Catheter

Abstract

To provide a catheter capable of suppressing the possibility of having difficulty in moving with respect to a sheath even when another member intrudes between a tip member and an inner peripheral surface of a sheath.SOLUTION: A catheter 1 includes a shaft 2 inserted into the body, a plurality of splines 3 connected to a tip side of the shaft 2, and a tip member 4 connected to each tip side of the plurality of splines 3. The outer shape of the tip member 4 is non-circular when viewed from a central axis direction of the shaft 2. An outer surface of the tip member 4 may have grooves formed, which continue from a tip side of the tip member 4 to a base end side.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to catheters. [Background technology]

[0002] A catheter is a type of medical device inserted into the body for diagnosis or treatment. One known example of a catheter includes a shaft and a basket electrode assembly connected to the tip of the shaft (see, for example, Patent Document 1). The basket electrode assembly includes a plurality of splines. The basket electrode assembly is configured to change shape from a contracted shape to an expanded shape by deforming the splines. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2016-507349 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 describes forming a mechanical connection point (hereinafter also referred to as a "tip member") at the distal end of the basket electrode assembly. The shape of such a tip member is usually approximately circular when viewed from the tip side in the axial direction of the catheter. Therefore, when a catheter is inserted into the lumen of a sheath and used, if a member such as a guidewire protruding from the tip of the catheter gets between the tip member and the inner circumferential surface of the sheath, the member may become stuck between the tip member and the inner circumferential surface of the sheath, making it difficult to move the catheter relative to the sheath.

[0005] The present disclosure has been made in consideration of the above-mentioned circumstances, and its purpose is to provide a catheter that can reduce the risk of the tip member becoming difficult to move relative to the sheath even if another member gets between the tip member and the inner surface of the sheath. [Means for solving the problem]

[0006] The catheter of the present disclosure includes a shaft to be inserted into the body, a plurality of splines connected to the distal end of the shaft, and a tip member connected to the distal end of each of the plurality of splines. The outer shape of the tip member is non-circular when viewed in the direction of the central axis of the shaft.

[0007] Any combination of the above components, and conversion of the expression of the present disclosure into a method, device, system, etc., are also valid as one aspect of the present disclosure. [Effects of the Invention]

[0008] The catheter of the present disclosure can reduce the risk of the distal end member becoming difficult to move relative to the sheath even if another member gets between the distal end member and the inner surface of the sheath. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a perspective view schematically showing an example of a deformation state near the tip of the catheter according to the first embodiment. [Figure 2] 1. FIG. 4 is a perspective view schematically showing another example of a deformation state near the tip of the catheter shown in FIG. [Figure 3] FIG. 2 is an enlarged perspective view of the tip member shown in FIG. [Figure 4] 2 is a view of the distal end member shown in FIG. 1 as seen from the distal end side in the central axis direction. [Figure 5] 2 is a view of the distal end member shown in FIG. 1 as seen from the base end side in the central axis direction. [Figure 6] 2 is a view seen from the distal end side in the central axis direction, schematically showing an example in which the distal end of the elongated member is disposed between the outer surface of the distal end member shown in FIG. 1 and the inner circumferential surface of the sheath. FIG. [Figure 7] FIG. 2 is a schematic diagram showing an example of the overall structure of the catheter shown in FIG. [Figure 8] FIG. 10 is a perspective view schematically showing a tip member of a catheter according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present disclosure will be described below with reference to preferred embodiments and drawings. The embodiments are illustrative and do not limit the present disclosure, and all features and combinations thereof described in the embodiments are not necessarily essential to the present disclosure. The same or equivalent components, parts, and processes shown in each drawing are designated by the same reference numerals, and redundant descriptions will be omitted where appropriate. The scale and shape of each part shown in each drawing are set for convenience to facilitate explanation and should not be interpreted as limiting unless otherwise specified. Furthermore, when terms such as "first" and "second" are used in this specification or claims, unless otherwise specified, these terms do not indicate any order or importance, but are intended to distinguish one configuration from another. Furthermore, some components that are not important for explaining the embodiments are omitted from each drawing.

