Rotation transmission structure, catheter and guide wire

Abstract

To provide a technology capable of improving rotation transmission performance of a rotation transmission member and adjusting rigidity of a rotation transmission structure.SOLUTION: A rotation transmission structure 20 includes a coil body 30 formed by winding of a wire 31, and a reinforcement body 40 that connects between adjacent wires 31 of the coil body 30. The reinforcement body 40 is provided such that rigidity in a prescribed area 21 in the longer direction is lower than rigidity in other areas 22 in the coil body 30 with the wires 31 connected to each other.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a rotation transmission structure, a catheter, and a guidewire. [Background technology]

[0002] Patent Document 1 discloses a medical device structure including a coil including adjacent windings and a member connecting the adjacent windings of the coil. The member connecting the adjacent windings of the coil is disposed in a part of the region between the adjacent windings so as to transmit torque between the adjacent windings. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 8,636,270 Summary of the Invention [Problem to be solved by the invention]

[0004] Although Patent Document 1 considers using a reinforcing body to improve the rotation transmission performance of the rotation transmission member, it does not consider using a reinforcing body to adjust the rigidity of the rotation transmission structure.

[0005] An object of the present invention is to provide a technique capable of improving the rotation transmitting performance of a rotation transmitting member and adjusting the rigidity of a rotation transmitting structure. [Means for solving the problem]

[0006] The rotational transmission structure of the present invention comprises a coil body formed by winding wire, and a reinforcing body connecting adjacent wires of the coil body, and the reinforcing body is arranged so that in the coil body in a state in which the wires are connected, the rigidity of a specified region in the longitudinal direction is lower than the rigidity of other regions.

[0007] According to the present invention, the rotation transmission performance of the rotation transmission structure can be improved compared to a coil body that is not connected by a reinforcing member, and the rigidity of the rotation transmission structure can be adjusted by the reinforcing member. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is an overall view of a catheter according to a first embodiment. [Diagram 2] 2 is an explanatory diagram showing the shaft portion, in which the distal tip, part of the middle layer, and part of the outer layer have been removed for the purpose of illustration. [Diagram 3] FIG. 3 is a cross-sectional view of the shaft portion and the distal tip. [Figure 4] FIG. 4 is a cross-sectional view of the rotation transmission structure. [Diagram 5] FIG. 5 is an exploded perspective view of the rotation transmission structure. [Figure 6] FIG. 6 is a cross-sectional view taken along line AA in FIG. [Figure 7] FIG. 7 is a cross-sectional view of the rotation transmission structure according to the second embodiment. [Figure 8] FIG. 8 is an exploded perspective view of the rotation transmission structure. [Figure 9] FIG. 9 is a cross-sectional view of the rotation transmission structure according to the third embodiment. [Figure 10] FIG. 10 is an exploded perspective view of the rotation transmission structure. [Figure 11] FIG. 11 is a cross-sectional view of the rotation transmission structure according to the fourth embodiment. [Figure 12] FIG. 12 is an exploded perspective view of the rotation transmission structure. [Figure 13] FIG. 13 is an overall view of a guidewire according to the fifth embodiment. [Figure 14] FIG. 14 is a perspective view showing a reinforcing body according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A preferred embodiment of the present invention will now be described.

[0010] The reinforcing member may be configured with a plurality of connecting parts provided at each portion connecting the wires, and the plurality of connecting parts may be arranged more sparsely in the predetermined region than in the other regions. With this configuration, the rigidity of the rotation transmission structure can be suitably adjusted by changing the arrangement of the plurality of connecting parts.

[0011] The plurality of connection parts may be arranged along a virtual spiral shape, and a pitch of the spiral shape in the predetermined region may be greater than a pitch of the spiral shape in the other region. With this configuration, the rigidity of the rotation transmission structure can be suitably adjusted by changing the pitch of the spiral shape.

[0012] The reinforcing member may be configured with a plurality of connecting parts provided at respective portions connecting the wires, and the Young's modulus of the material of the connecting parts arranged in the predetermined region may be smaller than the Young's modulus of the material of the connecting parts arranged in the other regions. With this configuration, the rigidity of the rotation transmission structure can be suitably adjusted by changing the Young's modulus of the material of the connecting parts.

