Medical equipment

Abstract

To provide medical equipment excellent in bond strength between metal wires and a resin member.SOLUTION: Medical equipment includes: a long member inserted in the body; one or more metal wires which are fixed to an end side of the long member and in which a surface including at least either an end or a base end is coated with a resin film; and a resin fixing part fixing to the long member one of the end and the base end, which are at least coated, of the one or more metal wires.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a medical device used for treating blood vessels and the like in the human body. [Background technology]

[0002] Conventionally, medical devices that are inserted into the human body to treat blood vessels and the like and are made of metal and resin members have been known (Patent Documents 1 and 2). Patent Document 2 discloses a catheter equipped with a metal wire that expands and contracts using a resin balloon. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-9998 [Patent Document 2] Special Publication No. 2007-530158 Summary of the Invention [Problem to be solved by the invention]

[0004] In medical devices equipped with metal wires, the metal wires may be joined to a resin member. In this case, it is not easy to ensure the joining strength between the metal wire and the resin member. Even with the above-mentioned prior art, there is still room for improvement in conventional medical devices in terms of ensuring the joining strength between the metal wire and another resin member to which the metal wire is joined.

[0005] An object of the present invention is to provide a medical device having excellent bonding strength between a metal wire and a resin member. [Means for solving the problem]

[0006] The present invention has been made to solve the above-mentioned problems, and can be realized in the following forms.

[0007] (1) One form of the present invention is a medical device comprising: a long member to be inserted into the body; one or more metal wires fixed to a tip side of the long member, the one or more metal wires having a surface including at least one of a tip and a base end coated with a resin film; and a resin fixing portion fixing at least one of the coated tips and base ends of the one or more metal wires to the long member.

[0008] According to this configuration, the resin film covering the metal wire is bonded to the resin fixing portion, thereby improving the bonding strength between the metal wire and the fixing portion.

[0009] (2) In the medical device of the above form, when there is one metal wire, the metal wire has a coil shape, and when there are multiple metal wires, the metal wire may or may not have a coil shape. When the metal wire has a coil shape, a space is formed inside the coil, and the resin film on one surface of adjacent portions of a coil is at least partially separated from the resin film on the other surface. When there are multiple metal wires, a space is formed inside by the multiple metal wires surrounding the coil, and the resin film on one surface of two different metal wires among the multiple metal wires may be at least partially separated from the resin film on the other surface.

[0010] According to this configuration, the resin film covering the metal wire is at least partially separated, which makes it possible to suppress the metal wire from being hindered in deformation, such as expansion and contraction in the axial direction and radial direction, due to bonding between the resin films.

[0011] (3) In the medical device of the above form, the size of the space of the one or more metal wires can be changed by changing the shape of the intermediate portion between the tip and base end, and the medical device may further include a resin membrane member in contact with the intermediate portion of the one or more metal wires.

[0012] According to this configuration, the size of the space can be changed, so that the medical device can be used, for example, to expand a narrowed portion of a blood vessel.

[0013] (4) In the medical device of the above form, the metal wire has a shape in cross section in which the distance from the center point of the metal wire in a first direction along the cross section to the surface of the metal wire is different from the distance from the center point to the surface of the metal wire in a second direction different from the first direction, and the resin film may include an inner layer in contact with the surface of the metal wire and an outer layer covering the inner layer.

[0014] According to this configuration, the cross section of the metal wire is a polygon such as a rectangle, etc. As a result, for example, when the metal wire of this embodiment is used to press against a hardened lesion in a blood vessel, it becomes easy to create a crack in the lesion.

[0015] (5) In the medical device of the above embodiment, the maximum thickness of the resin film may be 2 μm or more and 11 μm or less.

[0016] (6) In the medical device of the above aspect, the bonding strength between the metal wire and the resin film may be lower than the breaking strength of the metal wire.

[0017] According to this configuration, when the metal wire is pulled, it is possible to easily separate the metal wire from the resin film before the metal wire breaks, and therefore it is possible to suppress breakage of the metal wire, thereby suppressing the generation of metal fragments due to breakage of the metal wire and damage to the blood vessel wall, etc., due to the broken part of the metal wire.

[0018] According to this configuration, since the resin film is 2 μm or more, the risk of the metal wire being exposed to the outside can be reduced, and since the resin film is 11 μm or less, unnecessary increase in the outer diameter of the medical device can be suppressed. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is an explanatory diagram illustrating an example of the overall configuration of a medical device according to a first embodiment. [Diagram 2] FIG. 2 is an explanatory diagram illustrating a vertical cross section of the distal end portion of the medical device according to the first embodiment. [Diagram 3]FIG. 2 is an explanatory diagram illustrating a metal wire; [Figure 4] 1 is an explanatory diagram illustrating a joint between a metal wire and a balloon. FIG. [Diagram 5] FIG. 3 is an explanatory diagram illustrating a cross section taken along the line AA in FIG. 2. [Figure 6] 1 is an explanatory diagram illustrating a vertical cross section of a tip of a metal wire; [Figure 7] FIG. 4 is an explanatory diagram illustrating a vertical cross section of a base end of a metal wire. [Figure 8] FIG. 2 is an explanatory diagram illustrating a cross section of a metal wire. [Figure 9] FIG. 11 is an explanatory diagram illustrating a distal end portion of a medical device according to a second embodiment. [Figure 10] 10 is an explanatory diagram illustrating a cross section taken along the line BB in FIG. 9; [Figure 11] 10 is an explanatory diagram illustrating an enlarged view of an intersection X in FIG. 9; [Figure 12] 10 is an explanatory diagram illustrating a cross-sectional view of an intersection X in FIG. 9. [Figure 13] 10 is an explanatory diagram illustrating a cross-sectional view of an intersection X in FIG. 9. [Figure 14] 13 is an explanatory diagram illustrating a state in which the metal wire is separated from the tip fixing portion. FIG. [Figure 15] FIG. 11 is an explanatory diagram illustrating a state in which a metal wire is broken. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] First Embodiment A medical device 1A according to a first embodiment will be described with reference to Figs. 1 to 8. The size of each component of the medical device 1A shown in Figs. 1 to 8 is an example, and may be expressed on a scale different from the actual size. Hereinafter, the end portion located on the tip side of each component of the medical device 1A will be described as the "tip", and the portion including the "tip" and extending from the tip to the middle toward the base end will be described as the "tip portion". Similarly, the end portion located on the base end side of each component will be described as the "base end", and the portion including the "base end" and extending from the base end to the middle toward the tip side will be described as the "base portion".

