Catheter

Abstract

To provide a catheter that can proceed into a bent part of a lumen in the living body easily.SOLUTION: A catheter 1 includes: an outer tube 10; a first inner tube 20 disposed in a lumen of the outer tube 10; a second inner tube 21 disposed in the lumen of the outer tube 10 and outside the first inner tube 20; and a core wire 30 disposed in the lumen of the outer tube 10, outside the first inner tube 20, and outside the second inner tube 21. The core wire 30 is positioned on one side when a cross section of the lumen of the outer tube 10 is divided into two sides in a region where the core wire 30 is present of a distal region. The core wire 30 is fixed to at least one of the outer tube 10, the first inner tube 20, and the second inner tube 21. When the core wire 30 is viewed from an observation direction, the core wire 30 includes: a first section which meanders in a width direction and which includes a plurality of maximum parts.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a catheter used in a living body lumen of blood vessels such as coronary arteries, digestive organs such as bile ducts and pancreatic ducts, genital organs such as fallopian tubes, and urinary organs such as urethras.

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 to reach the affected area with the catheter, it was necessary for the user to transmit the fine movements and forces applied to the catheter 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 curved portions such as blood vessels, bile ducts, and pancreatic ducts. 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 having the first tube and the second tube disposed in its lumen, and a cylindrical member disposed on the outer periphery of the second tube. The distal end of the first tube is disposed more distally than the distal end of the second tube, the axial midpoint of the cylindrical member is more distal than the midpoint between the proximal end of the first tube and the 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 expands or contracts using a fluid, an outer shaft joined to the proximal end portion of the balloon and through which the fluid flows inside, and an inner shaft inserted across the inside of the outer shaft and the inside of the balloon and joined to the distal end portion of the balloon. The inner shaft has an extensible 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 the curved portion of the lumen in the 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 portion of a lumen in a living body.

Means for Solving the Problems

[0009] One embodiment of the catheter of the present invention that has solved 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, a second inner tube disposed in the lumen of the outer tube and outside the first inner tube, and a core wire disposed in the lumen of the outer tube outside the first inner tube and outside the second inner tube. In a region where the core wire exists within a distal region from the distal end of the outer tube to 20 cm proximal to the distal end, when the cross-section of the lumen of the outer tube is bisected, the core wire is located on one side. In the distal region, the core wire is fixed to at least one of the outer tube, the first inner tube, and the second inner tube. When viewed from an observation direction that is a direction perpendicular to the longitudinal axis direction of the outer tube, a direction in which the sum of the areas of all specific regions defined by the following requirements is maximized, and a direction in which 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, and the gist lies in the point that at least a part of the first section exists in the distal region. [Requirements] A 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] As described above, in the region where the core wire in the distal region exists, anisotropy can be imparted to the bending direction of the catheter in the distal region by the core wire being positioned on one side when the inner lumen cross-section of the outer tube is bisected. Further, since at least a part of the first section exists in the distal region, rigidity can be imparted to the distal region, making it easier to transmit the force applied to the proximal end of the catheter to the more distal side. Therefore, it is possible to facilitate the entry of the catheter into the curved portion of the lumen in the living body.

[0011] The distal end of the core wire is preferably fixed to at least one of the outer tube, the first inner tube, and the second inner tube.

[0012] The catheter preferably 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, the second inner tube, and the hub.

[0013] The distal end of the first section is preferably fixed to at least one of the outer tube, the first inner tube, and the second inner tube.

[0014] The catheter preferably 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, the second inner tube, and the hub.

[0015] Preferably, 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 first section.

[0016] The core wire preferably has a portion where the straight line connecting the two maximum portions existing in the first section becomes shorter from the proximal side to the distal side.

[0017] It is preferable that the shape of all specific regions can enclose the cross-sectional shape of the core wire. Note that the cross-sectional shape of the core wire refers to the shape of the cross-section perpendicular to the major axis when the core wire is in a straight state.

[0018] It is preferable that the first section of the core wire extends 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.

[0019] 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 preferably arranged in the inner cavity of the coil portion in the distal region.