[0013] The reinforcing member may be configured with a plurality of connecting parts provided at each portion connecting the wires, and the plurality of connecting parts may be arranged along an imaginary spiral shape in a direction opposite to the winding direction of the coil body. This configuration provides better rotation transmission performance than a configuration in which the plurality of connecting parts are arranged along an imaginary spiral shape in the same direction as the winding direction of the coil body.

[0014] The reinforcing body may be configured with a plurality of connecting parts provided at each portion connecting the wires, and the plurality of connecting parts may be arranged along a virtual multiple spiral shape. With this configuration, the range of rigidity that can be adjusted by the reinforcing body can be made larger than that of a configuration in which a plurality of connecting parts are arranged along a single spiral shape.

[0015] The reinforcing body may have an outer diameter equal to or smaller than a maximum outer diameter of the coil body. With this configuration, it is possible to prevent the outer diameter of the rotation transmission structure from becoming large due to the provision of the reinforcing body.

[0016] The reinforcing body may have an inner diameter equal to or larger than the minimum inner diameter of the coil body. With this configuration, it is possible to prevent the inner diameter of the rotation transmission structure from becoming smaller due to the provision of the reinforcing body.

[0017] The catheter of the present invention is a catheter including a shaft portion reinforced by the above-mentioned rotation transmission structure, and the predetermined region of the rotation transmission structure may be located on the distal side of the other region. With this configuration, it is possible to realize a catheter having excellent rotation transmission properties and ensuring flexibility of the distal end portion.

[0018] The guidewire of the present invention includes the above-mentioned rotation transmission structure and a core shaft inserted into the inner cavity of the rotation transmission structure, and the predetermined region of the rotation transmission structure may be located on the distal side of the other region. With this configuration, it is possible to realize a guidewire that has excellent rotation transmission properties and ensures flexibility of the distal end.

[0019] <Embodiment 1> Next, a first embodiment of the present invention will be described with reference to Fig. 1 to Fig. 6. In Fig. 1, the right side of the figure is the tip side (distal side) that is inserted into the body, and the left side is the rear end side (proximal side, base end side) that is operated by a technician such as a doctor.

[0020] 1 is an explanatory diagram showing a medical catheter (a type of medical device) 10 equipped with a rotation transmission structure 20. The catheter 10 includes a shaft portion 11, a distal tip 12 provided on the distal end side of the shaft portion 11, and a connector 13 provided on the proximal end side of the shaft portion 11. The rigidity of the distal portion 11A of the shaft portion 11 is lower than the rigidity of the portions other than the distal portion 11A. The portions of the shaft portion 11 other than the distal portion 11A are also referred to as the main body portion or proximal end portion of the shaft portion 11.

[0021] As shown in FIG. 2, the shaft portion 11 has, from the inside, an inner layer 14, a rotation transmission structure 20 as a reinforcing body, a middle layer 15, and an outer layer 16 in that order.

[0022] The inner layer 14 is made of resin and forms a lumen 17 for inserting a guide wire or other catheter therein. The resin material forming the inner layer 14 is not particularly limited, but in this embodiment, PTFE (polytetrafluoroethylene) is used. A rotation transmission structure 20 is formed on the outer periphery of the inner layer 14 as a reinforcing body. The configuration of the rotation transmission structure 20 will be described later.

[0023] An intermediate layer 15 made of resin is formed on the outer periphery of the rotation transmission structure 20, and covers the inner layer 14 and the rotation transmission structure 20. The resin material forming the intermediate layer 15 is not particularly limited, and polyamide, polyamide elastomer, polyester, polyurethane, etc. are used.

[0024] 3, the middle layer 15 covers the shaft portion 11 except for the tip 12. The middle layer 15 is bonded to the inner layer 14 in the gaps of the rotation transmission structure 20 (in other words, the gaps 32 between the adjacent wires 31).

[0025] An outer layer 16 made of resin is formed on the outer periphery of the middle layer 15 to cover the middle layer 15. The resin material forming the outer layer 16 is not particularly limited, and polyamide, polyamide elastomer, polyester, polyurethane, etc. are used, as with the middle layer 15. The outer layer 16 may be configured using resin materials with different hardness so that the shaft portion 11 is more flexible toward the tip portion 11A side. For example, the first outer layer 16A covering the tip portion 11A may be formed of a resin that is softer than the second outer layer 16B covering the portion other than the tip portion 11A.

