catheter

Abstract

To provide a catheter capable of inhibiting the catheter from sticking firmly to a wall of the lumen when causing the catheter to pass through a bent part of the lumen in the living body, and reducing a risk of damage to the lumen when a distal end part of the catheter inserted into the lumen in the living body hits a plaque or the like.SOLUTION: A catheter 1 includes an outer tube 10 having a distal end and a proximal end, which extends in a longitudinal axis direction, a first inner tube 20 disposed in a lumen of the outer tube 10, and a core wire 30 disposed in the lumen of the outer tube 10 and outside the first inner tube 20. When the core wire 30 is viewed in an observation direction, the core wire 30 includes a first section 40 which meanders in a width direction and which includes a plurality of maximum parts. In a main section 42 excluding 5% on both sides of a length in a longitudinal axis direction of the outer tube 10 of the first section 40, a shape of all specific regions 41 is a shape that can include a cross-sectional figure of the core wire 30 in the catheter.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a catheter used in a living body lumen such as a blood vessel such as a coronary artery, a digestive organ such as a bile duct or a pancreatic duct, a genital organ such as a fallopian tube, or a urinary organ such as a urethra.

Background Art

[0002] When a stenosis or occlusion is formed in a living body lumen, the movement of body fluids and cells moving within the lumen, such as blood, bile, pancreatic juice, sperm, fertilized eggs, urine, etc., is hindered, which causes various diseases and physical discomfort. Therefore, treatment using a catheter is performed to treat the stenosis or occlusion formed in the living body lumen. In order for the user to reach the affected area with the catheter, it is necessary to transmit the fine movements and forces applied by the user to the distal end of the catheter and pass through a complexly curved lumen.

[0003] Catheters have been developed that can efficiently transmit the pushing force applied by the user to the distal end of the catheter and can bend along the curved portions of blood vessels, bile ducts, pancreatic ducts, etc. For example, Patent Document 1 discloses a catheter including an outer tube, an inner tube inserted into the outer tube, a first core wire inserted between the outer tube and the inner tube and fixed to the outer tube or the inner tube, and a second core wire inserted in parallel with the first core wire and movable between the outer tube and the inner tube.

[0004] Patent Document 2 discloses a medical tube having a first tube through which a first guide wire is inserted, a second tube through which a second guide wire is inserted, an outer tube in whose lumen the first tube and the second tube are disposed, and a cylindrical member disposed on the outer periphery of the second tube, wherein a distal end of the first tube is disposed more distally than a distal end of the second tube, an axial midpoint of the cylindrical member is located more distally than a midpoint between a proximal end of the first tube and a distal end of the second tube, and the cylindrical member is not provided on the outer periphery of the first tube.

[0005] Patent Document 3 discloses a balloon catheter including a balloon that is inflated or deflated using a fluid, an outer shaft joined to a proximal end portion of the balloon and through which the fluid flows inside, and an inner shaft that is inserted across the inside of the outer shaft and the inside of the balloon and is joined to a distal end portion of the balloon, wherein the inner shaft has an extendable portion that can extend in the axial direction on the proximal end side of the joint portion with the balloon.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, the catheters described in Patent Documents 1 to 3 had room for improvement from the viewpoint of the operability of entering a curved tube in a living body.

[0008] The present invention has been made in view of the above circumstances, and an object thereof is to provide a catheter that can easily enter a curved tube in a living body.

Means for Solving the Problems

[0009] One embodiment of the catheter of the present invention that can solve the above problems includes an outer tube having a distal end and a proximal end and extending in the longitudinal axis direction, a first inner tube disposed in the lumen of the outer tube, and a core wire disposed in the lumen of the outer tube and outside the first inner tube. The core wire is in a direction perpendicular to the longitudinal axis direction of the outer tube, and when viewed from an observation direction that is the direction in which the sum of the areas of all specific regions defined by the following requirements is maximized and the longitudinal axis direction of the outer tube and the horizontal direction are parallel, the core wire has a first section that meanders in the width direction and has a plurality of maximum portions. In the main section excluding 5% of both ends of the length of the outer tube in the longitudinal axis direction in the first section, the gist lies in that the shape of all specific regions defined by the following requirements is a shape that can enclose the cross-sectional shape of the core wire. The cross-sectional shape of the core wire refers to the shape of a cross-section perpendicular to the major axis when the core wire is in a straight state. [Requirements] The specific region is a region surrounded by a straight line connecting two adjacent maximum portions in the longitudinal axis direction of the outer tube and the outer contour line of the core wire existing between the two maximum portions when the core wire is viewed from the observation direction.

[0010] The catheter is configured such that the shape of all specific regions existing in the main section of the core wire can enclose the cross-sectional shape of the core wire, so that the main section of the core wire can expand and contract in the longitudinal axis direction of the outer tube. When passing through the curved portion of the lumen in the living body, by the main section of the core wire expanding, it is possible to suppress the outer tube from strongly sticking to the tube wall. By suppressing strong sticking, the resistance force received by the catheter from the tube wall can be reduced, and the user can insert the catheter deeper with a small force. Also, when the distal end of the catheter inserted into the lumen in the living body hits a stenosis or plaque, etc., since the main section can contract to absorb the impact, the risk of the tube wall being damaged can also be reduced. Therefore, it is possible to easily and safely insert the catheter into the curved tube in the living body.

[0011] It is preferable that the average length of the straight line connecting the two maximum portions existing on the distal side is shorter than the average length of the straight line connecting the two maximum portions existing on the proximal side among the above main sections.

[0012] The core wire preferably has a portion where the length of the straight line connecting the two maximum portions existing in the main section becomes shorter from the proximal side toward the distal side.

[0013] The first section of the core wire preferably continues from the distal end of the core wire to a position at a length of 1 / 10 of the total length of the core wire from the distal end.

[0014] Another embodiment of the catheter of the present invention that can solve the above problems has an outer tube having a distal end and a proximal end and extending in the longitudinal axis direction, a first inner tube disposed in the lumen of the outer tube, and a core wire disposed in the lumen of the outer tube and outside the first inner tube. The core wire is in a direction perpendicular to the longitudinal axis direction of the outer tube, and when viewed from an observation direction that is the direction in which the sum of the areas of all specific regions defined by the following requirements is maximized and the longitudinal axis direction of the outer tube and the horizontal direction are parallel, the core wire has a first section that meanders in the width direction and has a plurality of maximum portions. The gist lies in that the first section can contract by 0.5% or more compared to the length of the first section in the longitudinal axis direction of the outer tube in a state where no external force is applied to the core wire. [Requirements] The specific region is a region surrounded by a straight line connecting two adjacent maximum portions in the longitudinal axis direction of the outer tube and the outer contour line of the core wire existing between the two maximum portions when the core wire is viewed from the observation direction.