[0020] In the region where the core wire exists within the distal region, it is preferable that the first section of the core wire is arranged on one side of the two regions partitioned by a virtual straight line passing through the centroid of the first inner tube and the centroid of the second inner tube in the inner cavity cross-section.

Advantages of the Invention

[0021] According to the catheter of the present invention, in the region where the core wire exists in the distal region, the core wire is positioned on one side when the inner cavity cross-section of the outer tube is bisected, so that anisotropy can be imparted to the bending manner of the catheter in the distal region. In addition, since at least a part of the first section exists in the distal region, rigidity can be imparted to the distal region, making it easier to transmit the force applied to the proximal end of the catheter to the more distal side. Therefore, it is possible to facilitate the entry of the catheter into the curved portion of the lumen in the living body.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0023] Hereinafter, the present invention will be specifically described with reference to the drawings. However, the present invention is not limited to the illustrated examples, and it is also possible to appropriately modify and implement within the range that can conform to the gist of the foregoing and following descriptions, and all of them are included in the technical scope of the present invention. In each figure, for the sake of convenience, hatching, reference signs, etc. may be omitted, but in such cases, reference shall be made to the specification and other figures. Also, the dimensions of various components in the drawings may differ from the actual dimensions because priority is given to facilitating the understanding of the features of the present invention.

[0024] One embodiment of the catheter of the present invention 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, a second inner tube disposed in the lumen of the outer tube and outside the first inner tube, and a core wire disposed in the lumen of the outer tube outside the first inner tube and outside the second inner tube. In the distal region from the distal end of the outer tube to 20 cm proximal to the distal end, in the region where the core wire exists, the core wire is located on one side when the cross-section of the lumen of the outer tube is bisected. In the distal region, the core wire is fixed to at least one of the outer tube, the first inner tube, and the second inner tube. When viewed from an observation direction that is perpendicular to the longitudinal axis direction of the outer tube 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 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 parts, and the gist lies in the fact that at least a part of the first section exists in the distal region. [Requirements] A specific region is a region surrounded by a straight line connecting two maximum parts 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 parts when the core wire is viewed from the observation direction.

[0025] As described above, in the region where the core wire exists in the distal region, the core wire is located on one side when the cross-section of the lumen of the outer tube is bisected, so that the catheter in the distal region can have anisotropy in the bending direction. In addition, since at least a part of the first section exists in the distal region, rigidity can be imparted to the distal region, making it easier to transmit the force applied to the proximal end of the catheter to the more distal side. Therefore, it is possible to easily insert the catheter into the curved portion of the lumen in the living body.

[0026] 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, a second inner tube 21 disposed in the lumen of the outer tube 10 and outside the first inner tube 20, and a core wire 30 disposed in the lumen of the outer tube 10 outside the first inner tube 20 and outside the second inner tube 21. 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.

[0027] 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.

[0028] 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.

[0029] The shape of the inner cavity cross-section of the outer tube 10 is not particularly limited. 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.

[0030] The outer tube 10 preferably has flexibility. This allows the outer tube 10 to be deformed along the shape of the tube in the living body. Also, for shape retention, the outer tube 10 preferably has elasticity.

[0031] The outer tube 10 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; a resin tube; or a combination of these, 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 with a mesh structure formed by simply crossing or braiding the wire rods, and a coil with the wire rods wound. 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.

[0032] The material constituting the outer tube 10 includes, for example, 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 resins such as PTFE, PFA, and ETFE, and polyvinyl chloride resins, and metals such as stainless steel, carbon steel, and nickel-titanium alloys.

[0033] 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, a structure using a metal braid such as stainless steel, carbon steel, or nickel-titanium alloy can be used as the intermediate layer of the resin tube constituting the outer tube 10.

[0034] 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 defined as the inner diameter of the outer tube 10.

[0035] 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-shaped 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 prevent moisture such as blood from entering the inner cavity of the outer tube 10 during the use of the catheter 1. 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, and for example, the material constituting the aforementioned outer tube 10 can be used. Note that the tip chip 12 is not provided at the distal end of the outer tube 10, and 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.