[0021] The medical device 1A is a catheter used for treating a narrowed portion of a blood vessel, for example.

[0022] Fig. 1 is an explanatory diagram illustrating the overall configuration of a medical device 1A. Fig. 2 is an explanatory diagram illustrating a vertical cross section of a distal end portion of the medical device 1A. The medical device 1A has a metal wire 10A, an inner shaft 20, a distal outer shaft 30, a proximal outer shaft 32, a balloon 40, a distal fixing portion 50A, a proximal fixing portion 51A, and a connector 60.

[0023] The metal wire 10A is wound in a spiral shape along the longitudinal direction of the medical device 1A to form a coil shape. The metal wire 10A will be described in detail later.

[0024] The inner shaft 20 is a cylindrical member disposed inside the balloon 40 and the distal outer shaft 30 and extending in the longitudinal direction of the medical device 1A. The distal end of the inner shaft 20 is joined to the distal fixing part 50A, and the proximal end is joined to the side wall of the distal outer shaft 30 to form a guidewire port 32. An inner lumen 21 is formed inside the inner shaft 20, and a user of the medical device 1A, such as a doctor, can insert the medical device 1A into the body along the guidewire by passing the guidewire (not shown) inserted in advance into the body through the inner lumen 21. The inner shaft 20 is an example of a long member.

[0025] The material of the inner shaft 20 is not particularly limited, but for example, polyurethane, polyamide, polyamide elastomer, polyethylene, polyolefin, polyester, polyester elastomer, etc. can be used.

[0026] The distal outer shaft 30 is disposed outside the inner shaft 20 and is a cylindrical member extending in the longitudinal direction of the medical device 1A. The distal end of the distal outer shaft 30 is joined to the proximal end of the balloon 40 and to the proximal fixing part 51A, and the proximal end is joined to the proximal outer shaft 32. An outer lumen 31 is formed inside the distal outer shaft 30 and the proximal outer shaft 32. A user of the medical device 1A, such as a doctor, can inject a fluid, such as a contrast medium or saline, into the inside of the balloon 40 through the outer lumen 31 by using an indeflator (not shown) connected to the connector 60.

[0027] The material of the distal outer shaft 30 is not particularly limited, but may be, for example, polyurethane, polyamide, polyamide elastomer, polyethylene, polyolefin, polyester, polyester elastomer, etc. The material of the proximal outer shaft 32 is not particularly limited, but may be, for example, stainless steel (SUS302, SUS304) or a superelastic alloy such as a Ni-Ti alloy.

[0028] The balloon 40 is a cylindrical member formed of a thin film of resin. The tip of the balloon 40 is joined to the tip fixing part 50A, and the base end is joined to the tip of the tip side outer shaft 30 and the base end fixing part 51A. When a fluid is introduced into the space inside the balloon 40, the balloon 40 is expanded toward the radially outward direction of the medical device 1A. The balloon 40 is inserted in a blood vessel or the like in a contracted form, and is expanded after being transported to the treatment site. The balloon 40 is an example of a resin film member.

[0029] The material of the balloon 40 is not particularly limited, and may be, for example, a resin or rubber. More specifically, polyolefins such as polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more of these, soft polyvinyl chloride resin, thermoplastic resins such as polyamide, polyamide elastomer, polyester, polyester elastomer, polyurethane, and fluororesin, silicone rubber, latex rubber, etc. may be used.

[0030] The tip fixing part 50A is a tubular member that constitutes the tip of the medical device 1A. A through hole that communicates with the inner lumen 21 is formed in the tip fixing part 50A, so that a guide wire can be inserted into the inner lumen 21 through the through hole of the tip fixing part 50A. The tip fixing part 50A functions as a fixing part that fixes the tip 12A of the metal wire 10A and the tip of the inner shaft 20.

[0031] The base end fixing portion 51A is a tubular member that covers the outer periphery of the tip portion of the tip side outer shaft 30. The base end fixing portion 51A functions as a fixing portion that fixes the base end 13A of the metal wire 10A and the tip of the tip side outer shaft 30.

[0032] The material of the distal end fixing part 50A and the proximal end fixing part 51A is not particularly limited, but for example, a flexible resin such as polyurethane or polyurethane elastomer can be used.

[0033] The connector 60 is a member that enables the medical device 1A attached to the base end of the base end side outer shaft 32 to be connected to another medical device (not shown).

