Guide wire, and atherectomy system

Abstract

To provide a guide wire capable of simplifying positioning of medical equipment inserted in vivo along the guide wire, and an atherectomy system.SOLUTION: A guide wire includes: an engaging body which has a core shaft, an open hole which is arranged on an end side of the core shaft and in which the core shaft is arranged, and an engaging part engaging an end part of an external device moving along the core shaft from a rear end side of the core shaft, and is movable along an axial direction of the core shaft; and a force imparting member which imparts to the engaging body a force in the direction heading for a specific position when it contacts the engaging body and the engaging body moves from the specific position on the core shaft.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a guidewire and an atherectomy system. [Background technology]

[0002] Guidewires are known as medical devices used to treat blood vessels, digestive organs, etc. Patent Document 1 discloses a technique in which a distal end stop is provided on a guidewire, and a medical device used in combination is prevented from moving distally beyond the distal end stop. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2005-527332 Summary of the Invention [Problem to be solved by the invention]

[0004] The conventional guidewire has room for improvement in terms of facilitating position adjustment within the body of a medical instrument that is inserted into the body along the guidewire. This problem also applies to an atherectomy system that includes a guidewire and an atherectomy device as a medical instrument.

[0005] The present invention has been made to solve the above-mentioned problems, and aims to provide a guidewire and an atherectomy system that can easily adjust the position inside the body of a medical device that is inserted into the body along the guidewire. [Means for solving the problem]

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

[0007] (1) One form of the present invention is a guide wire comprising: a core shaft; a through hole disposed on the tip side of the core shaft, with the core shaft disposed inside; and an engagement portion that engages with a tip portion of an external device that moves along the core shaft from the rear end side of the core shaft, the engagement portion being movable along the axial direction of the core shaft; and a force applying member that comes into contact with the engagement portion and applies a force to the engagement portion in a direction toward the specific position when the engagement portion moves from a specific position on the core shaft.

[0008] According to this configuration, the guidewire has an engaging body that engages with the external device. Since the engaging body is movable along the axial direction of the core shaft, it is possible to more easily adjust the position of the external device while controlling the movement of the external device. In addition, the guidewire has a force applying member that applies a force to the engaging body in a direction toward a specific position. When the engaging body moves from the specific position, the force applying member applies a force to return the engaging body to the specific position, thereby controlling the movement of the external device engaged with the engaging body.

[0009] (2) In the guidewire of the above embodiment, the inner diameter of the through hole may be smaller than the maximum outer diameter of the core shaft.

[0010] According to this configuration, when the external device passes through the maximum outer diameter portion located at the rear end side of the core shaft, the inner diameter of the through hole, which is smaller than the maximum outer diameter portion of the core shaft, is smaller than the inner diameter of the external device. Therefore, the clearance between the engagement body and the core shaft is smaller than the clearance between the external device and the core shaft. This makes it possible to suppress vibrations generated by the operation of the external device by the engagement body that engages with the external device.

[0011] (3) In the guidewire of the above aspect, the outer diameter of the rear end of the engagement body may be smaller than the maximum outer diameter of the core shaft.

[0012] With this configuration, when it is considered that the external device passes through the maximum outer diameter portion located on the rear end side of the core shaft, the outer diameter of the rear end of the engagement body, which is smaller than the maximum outer diameter portion of the core shaft, is smaller than the inner diameter of the external device. This allows the rear end of the engagement body to fit between the inner circumference of the external device and the outer circumference of the core shaft, maintaining a gap between the external device and the core shaft, and reducing wear of the core shaft caused by contact between the external device and the core shaft.

[0013] (4) In the guidewire of the above aspect, the engagement portion may be harder than the core shaft.

[0014] According to this configuration, since the engaging portion is harder than the core shaft, it is possible to reduce wear and the like that occurs when the engaging portion comes into contact with an external device.

[0015] (5) In the guidewire of the above aspect, the engaging portion may have an outer diameter that decreases more gradually from the distal end toward the proximal end.