[0026] As shown in Fig. 4, the rotation transmission structure 20 includes a coil body 30 and a reinforcing body 40. The rotation transmission structure 20 has a first region 21 and a second region 22 located closer to the base end than the first region 21. The first region 21 corresponds to a predetermined region in the longitudinal direction. The second region 22 corresponds to the other region. Specifically, the first region 21 constitutes the tip portion 11A of the shaft portion 11. The second region 22 constitutes the portion of the shaft portion 11 other than the tip portion 11A.

[0027] As shown in Fig. 4 and Fig. 5, the coil body 30 is formed by winding a wire 31. The wire 31 is a flat wire. The cross-sectional shape of the wire may be substantially rectangular, circular, or polygonal. The diameter of the wire 31 is substantially constant over its entire length. The material of the wire 31 is not particularly limited, but is preferably a material that is biocompatible and resistant to corrosion, such as stainless steel alloy (SUS), nickel titanium alloy (NiTi), titanium (Ti), platinum (Pt), tungsten (W), gold (Au), or silver (Ag).

[0028] The coil body 30 is wound in a spiral shape. The outer diameter and inner diameter of the coil body 30 are substantially constant over the entire length. When not connected by the reinforcing body 40, the coil body 30 has substantially constant bending rigidity and torsional rigidity over the entire length. In the coil body 30, adjacent wires 31 are not in contact with each other, and the coil body 30 is so-called sparsely wound. In other words, gaps 32 are formed between adjacent wires 31 in the coil body 30.

[0029] The reinforcing body 40 is a member that connects adjacent wires 31 of the coil body 30. The material of the reinforcing body 40 is not particularly limited, and may be the same material as the coil body 30 or a different material. Examples of the material of the reinforcing body 40 include metal materials such as stainless steel (SUS), nickel-titanium alloy (NiTi), titanium (Ti), and nickel-chromium alloy (NiCr), metal brazing material, and resin adhesive. The reinforcing body 40 may be formed from a part of the material that constitutes the coil body 30 by welding between the wires 31. In this embodiment, the reinforcing body 40 is formed from the same material over its entire area.

[0030] The reinforcing body 40 is provided so that the rigidity of the first region 21 is lower than the rigidity of the second region 22 in the coil body 30 in a state in which the wires 31 are connected. The reinforcing body 40 is provided in both the first region 21 and the second region 22. The rigidity of the first region 21 is higher than the rigidity of the coil body 30 not connected by the reinforcing body 40, and is lower than the rigidity of the second region 22. The rigidity of the rotation transmission structure 20 gradually decreases from the second region 22 to the first region 21. Examples of the rigidity index include bending rigidity and torsional rigidity.

[0031] The reinforcing body 40 is composed of a plurality of connection parts 41, 42 provided at each portion connecting the wires 31. Of the plurality of connection parts 41, 42, a plurality of connection parts 41 are arranged in the first region 21, and a plurality of connection parts 42 are arranged in the second region 22.

[0032] The multiple connection parts 41, 42 are arranged more sparsely in the first region 21 than in the second region 22. In other words, the density of the multiple connection parts 41 is smaller than the density of the multiple connection parts 42. The density of the multiple connection parts 41 can be calculated, for example, as the mass of the multiple connection parts 41 per unit length of the coil body 30. In this case, the unit length of the coil body 30 may be set appropriately according to the distribution of the multiple connection parts 41, 42. The density of the multiple connection parts 42 can be calculated in the same manner as the density of the multiple connection parts 41. The density of the multiple connection parts 41, 42 can be adjusted by changing the number, size, and arrangement of the connection parts (the pitch of the spiral shape and the number of threads of the spiral shape, which will be described later), etc.

[0033] The multiple connection parts 41, 42 are arranged along a virtual single helical shape S1. This helical shape S1 is in the opposite winding direction to the coil body 30. For example, when the coil body 30 is wound in a counterclockwise direction toward the tip (S winding), the multiple connection parts 41, 42 are arranged along a virtual helical shape S1 that is wound in a clockwise direction toward the tip (Z winding).

[0034] The pitch P1 of the spiral shape S1 in the first region 21 is larger than the pitch P2 of the spiral shape S1 in the second region 22. In other words, the rotation transmission structure 20 is configured such that the pitch of the spiral shape S1 is variable in order to adjust the rigidity. The pitch of the spiral shape S1 is the dimension between turns of the spiral shape S1 in the longitudinal direction of the rotation transmission structure 20. The pitch P1 of the spiral shape S1 in the first region 21 gradually increases toward the tip side.