[0015] As described above, by configuring the first section to be able to contract by 0.5% or more compared to the length of the first section in the longitudinal axis direction of the outer tube in a state where no external force is applied to the core wire, the first section of the core wire can expand and contract in the longitudinal axis direction of the outer tube. When passing through the curved portion of the lumen in the living body, the first section of the core wire can extend to suppress the outer tube from strongly adhering to the tube wall. By suppressing strong adhesion, the resistance force received by the catheter from the tube wall can be reduced, and the user can insert the catheter deeper with a small force. Also, when the distal end of the catheter inserted into the lumen in the living body hits a plaque or the like, the first section can contract to absorb the impact, so that the risk of damaging the tube wall can be reduced. Therefore, it is possible to easily and safely insert the catheter into the curved tube in the living body.

[0016] The distal end of the core wire is preferably located on the distal side of the central position of the outer tube.

[0017] The distal end of the core wire is preferably fixed to the outer tube or the first inner tube.

[0018] The distal end of the first section is preferably fixed to the outer tube or the first inner tube.

[0019] The catheter further has a hub at the proximal end of the outer tube, and the proximal end of the core wire is preferably fixed to at least one of the outer tube, the first inner tube, and the hub.

[0020] The catheter further has a hub at the proximal end of the outer tube, and the proximal end of the first section is preferably fixed to at least one of the outer tube, the first inner tube, and the hub.

[0021] The core wire preferably has a coil portion in which the core wire is spirally wound in the first section, and the first inner tube is disposed in the inner cavity of the coil portion.

[0022] The catheter preferably includes a second inner tube disposed outside the inner cavity of the outer tube and outside the first inner tube, and the first section is disposed between the first inner tube and the second inner tube.

Advantages of the Invention

[0023] According to the catheter of the present invention, when passing through a curved portion of a lumen in a living body, the main section or the first section of the core wire extends, thereby suppressing the outer tube from strongly adhering to the tube wall. By suppressing strong adhesion, the resistance force received by the catheter from the tube wall can be reduced, and the user can insert the catheter deeper with a small force. Further, when the distal end of the catheter inserted into the lumen in the living body hits a stenosis or plaque, etc., the main section or the first section can contract to absorb the impact, so that the risk of damaging the tube wall can also be reduced. Therefore, it is possible to easily and safely insert the catheter into a curved tube in a living body.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

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Figure 7

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Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

[0025] The present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to the illustrated examples, and appropriate modifications may be made within the scope of the spirit described above and below, and all such modifications are within the technical scope of the present invention. In the drawings, hatching and symbols may be omitted for convenience. In such cases, reference should be made to the specification and other drawings. Furthermore, the dimensions of various parts in the drawings may differ from the actual dimensions, as priority is given to helping understand the features of the present invention.

[0026] One embodiment of the catheter of the present invention comprises an outer tube having a distal end and a proximal end and extending in a longitudinal direction, a first inner tube disposed in the lumen of the outer tube, and a core wire disposed in the lumen of the outer tube and outside the first inner tube, wherein when the core wire is viewed in an observation direction perpendicular to the longitudinal axis of the outer tube and parallel to the horizontal direction, in which the sum of the areas of all specific regions defined by the following requirement is maximized, the core wire has a first section that meanders in the width direction and has multiple maximum portions, and in a main section of the first section, excluding 5% on each end of the length of the outer tube in the longitudinal direction, all of the specific regions defined by the following requirement have shapes that can contain the cross-sectional shape of the core wire: Note that the cross-sectional shape of the core wire refers to the shape of a cross section perpendicular to the long axis when the core wire is straight. [Requirement] The specific region is a region surrounded by a straight line connecting two maximum portions adjacent to each other in the longitudinal axis direction of the outer tube and the outer contour line of the core wire existing between the two maximum portions when the core wire is viewed from the observation direction.

[0027] The catheter according to the embodiment of the present invention is configured such that the shape of all specific regions existing in the main section of the core wire is a shape that can enclose the cross-sectional shape of the core wire, so that the main section of the core wire can expand and contract in the longitudinal axis direction of the outer tube. When passing through a curved portion of a lumen in a living body, by the main section of the core wire expanding, it is possible to suppress the outer tube from strongly sticking to the tube wall. By suppressing strong sticking, the resistance force received by the catheter from the tube wall can be reduced, and the user can insert the catheter deeper with a small force. Further, when the distal end of the catheter inserted into the lumen in a living body hits a stenosis or plaque, etc., the main section can contract to absorb the impact, so that the risk of damaging the tube wall can also be reduced. Therefore, it is possible to easily and safely insert the catheter into a curved tube in a living body. When the core wire is linear and extends along the longitudinal axis direction of the outer tube, when the catheter passes through a curved portion of the lumen in a living body and the core wire tries to follow the curvature of the outer tube, the outer surface of the core wire contacts the inner surface that hits the outside of the curve of the outer tube. According to the movement of this core wire, the outer surface of the outer tube of the catheter may come into contact with the tube wall that hits the outside of the curve of the tube in the living body and stick. On the other hand, the core wire provided in the catheter according to the embodiment of the present invention can follow the curvature of the lumen by the main section of the core wire expanding when passing through the curved portion of the lumen, so that the core wire can be made less likely to stretch in the curved portion of the lumen in a living body.

[0028] With reference to FIGS. 1 to 6, the overall configuration of the catheter will be described. FIG. 1 shows an enlarged cross-sectional view (partial side view) of the distal side of the catheter according to an embodiment of the present invention. FIG. 2 shows a cross-sectional view taken along line II-II of the catheter shown in FIG. 1. FIG. 3 shows a side view of the core wire shown in FIG. 1. FIG. 4 shows a cross-sectional view (partial side view) showing a modified example of the catheter according to an embodiment of the present invention. FIG. 5 shows a cross-sectional view taken along line V-V of the catheter shown in FIG. 4. FIG. 6 shows a side view of the core wire shown in FIG. 4. FIGS. 1, 2, 4, and 5 show a configuration example of a catheter 1 including an outer tube 10, a first inner tube 20 disposed in the lumen of the outer tube 10, and a core wire 30 disposed in the lumen of the outer tube 10 and outside the first inner tube 20. In each drawing, the right side of the paper surface corresponds to the distal side of the catheter, and the left side of the paper surface corresponds to the proximal side of the catheter.

[0029] In this specification, the proximal side refers to the side closer to the user's hand with respect to the extending direction of the outer tube 10, and the distal side refers to the opposite side of the proximal side, that is, the side to be treated. Further, the extending direction of the outer tube 10 is referred to as the longitudinal axis direction. The radial direction refers to the radial direction of various tubes, and in this specification, the inner side refers to the radial direction toward the axial center side of various tubes, and the outer side refers to the direction opposite to the inner side.

[0030] The outer tube 10 has a distal end and a proximal end and extends in the longitudinal axis direction. The outer tube 10 may have a plurality of lumens, but preferably has only one lumen. The lumen of the outer tube 10 extends in the longitudinal axis direction of the outer tube 10. The shape of the outer tube 10 is not particularly limited as long as there is a lumen, and for example, it can be in the shape of a hollow cylindrical column, a hollow polygonal column, or the like. Hereinafter, a cross-section perpendicular to the longitudinal axis direction of the lumen of the outer tube 10 is referred to as a lumen cross-section.