[0016] According to this configuration, the engaging portion that comes into contact with the external device is formed so that the rate of decrease in the outer diameter increases from the tip side to the rear end side, thereby reducing the area of ​​contact between the external device and the engaging portion and reducing wear on the engaging portion.

[0017] (6) One aspect of the present invention is provided as an atherectomy system. This atherectomy system may include the guide wire of the above aspect, and an atherectomy device that moves along the core shaft from the rear end side of the core shaft and has a tip portion that engages with the engagement body.

[0018] According to this configuration, the atherectomy system includes the guidewire and the atherectomy device of the above-mentioned configuration. The atherectomy device, which rotates, slides, etc. on the guidewire, engages with the engaging body, thereby preventing the atherectomy device from unintentionally advancing toward the distal end, and further reduces wear caused by the atherectomy device coming into contact with the core shaft.

[0019] The present invention can be realized in various aspects, for example, in the form of a medical device, a treatment device, an atherectomy system, and a method for manufacturing a guidewire. [Brief description of the drawings]

[0020] [Figure 1] 1A and 1B are explanatory diagrams illustrating an overall configuration of a guidewire and a partial configuration of an external device according to a first embodiment. [Diagram 2] FIG. 2 is an explanatory diagram of a partial configuration of the guidewire and external device of the first embodiment. [Diagram 3] FIG. 2 is an explanatory diagram of a longitudinal section of a portion of the configuration of the guidewire and an external device according to the first embodiment. [Figure 4] FIG. 2 is an explanatory diagram of a longitudinal section of a portion of the configuration of the guidewire and an external device according to the first embodiment. [Diagram 5] FIG. 2 is an explanatory diagram of a cross section of the guide wire of the first embodiment. [Figure 6] FIG. 2 is an explanatory diagram of a longitudinal section of a portion of the configuration of the guidewire and an external device according to the first embodiment. [Figure 7] FIG. 11 is an explanatory diagram of a vertical cross section of a partial configuration of an external device of a guidewire according to a second embodiment. [Figure 8] FIG. 11 is an explanatory diagram of a vertical cross section of a partial configuration of an external device of a guidewire according to a third embodiment. [Figure 9] FIG. 13 is an explanatory diagram of a vertical cross section of a partial configuration of an external device of a guidewire according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] First Embodiment FIG. 1 is an explanatory diagram of the overall configuration of the guidewire 1A of the first embodiment and a partial configuration of the external device 80. FIG. 2 is an explanatory diagram of the guidewire 1A and a partial configuration of the external device 80. FIG. 3 and FIG. 4 are explanatory diagrams of longitudinal sections of the guidewire 1A and a partial configuration of the external device 80. FIG. 5 is a cross-sectional view taken along the line AA in FIG. 3. The sizes of the components of the guidewire 1A and the external device 80 shown in FIGS. 1 to 6 are illustrative 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 guidewire 1A and the external device 80 will be referred to as the "tip", and the portion including the "tip" and extending from the tip to the middle toward the rear end will be referred to as the "tip portion". Similarly, the end portion located on the rear end side of each component will be referred to as the "rear end", and the portion including the "rear end" and extending from the rear end to the middle toward the tip side will be referred to as the "rear end portion".

[0022] The guidewire 1A is a medical instrument that is inserted into blood vessels or digestive organs by a doctor or the like and used for treatment or examination, and includes a core shaft 10, a coil 20, a distal joint 30, a proximal joint 40, an engagement body 50, a distal coil 60, and a proximal coil 70. The external device 80 is a medical device that is inserted into the body along the guidewire 1A, and includes a rotor 81 and a drive shaft 83. The external device 80 means a device separate from the guidewire 1A, and here, the external device 80 is configured as an atherectomy device for cutting and removing lesions formed in blood vessels. Here, a system including the guidewire 1A and the external device 80 is also called an atherectomy system. The external device 80 may be configured as a medical device other than an atherectomy device.