[0036] 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 fixing method 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.

[0037] The shape of the first inner tube 20 is not particularly limited as long as there is an inner cavity. For example, it can be in the shape of a hollow circular cylinder, a hollow polygonal cylinder, or the like. The first inner tube 20 may have a plurality of inner cavities, but preferably has only one inner cavity. The inner cavity of the first inner tube 20 preferably extends in the longitudinal axis direction of the outer tube 10.

[0038] The shape of the cross-section of the inner cavity 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.

[0039] The first inner tube 20 preferably has flexibility. Thereby, when deforming the outer tube 10 along the shape of the tube in the living body, the first inner tube 20 can also be deformed. Also, for shape retention, the first inner tube 20 preferably has elasticity.

[0040] The first inner tube 20 is a hollow body formed by arranging one or more wire rods in a predetermined pattern; a coated resin 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 formed by arranging wire rods 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.

[0041] 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.

[0042] 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, as an intermediate layer of the resin tube constituting the first inner tube 20, a structure using a metal braid such as stainless steel, carbon steel, or nickel-titanium alloy can be adopted.

[0043] As shown in FIGS. 1, 2, 4, and 5, the catheter 1 according to the 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. Regarding the shape, constituent material, properties, etc. of the second inner tube 21, reference can be made to the description of the relevant parts regarding the first inner tube 20. The first inner tube 20 and the second inner tube 21 may have the same shape, constituent material, and properties, or may be different.

[0044] 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.

[0045] 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 fixing is not particularly limited, and examples include connection by welding, soldering, adhesion with an adhesive, etc.

[0046] In the inner cavity of the outer tube 10, it may be configured such that no tube member other than the first inner tube 20 and the second inner tube 21 is disposed.

[0047] As shown in FIGS. 1, 2, 4, and 5, the core wire 30 is disposed in the inner cavity of the outer tube 10, outside the first inner tube 20 and outside the second inner tube 21. In the inner cavity of the outer tube 10, outside the first inner tube 20 and outside the second inner tube 21, only one core wire 30 may be disposed, or a plurality of core wires 30 may be disposed.

[0048] The core wire 30 is a linear member of single wire or stranded wire. As the core wire 30, metal wire materials such as stainless steel, carbon steel, 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 metal wire with a resin coating can be used. Among the materials constituting the core wire 30, a metal wire is preferably used, and stainless steel is more preferably used. Since the core wire 30 is configured 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.

[0049] 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.

[0050] 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 to the distal side, and it is more preferable that the entire core wire 30 continuously decreases in rigidity from the proximal side to the distal side. Also, the outer diameter of the core wire 30, that is, the thickness of the core wire 30, preferably becomes thinner from the proximal side to the distal side.

[0051] 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 a cross-section perpendicular to the major axis when the core wire 30 is in a straight state.

[0052] In the catheter 1 according to the embodiment of the present invention, in the distal region 13 from the distal end 101 of the outer tube 10 to 20 cm proximal to the distal end 101, in the region where the core wire 30 is present, the core wire 30 is located on one side when the inner lumen cross-section of the outer tube 10 is bisected. In the distal region 13, the core wire 30 is fixed to at least one of the outer tube 10, the first inner tube 20, and the second inner tube 21. When viewed from the observation direction, which is a direction perpendicular to the longitudinal axis direction of the outer tube 10 and in which the total area of all the specific regions 41 defined by the following requirements is maximized, the core wire 30 has a first section 40 that meanders in the width direction and has a plurality of maximum portions, and at least a part of the first section 40 exists in the distal region 13. [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.

[0053] As shown in FIGS. 1 and 4, in the catheter 1 according to the embodiment of the present invention, the distal region 13 refers to the region from the distal end 101 of the outer tube 10 to 20 cm proximal to the distal end 101.