[0031] The shape of the lumen cross-section of the outer tube 10 is not particularly limited, and for example, it can be circular, oval, polygonal, star-shaped, or a combination of these shapes. The oval shape includes an elliptical shape, an egg shape, and a rounded rectangular shape.

[0032] The outer tube 10 is preferably flexible, which allows the outer tube 10 to be deformed to conform to the shape of the vessel in the living body. In addition, the outer tube 10 is preferably elastic in order to maintain its shape.

[0033] The outer tube 10 may be a hollow body formed by arranging one or more wires in a predetermined pattern; a hollow body having a resin coating on at least one of the inner and outer surfaces; a resin tube; or a combination of these, for example, a combination of these connected in the longitudinal direction. Examples of hollow bodies having wires arranged in a predetermined pattern include cylindrical bodies having a mesh structure formed by simply crossing or weaving wires, and coils formed by winding wires. The wires may be one or more solid wires or one or more twisted wires. The resin tube can be manufactured, for example, by extrusion molding.

[0034] Examples of materials constituting the outer tube 10 include synthetic resins such as polyolefin resins such as polyethylene and polypropylene, polyamide resins such as nylon, polyester resins such as PET, aromatic polyether ketone resins such as PEEK, polyether polyamide resins, polyurethane resins, polyimide resins, fluorine-based resins such as PTFE, PFA, and ETFE, and polyvinyl chloride resins, as well as metals such as stainless steel, carbon steel, and nickel-titanium alloys.

[0035] The outer tube 10 may have a single-layer structure or a multi-layer structure. When the outer tube 10 has a multi-layer structure, for example, the outer tube 10 may have a resin tube that forms an intermediate layer made of a metal braid such as stainless steel, carbon steel, or a nickel-titanium alloy.

[0036] When the catheter 1 is used in the coronary artery, the inner diameter of the outer tube 10 is preferably 0.4 mm or more, more preferably 0.45 mm or more, and even more preferably 0.5 mm or more. When the catheter 1 is used in the coronary artery, the inner diameter of the outer tube is preferably 1.5 mm or less, more preferably 1.25 mm or less, and even more preferably 1 mm or less. When the inner cavity cross-sectional shape of the outer tube 10 is other than circular, the diameter of the inscribed circle of the inner cavity cross-sectional shape is taken as the inner diameter of the outer tube 10.

[0037] As shown in FIG. 4, the outer tube 10 may have a tip chip 12 at its distal end. The tip chip 12 is a lid-like member provided at the distal end of the outer tube 10 and does not necessarily block the entire distal end of the outer tube 10. For example, as shown in FIG. 4, the tip chip 12 may have a hole formed therein. Although not shown, the distal end of the outer tube 10 may be blocked by the tip chip 12. By having the tip chip 12 on the outer tube 10, it is possible to suppress moisture such as blood from entering the inner cavity of the outer tube 10 when the catheter 1 is used. In addition, the tip chip 12 serves as a guide at the tip of the catheter 1, and it is also possible to improve the insertability of the catheter 1. The material constituting the tip chip 12 is not particularly limited. For example, the material constituting the aforementioned outer tube 10 can be used. Note that, without providing the tip chip 12 at the distal end of the outer tube 10, the opening at the distal end of the outer tube 10 may be blocked by heat-sealing the distal end of the outer tube 10 or the like.

[0038] As shown in FIGS. 1, 2, 4, and 5, the first inner tube 20 is disposed in the inner cavity of the outer tube 10. The outer tube 10 and the first inner tube 20 may or may not be fixed to each other. The method of fixing when they are fixed is not particularly limited, and examples include connection by welding, soldering, adhesion with an adhesive, etc. The first inner tube 20 may or may not move in the longitudinal axis direction with respect to the outer tube 10.

[0039] The shape of the first inner tube 20 is not particularly limited as long as it has a lumen. For example, it can be in the shape of a hollow cylinder, a hollow polygonal column, or the like. The first inner tube 20 may have a plurality of lumens, but preferably has only one lumen. The lumen of the first inner tube 20 preferably extends in the longitudinal axis direction of the outer tube 10.

[0040] The shape of the cross-section of the lumen of the first inner tube 20 is not particularly limited. For example, it can be circular, oval, polygonal, star-shaped, or a combination of these shapes. Note that the oval shape includes elliptical, egg-shaped, and rounded rectangular shapes.

[0041] The first inner tube 20 preferably has flexibility. This allows the first inner tube 20 to also deform when deforming the outer tube 10 along the shape of the tube in the living body. Also, for shape retention, the first inner tube 20 preferably has elasticity.

[0042] The first inner tube 20 is a hollow body formed by arranging one or more wire rods in a predetermined pattern; a hollow body with resin coated on at least one of the inner surface or the outer surface of the hollow body; a resin tube; or a combination thereof, for example, those connected in the longitudinal axis direction. Examples of the hollow body with wire rods arranged in a predetermined pattern include a cylindrical body having a mesh structure formed by simply crossing or knitting the wire rods, and a coil formed by winding the wire rods. The wire rod may be one or more single wires or one or more stranded wires. The resin tube can be manufactured, for example, by extrusion molding.

[0043] As the material constituting the first inner tube 20, the same synthetic resin, metal, etc. as those of the outer tube 10 can be used. The materials of the first inner tube 20 and the outer tube 10 may be the same or different.

[0044] The first inner tube 20 may have a single-layer structure or a multi-layer structure. When the first inner tube 20 has a multi-layer structure, for example, a structure using a metal braid such as stainless steel, carbon steel, or nickel-titanium alloy can be adopted as the intermediate layer of the resin tube constituting the first inner tube 20.

[0045] As shown in FIGS. 1, 2, 4, and 5, the core wire 30 is disposed in the inner cavity of the outer tube 10 and outside the first inner tube 20. Only one core wire 30 may be disposed in the inner cavity of the outer tube 10 and outside the first inner tube 20, or a plurality of core wires 30 may be disposed.

[0046] The core wire 30 is a single-wire or stranded linear member. As the core wire 30, metal wire materials such as stainless steel, carbon steel, and nickel-titanium alloy, polyolefin resins such as polyethylene and polypropylene, polyamide resins such as nylon, polyester resins such as PET, aromatic polyether ketone resins such as PEEK, polyether polyamide resins, polyurethane resins, polyimide resins, fluorine resins such as PTFE, PFA, and ETFE, and threads formed from synthetic resins such as polyvinyl chloride resins can be used. The core wire 30 may have a structure combining a metal material and a synthetic resin material. For example, a braided product of a metal wire and a synthetic resin wire or a resin-coated metal wire can be used. Among the materials constituting the core wire 30, a metal wire is preferably used, and stainless steel is more preferably used. By configuring the core wire 30 in this way, it is possible to make it difficult for the core wire 30 to be damaged or deformed even when the core wire 30 is repeatedly bent.