[0023] The core shaft 10 is a long member extending in the longitudinal direction of the guidewire 1A. The core shaft 10 has a small diameter section 11 provided at the tip side and a large diameter section 12 provided at the rear end side. The outer diameter of the small diameter section 11 is smaller than the outer diameter of the large diameter section 12. The large diameter section 12 is the part of the core shaft 10 with the largest outer diameter. The large diameter section 12 extends to the rear end of the guidewire 1A, and the external device 80 is first inserted into the body along the large diameter section 12.

[0024] The material of the core shaft 10 is not particularly limited, but may be, for example, stainless steel (SUS302, SUS304, SUS316, etc.), a superelastic alloy such as a Ni-Ti alloy, or a piano wire.

[0025] The coil 20 is a member formed from a thin wire that covers the outer periphery of the tip portion of the core shaft 10. The coil 20 covers the tip side portion of the small diameter portion 11, which is the portion with the smallest outer diameter. The tip portion of the coil 20 is joined to the tip of the core shaft 10 by a tip side joint portion 30. The rear end portion of the coil 20 is joined to a position rearward of the tip of the core shaft 10 by a rear side joint portion 40.

[0026] The material of the coil 20 is not particularly limited, but examples thereof include stainless steel (SUS302, SUS304, SUS316, etc.), superelastic alloys such as Ni-Ti alloys, piano wire, platinum, gold, tungsten, and alloys of these.

[0027] The material of the tip side joint portion 30 and the rear side joint portion 40 is not particularly limited, but examples thereof include metal solders such as silver solder, gold solder, zinc, Sn-Ag alloy, and Au-Sn alloy, and adhesives such as epoxy-based adhesives.

[0028] The engaging body 50 is a cylindrical member with which the distal end of the external device 80 inserted into the body along the guide wire 1A engages, and has a first through hole 51 and an engaging portion 52. The engaging body 50 is configured to be movable on the core shaft 10. As described later, the engaging body 50 has a distal coil 60 connected to the distal end side and a proximal coil 70 connected to the proximal end side. Therefore, the engaging body 50 can move back and forth along the axial direction of the core shaft 10 until the expansion and contraction of at least one of the coils reaches its limit. The engaging portion 52 stops at a position where the forces received by the distal coil 60 and the proximal coil 70 are balanced. This position is also called the "initial position" or "specific position". The initial position where the engaging body 50 is disposed is an example of the specific position in the claims. The engaging body 50 is substantially spherical, and at least the distal and proximal sides of the outer circumferential surface are formed by curved surfaces. This makes it possible to prevent the engaging body 50 from damaging the inside of the body. The engagement body 50 is not a sphere with a uniform distance from the center to the periphery, but a sphere that is long in one direction like an egg. Therefore, in the longitudinal section shown in Fig. 3, the outer edge of the engagement body 50 has a shape close to an ellipse. The first through hole 51 is formed so as to penetrate the engagement body 50 along the long axis direction of the engagement body 50. The first through hole 51 is an example of a through hole described in the claims.

[0029] The engaging portion 52 is formed at the rear end of the engaging body 50, and is the portion of the engaging body 50 that comes into contact with the tip end of the external device 80. The engaging portion 52 is formed by a curved surface, and has a shape in which the outer diameter decreases toward the rear end. The degree of decrease in the outer diameter of the engaging portion 52 increases toward the rear end. Since the outer peripheral surface of the engaging portion 52 is a curved surface, the outer edge of the engaging portion 52 forms a curve in the vertical cross section of the engaging portion 52 shown in FIG. 3. The curvature of the curve formed by the outer edge of the engaging portion 52 is greater than the curvature of the curve formed by the outer edge of the tip of the engaging body 50.

[0030] The material of the engaging body 50 is not particularly limited, but may be, for example, a material having excellent wear resistance such as a cemented carbide alloy. The material of the engaging portion 52 is also not particularly limited, but may be, for example, a material having excellent wear resistance such as a cemented carbide alloy, and the hardness of the material forming the engaging portion 52 is greater than the hardness of the material forming the core shaft 10.

[0031] The front end of the engagement body 50 is joined to the rear end of the front coil 60 , and the rear end is joined to the front end of the rear coil 70 .