[0054] As shown in FIGS. 2 and 5, in the distal region 13, the core wire 30 is located in the lumen of one half of the outer tube 10 that is separated by a straight line 14 that bisects the cross-section of the lumen of the outer tube 10. A part of the core wire 30 may be located on one side when the cross-section of the lumen of the outer tube 10 in the distal region 13 is bisected, or the entire core wire 30 may be located on one side when the cross-section of the lumen of the outer tube 10 is bisected. The straight line 14 refers to a straight line that bisects the area of the cross-section of the lumen of the outer tube 10.

[0055] In the distal region 13, the core wire 30 may be fixed to at least one of the outer tube 10, the first inner tube 20, and the second inner tube 21. FIG. 4 shows a mode in which the core wire 30 is fixed to the outer surface of the first inner tube 20. Although not shown, 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 second inner tube 21.

[0056] It is preferable that 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. 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 second inner tube 21.

[0057] As shown in FIGS. 1, 3, 4, and 6, in a direction perpendicular to the longitudinal axis direction of the outer tube 10, in a direction in which the sum of the areas of all specific regions 41 specified as follows is maximized, and when the core wire 30 is viewed from an observation direction 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. Further, at least a part of the first section 40 exists in the distal region 13. The observation direction is a direction perpendicular to the longitudinal axis direction of the outer tube 10, and in a direction in which the sum of the areas of all specific regions 41 is maximized, and in a direction 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. When observing the specific region 41, it is observed from the observation direction without applying an external force to the core wire 30. Further, the observation direction is a direction in which the longitudinal axis direction of the outer tube 10 and the horizontal direction are parallel. In other words, it is 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 convex upward parallel to the paper surface, and the minimum portion is a portion convex downward parallel to the paper surface.

[0058] As described above, in the region where the core wire 30 of the distal region 13 exists, the way the catheter 1 bends in the distal region 13 can be made anisotropic by the core wire 30 being located on one side when the inner lumen cross-section of the outer tube 10 is bisected. Also, since at least a part of the first section 40 exists in the distal region 13, rigidity can be imparted to the distal region 13, making it easier to transmit the force applied to the proximal end of the catheter 1 to the more distal side. Therefore, it is possible to make it easier for the catheter 1 to enter the curved portion of the lumen in the living body.

[0059] 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 length of the straight line 31 connecting the maximum portions adjacent to each other in the longitudinal axis direction of the outer tube 10 being 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%.

[0060] The first section 40 may have a portion where 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 the same and a portion where 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 different.

[0061] A part of the core wire 30 may have the first section 40. Also, 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, that is, a straight portion.

[0062] 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 exist throughout the core wire 30. Thereby, flexibility can be imparted to the entire core wire 30.

[0063] As an aspect of the first section 40, a wavy aspect is represented in FIGS. 1 and 3. When the first section 40 is wavy, in the longitudinal axis direction of the outer tube 10, the amplitude of the wave may decrease toward the distal side only in a part of the first section 40. In the longitudinal axis direction of the outer tube 10, the amplitude of the wave may increase toward the distal side only in a part of the first section 40. In the longitudinal axis direction of the outer tube 10, the amplitude of the wave may decrease toward the distal side throughout the entire first section 40. In the longitudinal axis direction of the outer tube 10, the amplitude of the wave may increase toward the distal side throughout the entire first section 40. In the longitudinal axis direction of the outer tube 10, the period of the wave may become shorter toward the distal side only in a part of the first section 40. In the longitudinal axis direction of the outer tube 10, the period of the wave may become longer toward the distal side only in a part of the first section 40. In the longitudinal axis direction of the outer tube 10, the period of the wave may become shorter toward the distal side throughout the entire first section 40. In the longitudinal axis direction of the outer tube 10, the period of the wave may become longer toward the distal side throughout the entire first section 40.

[0064] Next, in addition to FIGS. 1 to 6, referring to FIGS. 7 to 12, the configuration of the catheter and the core wire will be described in more detail. FIG. 7 shows a side view representing a modified example of the core wire provided in the catheter according to the embodiment of the present invention. FIG. 8 shows a side view representing another modified example of the core wire provided in the catheter according to the embodiment of the present invention. FIG. 9 shows a side view representing a modified example of the catheter according to the embodiment of the present invention. FIG. 10 shows a side view representing another modified example of the core wire provided in the catheter according to the embodiment of the present invention. FIG. 11 shows a side view representing another modified example of the core wire provided in the catheter according to the embodiment of the present invention. FIG. 12 shows a side view representing another modified example of the core wire provided in the catheter according to the embodiment of the present invention.