[0011] [First embodiment] Fig. 1 is a perspective view schematically showing an example of a deformed state near the tip of a catheter 1 according to a first embodiment of the present disclosure. Fig. 2 is a perspective view schematically showing another example of a deformed state near the tip of the catheter 1. As shown in Figs. 1 and 2, the catheter 1 includes a shaft 2 to be inserted into a body, a plurality of splines 3a to 3f connected to the tip side of the shaft 2, and a tip member 4 connected to the tip sides of each of the plurality of splines 3a to 3f. Hereinafter, in a description common to each of the plurality of splines 3a to 3f, they will also be simply referred to as splines 3.

[0012] Hereinafter, in the catheter 1 and each of the components constituting the catheter 1, the direction along the central axis of the shaft 2 will be referred to as the "axial direction" or "central axis direction," and the radial direction and circumferential direction around the central axis of the shaft 2 will be referred to as the "radial direction" and "circumferential direction," respectively. In the catheter 1 and each of the components constituting the catheter 1, the side radially away from the central axis of the shaft 2 will be referred to as the "radially outer side," and the side radially approaching the central axis of the shaft 2 will be referred to as the "radially inner side." In the catheter 1 and each of the components constituting the catheter 1, of the two sides along the axial direction, the side inserted into the body will be referred to as the "distal side," and the side placed outside the body will be referred to as the "base end side."

[0013] The shaft 2 may be a long, cylindrical member. The length of the shaft 2 is, for example, 800 mm to 1800 mm. The outer diameter of the shaft 2 is, for example, 2.0 mm to 5.0 mm. The material forming the shaft 2 may be any flexible and biocompatible material. For example, the shaft 2 may be formed from a known resin such as polyolefin or polyamide.

[0014] The spline 3 is a member that connects the shaft 2 and the tip member 4. The spline 3 may be a cylindrical member like the shaft 2. The length of the spline 3 when extended linearly is, for example, 20 mm to 50 mm. The outer diameter of the spline 3 is, for example, 0.5 mm to 2.0 mm. The material that constitutes the spline 3 may be any material that is flexible and biocompatible. For example, the spline 3, like the shaft 2, is made of a known resin such as polyolefin or polyamide.

[0015] The splines 3 include at least a first spline 3a and a second spline 3b that are adjacent to each other in the circumferential direction. Figures 1 and 2 show an example in which the number of splines 3 is six. Specifically, the example shows the first spline 3a and the second spline 3b, the second spline 3b and the third spline 3c, the third spline 3c and the fourth spline 3d, the fourth spline 3d and the fifth spline 3e, the fifth spline 3e and the sixth spline 3f, and the sixth spline 3f and the first spline 3a, each of which is adjacent to each other in the circumferential direction.

[0016] The spline 3 is connected to the shaft 2. As an example, a part of the spline 3 including the base end (base end) is inserted into the tip side of the shaft 2. The base end of the spline 3 and the shaft 2 are joined to each other by a known joining method such as welding or bonding with an adhesive.

[0017] The splines 3 are configured to change shape in response to a deformation operation, which will be described later. Specifically, the shape of each spline 3 changes between a non-deployed or contracted shape in which the splines 3 are not deployed in the radial direction, and a deployed or expanded shape in which the splines 3 are deployed in the radial direction. In the deployed or expanded shape, at least a portion of each spline 3 is separated from each other. FIG. 1 shows an example of the deployed shape. FIG. 2 shows an example of the non-deployed shape.

[0018] As shown in FIGS. 1 and 2, each spline 3 may have one or more electrodes 5. The electrodes 5 are ring-shaped electrodes for potential measurement or ablation. The electrodes 5 of the same spline 3 are arranged spaced apart from one another along the longitudinal direction of the spline 3. In this case, the distance between adjacent electrodes 5 may be constant or may be different. Furthermore, the number of electrodes 5 of each spline 3 may be the same or different.

[0019] The electrodes 5 are made of a conductive material. For example, the electrodes 5 are made of a metal with good electrical conductivity, such as aluminum (Al), copper (Cu), stainless steel, gold (Au), or platinum (Pt). The length of the electrodes 5 along the splines 3 is, for example, 0.5 mm to 2.0 mm. The outer diameter of the electrodes 5 may be equal to or greater than the outer diameter of the splines 3, and is, for example, 0.5 mm to 2.0 mm. The sizes of the electrodes 5 may be the same or different.