[0032] The tip side coil 60 is formed of a thin wire that covers the outer periphery of the core shaft 10. The wire of the tip side coil 60 is wound loosely in a spiral shape to have gaps in the longitudinal direction. In other words, the pitch of the tip side coil 60 is larger than the wire diameter. The tip end of the tip side coil 60 is joined to the rear end joint 40. The rear end of the tip side coil 60 is joined to the tip end of the engagement body 50.

[0033] The rear end coil 70 is formed of a thin wire that covers the outer periphery of the core shaft 10. The wire of the rear end coil 70 is tightly wound in a spiral shape so that the gap in the longitudinal direction is small. In other words, the pitch of the rear end coil 70 is approximately the same as the wire diameter. The tip end of the rear end coil 70 is joined to the rear end of the engagement body 50. The rear end of the rear end coil 70 is joined to the outer periphery of the core shaft 10. The outer diameter of the rear end coil 70 is smaller than the diameter Dc1 of 82 of the external device 80.

[0034] When the engaging body 50 moves from the initial position to the tip side, the gaps between the wires of the tip side coil 60 shrink, so that the length of the tip side coil 60 in the long axis direction becomes smaller. When the wires of the tip side coil 60 come into contact with each other, the movement of the engaging body 50 to the tip side is restricted. In addition, the tip side coil 60 shrinks, and at the same time, the rear end coil 70 extends toward the tip side. The engaging body 50 joined to the rear end coil 70 is pulled toward the rear end as the rear end coil 70 tries to return to its original length. In addition, even if the engaging body 50 tries to move from the initial position to the rear end side, the gaps between the wires of the rear end coil 70 are small and the rear end coil 70 is wound tightly, so the movement of the engaging body 50 to the rear end side is restricted. The tip side coil 60 and the rear end coil 70 are examples of the force applying member described in the claims.

[0035] The rotating body 81 is provided at the tip of the external device 80, and a drive shaft 83 is connected to it. The rotating body 81 rotates by the rotation transmitted from the drive shaft 83. The rotating body 81 has a second through hole 82 for inserting the core shaft 10. The drive shaft 83 is a coil formed of a wire wound in a spiral shape. The tip of the drive shaft 83 is connected to the rear end of the rotating body 81. When the external device 80 is in use, the rear end of the drive shaft 83 extends outside the body and is connected to a controller or the like for a doctor or the like to operate the external device 80. The inner peripheral surface of the tip of the rotating body 81 is shaped to fit along the outer peripheral surface of the engagement portion 52.

[0036] When the external device 80 is inserted into the body along the guide wire 1A and advanced toward the distal end of the guide wire 1A, the rotating body 81 comes into contact with the engaging body 50. The rotating body 81 comes into contact with the engaging portion 52 in particular. When the external device 80 is advanced further toward the distal end, the rotating body 81 pushes the engaging body 50 toward the distal end. When the engaging body 50 moves toward the distal end, the distal coil 60 contracts, and the proximal coil 70 expands. The distal coil 60 tries to return to its original shape, thereby pushing the engaging body 50 back toward the proximal end. On the other hand, the proximal coil 70 tries to return to its original shape, thereby pulling the engaging body 50 back toward the proximal end. As a result, a force acts to maintain the engaging body 50 in its initial position. When the rotating body 81 pushes the distal coil 60, the gap between the wires of the distal coil 60 becomes smaller, and when the wires come into contact with each other, the shrinking of the distal coil 60 stops. This limits the movement of the engaging body 50 toward the distal end. In addition, when a force is applied that causes the engaging body 50 to move toward the rear end, such as by being pressed by the wall of a blood vessel, the dense wire of the rear end coil 70 limits the movement of the engaging body 50 toward the rear end.

[0037] The rotor 81 is driven (rotated) by power (rotational force) transmitted from the drive shaft 83. At this time, when the rotor 81 is driven (rotated), vibrations are generated in which the rotor 81 reciprocates in a direction along the core shaft 10 (front-rear direction) and in a direction perpendicular to the core shaft 10 (left-right direction and up-down direction). Conventionally, this vibration caused the rotor 81 to slide on the core shaft 10, and there was a risk that the core shaft 10 was scraped and broken due to friction. On the other hand, according to the guide wire 1A of this embodiment, the vibrations of the rotor 81 are transmitted to the tip-side coil 60 and the rear-end coil 70 via the engagement body 50, and are therefore attenuated by the restoring forces of the tip-side coil 60 and the rear-end coil 70. This reduces the risk that the core shaft 10 will break due to friction with the rotor 81.