[0035] The size of connection portion 41 is smaller than the size of connection portion 42. Specifically, the dimension of connection portion 41 is smaller than the dimension of connection portion 42 in the winding direction of wire 31. The sizes of the multiple connection portions 41, 42 gradually decrease toward the tip side.

[0036] As shown in FIG. 6, the outer diameter of the reinforcing body 40 is equal to or smaller than the maximum outer diameter of the coil body 30. In other words, the reinforcing body 40 is disposed on the inner circumferential side of the imaginary cylindrical surface 34A circumscribing the outer circumferential surface 34 of the coil body 30. The inner diameter of the reinforcing body 40 is equal to or larger than the minimum inner diameter of the coil body 30. In other words, the reinforcing body 40 is disposed on the outer circumferential side of the imaginary cylindrical surface 35A inscribed in the inner circumferential surface 35 of the coil body 30. That is, the reinforcing body 40 is in a form in which a plurality of connecting portions 41, 42 are disposed in the gaps 32 between the adjacent wires 31. The outer surface of the reinforcing body 40 is flush with the outer circumferential surface 34 of the coil body 30. The inner surface of the reinforcing body 40 is flush with the inner circumferential surface 35 of the coil body 30. The size and arrangement of the reinforcing body 40 are not limited to this. For example, in the radial direction of the coil body 30, the dimension of the reinforcing body 40 (connections 41, 42) may be smaller than the thickness dimension of the wire 31, and the connections 41, 42 may be located between the outer circumferential surface 34 and the inner circumferential surface 35.

[0037] Next, the effects of this embodiment will be described.

[0038] According to the rotation transmission structure 20 of the present embodiment, the rotation transmission performance of the rotation transmission structure 20 can be improved compared to a coil body that is not connected by the reinforcing body 40, and the rigidity of the rotation transmission structure 20 can be adjusted by the reinforcing body 40. For example, according to the rotation transmission structure 20, the rigidity can be increased in the portion of the shaft portion 11 other than the tip portion 11A, thereby improving the operability of the catheter 10, and the flexibility of the rotation transmission structure 20 can be ensured in the tip portion 11A of the shaft portion 11.

[0039] In order to confirm the effect of this embodiment, the pitch of the helical shape in the reinforcement was changed, and the bending rigidity of the rotation transmission structure was obtained by simulation. From this result, it was confirmed that the bending rigidity decreases when the pitch of the helical shape in the reinforcement is increased. In addition, the pitch of the helical shape in the reinforcement was changed, and the torsional rigidity of the rotation transmission structure was obtained by simulation. From this result, it was confirmed that the torsional rigidity decreases when the pitch of the helical shape in the reinforcement is increased. Furthermore, it was confirmed that when the pitch is increased stepwise, under certain conditions, the bending rigidity tends to be smaller than the torsional rigidity. From this result, it was suggested that the bending rigidity and torsional rigidity according to the medical device to which the rotation transmission structure 20 is applied can be realized by the reinforcement 40, for example, by reducing the bending rigidity while ensuring the torsional rigidity according to the part of the rotation transmission structure 20.

[0040] Furthermore, in a configuration in which a slot pattern is formed on the side surface of a tubular member in order to adjust the rigidity of the rotation transmission structure, when a rotational force is applied to the rotation transmission structure, stress is concentrated on the opening edge of the slot formed in the tubular member, raising concerns that the rotation transmission structure may break, etc. In contrast, in this embodiment, when a rotational force is applied to the rotation transmission structure 20, even if some of the connections between the wires 31 in the coil body 30 come loose, breakage of the coil body 30 itself can be avoided.

[0041] In this embodiment, the multiple connection parts 41, 42 are arranged more sparsely in the first region 21 than in the second region 22. Therefore, by changing the arrangement of the multiple connection parts 41, 42, the rigidity of the rotation transmission structure 20 can be suitably adjusted.

[0042] In this embodiment, the pitch P1 of the spiral shape S1 in the first region 21 is larger than the pitch P2 of the spiral shape S1 in the second region 22. Therefore, by changing the pitches P1, P2 of the spiral shape S1, the rigidity of the rotation transmission structure 20 can be suitably adjusted.

[0043] In this embodiment, the multiple connection parts 41, 42 are arranged along an imaginary spiral shape S1 that is oriented in the opposite direction to the winding direction of the coil body 30. Therefore, compared to a configuration in which the multiple connection parts 41, 42 are arranged along an imaginary spiral shape S1 that is oriented in the same direction as the winding direction of the coil body 30, the rotation transmission performance is better.