[0020] Conductive wires are individually and electrically connected to the electrodes 5. The conductive wires pass from inside the spline 3 through the shaft 2 and the handle 8 (described later) and are connected to an external power supply device via the handle 8. As an example, the conductive wires connected to the electrodes 5 of the first spline 3a pass through the lumen (not shown) of the first spline 3a while being electrically insulated from each other. The same applies to the splines 3 other than the first spline 3a.

[0021] 1 and 2, the tip member 4 may house a portion of the spline 3 including the tip (hereinafter referred to as the "tip portion"). In other words, the tip portion of the spline 3 may be covered with the tip member 4. The tip member 4 may be made of any material, but as an example, it is made of a known resin such as nylon, nylon elastomer, polycarbonate, etc., or a known metal such as stainless steel, etc.

[0022] The tip of a long deformation member 14 is fixed to the tip member 4. The deformation member 14 passes through the shaft 2, and the base end of the deformation member 14 is fixed to a slide member 13 (see Figure 7), which will be described later. The deformation member 14 has a lumen that extends in the axial direction and opens at the tip. The lumen of the deformation member 14 can accommodate a long member such as a guidewire, and the long member can protrude from the opening at the tip of the deformation member 14.

[0023] FIG. 3 is an enlarged perspective view of the tip member 4. FIG. 4 is a view of the tip member 4 as seen from the tip side in the axial direction of the catheter 1. As shown in FIG. 4, the outer shape of the tip member 4 is non-circular as seen in the axial direction. Specifically, the outer surface of the tip member 4 has at least one outer wall convex portion 22 that protrudes radially outward and at least one outer wall concave portion 24 that is recessed radially inward as seen in the axial direction. In the example shown in FIG. 3, a portion of the outer surface of the tip member 4 is formed by an outer wall 26. That is, the outer wall 26 has at least one outer wall convex portion 22 and at least one outer wall concave portion 24.

[0024] As shown in Fig. 3, the outer wall recess 24 continues from the tip side to the base end side of the tip member 4. In other words, the outer wall recess 24 is formed as a groove that continues from the tip side to the base end side of the tip member 4 on the outer surface of the tip member 4. A plurality of outer wall recesses 24 are formed on the outer surface of the tip member 4 at different positions in the circumferential direction. The number of outer wall recesses 24 may be the same as the number of splines 3. In the example shown in Fig. 3, the number of outer wall recesses 24 is six, which is the same as the number of splines 3 shown in Figs. 1 and 2 (six).

[0025] As shown in Fig. 3, the outer wall protrusions 22 are continuous from the tip end side to the base end side of the tip member 4. A plurality of outer wall protrusions 22 are formed on the outer surface of the tip member 4 at different positions in the circumferential direction. The number of outer wall protrusions 22 may be the same as the number of splines 3. In the example shown in Fig. 3, the number of outer wall protrusions 22 is six, which is the same as the number of splines 3 shown in Figs. 1 and 2 (six).

[0026] As shown in FIG. 4, outer wall convex portions 22 and outer wall concave portions 24 are formed on the outer surface of the tip member 4 so as to be alternately arranged along the circumferential direction when viewed in the axial direction. In the example shown in FIG. 4, six outer wall convex portions 22 and six outer wall concave portions 24 are arranged so as to be alternately arranged one by one. The outer shape of the tip member 4 can also be said to be petal-shaped when viewed in the axial direction. In the example shown in FIG. 4, the outer shape of the tip member 4 is curved as a whole when viewed in the axial direction. Specifically, when viewed in the axial direction, the outer wall convex portions 22, the outer wall concave portions 24, and the boundary portions between the outer wall convex portions 22 and the outer wall concave portions 24 are each continuous in a curved shape. In the example shown in FIG. 4, the outer wall convex portions 22 are arc-shaped when viewed in the axial direction. Hereinafter, the outer wall convex portions 22 will be simply referred to as convex portions, and the outer wall concave portions 24 will be simply referred to as concave portions.

