating 61, swollen by the supplied liquid, are exposed to the outside of the hydrophobic coating 62 through this opening, thereby increasing the hydrophilicity of the outer surface of the guidewire 10.

[0048] The hydrophobic coating 62 has an open state, for example, by forming a mesh structure of the hydrophobic coating 62, or by naturally forming local gaps, cracks or perforations during the formation of the hydrophobic coating 62, or by applying a certain surface processing to the hydrophobic coating 62 after it has been formed by a known coating formation method.

[0049] According to the guidewire 10 having this three-layer structure, the outer surface of the guidewire 10 can be kept from sticking and the static friction coefficient can be reduced even when the surrounding moisture is reduced by configuring a hydrophobic coating 62 on the outside of the hydrophilic coating 61 and the intermediate layer 63. On the other hand, by configuring the hydrophobic coating 62 to be permeable to liquid, the liquid reaches the inner side of the hydrophobic coating 62 from the outer surface. The intermediate layer 63, which contains components of the hydrophilic coating material, and the hydrophilic coating 61 swell, thereby increasing the hydrophilicity of the outer surface of the guidewire 10. Therefore, a guidewire 10 with a simple structure and good operability is achieved.

[0050] Even with a first cover layer 6 having a three-layer structure, the presence of a hydrophobic coating 62 on the outermost layer can reduce the static friction coefficient. Furthermore, the swelling of the middle layer 63 and the hydrophilic coating 61, which increases the hydrophilicity of the outer surface of the guidewire 10 (the middle layer 63 and the hydrophilic coating 61 partially seep out from the hydrophobic coating 62), can also reduce the dynamic friction coefficient, thus achieving a guidewire that combines two opposite properties and has good operability.

[0051] In particular, since the first cover layer 6 has a three-layer structure, the durability of the hydrophobic coating 63 is improved, and even if the hydrophobic coating 63 disappears due to operation, the intermediate layer 63 contains components of hydrophobic coating material, thus suppressing the increase of the static friction coefficient.

Claims

1. A medical device, the medical device comprising: A long, narrow core; A cylindrical body, wherein the cylindrical body is disposed on the outside of the core body; A hydrophilic coating, formed of a first coating material, is disposed on the outer peripheral surface of the cylindrical body; as well as A hydrophobic coating, formed of a second coating material, is disposed radially outside the hydrophilic coating. The hydrophilic coating is configured to absorb water.

2. The medical device according to claim 1, wherein, An opening is formed on the hydrophobic coating that communicates with the outer surface of the hydrophilic coating.

3. The medical device according to claim 1 or 2, wherein, In the presence of liquid, the hydrophilic coating swells and is exposed on the outer surface of the hydrophobic coating.

4. The medical device according to claim 1, wherein, Between the hydrophilic coating and the hydrophobic coating, there is an intermediate layer formed by the first coating material and the second coating material.

5. The medical device according to claim 1 or 4, wherein, The second coating material contains one or more polar solvents selected from lower chain alcohols, lower alkyl ethers, acetone, halogenated solvents and lower alkylamines.

6. The medical device according to claim 4 or 5, wherein, An opening is formed on the hydrophobic coating that connects to the outer surface of the intermediate layer.

7. The medical device according to claim 4 or 5, wherein, In the presence of liquid, at least one of the intermediate layer and the hydrophilic coating swells and is exposed on the outer surface of the hydrophobic coating.

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