[0065] As shown in FIG. 7, it is preferable that the average length of the straight line 31 connecting the two maximum portions existing on the distal side is shorter than the average length of the straight line 31 connecting the two maximum portions existing on the proximal side in the first section 40. That is, the average length of the straight line 31 connecting two adjacent maximum portions in the longitudinal axis direction of the outer tube 10 existing in the proximal half of the first section 40 is shorter than the average length of the straight line 31 connecting two adjacent maximum portions in the longitudinal axis direction of the outer tube 10 existing in the distal half of the first section 40. As a result, it becomes easier to finely curve on the distal side of the first section 40, so that the operability of the catheter 1 within the curved portion of the lumen in the living body can be improved.

[0066] As shown in FIG. 7, the core wire 30 preferably has a portion where the straight line 31 connecting two adjacent maximum portions in the longitudinal axis direction of the outer tube 10 existing in the first section 40 becomes shorter from the proximal side to the distal side. Thereby, it becomes easier to finely curve on the distal side of the first section 40, so that the operation within a thin tube in the living body can be facilitated.

[0067] The first section 40 preferably has a portion where the axial length of the core wire 30 existing between two adjacent maximum portions in the longitudinal axis direction of the outer tube 10 becomes shorter from the proximal side to the distal side. Also, it is preferable that the axial length of the core wire 30 existing between two adjacent maximum portions in the longitudinal axis direction of the outer tube 10 becomes shorter from the proximal side to the distal side throughout the entire first section 40. Here, the axial length of the core wire 30 refers to the path length 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 finely curved on the distal side of the first section 40, and the catheter 1 can also be easily thinned, so that the operability of the catheter 1 within the curved tube can be improved.

[0068] As shown in FIGS. 1, 3, 4, and 6, it is preferable that the shape of all the 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. 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 is defined here as the cross-sectional shape of the core wire 30. By configuring the shape of all the specific regions 41 to be a shape that can enclose the cross-sectional shape of the core wire 30, this portion can easily expand and contract in the longitudinal axis direction. When passing through a curved lumen in the living body, when the first section 40 of the core wire 30 extends, it is possible to suppress 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. Also, when the distal end of the catheter 1 inserted into the lumen in the living body hits a stenosis or plaque, etc., since the first section 40 can contract to absorb the impact, the risk of damaging the tube wall can also be reduced. It should be noted that it is also possible to make the shape of only some of the specific regions 41 existing in the first section 40 a shape that can enclose the cross-sectional shape of the core wire 30.

[0069] In the catheter 1 according to the embodiment of the present invention, it is preferable that the outer diameter of the core wire 30 in a part of the cross-section is 5% or more, 8% or more, 10% or more of the inner diameter of the outer tube 10. It is preferable that the outer diameter of the core wire 30 in a part of the cross-section of the catheter 1 is 50% or less, 40% or less, 35% or less of the inner diameter of the outer tube 10. It is preferable that the outer diameter of the core wire 30 in all cross-sections of the catheter 1 is 5% or more, 8% or more, 10% or more of the inner diameter of the outer tube 10. It is preferable that the outer diameter of the core wire 30 in all cross-sections of the catheter 1 is 50% or less, 40% or less, 35% or less of the inner diameter of the outer tube 10.

[0070] The core wire 30 may be partially present between the distal end of the outer tube 10 and the proximal end of the outer tube 10. Also, 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.