[0034] The metal wire 10A will be described in detail. FIG. 3 is an explanatory diagram illustrating the metal wire 10A. In a side view as shown in FIG. 3, the metal wire 10A has a coil shape wound in a spiral shape, and a substantially cylindrical space portion 15A is formed inside. The size of the space portion 15A of the metal wire 10A can be changed by expanding and contracting the coil. A balloon 40 is disposed in the space portion 15A. As a result, when the balloon 40 expands and contracts, the metal wire 10A also expands and contracts according to the expansion and contraction of the balloon 40. An intermediate portion 14A is formed between the tip end 12A and the base end 13A of the metal wire 10A, and the size of the space portion 15A changes as the shape of the intermediate portion 14A changes. In this embodiment, the metal wire 10A has a coil shape formed by winding one wire in a spiral shape, but the metal wire 10A may have a coil shape formed by winding a plurality of wires in a spiral shape.

[0035] FIG. 4 is an explanatory diagram illustrating a joint between a metal wire 10A and a balloon 40. The entire outer peripheral surface of the metal wire 10A, including the tip 12A, the middle portion 14A, and the base end 13A, is covered with a resin film 16A. Therefore, the outer peripheral surface of the metal wire 10A is not exposed to the outside. The resin film 16A has a two-layer structure of an inner layer 17A that contacts the surface of the metal wire 10A and an outer layer 18A that contacts the surface of the inner layer 17A. The outer layer 18A of the metal wire 10A is joined to the surface of the balloon 40. Both the outer layer 18A and the balloon 40 are made of resin, so they can be joined well. On the other hand, since the metal wire 10A is a loosely wound coil, a gap 11A is formed between adjacent metal wires 10A. Therefore, the resin films 16A formed on the surfaces of the adjacent metal wires 10A are not joined to each other. In other words, the resin films 16A formed on the surfaces of the adjacent metal wires 10A are separated.

[0036] Fig. 5 is an explanatory diagram illustrating the AA cross section of Fig. 2. As described above, the outer layer 18A of the metal wire 10A is bonded to the surface of the balloon 40. Here, the entire middle portion 14A of the metal wire 10A is bonded to the outer periphery of the balloon 40, but only a part of the middle portion 14A may be bonded to the balloon 40.

[0037] Fig. 6 is an explanatory diagram illustrating a vertical cross section of the tip 12A of the metal wire 10A. As shown in Fig. 6, the tip 12A of the metal wire 10A is covered with a resin film 16A. As a result, the resin film 16A is provided between the outer peripheral surface of the tip 12A of the metal wire 10A and the tip fixing part 50A, and the resin film 16A is also provided between the outer peripheral surface of the tip 12A of the metal wire 10A and the tip of the balloon 40. Therefore, the metal wire 10A and other members such as the tip fixing part 50A and the balloon 40 are mainly bonded by the resin film 16A.

[0038] 7 is an explanatory diagram illustrating a vertical cross section of the base end 13A of the metal wire 10A. As shown in FIG. 7, the base end 13A of the metal wire 10A is also covered with a resin film 16A. As a result, the resin film 16A is provided between the outer peripheral surface of the base end 13A of the metal wire 10A and the base end fixing part 51A, and the resin film 16A is also provided between the outer peripheral surface of the base end 13A of the metal wire 10A and the base end of the balloon 40. Therefore, the metal wire 10A and other members such as the base end fixing part 51A and the balloon 40 are mainly bonded by the resin film 16A.

[0039] FIG. 8 is an explanatory diagram illustrating a cross section of the metal wire 10A. The cross section of the metal wire 10A is rectangular. Therefore, in the cross section of the metal wire 10A, the lengths of two opposing sides (long sides and long sides, or short sides and short sides) are approximately the same, and the lengths of two sides (long sides and short sides) that are approximately perpendicular to each other are different. The "first distance La" in FIG. 8 represents the distance from the center point C of the metal wire 10A to the surface of the metal wire 10A in the first direction Da along the cross section of the metal wire 10A. Here, the first distance La represents the length in the direction parallel to the width direction of the rectangle. Also, the "second distance Lb" represents the distance from the center point C of the metal wire 10A to the surface of the metal wire 10A in the second direction Db different from the first direction Da. Here, the second distance Lb represents the length in the direction parallel to the thickness direction of the rectangle. The cross section of the metal wire 10A has a shape such that the first distance La and the second distance Lb are different, and in this embodiment, the first distance La is greater than the second distance Lb.

[0040] In FIG. 8, the first direction Da and the second direction Db are drawn to be perpendicular to each other, but they do not have to be perpendicular to each other. The angle of the second direction Db with respect to the first direction Da can be any angle between 0 degrees and 180 degrees, and for example, the angle between the first direction Da and the second direction Db may be 30 degrees or 60 degrees. Shapes in which the first distance La and the second distance Lb are different include polygons such as triangles and pentagons. When the cross section of the metal wire 10A is polygonal, it is easy to create a crack in the lesion by pressing the corners of the metal wire 10A against the hardened lesion.

[0041] The material of the metal wire 10A is not particularly limited, but may be, for example, tungsten, stainless steel (SUS302, SUS304, SUS316, etc.), a superelastic alloy such as a Ni-Ti alloy, piano wire, platinum, gold, or an alloy thereof.