[0047] The core wire 30 preferably has flexibility. Thereby, the core wire 30 can be deformed along the shape of the tube in the living body. Further, for shape retention, the core wire 30 preferably has elasticity.

[0048] In order to make it easier to deform on the distal side, the core wire 30 preferably has a portion where the rigidity decreases from the proximal side toward the distal side, and more preferably, the entire core wire 30 continuously decreases in rigidity from the proximal side toward the distal side. Further, it is also preferable that the outer diameter of the core wire 30, that is, the thickness of the core wire 30, becomes thinner from the proximal side toward the distal side.

[0049] The cross-sectional shape of the core wire 30 is not particularly limited, and for example, it can be circular, oval, polygonal, star-shaped, or a combination of these shapes. The oval shape includes elliptical, egg-shaped, and rounded rectangular shapes. The cross-sectional shape of the core wire 30 refers to the shape of the cross-section perpendicular to the major axis when the core wire 30 is in a straight state.

[0050] The core wire 30 may be fixed to the inner surface of the outer tube 10, or the core wire 30 may be fixed to the outer surface of the first inner tube 20.

[0051] Preferably, at least a part of the core wire 30 is movable in the longitudinal axis direction with respect to the outer tube 10. It is also preferable that at least a part of the core wire 30 is movable in the longitudinal axis direction with respect to the first inner tube 20.

[0052] The core wire 30 may be partially present from the proximal end to the middle of the outer tube 10 toward the distal end, or between the distal end of the outer tube 10 and the proximal end of the outer tube 10. Further, the core wire 30 may be present without interruption from the distal end of the outer tube 10 to the proximal end of the outer tube 10.

[0053] As shown in FIGS. 1, 3, 4, and 6, when the core wire 30 is viewed from an observation direction that is perpendicular to the longitudinal axis direction of the outer tube 10, is in the direction in which the sum of the areas of all the specific regions 41 specified as follows is maximized, and in which the longitudinal axis direction of the outer tube 10 and the horizontal direction are parallel, the core wire 30 has a first section 40 that meanders in the width direction and has a plurality of maximum portions. The observation direction is perpendicular to the longitudinal axis direction of the outer tube 10, is in the direction in which the sum of the areas of all the specific regions 41 is maximized, and in which the longitudinal axis direction of the outer tube 10 and the horizontal direction are parallel. When the core wire 30 is viewed from the observation direction, as shown in FIGS. 1, 3, 4, and 6, the portion where the shape of the core wire 30 changes from rising to the right to falling to the right is the maximum portion. Note that when the core wire 30 is viewed from the observation direction, the portion where the shape of the core wire 30 changes from falling to the right to rising to the right is the minimum portion 32. As shown in FIGS. 1, 3, 4, and 6, the specific region 41 is a region surrounded by a straight line 31 connecting adjacent maximum portions 30a and 30b and the outer contour line of the core wire 30 existing between the maximum portions 30a and 30b when the core wire 30 is viewed from the observation direction. Note that when observing the specific region 41, it is observed from the observation direction without applying an external force to the core wire 30. Furthermore, the observation direction is the direction in which the longitudinal axis direction of the outer tube 10 and the horizontal direction are parallel, or in other words, the direction when the longitudinal axis direction of the outer tube 10 is the left - right direction of the observer. For example, FIG. 1 is a drawing when the core wire 30 is observed from the observation direction. In FIG. 1, the maximum portion of the core wire 30 is a portion that is parallel to the paper surface and convex upward, and the minimum portion is a portion that is parallel to the paper surface and convex downward.

[0054] As shown in FIGS. 1, 3, 4, and 6, the catheter 1 according to the embodiment of the present invention has, in the main section 42 of the first section 40 excluding 5% at both ends in the longitudinal axis direction of the outer tube 10, the shape of all specific regions 41 when the core wire 30 is viewed from the observation direction is a shape that can enclose the cross-sectional shape of the core wire 30. Here, the cross-sectional shape of the core wire 30 refers to the shape of a cross-section perpendicular to the major axis when the core wire 30 is in a straight state. When the cross-sectional shape of the core wire 30 is not constant, that is, when the cross-sectional shape of the core wire 30 varies depending on the location, the cross-sectional shape with the smallest area among the cross-sectional shapes of the core wire 30 in the main section 42 is defined as the cross-sectional shape of the core wire 30 here. By configuring the shape of all specific regions 41 to be a shape that can enclose the cross-sectional shape of the core wire 30, the main section 42 can expand and contract in the longitudinal axis direction of the outer tube 10. When passing through the curved portion of the lumen in the living body, the main section 42 of the core wire 30 can extend, thereby suppressing the outer tube 10 from strongly adhering to the tube wall. By suppressing strong adhesion, the resistance force received by the catheter 1 from the tube wall can be reduced, and the user can insert the catheter 1 deeper with a small force. Further, when the distal end of the catheter 1 inserted into the lumen in the living body hits a stenosis or plaque, etc., the main section 42 can contract to absorb the impact, so that the risk of damaging the tube wall can also be reduced. Therefore, it is possible to easily and safely insert the catheter 1 into the curved tube in the living body.

[0055] It exists in the first section 40, and the length of the straight line 31 connecting the maximum portions adjacent to each other in the longitudinal axis direction of the outer tube 10 may be constant or may vary. Here, the fact that the length of the straight line 31 connecting the maximum portions adjacent to each other in the longitudinal axis direction of the outer tube 10 is constant includes a mode in which the length of the straight line 31 connecting the maximum portions adjacent to each other in the longitudinal axis direction of the outer tube 10 fluctuates within ±10%.

[0056] The first section 40 may have a portion where the straight lines 31 connecting adjacent maximum portions in the longitudinal axis direction of the outer tube 10 are the same length, and a portion where the straight lines 31 connecting adjacent maximum portions in the longitudinal axis direction of the outer tube 10 are different lengths.

[0057] A part of the core wire 30 may have the first section 40. Furthermore, one core wire 30 may have only one first section 40, or may have two or more first sections 40. The core wire 30 may have a portion that does not meander in the width direction of the core wire 30, i.e., a straight portion.

[0058] The proximal end 402 of the first section 40 may coincide with the proximal end 302 of the core wire 30, and the distal end 401 of the first section 40 may coincide with the distal end 301 of the core wire 30. The first section 40 may extend throughout the entire core wire 30, thereby providing flexibility to the entire core wire 30.