[0027] Fig. 5 is a view of the tip member 4 as viewed from the base end side in the axial direction. As shown in Fig. 5, when viewed from the base end side in the axial direction, an inner wall 28 constituting the inner surface of the tip member 4 has a plurality of inner wall recesses 30 recessed radially outward and a plurality of inner wall protrusions 32 protruding radially inward at positions adjacent to the inner wall recesses 30 in the circumferential direction. When viewed from the base end side in the axial direction, the inner surface of the tip member 4 is a surface facing a space in which the tip end of the spline 3 is accommodated. The tip member 4 has an accommodation portion 34 that accommodates the tip end of the spline 3 in an area surrounded by the inner wall 28. In Fig. 5, the position where the tip end of the spline 3 is accommodated is indicated by a dashed line.

[0028] The tip end of the spline 3 is accommodated in the accommodation portion 34 at a position corresponding to the inner wall recess 30. In the example shown in FIG. 5, the inner wall recess 30 is arc-shaped. The inner wall recess 30 is disposed at a position corresponding to the outer wall protrusion 22. The inner wall protrusion 32 is disposed at a position corresponding to the outer wall recess 24. In the example shown in FIG. 5, the outer wall 26 and the inner wall 28 are configured as a common wall portion, and this wall portion has approximately the same thickness at any position in the circumferential direction. In other words, when viewed from the axial direction, the shape of the surface that constitutes the inner wall 28 is approximately similar to the shape of the surface that constitutes the outer wall 26.

[0029] The outer wall recess 24 is located between the tip ends of two adjacent splines 3 housed in the tip member 4. In other words, the tip ends of the splines 3 are housed between two adjacent outer wall recesses 24. Specifically, one outer wall recess 24 is located between each of the tip ends of all adjacent splines 3 among the plurality of splines 3. The outer wall recess 24 is aligned with the direction in which the tip end of at least one spline 3 among the plurality of splines 3 extends. In the example shown in FIG. 5 , the tip ends of all splines 3 are housed in the housing portion 34 of the tip member 4, oriented along the axial direction. In other words, in this embodiment, the outer wall recess 24 extends along the axial direction. The tip ends of the splines 3 and the tip member 4 may be joined to each other by a known joining method such as welding or bonding with an adhesive.

[0030] As shown in Figure 3, the tip member 4 has a tip surface portion 36 at the tip of the tip member 4 that forms a tip surface along a plane perpendicular to the axial direction. The tip member 4 has a boundary portion 38 located at the boundary between the tip surface portion 36 and the outer wall 26. The surface of the boundary portion 38 is smoothly continuous between the tip surface of the tip surface portion 36 and the surface that forms the outer wall 26. The side of the tip surface portion 36 opposite the tip surface, i.e., the surface on the base end side, faces the tip of the spline 3.

[0031] The tip member 4 has an opening 40 that penetrates the tip surface portion 36 in the axial direction. The elongated member protruding from the lumen of the deformation member 14 shown in FIGS. 1 and 2 can protrude distally beyond the tip member 4 through the opening 40. The lumen of the deformation member 14 and the opening 40 of the tip member 4 may be in communication. When a guidewire is used as the elongated member, the guidewire can be used as a core material of the catheter 1.

[0032] Incidentally, when the catheter 1 is moved toward the base end with a long member such as a guidewire protruding through the opening 40 of the distal end member 4, the long member may bend from a position distal to the opening 40 toward the base end, and the tip of the long member may be positioned radially outward of the outer wall 26. In this case, the tip of the long member is positioned between the surface that constitutes the outer wall 26 of the distal end member 4 and the inner circumferential surface 52 of the sheath 50 that houses the catheter 1.

[0033] FIG. 6 is a view from the distal end in the axial direction, schematically illustrating an example in which the distal end 60 of the elongated member is disposed between the outer surface of the distal end member 4 and the inner circumferential surface 52 of the sheath 50. In FIG. 6, the elongated member is not illustrated except for the distal end 60. As shown in FIG. 6, the distal end 60 of the elongated member is disposed between the outer wall recess 24 of the outer wall 26 of the distal end member 4 and the inner circumferential surface 52 of the sheath 50. Of the region between the outer wall 26 of the distal end member 4 and the inner circumferential surface 52 of the sheath 50, the region between the outer wall recess 24 and the inner circumferential surface 52 can ensure the widest circular region as viewed in the axial direction. Therefore, the distal end 60 of the elongated member is less likely to become clogged between the distal end member 4 and the inner circumferential surface 52 of the sheath 50, thereby reducing the risk of the catheter 1 becoming difficult to move relative to the sheath 50.