[0042] As described above, the resin film 16A has an inner layer 17A that contacts the surface of the metal wire 10A. The resin film 16A also has an outer layer 18A that contacts the surface of the inner layer 17A. Since the inner layer 17A and the outer layer 18A are thin films, the cross-sectional shape of the metal wire 10A is close to the cross-sectional shape of the metal wire 10A, which is rectangular in this embodiment. The maximum thickness of the resin film 16A is 2 μm or more and 11 μm or less. The maximum thickness of the resin film 16A is preferably 3 μm or more and 11 μm or less, and more preferably 3 μm or more and 10 μm or less. When the metal wire 10A has a shape formed from a plurality of planes such as a rectangular parallelepiped as in this embodiment, the thickness of the resin film 16A covering each plane may be different. For example, when the cross section of the metal wire 10A is rectangular, the thickness Ta of the resin film 16A in the width direction can be 3 μm or more and 4 μm or less, and the thickness Tb of the resin film 16A in the thickness direction can be 7 μm or more and 10 μm or less.

[0043] The material of the resin film 16A is not particularly limited, and may be, for example, polyamideimide, polyamide, polyimide, polyurethane, nylon, etc. The resin film 16A may be made of the same material as that used for other members joined to the resin film 16A, such as the inner shaft 20, the distal outer shaft 30, the balloon 40, the distal fixing part 50A, or the proximal fixing part 51A. The inner layer 17A and the outer layer 18A may be made of the same material or different materials.

[0044] FIG. 14 is an explanatory diagram illustrating a state in which the metal wire 10A has been separated from the tip fixing portion 50A. In this embodiment, the bonding strength between the metal wire 10A and the resin film 16A (see FIGS. 6 and 7) is lower than the breaking strength of the metal wire 10A. More specifically, since the bonding strength between the metal wire 10A and the inner layer 17A (see FIGS. 6 and 7) is lower than the breaking strength of the metal wire 10A, when the metal wire 10A is pulled, the metal wire 10A is likely to separate from the inner layer 17A before the metal wire 10A breaks. The bonding strength and breaking strength referred to here are both in N / mm 2 The strength represented by the formula (1) is the breaking strength of the metal wire 10A alone, and does not include the breaking strength of the resin film 16A covering the metal wire 10A. In this embodiment, the bonding strength between the metal wire 10A and the resin film 16A is substantially equal at any position on the contact surface between the metal wire 10A and the resin film 16A, so that the bonding strength between the tip 12A of the metal wire 10A and the resin film 16A is substantially equal to the bonding strength between the base end 13A of the metal wire 10A and the resin film 16A. FIG. 14 shows a state in which the metal wire 10A has been pulled out from the tip fixing portion 50A. In detail, the metal wire 10A is shown with the resin film 16A that has been peeled off after being separated from the inner layer 17A and covering the tip 12A. In the state shown in FIG. 14, it is highly likely that the resin film 16A (see FIG. 6) that covered the tip 12A of the metal wire 10A remains in the tip fixing portion 50A.

[0045] FIG. 15 is an explanatory diagram illustrating a state in which the metal wire 10A breaks in the medical device of the comparative example. The medical device of the comparative example has the same configuration as the medical device 1A of the present embodiment, except that the bonding strength between the metal wire 10A and the resin film 16A is higher than the breaking strength of the metal wire 10A compared to the medical device 1A of the present embodiment. Therefore, in the medical device of the comparative example, when the metal wire 10A is pulled, the metal wire 10A is likely to break before the metal wire 10A separates from the inner layer 17A (see FIGS. 6 and 7). When the metal wire 10A breaks, there is a risk that metal pieces will be generated from the broken parts 10R1 and 10R2 of the metal wire 10A. In addition, since the broken parts 10R1 and 10R2 are the parts where the metal wire 10A breaks due to being pulled, there is a high possibility that the tips of the broken parts 10R1 and 10R2 are sharp, and therefore there is a risk of damaging the blood vessel wall or the like. In the medical device 1A of this embodiment, when the metal wire 10A is pulled, the metal wire 10A is easily separated from the inner layer 17A (resin film 16A) before the metal wire 10A breaks, thereby preventing the breakage of the metal wire 10A, thereby preventing the generation of metal fragments due to the breakage of the metal wire 10A and damage to blood vessel walls, etc., caused by the broken parts of the metal wire 10A.

[0046] The metal wire 10A can be produced, for example, by the following method. First, the metal wire 10A is produced with a cross-sectional dimension of 50 μm thick and 120 μm wide. Next, a resin film 16A is formed on the outer periphery of the metal wire 10A by coating using a die. For example, a die with a hole size of 60 μm long and 150 μm wide or 70 μm long and 150 μm wide can be used. In the coating process, the metal wire 10A is first passed through the die to coat the outer periphery of the metal wire 10A with an inner layer 17A. Then, the inner layer 17A is baked at a maximum temperature of 250 degrees. Next, the metal wire 10A covered with the inner layer 17A is passed through the die again to coat the outer periphery of the inner layer 17A with an outer layer 18A. Then, the outer layer 18A is baked at a maximum temperature of 300 degrees. In the first coating, by baking the inner layer 17A at a temperature lower than 300 degrees at which a polyimide layer precipitates, the polyimide layer does not precipitate on the inner layer 17A, thereby improving the adhesion between the inner layer 17A and the outer layer 18A. In the second coating, by baking the outer layer 18A at 300 degrees or higher, the polyimide layer precipitates, thereby improving the hardness of the resin film 16A.