[0059] As an embodiment of the first section 40, a wave-shaped embodiment is shown in Figs. 1 and 3. When the first section 40 has a wave shape, the wave amplitude may decrease toward the distal side in only a part of the first section 40 in the longitudinal axial direction of the outer tube 10. The wave amplitude may increase toward the distal side in only a part of the first section 40 in the longitudinal axial direction of the outer tube 10. The wave amplitude may decrease toward the distal side throughout the entire first section 40 in the longitudinal axial direction of the outer tube 10. The wave amplitude may increase toward the distal side throughout the entire first section 40 in the longitudinal axial direction of the outer tube 10. The wave period may decrease toward the distal side in only a part of the first section 40 in the longitudinal axial direction of the outer tube 10. The wave period may increase toward the distal side in only a part of the first section 40 in the longitudinal axial direction of the outer tube 10. The wave period may decrease toward the distal side throughout the entire first section 40 in the longitudinal axial direction of the outer tube 10. In the longitudinal direction of outer tube 10, the wave period may increase distally throughout first section 40.

[0060] Next, the configuration of the catheter and the core wire provided in the catheter will be described in more detail with reference to FIGS. 7 to 14 in addition to FIGS. 1 to 6. FIG. 7 is a side view showing a modified core wire provided in a catheter according to an embodiment of the present invention. FIG. 8 is a side view showing another modified core wire provided in a catheter according to an embodiment of the present invention. FIG. 9 is a cross-sectional view (partially a side view) showing a modified catheter according to an embodiment of the present invention. FIG. 10 is a side view showing a modified catheter according to an embodiment of the present invention. FIG. 11 is a side view showing another modified core wire provided in a catheter according to an embodiment of the present invention. FIG. 12 is a side view showing another modified core wire provided in a catheter according to an embodiment of the present invention. FIG. 13 is a side view showing another modified core wire provided in a catheter according to an embodiment of the present invention. FIG. 14 is a perspective cross-sectional view showing another modified catheter according to an embodiment of the present invention.

[0061] 7, it is preferable that the average length of the straight lines 31 connecting two local maximum portions located on the distal side of the main section 42 is shorter than the average length of the straight lines 31 connecting two local maximum portions located on the proximal side of the main section 42. In other words, the average length of the straight lines 31 connecting two local maximum portions located in the distal half of the main section 42 and adjacent in the longitudinal axis direction of the outer tube 10 is shorter than the average length of the straight lines 31 connecting two local maximum portions located in the proximal half of the main section 42 and adjacent in the longitudinal axis direction of the outer tube 10, which makes it easier for the core wire 30 to bend finely on the distal side of the main section 42, thereby improving the steerability of the catheter 1 within a curved vessel.

[0062] It is preferable that the first section 40 has a portion where the axial length of the core wire 30 existing between two maximum diameter portions adjacent in the longitudinal axis direction of the outer tube 10 becomes shorter from the proximal side toward the distal side. Also, it is preferable that the axial length of the core wire 30 existing between two maximum diameter portions adjacent in the longitudinal axis direction of the outer tube 10 becomes shorter from the proximal side toward the distal side throughout the entire first section 40. Here, the axial length of the core wire 30 refers to the length of the path of the core wire 30 and refers to the length when the core wire 30 is in a straight state. With such a configuration, the core wire 30 can be easily and finely curved on the distal side of the first section 40, and the catheter 1 can be easily made thinner, so that the operability of the catheter 1 in a curved tube can be improved.

[0063] As shown in FIG. 7, it is preferable that the core wire 30 has a portion where the length of the straight line 31 connecting two maximum diameter portions adjacent in the longitudinal axis direction of the outer tube 10 existing in the main section 42 becomes shorter from the proximal side toward the distal side. Thereby, since it becomes easy to finely curve on the distal side of the main section 42, the operation in a thin tube in the living body can be facilitated.

[0064] As shown in FIG. 7, it is preferable that the core wire 30 has a portion where the length of the straight line 31 connecting two maximum diameter portions adjacent in the longitudinal axis direction of the outer tube 10 existing in the first section 40 becomes shorter from the proximal side toward the distal side. Thereby, since it can be easily and finely curved on the distal side of the first section 40, the operation in a thin tube in the living body can be facilitated. Note that the core wire 30 can also be configured such that the length of the straight line 31 connecting two maximum diameter portions adjacent in the longitudinal axis direction of all the outer tubes 10 existing in the first section 40 becomes shorter from the proximal side toward the distal side.

[0065] As shown in FIG. 8 , the first section 40 of the core wire 30 preferably extends from the distal end 301 of the core wire 30 to a position 400 that is 1 / 10 of the total length of the core wire 30 from the distal end 301. If the core wire 30 extends in a substantially straight line in the longitudinal direction of the outer tube 10 from the distal end 301 to the position 400 that is 1 / 10 of the total length of the core wire 30 from the distal end 301, the distal end 301 may strike the outer tube 10 and break through it. By having the first section 40 extend at least from the distal end 301 of the core wire 30 to the position 400 that is 1 / 10 of the total length of the core wire 30 from the distal end 301, the portion of the first section 40 other than the distal end 301 is more likely to come into contact with the outer tube 10. This reduces the risk that the distal end 301 of the core wire 30 will accidentally break through the outer tube 10. Here, the total length of the core wire 30 refers to the length in the longitudinal direction of the outer tube 10 in the section in which the core wire 30 exists, and does not refer to the axial length of the core wire 30, i.e., the path length.

[0066] 9, the distal end 301 of the core wire 30 is preferably located distal to the central position 11 of the outer tube 10. The central position 11 of the outer tube 10 refers to the central portion of the length of the outer tube 10 in the longitudinal direction. By locating the distal end 301 of the core wire 30 distal to the central position 11 of the outer tube 10, flexibility can be imparted to the distal side of the outer tube 10, thereby improving the steerability of the catheter 1 on the distal side.

[0067] The core wire 30 may include one or more first sections 40. The first section 40 is preferably located on the distal side of the core wire 30, but may also be located in the central portion or on the proximal side. For example, as shown in FIG. 8, the first section 40 may be located at the distal end, and the core wire 30 may extend linearly proximal to the first section 40.

[0068] The distal end of the core wire 30 is preferably fixed to the outer tube 10 or the first inner tube 20. Fig. 4 shows an embodiment in which the distal end of the core wire 30 is fixed to the outer surface of the first inner tube 20. Although not shown, the distal end of the core wire 30 may also be fixed to the inner surface of the outer tube 10. Fixing the distal end of the core wire 30 to the outer tube 10 or the first inner tube 20 reduces the risk that the distal end 301 of the core wire 30 will break through the outer tube 10. Furthermore, with the above configuration, the position of the core wire 30 in the radial direction of the outer tube 10 is less likely to change, thereby improving operability.

[0069] The distal end of the first section 40 is preferably fixed to the outer tube 10 or the first inner tube 20. Fig. 4 shows an embodiment in which the distal end of the first section 40 is fixed to the outer surface of the first inner tube 20. Although not shown, the distal end of the first section 40 may also be fixed to the inner surface of the outer tube 10. Fixing the distal end of the first section 40 to the outer tube 10 or the first inner tube 20 makes it less likely that the position of the first section 40 in the radial direction of the outer tube 10 will change, thereby improving operability.