[0038] FIG. 6 is an explanatory diagram of a longitudinal cross section of a portion of the configuration of the guidewire 1A and the external device 80 according to the first embodiment.

[0039] The first through hole 51 is formed to penetrate the engagement body 50 along the long axis direction of the engagement body 50. The diameter Db1 of the first through hole 51 is substantially the same in the long axis direction. The diameter Db1 of the first through hole 51 is larger than the outer diameter Da1 of the small diameter portion 11. The diameter Db1 of the first through hole 51 is smaller than the outer diameter Da2 of the large diameter portion 12. Since the external device 80 is inserted from the rear end side of the guidewire 1A along the large diameter portion 12, the diameter Dc1 of the second through hole 82 of the external device 80 is larger than the outer diameter Da2 of the large diameter portion 12. As a result, the diameter Db1 of the first through hole 51, which is smaller than the outer diameter Da2 of the large diameter portion 12, is smaller than the diameter Dc1 of the second through hole 82. Therefore, the clearance between the engagement body 50 and the core shaft 10 is smaller than the clearance between the external device 80 and the core shaft 10. This makes it difficult for the external device 80 to directly contact the surface of the core shaft 10, and makes it possible to stably push the external device 80 along the axis of the core shaft 10 while suppressing the generation of friction.

[0040] The outer diameter Db2 of the rear end of the engagement body 50 is smaller than the outer diameter Da2 of the large diameter portion 12. Since the external device 80 is inserted from the rear end side of the guidewire 1A along the large diameter portion 12, the diameter Dc1 of the second through hole 82 of the external device 80 is larger than the outer diameter Da2 of the large diameter portion 12. As a result, the outer diameter Db2 of the rear end of the engagement body 50, which is smaller than the outer diameter Da2 of the large diameter portion 12, is smaller than the diameter Dc1 of the second through hole 82. As a result, when the external device 80 engages with the engagement body 50, a part of the rear end of the engagement body 50 enters the second through hole 82. As a result, a gap between the external device 80 and the core shaft 10 can be maintained, and wear of the core shaft 10 caused by the external device 80 contacting the core shaft 10 can be reduced.

[0041] According to the guidewire 1A of the present embodiment described above, the guidewire 1A has the engagement body 50 that is movable along the axial direction of the core shaft 10. Since the engagement body 50 is movable along the axial direction of the core shaft 10, it is possible to more easily adjust the position of the external device 80 while controlling the movement of the external device 80. For example, in the case where the engagement body 50 is fixed to the guidewire 1A, if the external device 80 moves further in the axial direction while engaged with the engagement body 50, the guidewire 1A also moves in the axial direction. This may cause the guidewire 1A to come off from the treatment site. On the other hand, since the engagement body 50 is movable relative to the guidewire 1A, the external device 80 can be moved in the axial direction together with the engagement part 52 while the position of the guidewire 1A is fixed at the treatment site during treatment. In other words, it is possible to prevent the entire guidewire 1A from moving toward the distal end unintentionally when the external device 80 pushes the engaging body 50 toward the distal end, or to prevent the entire guidewire 1A from moving toward the proximal end unintentionally when the external device 80 pulls the engaging portion 52 toward the proximal end. This reduces the possibility that the guidewire 1A will damage a blood vessel at the distal end or will slip out of the lesion toward the proximal end.