[0047] A method of using the medical device 1A will be illustrated. The medical device 1A is used, for example, for treating calcified lesions formed in blood vessels. First, the medical device 1A is inserted along a guide wire placed in the blood vessel with the balloon 40 in a deflated state. When the balloon 40 reaches the lesion, a fluid for expanding the balloon 40 is flowed into the inside of the balloon 40. The fluid pushes the balloon 40 open, causing it to expand and press against the lesion. At this time, the metal wire 10A provided on the outer periphery of the balloon 40 is pressed against the lesion, thereby making it possible to create a crack in the lesion, and thus making it easy to expand the lesion.

[0048] According to the medical device 1A of the present embodiment described above, the surface of the metal wire 10A is covered with the resin film 16A from the tip 12A to the base end 13A. For example, in a joining form in which the metal wire 10A is directly joined to another resin member, the anchor effect may not be fully exerted at the joining interface. However, in the medical device 1A of the present embodiment, the resin film 16A is provided between the metal wire 10A and the balloon 40, the tip fixing part 50A, and the base fixing part 51A, which are resin members constituting the medical device 1A. This allows the anchor effect to be exerted between the resin film 16A and the resin member, and the joining strength between the metal wire 10A and the resin member is improved. In addition, by welding the resin film 16A and the other resin members constituting the medical device 1A by heat or the like, the resin film 16A and the resin member become compatible with each other, and the joining strength is improved. Furthermore, by suppressing the direct contact of the metal wire 10A with the blood vessel wall or the like, the risk of the metal wire 10A damaging the blood vessel wall or the like can be reduced.

[0049] In the coil-shaped metal wire 10A, the resin films 16A of adjacent metal wires 10A are not joined to each other and are separated from each other. This reduces the risk that the joining of the resin films 16A will hinder the expansion and contraction of the metal wire 10A due to the expansion and contraction of the balloon 40. For example, when the balloon 40 is deformed to be folded when it contracts, the metal wire 10A can be deformed from the coil shape to a shape that fits the outer periphery of the balloon 40.

[0050] The metal wire 10A can change the size of the space 15A by changing the shape of the intermediate portion 14A. In this embodiment, the shape of the intermediate portion 14A changes according to the expansion and contraction of the balloon 40. For example, when the balloon 40 is contracted, the intermediate portion 14A has a coil shape with a small outer diameter and a dense pitch. Alternatively, when the outer periphery of the balloon 40 is folded, the intermediate portion 14A has a shape that is arranged between the folded outer periphery of the balloon 40. When the balloon 40 is expanded, the intermediate portion 14A also expands radially outward and can change to a coil shape with a larger outer diameter than in the contracted state. This allows the medical device 1A to be used in treatments such as treatment of a narrowed portion of a blood vessel, which expands a lumen. In addition, the medical device 1A is provided with a membrane member that can expand and contract radially, such as the balloon 40, which can facilitate the shape change of the metal wire 10A.

[0051] The metal wire 10A has a shape in which a first distance La from a center point C of the metal wire 10A to a surface of the metal wire 10A in a first direction Da along the cross section is different from a second distance Lb from the center point C of the metal wire 10A to a surface of the metal wire 10A in a second direction Db different from the first direction Da. In this embodiment, the cross section of the metal wire 10A is rectangular, so that the first distance La and the second distance Lb are different. This allows the corners of the rectangle to locally press the lesion when expanding the lesion, making it easy to create a crack in the lesion. In addition, when the balloon 40 is in a contracted state, the radial thickness of the medical device 1A can be made smaller even with the same cross-sectional area, compared to when the cross section of the metal wire 10A is a circle close to a perfect circle, so that the outer diameter of the medical device 1A can be kept small. This makes it easy to pass the medical device 1A through the lesion. Furthermore, for example, if metal wire 10A is arranged so that the radial direction of balloon 40 coincides with the direction in which metal wire 10A is thicker, the thickness of metal wire 10A increases in the direction of X-ray irradiation during surgery, thereby improving visibility under X-rays.

[0052] The resin film 16A is formed of two layers, an inner layer 17A and an outer layer 18A. For example, if the cross section is polygonal and the resin film 16A is formed of a single film, it is difficult to make the film thickness at the corners of the polygon sufficiently thick, and there is a risk that the metal wire 10A will be exposed to the outside. In this embodiment, the metal wire 10A has two films, the inner layer 17A and the outer layer 18A, formed at the corners of the metal wire 10A, thereby reducing the risk that the corners of the metal wire 10A will be exposed to the outside. This makes it possible to prevent the bonding strength between the corners of the metal wire 10A and other resin members from decreasing. In addition, it is possible to reduce the risk that the metal wire 10A will directly contact a blood vessel wall or the like and damage the blood vessel wall or the like.

[0053] The maximum thickness of the resin film 16A is 2 μm to 11 μm. By making the film thickness 2 μm or more, it is possible to reduce the possibility of direct bonding between the outer periphery of the metal wire 10A and other resin members. In addition, it is possible to increase the amount of resin compatibility at the bonding portion between the resin film 16A and other resin members. As a result, it is possible to improve the bonding strength between the metal wire 10A and the resin members. In addition, by preventing the metal wire 10A from directly contacting the blood vessel wall, etc., it is possible to reduce the risk of the metal wire 10A damaging the blood vessel wall, etc. In addition, by making the film thickness 11 μm or less, it is possible to keep the outer diameter of the metal wire 10A small, making it easier to pass the medical device 1A through the lesion, etc.