[0071] As shown in FIG. 8, it is preferable that the first section 40 of the core wire 30 extends from the distal end 301 of the core wire 30 to a position 400 that is a length equal to 1 / 10 of the total length of the core wire 30 from the distal end 301. When the section from the distal end 301 of the core wire 30 to the position 400 that is a length equal to 1 / 10 of the total length of the core wire 30 from the distal end 301 extends substantially linearly in the longitudinal axis direction of the outer tube 10, there is a possibility that the distal end 301 may abut against the outer tube 10 and pierce through the outer tube 10. At least, by the presence of the first section 40 from the distal end 301 of the core wire 30 to the position 400 that is a length equal to 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. Therefore, the risk that the distal end 301 of the core wire 30 accidentally pierces through the outer tube 10 can be reduced. Here, the total length of the core wire 30 refers to the length in the longitudinal axis direction of the outer tube 10 in the section where the core wire 30 is present, and does not refer to the axial length of the core wire 30, that is, the path length.

[0072] The core wire 30 may have one first section 40 or may have a plurality of first sections 40. The first section 40 is preferably located on the distal side of the core wire 30, but may also be arranged in the central portion or on the proximal side. For example, as shown in FIG. 8, the first section 40 may be arranged at the distal end, and the core wire 30 may extend linearly on the proximal side of the first section 40.

[0073] The distal 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 second inner tube 21. In FIG. 4, a mode in which the distal end of the core wire 30 is fixed to the outer surface of the first inner tube 20 is shown. Although not shown, the distal end of the core wire 30 may be fixed to the inner surface of the outer tube 10, or the distal end of the core wire 30 may be fixed to the outer surface of the second inner tube 21. By fixing the distal end of the core wire 30 to at least one of the outer tube 10, the first inner tube 20, and the second inner tube 21, the risk that the distal end 301 of the core wire 30 pierces through the outer tube 10 can be reduced. Further, 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, and the operability can be improved.

[0074] The distal 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 second inner tube 21. In FIG. 4, a mode in which the distal end of the first section 40 is fixed to the outer surface of the first inner tube 20 is shown. Although not shown, the distal end of the first section 40 may be fixed to the inner surface of the outer tube 10, or the distal end of the first section 40 may be fixed to the outer surface of the second inner tube 21. By fixing the distal end of the first section 40 to at least one of the outer tube 10, the first inner tube 20, and the second inner tube 21, 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.

[0075] As shown in FIG. 9, 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 a guide wire port 51 communicating with the lumen of the first inner tube 20 inside thereof, and is a member used when introducing a guide wire into the lumen of the first inner tube 20 or injecting a contrast agent, a drug solution, or the like.

[0076] 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, the second inner tube 21, and the hub 50. FIG. 4 shows a mode in which the proximal end of the core wire 30 is fixed to the outer surface of the first inner tube 20. Although not shown, the proximal end of the core wire 30 may be fixed to the outer surface of the second inner tube 21, 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, the second inner tube 21, and the hub 50, the core wire 30 is less likely to move radially within the outer tube 10, and the operability can be improved.

[0077] 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, the second inner tube 21, and the hub 50. FIG. 4 shows a mode in which the proximal end of the first section 40 is fixed to the outer surface of the first inner tube 20. Although not shown, the proximal end of the first section 40 may be fixed to the outer surface of the second inner tube 21, 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, the second inner tube 21, and the hub 50, the first section 40 is less likely to move radially within the outer tube 10, and the operability can be improved.

[0078] 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 be fixed to other members such as various tubes and hubs 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.

[0079] The method of fixing when 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 hubs 50 is not particularly limited. For example, embedding by thermally welding various tubes, brazing such as soldering, welding, adhesion with an adhesive, connection by caulking, etc. can be mentioned.

[0080] Also, when the tip chip 12 is provided at the distal end of the outer tube 10, the tip chip 12 and the distal end of the core wire 30 may be fixed, or the tip chip 12 and the distal end of the first section 40 may be fixed. The presence of a fixed end with the distal end of the core wire 30 or the first section 40 at the tip chip 12 portion makes it easier to effectively bend the catheter 1 by operation.

[0081] As shown in FIG. 4, the core wire 30 has a coil portion 43 in which the core wire 30 is spirally wound around the first section 40, and it is preferable that the first inner tube 20 is disposed in the inner cavity of the coil portion 43 in the distal region 13.