[0042] The guide wire 1A has a distal coil 60 and a proximal coil 70 as force applying members that apply a force to the engaging body 50 in a direction toward a specific position. When the engaging body 50 moves from a specific position, the distal coil 60 and the proximal coil 70 apply a force to return the engaging body 50 to the specific position, thereby controlling the movement of the external device 80 engaged with the engaging body 50. When the gap between the wires of the distal coil 60 becomes small and the wires come into contact with each other, the movement of the engaging body 50 toward the distal side can be restricted. This restricts the movement of the external device 80 toward the distal side unintentionally by the user, and prevents the external device 80 from riding on the coil 20. Since the wires of the proximal coil 70 are densely wound, the amount of contraction of the proximal coil 70 is small, so that the movement of the engaging body 50 toward the proximal side can be restricted even if a force is applied to move the engaging body 50 toward the proximal side. For example, if the engaging body 50 is fixed on the guidewire 1A and does not have a force applying member, the rotating body 81, which rotates and vibrates while operating, repeatedly comes into contact with the engaging body 50, causing the position of the guidewire 1A to deviate from the treatment site, making it difficult to adjust the position of the external device 80. In contrast, the guidewire 1A of this embodiment has a force applying member, which absorbs and attenuates the rotation and vibration of the rotating body 81. This reduces the force caused by the operation of the rotating body 81 that is transmitted to the entire guidewire 1A. Therefore, the guidewire 1A can be stably positioned at the treatment site, making it easy to adjust the position of the external device 80.

[0043] The diameter Db1 of the first through hole 51 of the engagement body 50 is smaller than the outer diameter Da2 of the large diameter portion 12 of the core shaft 10, which has the largest outer diameter. As a result, the diameter Db1 of the first through hole 51 is smaller than the diameter Dc1 of the second through hole 82 of the external device 80 inserted through the large diameter portion 12 of the core shaft 10. Therefore, the clearance between the engagement body 50 and the core shaft 10 is smaller than the clearance between the external device 80 and the core shaft 10. As a result, vibrations and the like generated in the engagement body 50 are suppressed by the contact between the inner circumferences of the core shaft 10 and the engagement body 50. That is, the width of the radial movement of the engagement body 50 relative to the core shaft 10 becomes relatively small. By engaging such an engagement body 50 with the external device 80, the width of the radial movement of the external device 80 relative to the core shaft 10 becomes small. As a result, vibrations and the like generated by the operation of the external device 80 can be suppressed by the engagement body 50 engaged with the external device 80. By suppressing vibrations of the external device 80, the external device 80 can travel along a stable path, improving the safety and efficiency of the procedure. In addition, it is possible to suppress the guidewire 1A from coming off the treatment site due to vibrations of the external device 80.

[0044] The outer diameter Db2 of the rear end of the engagement body 50 is smaller than the outer diameter Da2 of the large diameter portion 12 of the core shaft 10, which has the largest outer diameter. As a result, the outer diameter Db2 of the rear end of the engagement body 50 is smaller than the diameter Dc1 of the second through hole 82 of the external device 80 inserted through the large diameter portion 12 of the core shaft 10. As a result, the rear end of the engagement body 50 enters the second through hole 82, and a gap is maintained between the external device 80 and the core shaft 10, thereby reducing wear of the core shaft 10 caused by the external device 80 coming into contact with the core shaft 10. As a result, breakage of the core shaft 10 can be suppressed, improving the safety of treatment. In addition, the reduction in support force caused by a reduction in the rigidity of the core shaft 10 during use of the external device 80 can be suppressed.

[0045] The hardness of the engagement portion 52 is greater than the hardness of the core shaft 10. Since the engagement portion 52 is harder than the core shaft 10, it is possible to reduce wear caused by the contact of the engagement body 50 with the external device 80. This makes it possible to suppress the generation of metal chips caused by wear of the engagement body 50. Furthermore, if the shape of the engagement portion 52 changes, the frictional form between the engagement portion 52 and the external device 80 changes, and there is a risk of resistance being generated that inhibits the operation of the external device 80. Since the engagement portion 52 is less worn, it is possible to suppress the generation of resistance caused by contact between the engagement portion 52 and the external device, and the external device 80 can be operated stably.