[0054] The bonding strength between metal wire 10A and resin film 16A is lower than the breaking strength of metal wire 10A. This makes it easier to separate metal wire 10A from resin film 16A before metal wire 10A breaks when metal wire 10A is pulled. This makes it possible to suppress breakage of metal wire 10A, thereby suppressing the generation of metal fragments due to breakage of metal wire 10A and damage to blood vessel walls, etc., due to the broken portion of metal wire 10A (see FIG. 15).

[0055] <Second embodiment> A medical device 1B according to a second embodiment will be described with reference to FIGS.

[0056] The medical device 1B is a thrombus recovery device used to recover a thrombus or the like from within a blood vessel.

[0057] 9 is an explanatory diagram illustrating the distal end of the medical device 1 B. The medical device 1 B has a metal wire 10 B, a shaft 70, a distal end fixing part 50 B, a proximal end fixing part 51 B, and an operation wire 80.

[0058] Comparing the metal wire 10A of the first embodiment with the metal wire 10B of the second embodiment, the difference is that the metal wire 10A is formed in a coil shape, whereas the metal wire 10B is formed in a mesh shape. Explanation of the points common to the metal wire 10A and the metal wire 10B will be omitted. Details of the metal wire 10B will be described later.

[0059] The shaft 70 is a long cylindrical member having a lumen 71 therein.

[0060] The tip fixing portion 50B is a resin member that ties together and fixes the tips of the metal wires 10B.

[0061] The base end fixing portion 51B is a resin member that fixes the base ends of the metal wires 10B together. A part of the base end fixing portion 51B is joined to the base ends of the metal wires 10B, and another part is joined to the operation wire 80. The base end fixing portion 51B functions as a fixing portion that fixes the metal wires 10B to the operation wire 80. Since the outer periphery of the operation wire 80 is covered with the resin portion 81, a part of the base end fixing portion 51B is fixed to the resin portion 81, and another part is fixed to the resin film 16B of the metal wires 10B.

[0062] The operation wire 80 is a long member whose tip end is joined to the base end fixing part 51B and extends to the base end side of the medical device 1B through the lumen 71. A user of the medical device 1B, such as a doctor, can use the operation wire 80 to move the metal wire 10B in the axial direction.

[0063] The details of the metal wire 10B will be described. The metal wire 10B is surrounded by a plurality of metal wires 10B to form a space 15B inside. The plurality of metal wires 10B can change the size of the space 15B by changing the distance between them at least in a part. The plurality of metal wires 10B cross each other to form a net, and thrombi and the like can be captured in the space 15B and transported to the outside of the body. At the tip side of the metal wire 10B, the plurality of metal wires 10B cross, and the mesh formed by the crossing of the metal wires 10B is formed to a size that prevents the thrombi captured in the space 15B from leaking to the outside. At the base end side of the metal wire 10B, the interval between the metal wires 10B is formed to a size that allows the thrombi to be contained in the space 15B. When the medical device 1B is inserted into the body, the metal wire 10B is contained in the lumen 71 in a contracted state, and the shaft 70 is disposed near the thrombi and then moved to the outside from the tip of the lumen 71.

[0064] Fig. 10 is an explanatory diagram illustrating the cross section BB of Fig. 9. An intermediate portion 14B is formed between the tip and base ends of the metal wire 10B. Since the intermediate portion 14B has an expanded shape that forms a space portion 15B, when the metal wire 10B moves from the inside to the outside of the shaft 70, the metal wire 10B expands radially outward.

[0065] Fig. 11 is an explanatory diagram illustrating an enlarged view of an intersection X of the metal wire 10B shown in Fig. 9. The outer periphery of the metal wire 10B is covered with a resin film 16B. Although omitted in Fig. 11, the resin film 16B is formed over the entire length of the metal wire 10B. The resin film 16B has an inner layer 17B that covers the surface of the metal wire 10B and an outer layer 18B that covers the surface of the inner layer 17B.

[0066] 12 and 13 are explanatory diagrams illustrating cross-sectional views of the intersection X of the metal wire 10B shown in FIG. 9. As shown in FIG. 12 and FIG. 13, the cross section of the metal wire 10B is rectangular. Here, FIG. 12 illustrates a form in which the resin films 16B of the metal wires 10B intersecting at the intersection X are not bonded. That is, the resin films 16B covering the metal wires 10B are separated from each other at the intersection X. At the intersection X, a gap 11B is formed between the metal wires 10B. Since the resin films 16B are not bonded to each other, the metal wires 10B can move and deform independently of each other. Furthermore, in the section S near the intersection X, no resin film 16B is provided to bond the multiple metal wires 10B to each other. Therefore, the metal wires 10B are separated from each other at the intersection X and at the portions other than the intersection X. Also, FIG. 13 illustrates a form in which the resin films 16B of the metal wires 10B intersecting at the intersection X are bonded. In this case, only the outer layer 18B of the resin film 16B may be bonded, or the entire resin film 16B including the inner layer 17B may be mutually compatible and bonded. In the section S near the intersection X, no resin film 16B is provided to bond the multiple metal wires 10B to each other. Therefore, the metal wires 10B are bonded to each other at the intersection X, but are separated from each other in the portions other than the intersection X.