[0082] The coil portion 43 is the portion where the core wire 30 is spirally wound. In the coil portion 43, it is preferable that there are a plurality of maximum portions. The coil portion 43 may exist at a plurality of locations on a single core wire 30. The entire core wire 30 may be the coil portion 43.

[0083] The coil diameter of the coil portion 43 may be constant. When the coil portion 43 is viewed axially, it has an annular shape, and 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 a mode in which the coil diameter varies within ±10%. Also, the coil diameter of the coil portion 43 may not be constant and may change. 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 toward 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 toward the distal side. In the longitudinal axis direction of the outer tube 10, the entire core wire 30 may have a smaller coil diameter toward the distal side. In the longitudinal axis direction of the outer tube 10, the entire core wire 30 may have a larger coil diameter toward the distal side.

[0084] The winding pitch of the coil of the coil portion 43 may be constant. Here, the winding pitch of the coil being constant includes a 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 change. 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 toward 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 toward the distal side. In the longitudinal axis direction of the outer tube 10, the entire core wire 30 may have a smaller winding pitch toward the distal side. In the longitudinal axis direction of the outer tube 10, the entire core wire 30 may have a larger winding pitch toward the distal side.

[0085] Since the first inner tube 20 is disposed in the inner cavity of the coil portion 43, when a force is applied from the outside of the catheter 1 or the like, the coil portion 43 can protect the first inner tube 20, so that damage to the first inner tube 20 can be suppressed. Further, even when the user applies excessive force and the guide wire passing through the inner cavity of the first inner tube 20 penetrates from the side surface of the first inner tube 20, the coil portion 43 suppresses the tip of the guide wire from penetrating in the side surface direction, so that the tip of the guide wire can be retained in the inner cavity of the first inner tube 20 and the guide wire can be advanced to the distal end of the first inner tube 20.

[0086] The core wire 30 has a coil portion 43 in which the core wire 30 is spirally wound around the first section 40. The first inner tube 20 is disposed in the inner cavity 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 in contact with each other. Further, the core wire 30 has a coil portion 43 in which the core wire 30 is spirally wound around the first section 40. The first inner tube 20 is disposed in the inner cavity 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. Since the first inner tube 20 is disposed in the inner cavity of the coil portion 43, when a force is applied from the outside of the catheter 1 or the like, the coil portion 43 can protect the first inner tube 20, so that damage to the first inner tube 20 can be suppressed. Further, when the inner surface of the coil portion 43 and the outer surface of the first inner tube 20 are fixed, the generation of frictional heat generated between the coil portion 43 and the inner tube 20 due to the coil portion 43 rubbing against the inner tube 20 can be suppressed. Note 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. Further, the inner surface of the coil portion 43 and the outer surface of the first inner tube 20 may not be fixed.

[0087] FIG. 2 shows a mode in which the core wire 30 when viewed from the longitudinal axis direction is disposed on one side of two regions partitioned by a virtual straight line 22 passing through the center of gravity 20a of the first inner tube 20 and the center of gravity 21a of the second inner tube 21.

[0088] As shown in FIG. 2, in the region where the core wire 30 exists within the distal region 13, it is preferable that the first section 40 of the core wire 30 is disposed on one side of two regions partitioned by a virtual straight line 22 passing through the center of gravity 20a of the first inner tube 20 and the center of gravity 21a of the second inner tube 21 in the inner cavity cross-section. By adopting such a configuration, anisotropy can be imparted to the bending manner of the catheter 1 in the region where the core wire 30 exists, so that the operability when entering the curved portion of the lumen in the living body can be improved. In the region where the core wire 30 exists within the distal region 13, a part of the first section 40 of the core wire 30 may be disposed on one side of two regions partitioned by a virtual straight line 22 passing through the center of gravity 20a of the first inner tube 20 and the center of gravity 21a of the second inner tube 21 in the inner cavity cross-section, or the entire first section 40 of the core wire 30 may be disposed. Note that, not limited to the distal region 13, the entire core wire 30 may be disposed on one side of two regions partitioned by a virtual straight line 22 passing through the center of gravity 20a of the first inner tube 20 and the center of gravity 21a of the second inner tube in all inner cavity cross-sections where the core wire 30 exists. Also, in all inner cavity cross-sections where the core wire 30 exists, a part of the core wire 30 may be disposed on one side of two regions partitioned by a virtual straight line 22 passing through the center of gravity 20a of the first inner tube 20 and the center of gravity 21a of the second inner tube.