[0044] In this embodiment, the outer diameter of the reinforcing body 40 is equal to or smaller than the maximum outer diameter of the coil body 30. Therefore, the provision of the reinforcing body 40 can prevent the outer diameter of the rotation transmission structure 20 from becoming larger. The inner diameter of the reinforcing body 40 is equal to or larger than the minimum inner diameter of the coil body 30. Therefore, the provision of the reinforcing body 40 can prevent the inner diameter of the rotation transmission structure 20 from becoming smaller. Furthermore, in this embodiment, the reinforcing body 40 is disposed in the gap 32 between the wires 31. Therefore, when the rotation transmission structure 20 is pushed in, the pushing force can be more easily transmitted to the tip side, and the pushability of the rotation transmission structure 20 can be further improved.

[0045] The catheter 10 of this embodiment is a catheter 10 including a shaft portion 11 reinforced by the above-mentioned rotation transmission structure 20, and the first region 21 of the rotation transmission structure 20 is located closer to the tip side than the second region 22. This makes it possible to realize a catheter 10 that has excellent rotation transmission properties and ensures flexibility of the tip portion 11A.

[0046] <Embodiment 2> 7 and 8, the rotation transmission structure 220 according to the second embodiment differs from the first embodiment in the configuration of the reinforcing body. The same components as those in the first embodiment are given the same reference numerals and the duplicated description will be omitted.

[0047] The rotation transmission structure 220 includes a coil body 30 and a reinforcing body 240. The rotation transmission structure 220 has a first region 21, a second region 22 located closer to the base end than the first region 21, and an intermediate region 23 located between the first region 21 and the second region 22. The first region 21 corresponds to a predetermined region in the longitudinal direction. The second region 22 corresponds to the other region. Specifically, the first region 21 constitutes the tip portion 11A of the shaft portion 11. The second region 22 constitutes the base end portion of the shaft portion 11.

[0048] The reinforcing body 240 is provided so that the rigidity of the first region 21 is lower than the rigidity of the second region 22 in the coil body 30 in a state in which the wires 31 are connected. The reinforcing body 240 is provided in the first region 21, the second region 22, and the intermediate region 23. The rigidity of the first region 21 is higher than the rigidity of the coil body 30 not having the reinforcing body 240, and lower than the rigidity of the second region 22 and the intermediate region 23. The rigidity of the intermediate region 23 is lower than the rigidity of the second region 22. The rigidity of the rotation transmission structure 220 decreases in multiple stages from the second region 22 to the first region 21. Examples of the rigidity index include bending rigidity and torsional rigidity.

[0049] The reinforcing body 240 is composed of a plurality of connection parts 241, 242, 243 provided at each portion connecting the wires 31. Of the plurality of connection parts 241, 242, 243, the plurality of connection parts 241 are arranged in the first region 21, and the plurality of connection parts 242 are arranged in the second region 22. The plurality of connection parts 243 are arranged in the intermediate region 23. The plurality of connection parts 241 correspond to the connection parts arranged in a predetermined region. The plurality of connection parts 242 correspond to the connection parts arranged in another region.

[0050] The multiple connection parts 241, 242, 243 are arranged along virtual four spiral shapes S1 to S4. Each of the four spiral shapes S1 to S4 is opposite to the winding direction of the coil body 30. For example, when the coil body 30 is wound in a counterclockwise direction toward the tip (S winding), the multiple connection parts 241, 242, 243 are arranged along virtual spiral shapes S1 to S4 that are wound in a clockwise direction toward the tip (Z winding). The four spiral shapes S1 to S4 are arranged to be shifted from each other by 90° in the circumferential direction. The density of the multiple connection parts 241 is equal to the density of the multiple connection parts 242.

[0051] The Young's modulus of the material forming the connection portion 241 is smaller than the Young's modulus of the material forming the connection portion 242. Specifically, the multiple connection portions 241 are made of the same first material. In FIG. 8, the connection portions made of the first material are shown in black. The multiple connection portions 242 are made of the same second material. In FIG. 8, the connection portions made of the second material are shown in white. The Young's modulus of the first material is smaller than the Young's modulus of the second material. Half of the multiple connection portions 243 are made of the first material, and the remaining half of the multiple connection portions 243 are made of the second material. The multiple connection portions 243 made of the first material are arranged along two spiral shapes S1 and S3 out of the four spiral shapes S1 to S4. The multiple connection portions 243 made of the second material are arranged along the other two spiral shapes S2 and S4 out of the four spiral shapes S1 to S4.