[0067] A method of using the medical device 1B of the second embodiment will be described. First, the medical device 1B is inserted into a blood vessel. With the tip of the shaft 70 positioned distally of the thrombus, the metal wire 10B is moved from the tip of the shaft 70 to the outside, and the metal wire 10B is expanded. After the shaft 70 is moved proximally of the thrombus, the metal wire 10B is moved proximally to accommodate the thrombus in the space 15B. Thereafter, the metal wire 10B and the shaft 70 are pulled proximally to transport the thrombus out of the body.

[0068] According to the medical device 1B described above, the surface of the metal wire 10B is covered with the resin film 16B, so that the bonding strength between the metal wire 10B and the resin-made base end fixing part 51B is improved. In addition, in the case where the metal wires 10B are bonded to each other at the intersection X of the metal wires 10B as shown in FIG. 13, the bonding of the resin film 16B improves the bonding strength between the metal wires 10B at the intersection X. In addition, since the metal wire 10B is covered with the resin film 16B, it is possible to reduce the risk that the metal wire 10B will come into direct contact with a blood vessel wall or the like and cause damage to the blood vessel wall or the like. In addition, since the metal wire 10B does not come into direct contact with the inner wall of the shaft 70, it is possible to improve the sliding property between the metal wire 10B and the shaft 70.

[0069] The resin film 16B covering each metal wire 10B is at least partially separated. For example, the resin film 16B may be separated over the entire intermediate portion 14B including the intersection X as shown in Fig. 12. Alternatively, the resin films 16B may be joined together at the intersection X and the intermediate portion 14B other than the intersection X may be separated as shown in Fig. 13. By separating at least a portion of the resin film 16B, it is possible to reduce the risk that the joining of the resin film 16B will hinder the radial expansion of the metal wire 10B.

[0070] The size of space 15B can be changed by changing the shape of middle portion 14B of metal wire 10B. As a result, for example, by disposing metal wire 10B near a blood vessel wall, it is possible to collect a thrombus formed along the blood vessel wall.

[0071] The cross-sectional shape of the metal wire 10B is rectangular. This allows the relatively wide flat surface of the metal wire 10B to receive the thrombus contained inside the space 15B when it moves to the tip side of the metal wire 10B, and prevents the thrombus from leaking out of the space 15B. In addition, for example, when the metal wire 10B is arranged so that the direction in which the metal wire 10B expands and contracts coincides with the direction in which the metal wire 10B is thicker, the thickness of the metal wire 10B increases in the direction of X-ray irradiation during surgery, improving visibility under X-rays.

[0072] <Modification> The present invention is not limited to the above-described embodiment, and can be embodied in various forms without departing from the spirit and scope of the invention. For example, the following modifications are also possible.

[0073] <Variation 1> In the first embodiment, the metal wires (10A, 10B) are rectangular, but the cross-sectional shape of the metal wires (10A, 10B) is not limited to a rectangle, and may be formed into a circular shape such as a circle or an ellipse, or a polygonal shape such as a square, a trapezoid, a triangle, etc. In addition, the cross-sectional shape of the metal wires (10A, 10B) is not limited to a line-symmetric or point-symmetric shape.

[0074] <Variation 2> In the first embodiment, the end faces of the tip 12A and base 13A of the metal wire 10A are not covered with the resin film 16A, but the end faces of the tip 12A and base 13A may be covered with the resin film 16A.

[0075] <Modification 3> When the metal wire (10A, 10B) has a shape in which the first distance La from the center point C of the metal wire (10A, 10B) to the surface of the metal wire (10A, 10B) in a first direction Da along the cross section is different from the second distance Lb from the center point C to the surface of the metal wire (10A, 10B) in a second direction Db different from the first direction Da, this indicates that there is at least one combination in which the first distance La and the second distance Lb are different. In other words, it is not denied that there is a combination in which the first distance La and the second distance Lb are the same in the cross-sectional shape of the metal wire (10A, 10B). For example, when the cross section of the metal wire (10A, 10B) is rectangular, the distance in the first direction Da and the distance in the second direction Db extending in the opposite direction by 180 degrees are approximately the same, but the first distance La and the second distance Lb are different at least in the combination of the first distance La and the second distance Lb in FIG. 8. On the other hand, a case where there is no combination in which the first distance La and the second distance Lb are different is, for example, a perfect circle shape.

[0076] <Modification 4> In the first and second embodiments, the resin films (16A, 16B) have the inner layer (17A, 17B) and the outer layer (18A, 18B), but the resin films (16A, 16B) do not have to have the inner layer (17A, 17B) and the outer layer (18A, 18B). For example, the resin films (16A, 16B) may be one film formed from one resin material. Alternatively, the resin films (16A, 16B) may be formed from three or more layers.

[0077] <Variation 5> In the metal wire 10A of the medical device 1A of the first embodiment, the resin films 16A of adjacent metal wires 10A are separated from each other in all parts of the metal wire 10A wound in a coil shape, but they may be separated only in parts without being separated in all parts. For example, two adjacent metal wires 10A may be joined in parts in the circumferential direction, and the other parts may be separated. In the metal wire 10B of the second embodiment 1B, the resin films 16B of all intersections X of the metal wire 10B may be separated from each other. Or, the resin films 16B of the intersections X may be separated from each other in parts, and the other parts of the resin films 16B may be joined.

[0078] <Variation 6> The long member is not limited to the inner shaft 20, the distal outer shaft 30, the shaft 70, or the operation wire 80. The long member refers to a member that is provided extending in the longitudinal direction of the medical device (1A, 1B). The long member does not have to be provided over the entire length of the medical device (1A, 1B), and may be provided in a part of the medical device (1A, 1B).