[0046] The engagement portion 52 has a larger reduction in outer diameter from the tip side to the rear end side. This reduces the contact area between the external device 80 and the engagement portion 52, and reduces wear of the engagement portion 52. In particular, since the outer peripheral surface of the engagement portion 52 is formed by a curved surface and the reduction in outer diameter increases toward the rear end side, the curvature formed by the curve of the rear end of the engagement portion 52 in a vertical cross-sectional view is larger than the curvature formed by the curve of the tip of the engagement portion 52. This reduces the contact area between the outer peripheral surface of the engagement portion 52 and the external device 80, and reduces wear of the engagement portion 52. This suppresses the generation of metal chips due to wear of the engagement body 50. In addition, it is possible to reduce the possibility that the operation of the rotating body 81 is hindered due to a change in the shape of the engagement portion 52. In addition, it is possible to suppress a decrease in the operating efficiency of the external device 80 due to the engagement of the engagement portion 52 and the rotating body 81.

[0047] The atherectomy system may include a guidewire 1A and an external device 80 such as an atherectomy device. The atherectomy system includes the guidewire 1A, which allows easy position adjustment of the atherectomy device. In particular, when the guidewire 1A is inserted into a lesion and an atherectomy device is inserted along the guidewire 1A, the atherectomy device engaged with the engagement portion 52 can be moved in the axial direction even when the position of the guidewire 1A is fixed. Furthermore, the distal coil 60 and the proximal coil 70 limit unintended movement of the external device 80 by the user, so that an atherectomy system with excellent operability can be provided.

[0048] <Second embodiment> FIG. 7 is an explanatory diagram of a longitudinal cross section of a guidewire 1B and an external device 80 according to the second embodiment.

[0049] The guidewire 1B of the second embodiment differs from the guidewire 1A of the first embodiment in that it does not have a rear end coil 70. Descriptions of parts common to the first embodiment will be omitted.

[0050] The guidewire 1B does not have a member equivalent to the rear end coil 70 of the guidewire 1A of the first embodiment. For example, by setting the rigidity of the tip side coil 60 to be high, the force pushing the engagement body 50 back to the initial position becomes strong, and the movement of the engagement body 50 can be controlled only by the tip side coil 60. In the guidewire 1B, the engagement body 50 can also move along the axial direction of the core shaft 10, and the position of the external device 80 can be easily adjusted. In addition, since the tip side coil 60 is provided, it is possible to prevent the external device 80 from moving unintentionally to the tip side by the user and running onto the coil 20, etc. In addition, even if the engagement body 50 moves to the rear end side, the tip side coil 60 pulls the engagement body 50 to the tip side, thereby restricting the movement of the engagement body 50 to the rear end side.

[0051] <Third embodiment> FIG. 8 is an explanatory diagram of a longitudinal cross section of a guidewire 1C and an external device 80 according to the third embodiment.

[0052] The guidewire 1C of the third embodiment differs from the guidewire 1A of the first embodiment in that it does not have a distal coil 60. Descriptions of parts common to the first embodiment will be omitted.

[0053] The guidewire 1C does not have a member equivalent to the distal end coil 60 of the guidewire 1A of the first embodiment. For example, by setting the rigidity of the rear end coil 70 high, the force that tries to pull the engagement body 50 back to the initial position becomes strong, and the movement of the engagement body 50 can be controlled only by the rear end coil 70. In the guidewire 1C, the engagement body 50 can also move along the axial direction of the core shaft 10, and the position adjustment of the external device 80 can be easily performed. In addition, since the rear end coil 70 is provided, even if a force that tries to move the engagement body 50 to the rear end side is applied, the movement of the engagement body 50 to the rear end side can be restricted. In addition, even if the engagement body 50 moves to the distal end side, the rear end coil 70 pulls the engagement body 50 to the rear end side, so that the movement of the engagement body 50 to the distal end side can be restricted.

[0054] <Fourth embodiment> FIG. 9 is an explanatory diagram of a longitudinal cross section of a guidewire 1D and an external device 80 according to the fourth embodiment.

[0055] The guidewire 1D of the fourth embodiment differs from the guidewire 1A of the first embodiment in that it has a tip side elastic member 61 and a rear side elastic member 71. Descriptions of parts common to the first embodiment will be omitted.