[0070] 10, the catheter 1 according to the embodiment of the present invention preferably further has a hub 50 at the proximal end of the outer tube 10. The hub 50 has therein a guidewire port 51 that communicates with the lumen of the first inner tube 20, and is a member that is used when introducing a guidewire into the lumen of the first inner tube 20, or when injecting a contrast agent, a medicinal solution, or the like.

[0071] The catheter 1 according to the embodiment of the present invention further has a hub 50 at the proximal end of the outer tube 10, and the proximal end of the core wire 30 is preferably fixed to at least one of the outer tube 10, the first inner tube 20, and the hub 50. In FIG. 4, a mode in which the proximal end of the core wire 30 is fixed to the outer surface of the first inner tube 20 is shown. Although not shown, the proximal end of the core wire 30 may be fixed to the inner surface of the outer tube 10, or the proximal end of the core wire 30 may be fixed to the inner surface of the guide wire port 51 of the hub 50. By fixing the proximal end of the core wire 30 to at least one of the outer tube 10, the first inner tube 20, and the hub 50, the position of the core wire 30 in the radial direction of the outer tube 10 is less likely to change, and the operability can be improved.

[0072] The catheter 1 according to the embodiment of the present invention further has a hub 50 at the proximal end of the outer tube 10, and the proximal end of the first section 40 is preferably fixed to at least one of the outer tube 10, the first inner tube 20, and the hub 50. In FIG. 4, a mode in which the proximal end of the first section 40 is fixed to the outer surface of the first inner tube 20 is shown. Although not shown, the proximal end of the first section 40 may be fixed to the inner surface of the outer tube 10, or the proximal end of the first section 40 may be fixed to the inner surface of the guide wire port 51 of the hub 50. By fixing the proximal end of the first section 40 to at least one of the outer tube 10, the first inner tube 20, and the hub 50, the position of the first section 40 in the radial direction of the outer tube 10 is less likely to change, and the operability can be improved.

[0073] It is not essential that the distal end of the core wire 30, the distal end of the first section 40, the proximal end of the core wire 30, and the proximal end of the first section 40 are fixed to other members such as various tubes and the hub 50. That is, the distal end of the core wire 30, the distal end of the first section 40, the proximal end of the core wire 30, and the proximal end of the first section 40 may not be fixed to other members.

[0074] In the catheter 1 according to the embodiment of the present invention, the distal end portion of the main section 42 of the core wire 30 may or may not be fixed to at least one of the outer tube 10, the first inner tube 20, and the hub 50. Further, the proximal end portion of the main section 42 of the core wire 30 may or may not be fixed to at least one of the outer tube 10, the first inner tube 20, and the hub 50. By adopting the above configuration, the position of the main section 42 in the radial direction of the outer tube 10 is less likely to change, and the operability can be improved.

[0075] The method of fixing the distal end portion of the core wire 30, the distal end portion of the first section 40, the proximal end portion of the core wire 30, and the proximal end portion of the first section 40 to other members such as various tubes and the hub 50 is not particularly limited. For example, embedding by thermally welding various tubes, brazing such as soldering, welding, adhesion by an adhesive, connection by caulking, etc. can be mentioned.

[0076] When the tip chip 12 is provided at the distal end portion of the outer tube 10, the tip chip 12 and the distal end portion of the core wire 30 may be fixed, or the tip chip 12 and the distal end portion of the first section 40 may be fixed. By having a fixed end with the distal end portion of the core wire 30 or the first section 40 at the tip chip 12 portion, the catheter 1 can be effectively bent more easily by operation.

[0077] The outer diameter of the core wire 30 in a partial cross section of the catheter 1 according to the embodiment of the present invention is preferably 5% or more, 8% or more, 10% or more of the inner diameter of the outer tube 10. The outer diameter of the core wire 30 in a partial cross section of the catheter 1 is preferably 50% or less, 40% or less, 35% or less of the inner diameter of the outer tube 10. The outer diameter of the core wire 30 in all cross sections of the catheter 1 is preferably 5% or more, 8% or more, 10% or more of the inner diameter of the outer tube 10. The outer diameter of the core wire 30 in all cross sections of the catheter 1 is preferably 50% or less, 40% or less, 35% or less of the inner diameter of the outer tube 10.

[0078] As shown in Figures 4 and 6 to 9, the core wire 30 preferably has a coil portion 43 in which the core wire 30 is wound helically in the first section 40. The corrugated first section 40 as shown in Figure 1 is easily bent in the height direction of the waves, so the catheter 1 must be advanced into a curved vessel within a living body while taking into consideration this bendability. On the other hand, when the first section 40 is a coil portion 43 in which the core wire 30 is wound helically as shown in Figures 4 and 6 to 9, the first section 40 is less likely to bend in a direction that is easy for the user to do so. This eliminates the need for the user to consider the bendability of the first section 40, making it easier to control the advancement direction of the catheter 1 and facilitate its advancement into a curved vessel within a living body.

[0079] As shown in FIG. 4, the core wire 30 has a coil portion 43 in which the core wire 30 is spirally wound in the first section 40, and it is more preferable that the first inner tube 20 is disposed in the inner cavity of the coil portion 43.

[0080] The coil portion 43 is a portion of the core wire 30 that is wound in a spiral shape. It is preferable that the coil portion 43 has a plurality of maximum peaks. A single core wire 30 may have a plurality of coil portions 43. The entire core wire 30 may be the coil portion 43.

[0081] The coil diameter of the coil portion 43 may be constant. When the coil portion 43 is viewed axially, it has an annular shape. The outer diameter of the annulus from one maximum portion to the maximum portion adjacent in the longitudinal axis direction of the outer tube 10 is defined as the coil diameter of the coil portion 43. Here, the coil diameter being constant includes the mode in which the coil diameter varies within ±10%. Also, the coil diameter of the coil portion 43 may not be constant and may vary. For example, in the longitudinal axis direction of the outer tube 10, only a part of the core wire 30 may have a smaller coil diameter towards the distal side. In the longitudinal axis direction of the outer tube 10, only a part of the core wire 30 may have a larger coil diameter towards the distal side. In the longitudinal axis direction of the outer tube 10, the coil diameter may become smaller towards the distal side over the entire core wire 30. In the longitudinal axis direction of the outer tube 10, the coil diameter may become larger towards the distal side over the entire core wire 30.

[0082] The winding pitch of the coil of the coil portion 43 may be constant. Here, the winding pitch of the coil being constant includes the mode in which the winding pitch of the coil varies within ±10%. Also, the winding pitch of the coil of the coil portion 43 may not be constant and may vary. For example, in the longitudinal axis direction of the outer tube 10, only a part of the core wire 30 may have a smaller winding pitch towards the distal side. In the longitudinal axis direction of the outer tube 10, only a part of the core wire 30 may have a larger winding pitch towards the distal side. In the longitudinal axis direction of the outer tube 10, the winding pitch of the coil may become smaller towards the distal side over the entire core wire 30. In the longitudinal axis direction of the outer tube 10, the winding pitch of the coil may become larger towards the distal side over the entire core wire 30.