[0034] The boundary portion 38 of the distal end member 4 may function as a guide portion that guides the distal end 60 of the elongated member to the position of the outer wall recess 24 of the outer wall 26. Specifically, as described above, the surface of the boundary portion 38 is smoothly continuous between the distal end surface of the distal surface portion 36 and the surface that constitutes the outer wall 26. Therefore, when the elongated member is curved from a position distal to the opening 40 toward the base end, the distal end 60 of the elongated member can slide over the surface of the boundary portion 38 and be guided to the position of the outer wall recess 24.

[0035] Fig. 7 is a schematic diagram showing an example of the overall structure of the catheter 1. As shown in Fig. 7, the catheter 1 may include a handle 8 connected to the base end side of the shaft 2. The handle 8 is a portion that is gripped by an operator such as a doctor when using the catheter 1. The handle 8 may include a handle main body 11 attached to the base end side of the shaft 2, a rotation operation unit 12, and a slide member 13.

[0036] The handle body 11 corresponds to the part that the operator actually grips. The handle body 11 may have any shape. For example, the handle body 11 has a shape that extends along the central axis of the shaft 2. The handle body 11 is made of a known resin such as polycarbonate, polyacetal, ABS, etc.

[0037] The rotation operation unit 12 is a part that accepts operations such as rotation when bending or flexing the vicinity of the tip of the shaft 2 in both directions. The base ends of a pair of pull wires are fixed to the rotation operation unit 12 within the handle main body 11. The tips of the pair of pull wires pass from the handle main body 11 through the shaft 2 and are fixed to the tip side of the shaft 2. Therefore, when the rotation operation unit 12 is operated, the pull wires are pulled toward the base end, and the tip side of the shaft 2 to which the tips of the pull wires are fixed is bent or flexed.

[0038] The slide member 13 is a part that receives a deformation operation such as a sliding operation by an operator when the shape of the spline 3 is changed between the undeployed or contracted shape and the expanded or expanded shape. The slide member 13 is slidable along the central axis of the shaft 2 in the handle body 11.

[0039] The base end of the deformation member 14 is fixed to the slide member 13. The tip of the deformation member 14 passes from inside the handle main body 11 through the shaft 2 and is fixed inside the tip member 4. The slide member 13 is movable to any position along the central axis of the shaft 2 in the handle main body 11. Therefore, depending on the position of the slide member 13, the shape of the spline 3 can be deformed to the undeployed shape or contracted shape, the deployed shape or expanded shape, or any intermediate shape between the undeployed shape and the deployed shape.

[0040] [Second embodiment] 8 is a perspective view schematically showing a tip member 4A of a catheter according to a second embodiment. The catheter according to this embodiment has a tip member 4A instead of the tip member 4 of the catheter 1 according to the first embodiment. The catheter according to this embodiment has the same configuration as the catheter 1 according to the first embodiment except for the tip member 4A, and therefore, description thereof will be omitted where appropriate.

[0041] The distal end surface formed by the distal end surface portion 36A of the distal end member 4A has a shape that curves radially outward toward the base end. This allows the distal end surface portion 36A to function as a guide portion that guides the distal end 60 of the elongated member to the position of the outer wall recess 24 of the outer wall 26. Specifically, because the distal end surface of the distal end surface portion 36A has a shape that curves radially outward toward the base end, when the elongated member curves from a position distal to the opening 40 toward the base end, the distal end 60 of the elongated member slides over the distal end surface of the distal end surface portion 36A and is easily guided to the position of the outer wall recess 24. Furthermore, the curved shape of the distal end surface of the distal end surface portion 36A can make it less likely to injure body tissue.

[0042] The embodiments of the present disclosure have been described in detail above. The above-described embodiments merely illustrate specific examples of implementing the present disclosure. The content of the embodiments does not limit the technical scope of the present disclosure, and many design modifications, such as changes, additions, and deletions of components, are possible within the scope of the concept of the present disclosure defined in the claims. A new embodiment with a design modification combines the effects of the combined embodiments and modifications. Any combination of components included in each embodiment is also effective as an aspect of the present disclosure. Hatching on cross sections in the drawings does not limit the material of the hatched objects.