[0052] Next, the effects of this embodiment will be described.

[0053] According to rotation transmission structure 220 of the present embodiment, it is possible to improve the rotation transmission performance compared to a coil body that is not connected by reinforcing body 240, and it is also possible to adjust the rigidity of rotation transmission structure 220 by reinforcing body 240. For example, according to rotation transmission structure 220, it is possible to increase the rigidity in the portion of shaft portion 11 other than tip portion 11A, thereby improving the operability of catheter 10, and ensure the flexibility of rotation transmission structure 220 in tip portion 11A of shaft portion 11.

[0054] In order to confirm the effect of this embodiment, the Young's modulus of the material forming the multiple connecting parts was changed, and the bending rigidity of the rotation transmission structure was obtained by simulation. From this result, it was confirmed that the bending rigidity is reduced by reducing the Young's modulus of the material forming the multiple connecting parts. In addition, the Young's modulus of the material forming the multiple connecting parts was changed, and the torsional rigidity of the rotation transmission structure was obtained by simulation. From this result, it was confirmed that the torsional rigidity is reduced by reducing the Young's modulus of the material forming the multiple connecting parts. Furthermore, it was confirmed that when the Young's modulus of the material forming the reinforcing body is reduced in stages, under certain conditions, the bending rigidity tends to be smaller than the torsional rigidity. From this result, it was suggested that the reinforcing body 240 can realize the bending rigidity and torsional rigidity according to the medical device to which the rotation transmission structure 220 is applied, for example, by reducing the bending rigidity while ensuring the torsional rigidity according to the part of the rotation transmission structure 220.

[0055] The Young's modulus of the material of the connection portion 241 arranged in the first region 21 is smaller than the Young's modulus of the material of the connection portion 242 arranged in the second region 22. Therefore, by changing the Young's modulus of the material of the connection portions 241 and 242, the rigidity of the rotation transmission structure 220 can be suitably adjusted.

[0056] The multiple connection parts 241, 242 are arranged along virtual multiple spiral shapes S1 to S4. Therefore, the range of rigidity that can be adjusted by the multiple connection parts 241 and the multiple connection parts 242 can be made larger than in a configuration in which the multiple connection parts 241, 242 are arranged along a single spiral shape.

[0057] In this embodiment, since a plurality of connection parts 243 made of materials having different Young's moduli are arranged in the intermediate region 23, the rigidity of the rotation transmission structure 220 can be gradually changed.

[0058] <Embodiment 3> 9 and 10, the rotation transmission structure 320 according to the third embodiment differs from the first embodiment in the configuration of the reinforcing body. The same components as those in the first embodiment are given the same reference numerals and the duplicated description will be omitted.

[0059] The reinforcing body 340 is composed of a plurality of connection parts 341, 342 provided at each portion connecting the wires 31. Of the plurality of connection parts 341, 342, the plurality of connection parts 341 are arranged in the first region 21, and the plurality of connection parts 342 are arranged in the second region 22. The plurality of connection parts 341, 342 are arranged along a virtual single spiral shape S1. This spiral shape S1 is opposite to the winding direction of the coil body 30. For example, when the coil body 30 is wound in a counterclockwise direction toward the tip (S winding), the plurality of connection parts 341, 342 are arranged along a virtual spiral shape S1 wound in a clockwise direction toward the tip (Z winding).

[0060] The multiple connection parts 341, 342 are arranged more sparsely in the first region 21 than in the second region 22. In other words, the density of the multiple connection parts 341 is lower than the density of the multiple connection parts 342. The density of the multiple connection parts 341 can be calculated, for example, as the mass of the multiple connection parts 341 per unit length of the coil body 30. The density of the multiple connection parts 342 can be calculated in a similar manner. In this case, the unit length of the coil body 30 may be set appropriately depending on the distribution of the multiple connection parts 341, 342.

[0061] The pitch P1 of the spiral shape S1 in the first region 21 is larger than the pitch P2 of the spiral shape S1 in the second region 22. The pitch of the spiral shape S1 is the dimension between turns of the spiral shape S1 in the longitudinal direction of the rotation transmission structure 320. The pitch P1 of the spiral shape S1 in the first region 21 is the same throughout, and the pitch P2 of the spiral shape S1 in the second region 22 is the same throughout. In other words, the pitch of the spiral shape S1 increases stepwise toward the tip side.