[0083] Since the first inner tube 20 is disposed in the lumen of the coil section 43, the coil section 43 can protect the first inner tube 20 when force is applied from outside the catheter 1, thereby preventing damage to the first inner tube 20. Even if the user applies excessive force and the guidewire passing through the lumen of the first inner tube 20 breaks through the side of the first inner tube 20, the coil section 43 prevents the tip of the guidewire from breaking through in the lateral direction, so the tip of the guidewire can be kept within the lumen of the first inner tube 20, and the guidewire can be advanced to the distal end of the first inner tube 20.

[0084] The core wire 30 may have a coil portion 43 in which the core wire 30 is wound helically in the first section 40, the first inner tube 20 is disposed in the lumen of the coil portion 43, and the inner surface of the coil portion 43 may be in contact with the outer surface of the first inner tube 20. Alternatively, the core wire 30 may have a coil portion 43 in which the core wire 30 is wound helically in the first section 40, the first inner tube 20 is disposed in the lumen of the coil portion 43, and the inner surface of the coil portion 43 and the outer surface of the first inner tube 20 may be fixed. By disposing the first inner tube 20 in the lumen of the coil portion 43, the coil portion 43 can protect the first inner tube 20 when force is applied from outside the catheter 1, and damage to the first inner tube 20 can be suppressed. Furthermore, if the inner surface of the coil portion 43 and the outer surface of the first inner tube 20 are fixed, frictional heat generated between the coil portion 43 and the inner tube 20 due to friction between the coil portion 43 and the inner tube 20 can be suppressed. It should be noted that the inner surface of the coil portion 43 and the outer surface of the first inner tube 20 may not be in contact with each other. Also, the inner surface of the coil portion 43 and the outer surface of the first inner tube 20 may not be fixed to each other.

[0085] As the aspect of the first section 40, it shows a wavy shape, particularly a sine wave shape, in FIGS. 1 and 3, and a spiral shape in FIGS. 4 and 6 to 9. However, the embodiments of the first section 40 are not limited to this, and it is sufficient that the core wire 30 meanders in the width direction and has a plurality of maximum portions. As embodiments of the first section 40, for example, there are a rectangular wave shape as shown in FIG. 11, a triangular wave shape as shown in FIG. 12, an arc shape as shown in FIG. 13, etc. Although not shown, there are also sawtooth wave shapes, trapezoidal wave shapes, etc. In addition, those combining the shapes of these first sections 40, for example, those connecting them in the longitudinal axis direction may also be acceptable.

[0086] Next, referring to FIG. 14, another embodiment of the catheter will be described. FIG. 14 represents a perspective cross-sectional view showing another modification of the catheter according to the embodiment of the present invention.

[0087] As shown in FIG. 14, the catheter 1 may include a second inner tube 21 disposed inside the lumen of the outer tube 10 and outside the first inner tube 20. Regarding the shape, constituent material, properties, etc. of the second inner tube 21, reference can be made to the places where the corresponding description of the first inner tube 20 is described. The first inner tube 20 and the second inner tube 21 may have the same shape, constituent material, and properties, or may be different.

[0088] The second inner tube 21 may move or may not move in the longitudinal axis direction with respect to the outer tube 10. Also, the second inner tube 21 may move or may not move in the longitudinal axis direction with respect to the first inner tube 20.

[0089] The outer tube 10 and the second inner tube 21 may be fixed to each other or may not be fixed. Also, the first inner tube 20 and the second inner tube 21 may be fixed to each other or may not be fixed. The fixing method when being fixed is not particularly limited, and examples include connections such as welding, soldering, and adhesion with an adhesive.

[0090] The lumen of the outer tube 10 may be configured so that no tube members other than the first inner tube 20 are disposed in the lumen of the outer tube 10. Also, the lumen of the outer tube 10 may be configured so that no tube members other than the first inner tube 20 and the second inner tube 21 are disposed in the lumen of the outer tube 10.

[0091] At least a portion of the core wire 30 may be longitudinally movable relative to the second inner tube 21 .

[0092] The core wire 30 may be fixed to the second inner tube 21. For example, a portion of the core wire 30 may be fixed to the outer surface of the second inner tube 21. The distal end of the core wire 30 may be fixed to the second inner tube 21. The proximal end of the core wire 30 may be fixed to the second inner tube 21. With the above configuration, the position of the core wire 30 in the radial direction of the outer tube 10 is less likely to change, thereby improving operability. Furthermore, the distal end of the first section 40 may be fixed to the second inner tube 21. The proximal end of the first section 40 may be fixed to the second inner tube 21. With the above configuration, the position of the first section 40 in the radial direction of the outer tube 10 is less likely to change, thereby improving operability of the catheter 1.

[0093] The distal end of the main section 42 of the core wire 30 may or may not be fixed to the second inner tube 21. Furthermore, the proximal end of the main section 42 of the core wire 30 may or may not be fixed to the second inner tube 21. With the above-described configuration, the position of the main section 42 in the radial direction of the outer tube 10 is less likely to change, thereby improving the operability of the catheter 1.

[0094] The catheter 1 according to an embodiment of the present invention includes a second inner tube 21 disposed in the inner cavity of the outer tube 10 and outside the first inner tube 20. A part of the core wire 30 may be disposed between the first inner tube 20 and the second inner tube 21. A part of the core wire 30 may be disposed between the first inner tube 20 and the second inner tube 21, or the entire core wire 30 may be disposed between the first inner tube 20 and the second inner tube 21. That is, a part of the core wire 30 may be sandwiched between the first inner tube 20 and the second inner tube 21, or the entire core wire 30 may be sandwiched between the first inner tube 20 and the second inner tube 21.

[0095] As shown in FIG. 14, the catheter 1 according to an embodiment of the present invention includes a second inner tube 21 disposed in the inner cavity of the outer tube 10 and outside the first inner tube 20. A first section 40 is preferably disposed between the first inner tube 20 and the second inner tube 21. A part of the first section 40 may be disposed between the first inner tube 20 and the second inner tube 21, or the entire first section 40 may be disposed between the first inner tube 20 and the second inner tube 21. That is, a part of the first section 40 may be sandwiched between the first inner tube 20 and the second inner tube 21, or the entire first section 40 may be sandwiched between the first inner tube 20 and the second inner tube 21. By disposing the first section 40 between the first inner tube 10 and the second inner tube 20, the expansion and contraction of the first section 40 with respect to the bending of the catheter 1 in the non-existent direction of the first inner tube 20 and the second inner tube 21 at this portion can easily act, and the operability of the catheter 1 can be improved.