[0079] <Variation 7> In the first embodiment, the metal wire 10A is formed into a coil shape by winding one wire in a spiral shape, but the metal wire 10A may be formed into a coil shape by winding multiple wires in a spiral shape. For example, the metal wire 10A may be formed into a coil shape by winding a strand formed by bundling multiple wires in a spiral shape.

[0080] <Variation 8> In the medical device 1A of the first embodiment, both the distal end fixing part 50A and the proximal end fixing part 51A are made of resin. However, one of the distal end fixing part 50A and the proximal end fixing part 51A may not be made of resin. Even in this case, the joint strength between the other fixing part made of resin and the metal wire 10A can be improved. The same applies to the distal end fixing part 50B and the proximal end fixing part 51B of the medical device 1B of the second embodiment. Moreover, the medical device 1A of the first embodiment may not have either the distal end fixing part 50A or the proximal end fixing part 51A. Even in this case, if the other fixing part is made of resin, the joint strength with the metal wire 10A can be improved. The same applies to the medical device 1B of the second embodiment.

[0081] <Variation 9> Although the medical device 1A which is a catheter and the medical device 1B which is a thrombus retrieval device are shown as embodiments, the embodiments are not limited to these medical devices. For example, the present invention can also be applied to a guidewire or the like.

[0082] <Modification 10> In the first embodiment, the entire outer peripheral surface of the metal wire 10A is covered with the resin film 16A, and in the second embodiment, the outer peripheral surface of the metal wire 10B is covered with the resin film 16B formed over the entire length of the metal wire 10B, but this is not limited thereto. It is sufficient that the surface of the metal wire, including at least one of the tip and base ends, is covered with a resin film, and it is sufficient that at least one of the tip and base ends that is covered is fixed by a tip fixing part or a base end fixing part.

[0083] <Modification 11> In the first embodiment, the bonding strength between the metal wire 10A and the resin film 16A is lower than the breaking strength of the metal wire 10A, but in the second embodiment, the bonding strength between the metal wire 10B and the resin film 16B may be lower than the breaking strength of the metal wire 10B. In the first embodiment, the bonding strength between the metal wire 10A and the resin film 16A is substantially equal at any position on the contact surface between the metal wire 10A and the resin film 16A, so that the bonding strength between the tip 12A of the metal wire 10A and the resin film 16A is substantially equal to the bonding strength between the base end 13A of the metal wire 10A and the resin film 16A, but this is not limited to this. The bonding strength may differ depending on the position of the contact surface, and for example, the bonding strength between the tip 12A of the metal wire 10A and the resin film 16A may be lower than the bonding strength between the base end 13A of the metal wire 10A and the resin film 16A. In such a case, tip end 12A of metal wire 10A is more likely to separate from resin film 16A than base end 13A. [Explanation of symbols]

[0084] 1A, 1B: Medical equipment 10A, 10B...metal wire 11A, 11B...Gap 12A…Tip of metal wire 13A…Base end of metal wire 14A, 14B...middle part 15A, 15B…Space section 16A, 16B…Resin film 17A, 17B…Inner layer 18A, 18B...outer layer 20…Inner shaft 21…Inner lumen 30…Tip side outer shaft 31…Outer lumen 32...Base end outer shaft 40…Balloon 50A, 50B…Tip fixing part 51A, 51B...Proximal end fixing part 60…Connector 70…Shaft 80…Operation wire 81…Resin part C: Center point of metal wire Da…First direction Db...Second direction La…1st distance Lb…Second distance Ta: Film thickness in width direction Tb: Film thickness in thickness direction

Claims

1. A medical device, an elongated member to be inserted into the body; one or more metal wires fixed to a distal end side of the elongated member, the one or more metal wires having a surface including at least one of a distal end and a proximal end coated with a resin film; A medical device comprising: a resin fixing portion that fixes at least one of the coated tip and base ends of the one or more metal wires to the elongated member.

2. 10. The medical device of claim 1, The metal wire is When there is one metal wire, it has a coil shape, and when there are multiple metal wires, it may or may not have a coil shape, When the metal wire has a coil shape, a space is formed inside the coil, and the resin film on one surface of adjacent portions of one coil is at least partially separated from the resin film on the other surface, When there are multiple metal wires, the space is formed inside by the multiple metal wires surrounding each other, and the resin film on one surface of two different metal wires among the multiple metal wires is at least partially separated from the resin film on the other surface of the medical device.

3. The medical device according to claim 1 or claim 2, the one or more metal wires are capable of changing the size of the space by changing the shape of an intermediate portion between the tip end and the base end; The medical device further comprises: A medical device comprising the resin membrane member in contact with the intermediate portion of the one or more metal wires.

4. The medical device according to claim 1 or claim 2, the metal wire has a shape in a cross section in which a distance from a center point of the metal wire to a surface of the metal wire in a first direction along the cross section is different from a distance from the center point to the surface of the metal wire in a second direction different from the first direction; The medical device, wherein the resin film includes an inner layer in contact with the surface of the metal wire and an outer layer covering the inner layer.

5. The medical device according to claim 1 or claim 2, A medical device, wherein the maximum thickness of the resin film is 2 μm or more and 11 μm or less.

6. The medical device according to claim 1 or claim 2, A medical device, wherein the bonding strength between the metal wire and the resin film is lower than the breaking strength of the metal wire.

Images