[0062] In this embodiment, a simple configuration in which the pitch of the spiral shape is changed in stages makes it possible to suitably adjust the rigidity of the rotation transmission structure 320. The rigidity of the rotation transmission structure 320 decreases in stages from the second region 22 to the first region 21.

[0063] <Embodiment 4> A rotation transmission structure 420 according to the fourth embodiment differs from the first embodiment in the configuration of the reinforcing body as shown in Figures 11 and 12. The same components as those in the first embodiment are denoted by the same reference numerals and redundant explanations will be omitted.

[0064] The reinforcing body 440 is composed of a plurality of connecting parts 441, 442 provided at each portion connecting the wires 31. Of the plurality of connecting parts 441, 442, the plurality of connecting parts 441 are arranged in the first region 21, and the plurality of connecting parts 442 are arranged in the second region 22. The plurality of connecting parts 441 are arranged along a virtual single spiral shape S1. The plurality of connecting parts 442 are arranged along virtual double spiral shapes S1, S2. These spiral shapes S1, S2 are opposite to the winding direction of the coil body 30. For example, when the coil body 30 is wound in a counterclockwise direction toward the tip (S winding), the plurality of connecting parts 441, 442 are arranged along a virtual spiral shape S1 wound in a clockwise direction toward the tip (Z winding). The pitch P1 of the spiral shape S1 is the same as the pitch P2 of the spiral shape S2.

[0065] In this embodiment, the rigidity of the rotation transmission structure 420 can be suitably adjusted by a simple configuration in which the number of threads of the spiral shapes S1, S2 is changed. The rigidity of the rotation transmission structure 420 decreases stepwise from the second region 22 to the first region 21.

[0066] <Embodiment 5> A rotation transmission structure 520 according to the fifth embodiment differs from the first embodiment in that it constitutes a guide wire 510. The same components as those in the first embodiment are given the same reference numerals and overlapping descriptions will be omitted.

[0067] 13 is an explanatory diagram showing a guidewire (a type of medical device) 510 having a rotation transmission structure 520. The guidewire 510 includes a rotation transmission structure 520, a core shaft 511 inserted into the inner cavity of the rotation transmission structure 520, and the like. A tip of the rotation transmission structure 520 and a tip of the core shaft 511 are connected by a tip brazing part 512, and a base end of the rotation transmission structure 520 and an intermediate part of the core shaft 511 are connected by a rear end brazing part 513.

[0068] The rotation transmission structure 520 includes a coil body 30 and a reinforcing body 40. The rotation transmission structure 520 has a first region 21 and a second region 22 located closer to the base end than the first region 21. The first region 21 corresponds to a predetermined region in the longitudinal direction. The second region 22 corresponds to the other region. The configuration of the rotation transmission structure 520 is the same as that of the first embodiment, and therefore a description thereof will be omitted.

[0069] In the guidewire 510 of the present embodiment, the first region 21 in the rotation transmission structure 520 is located closer to the distal end than the second region 22. This makes it possible to realize a guidewire 510 that has excellent rotation transmission properties and ensures flexibility at the distal end.

[0070] <Other embodiments> The present invention is not limited to the embodiments described above and illustrated in the drawings, and the following embodiments are also included within the technical scope of the present invention.

[0071] (1) In addition to the above embodiments, the positions and ranges of the first region and the second region in the rotation transmission structure can be changed as appropriate. For example, the first region is not limited to the tip of the shaft portion, and may constitute any region in the shaft portion where flexibility is required. The second region is not limited to the base end side of the first region, and may be located on the tip end side. The second region is not limited to all regions other than the first region, and may constitute a portion of the region. Furthermore, the rotation transmission structure may have a third region other than the intermediate region that has a rigidity different from both the first region and the second region.

[0072] (2) The configuration for changing the rigidity of the rotation transmission structure by using a reinforcing body is not limited to the configuration of the above embodiment. For example, the rigidity of the rotation transmission structure can be changed by changing one or a combination of a number of the following: the size of the reinforcing body, the physical properties of the material forming the reinforcing body, the pitch of the helical shape, and the number of threads of the helical shape.