[0096] Another embodiment of the catheter of the present invention includes an outer tube 10 having a distal end and a proximal end and extending in the longitudinal axis direction, a first inner tube 20 disposed in the lumen of the outer tube 10, and a core wire 30 disposed in the lumen of the outer tube 10 and outside the first inner tube 20. When viewed from an observation direction that is perpendicular to the longitudinal axis direction of the outer tube 10 and in which the sum of the areas of all specific regions 41 defined by the following requirements is maximized, and in which the longitudinal axis direction of the outer tube 10 and the horizontal direction are parallel, the core wire 30 has a first section 40 that meanders in the width direction and has a plurality of maximum portions. The gist of the first section 40 is that it can contract by 0.5% or more compared to the length of the first section 40 in the longitudinal axis direction of the outer tube 10 in a state where no external force is applied to the core wire 30. [Requirements] The specific region 41 is a region surrounded by a straight line 31 connecting two adjacent maximum portions in the longitudinal axis direction of the outer tube 10 and the outer contour line of the core wire 30 existing between the two maximum portions when the core wire 30 is viewed from the observation direction.

[0097] The greater the contraction width of the first section 40, the greater the impact absorption force due to the contraction of the first section 40. For this reason, it is preferable that the first section 40 can contract by 1% or more, more preferably 2% or more, and even more preferably 3% or more compared to the length of the first section 40 in the longitudinal axis direction in a state where no external force is applied to the catheter 1. Also, since the first section 40 may become too flexible if the contraction width is too large, it is preferable that the contraction of the first section 40 is 40% or less, more preferably 30% or less, and even more preferably 20% or less compared to the length of the first section 40 in the longitudinal axis direction in a state where no external force is applied to the catheter 1.

[0098] As described above, by configuring the first section 40 to be contractible by 0.5% or more compared to the length of the first section 40 in the longitudinal direction of the outer tube 10 when no external force is applied to the core wire 30, the first section 40 can expand and contract in the longitudinal direction of the outer tube 10. When passing through a curved portion of a lumen in a living body, the expansion of the first section 40 of the core wire 30 prevents the outer tube 10 from strongly adhering to the lumen wall. By preventing strong adhering, the resistance force that the catheter 1 receives from the lumen wall can be reduced, allowing the user to advance the catheter 1 deeper with less force. Furthermore, if the distal end of the catheter 1 inserted into a lumen in a living body hits plaque or the like, the contraction of the first section 40 can absorb the impact, thereby reducing the risk of damaging the lumen wall. Therefore, the catheter 1 can be easily and safely advanced into a curved lumen in a living body. Note that the configuration of the catheter 1 described with reference to FIGS. 1 to 14 can be appropriately applied to the catheter 1 of this embodiment. [Explanation of symbols]

[0099] 1: Catheter 10: Outer tube 101: Distal end of outer tube 11: Center position 12: Tip 20: First inner tube 21: Second inner tube 30: Core wire 301: Distal end of core wire 302: Proximal end of core wire 30a: Maximum part 30b: Maximum part 31: Line connecting the two maxima 32 : Minimum part 40: First Section 400: 1 / 10 of the total length of the core wire 401: Distal end of first section 402: Proximal end of first section 41: Specific area 42: Main interval 43: Coil part 50: Hub 51: Guide wire port

Claims

1. An outer tube having a distal end and a proximal end and extending in the longitudinal axis direction, A first inner tube disposed in the inner cavity of the outer tube, A core wire disposed in the inner cavity of the outer tube and outside the first inner tube, A hub provided at the proximal end of the outer tube, and comprising: When viewed from an observation direction which is a direction perpendicular to the longitudinal axis direction of the core wire and in which the sum of the areas of all specific regions defined by the following requirements is maximized, and in which the longitudinal axis direction and the horizontal direction are parallel, the core wire has a first section that meanders in the width direction and has a plurality of maximum portions, In the main section excluding 5% of both ends of the length in the longitudinal axis direction of the first section, the shape of all specific regions defined by the following requirements is a shape that can enclose the cross-sectional shape of the core wire, The distal end of the core wire is fixed to the outer tube or the first inner tube, The first section of the core wire is a catheter that continues from the distal end of the core wire to a position at a length of 1 / 10 of the total length of the core wire from the distal end of the core wire. The cross-sectional shape of the core wire refers to the shape of a cross-section perpendicular to the major axis when the core wire is in a straight state. [Requirements] The specific region is a region surrounded by a straight line connecting two adjacent maximum portions in the longitudinal axis direction and the outer contour line of the core wire existing between the two maximum portions when the core wire is viewed from the observation direction.

2. The catheter according to claim 1, wherein the average length of the straight line connecting the two maximum portions existing on the distal side is shorter than the average length of the straight line connecting the two maximum portions existing on the proximal side among the main sections.

3. The catheter according to claim 1 or 2, wherein the core wire has a portion where the length of the straight line connecting the two maximum portions existing in the main section becomes shorter from the proximal side to the distal side.

4. An outer tube having a distal end and a proximal end and extending in the longitudinal axis direction, A first inner tube disposed in the inner cavity of the outer tube, A core wire disposed in the inner cavity of the outer tube and outside the first inner tube, A hub provided at the proximal end of the outer tube, and comprising: When viewed from an observation direction that is perpendicular to the longitudinal axis direction of the core wire and in which the sum of the areas of all specific regions defined by the following requirements is maximized, and in which the longitudinal axis direction and the horizontal direction are parallel, the core wire has a first section that meanders in the width direction and has a plurality of maximum portions. The first section is contractible by 0.5% or more compared to the length of the first section in the longitudinal axis direction in a state where no external force is applied to the core wire. The first section of the core wire is a catheter that extends from the distal end of the core wire to a position that is 1 / 10 of the total length of the core wire longer than the distal end of the core wire. [Requirements] The specific region is a region surrounded by a straight line connecting two adjacent maximum portions in the longitudinal axis direction and the outer contour line of the core wire existing between the two maximum portions when the core wire is viewed from the observation direction.

5. The catheter according to any one of claims 1 to 4, wherein the distal end of the core wire is located more distally than the central position of the outer tube.

6. The catheter according to claim 4 or 5, wherein the distal end portion of the core wire is fixed to the outer tube or the first inner tube.

7. The catheter according to any one of claims 1 to 6, wherein the distal end portion of the first section is fixed to the outer tube or the first inner tube.

8. The catheter according to any one of claims 1 to 7, wherein the proximal end portion of the core wire is fixed to at least one of the outer tube, the first inner tube, and the hub.

9. The catheter according to any one of claims 1 to 8, wherein the proximal end portion of the first section is fixed to at least one of the outer tube, the first inner tube, and the hub.

10. The core wire has a coil portion in which the core wire is spirally wound around the first section. The catheter according to any one of claims 1 to 9, wherein the first inner tube is disposed in the inner cavity of the coil portion.

11. It includes a second inner tube disposed inside the inner cavity of the outer tube and outside the first inner tube. The catheter according to any one of claims 1 to 9, wherein the first section is disposed between the first inner tube and the second inner tube.

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