[0089] 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 8. However, the implementation aspect of the first section 40 is 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 the implementation aspect of the first section 40, for example, there are a rectangular wave shape as shown in FIG. 10, a triangular wave shape as shown in FIG. 11, an arc shape as shown in FIG. 12, etc. Although not shown, other shapes such as a sawtooth wave shape and a trapezoidal wave shape can also be mentioned. Also, a combination of these shapes of the first section 40, for example, those connected in the longitudinal axis direction, may be used.

Explanation of Reference Numerals

[0090] 1: Catheter 10: Outer tube 101: Distal end of the outer tube 12: Tip 13: Distal region 14: Straight line 20: First inner tube 20a: Center of gravity of the first inner tube 21: Second inner tube 21a: Center of gravity of the second inner tube 22: Virtual straight line 30: Core wire 301: Distal end of the core wire 302: Proximal end of the core wire 30a: Maximum part 30b: Maximum part 31: Straight line connecting two maximum parts 32: Minimum part 40: First section 400: Position at a length of 1 / 10 of the total length of the core wire 401: Distal end of the first section 402: Proximal end of the first section 41: Specific region 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 second inner tube disposed in the inner cavity of the outer tube and outside the first inner tube, A core wire disposed in the inner cavity of the outer tube, outside the first inner tube and outside the second inner tube, and comprising: In a distal region from the distal end of the outer tube to 20 cm proximal to the distal end, in a region where the core wire is present, when the inner cavity cross-section of the outer tube is bisected, the core wire is located on one side, In the distal region, the core wire is fixed to at least one of the outer tube, the first inner tube, and the second inner tube, When viewed from an observation direction that is a direction perpendicular to the longitudinal axis direction of the core wire, a direction in which the sum of the areas of all specific regions defined by the following requirements is maximized, and a direction 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, At least a part of the first section exists in the distal region, The shape of the specific region is a shape that can enclose the cross-sectional shape of the core wire, The cross-sectional shape of the core wire is a catheter having a 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 an 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 a distal end portion of the core wire is fixed to at least one of the outer tube, the first inner tube, and the second inner tube.

3. Further, it has a hub at the proximal end of the outer tube, The catheter according to claim 1 or 2, wherein the proximal end of the core wire is fixed to at least one of the outer tube, the first inner tube, the second inner tube, and the hub.

4. The catheter according to any one of claims 1 to 3, wherein the distal end of the first section is fixed to at least one of the outer tube, the first inner tube, and the second inner tube.

5. Further, it has a hub at the proximal end of the outer tube, The catheter according to any one of claims 1 to 4, wherein the proximal end of the first section is fixed to at least one of the outer tube, the first inner tube, the second inner tube, and the hub.

6. The catheter according to any one of claims 1 to 5, 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 within the first section.

7. The catheter according to any one of claims 1 to 6, wherein the core wire has a portion where the straight line connecting the two maximum portions existing in the first section becomes shorter from the proximal side to the distal side.

8. The catheter according to any one of claims 1 to 7, wherein the shape of all the specific regions is a shape that can enclose the cross-sectional shape of the core wire.

9. The catheter according to any one of claims 1 to 8, wherein the first section of the core wire extends 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.

10. The core wire has a coil portion in which the core wire is spirally wound in the first section, The catheter according to any one of claims 1 to 9, wherein the first inner tube is disposed in the lumen of the coil portion in the distal region. **Claim 11** The catheter according to any one of claims 1 to 9, wherein, in a region where the core wire exists within the distal region, the first section of the core wire is disposed on one side of two regions partitioned by a virtual straight line passing through the center of gravity of the first inner tube and the center of gravity of the second inner tube in the cross-section of the lumen.

Images