[0073] (3) The reinforcing body is not limited to being formed by a plurality of connecting parts, and may be formed by a single member. In such a case, as shown in Fig. 14, the reinforcing body 640 may be formed in a longitudinal shape with a width dimension that decreases toward the tip side, and the first region 21 and the second region 22 may have portions with different width dimensions of the reinforcing body 640. Moreover, the reinforcing body 640 formed by such a single member may be provided on the outside of the coil body 30 as shown in Fig. 14, or may be provided on the inside of the coil body.

[0074] (4) The multiple connection parts may be arranged along an imaginary spiral shape in the same direction as the winding direction of the coil body. The multiple connection parts do not have to be arranged along an imaginary spiral shape, and may be arranged, for example, along the longitudinal direction of the coil body.

[0075] (5) The configuration of the coil body can be changed in addition to the above-described embodiment. For example, the coil body may have regions with different rigidity when not connected by a reinforcing member. The coil body may have no gaps between the wires and may be tightly wound. The winding direction of the coil body is not limited.

[0076] (6) In the above embodiment, the diameter of the wire is substantially constant over the entire length. However, the diameter of the wire may be tapered from the base end to the tip end.

[0077] (7) The manner in which the rigidity of the rotation transmission structure is changed is not limited to the configurations in the above embodiments. The rigidity of the rotation transmission structure may be changed gradually or in an arbitrary number of stages.

[0078] (8) The rotation transmission structure may be provided in a medical device other than a catheter, such as a guide wire, etc. The rotation transmission structure may be coated with a resin layer or the like depending on the medical device to be used. [Explanation of symbols]

[0079] 10 Catheter 11 Shaft section 11A Tip 12 Tip 13 Connectors 20,220,320,420,520 Rotation transmission structure 21 First area (predetermined area) 22 Other Areas (Second Area) 23 Intermediate area 30 Coil body 31 Wire 32 Gap 34 Outer surface 34A Virtual cylindrical surface 35 Inner peripheral surface 35A Virtual cylindrical surface 40,240,340,440,640 Reinforcement 41, 241, 341, 441 Connections (connections arranged in a designated area) 42,242,342,442 connectors (connectors located in other regions) 243 Connection 510 Guidewire 511 Core shaft S1, S2, S3, S4 Spiral shape

Claims

1. A coil body formed by winding a wire; a reinforcing body that connects adjacent wires of the coil body, A rotational transmission structure characterized in that the reinforcing member is arranged so that the rigidity of a predetermined region in the longitudinal direction of the coil body in a state in which the wires are connected is lower than the rigidity of other regions.

2. The reinforcing body is configured by a plurality of connection parts provided at each portion connecting the wires, 2. The rotation transmission structure according to claim 1, wherein the plurality of connection portions are arranged more sparsely in the predetermined region than in the other regions.

3. The plurality of connection portions are arranged along an imaginary spiral shape, 3. The rotation transmission structure according to claim 2, wherein the pitch of the spiral shape in the predetermined region is larger than the pitch of the spiral shape in the other region.

4. The reinforcing body is configured by a plurality of connection parts provided at each portion connecting the wires, 4. The rotation transmission structure according to claim 1, wherein the Young's modulus of the material of the connection portion disposed in the specified region is smaller than the Young's modulus of the material of the connection portion disposed in the other region.

5. The reinforcing body is configured by a plurality of connection parts provided at each portion connecting the wires, 5. The rotation transmission structure according to claim 1, wherein the plurality of connection portions are arranged along an imaginary spiral shape in a direction opposite to a winding direction of the coil body.

6. The reinforcing body is configured by a plurality of connection parts provided at each portion connecting the wires, 6. The rotation transmission structure according to claim 1, wherein the plurality of connection portions are arranged along an imaginary multiple spiral shape.

7. 7. The rotation transmission structure according to claim 1, wherein an outer diameter of the reinforcing member is equal to or smaller than a maximum outer diameter of the coil body.

8. 8. The rotation transmission structure according to claim 1, wherein an inner diameter of the reinforcing member is equal to or larger than a minimum inner diameter of the coil body.

9. A catheter comprising a shaft portion reinforced by the rotation transmission structure according to any one of claims 1 to 8, A catheter characterized in that the predetermined region in the rotation transmission structure is located closer to the tip side than the other region.

10. A guide wire comprising: the rotation transmission structure according to any one of claims 1 to 8; and a core shaft inserted into an inner cavity of the rotation transmission structure, The guidewire, wherein the predetermined region of the rotation transmission structure is located distally of the other region.

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