[0056] The guidewire 1D has a distal elastic member 61 and a rear elastic member 71. The distal elastic member 61 and the rear elastic member 71 are made of an elastic resin material that expands and contracts in the longitudinal direction of the guidewire 1D. The distal end of the distal elastic member 61 is joined to the rear joint 40, and the rear end is joined to the distal end of the engagement body 50. The distal end of the rear elastic member 71 is joined to the rear end of the engagement body 50, and the rear end is joined to the outer periphery of the core shaft 10. In the guidewire 1D, the engagement body 50 is also movable along the axial direction of the core shaft 10, and the position of the external device 80 can be easily adjusted.

[0057] Each embodiment can be modified, including the examples shown below.

[0058] <Variation 1> The wire constituting the coils (coil 20, front end coil 60, rear end coil 70, drive shaft 83) included in each embodiment may be a solid wire or a twisted wire. Also, instead of the coil 20, a first coil covering the core shaft 10 and a second coil further covering the first coil may be provided. Also, the front end of the core shaft 10 may be covered by a metal or resin tube instead of the coil 20. Also, the coil 20 may not be provided.

[0059] <Variation 2> The distal coil 60 does not have to be joined to the core shaft 10 by the rear end joint portion 40. The distal coil 60 may be joined to the core shaft 10 by a joint portion other than the rear end joint portion.

[0060] <Modification 3> The rear end coil 70 may be wound sparsely so that there are gaps between the wires. Even if the rear end coil 70 is wound sparsely, for example, by setting the rigidity of the rear end coil 70 to be high, the amount of contraction of the rear end coil 70 can be reduced, and movement of the engagement body 50 toward the rear end can be restricted.

[0061] <Modification 4> The shape of the engagement body 50 does not have to be spherical, for example, the engagement body 50 may be cylindrical with an outer diameter that is substantially constant along the long axis direction. Also, the diameter Db1 of the first through hole 51 of the engagement body 50 does not have to be substantially constant in the long axis direction.

[0062] <Variation 5> The engaging body 50 and the external device 80 included in each embodiment may simply be in contact with each other, or may be engaged with each other. When engaging with each other, for example, a recess provided in the engaging body 50 and a protrusion provided at the tip of the external device 80 may be fitted together. [Explanation of symbols]

[0063] 1A, 1B, 1C, 1D...Guidewire 10...Core shaft 11…Small diameter part 12…Large diameter section 20…Coil 30…Tip side joint part 40…Rear side joint part 50...Engagement body 51...First through hole 52...Engagement portion 60…Tip coil 61... Tip elastic member 70…Rear end coil 71... Rear end elastic member 80…External device 81...Rotating body 82...Second through hole 83…Drive shaft Da1…Outer diameter of small diameter part Da2: Outside diameter of large diameter part Db1: Diameter of the first through hole Db2: Outer diameter of rear end of engagement body Dc1: Diameter of the second through hole

Claims

1. A guide wire, comprising: a core shaft; a engaging body disposed on the tip side of the core shaft, having a through hole with the core shaft disposed therein, and an engaging portion that engages with the tip of an external device that moves along the core shaft from the rear end side of the core shaft, the engaging body being movable along the axial direction of the core shaft; a force applying member that contacts the engaging body and applies a force in a direction toward the specific position to the engaging body when the engaging body moves from a specific position on the core shaft.

2. The guide wire according to claim 1, wherein the inner diameter of the through hole is smaller than the maximum outer diameter of the core shaft.

3. The guide wire according to claim 1 or claim 2, wherein the outer diameter of the rear end of the engaging body is smaller than the maximum outer diameter of the core shaft.

4. The guide wire according to claim 1 or claim 2, wherein the engaging portion is harder than the core shaft.

5. The guide wire according to claim 1 or claim 2, wherein the degree of decrease in the outer diameter of the engaging portion increases from the tip side toward the rear end side.

6. An atelectomy system, comprising: the guide wire according to claim 1 or claim 2; and an atelectomy device that moves along the core shaft from the rear end side of the core shaft and whose tip engages with the engaging body.

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