[0043] For example, although the direction in which the outer wall recess 24 extends is described as being along the axial direction, the direction in which the outer wall recess 24 extends does not necessarily have to be along the axial direction.

[0044] The distal end member 4 may also be polygonal when viewed from the distal end side in the axial direction. In this case, the splines 3 may be accommodated at positions corresponding to the vertices of the polygon. In other words, the number of splines 3 may be the same as the number of vertices of the polygon. In this case, the distal end of an elongated member such as a guidewire may be positioned at the position of the straight line portion between adjacent vertices of the polygon. The vertices of the polygon may be chamfered.

[0045] The embodiments may be specified by the following items.

[0046] [1st item] a shaft (2) to be inserted into the body; a plurality of splines (3) connected to the tip side of the shaft (2); and a tip member (4) connected to the tip side of each of the plurality of splines (3), The outer shape of the tip member (4) is non-circular when viewed from the central axis direction of the shaft (2). Catheter (1).

[0047] According to the catheter 1 of the first aspect, the outer shape of the distal end member 4 is non-circular when viewed from the central axis direction, and therefore, when the catheter 1 is inserted into the lumen of a sheath, a gap is likely to form between the inner circumferential surface 52 of the sheath and the distal end member 4. Therefore, even if another member gets between the distal end member 4 and the inner circumferential surface 52 of the sheath 50, it is possible to reduce the risk that the catheter 1 will become difficult to move relative to the sheath 50.

[0048] [Second item] The catheter (1) according to item 1, wherein a continuous groove is formed on the outer surface of the tip member (4) from the tip side to the base end side of the tip member (4).

[0049] According to the catheter 1 of the second aspect, another member can be placed at a position corresponding to the groove formed on the outer surface of the distal end member 4, and the other member can pass through the distal end to the proximal end of the distal end member 4. Therefore, even if the other member gets between the distal end member 4 and the inner circumferential surface 52 of the sheath 50, the other member is prevented from getting stuck between the distal end member 4 and the inner circumferential surface 52 of the sheath 50, and the catheter 1 is prevented from becoming difficult to move relative to the sheath.

[0050] [3rd item] The tip member (4) accommodates the tip portions of the plurality of splines (3), The groove is aligned along the direction in which the tip of at least one of the plurality of splines (3) extends. A catheter (1) as described in item 2.

[0051] According to the catheter 1 of the third aspect, the groove formed in the distal end member 4 is aligned with the direction in which the distal end of the spline 3 extends, and therefore the groove can be disposed, for example, at a position adjacent to the position where the distal end member 4 accommodates the spline 3. Therefore, the groove can be formed without impairing the function of the distal end member 4 to bundle the multiple splines 3.

[0052] [4th item] The groove is located between the tips of adjacent splines (3) among the plurality of splines (3). A catheter (1) as described in item 3.

[0053] According to the catheter (1) relating to the fourth item, the groove can be formed by utilizing the space between the tip ends of the adjacent splines (3).

[0054] [Item 5] The tip member (4) has a plurality of grooves formed at different positions in the circumferential direction around the central axis of the shaft (2), A groove is located between the tip portions of all adjacent splines (3) among the plurality of splines (3). A catheter (1) as described in item 4.

[0055] According to the catheter (1) relating to the fifth item, grooves can be formed by utilizing the spaces between the respective tip ends of all adjacent splines (3).

[0056] [Item 6] On the outer surface of the tip member (4), at least one convex portion (22) protruding away from the central axis in the radial direction around the central axis of the shaft (2) and at least one concave portion (24) recessed toward the central axis in the radial direction are formed when viewed from the axial direction. A catheter (1) according to any one of items 1 to 5.

[0057] According to the catheter (1) relating to the sixth item, the shape of the tip member (4) can be adapted to the shape of the spline (3) to be housed therein, while being able to prevent other members from getting stuck between the tip member (4) and the inner circumferential surface (52) of the sheath (50).

[0058] [Item 7] On the outer surface of the tip member (4), convex portions (22) and concave portions (24) are formed so as to be alternately arranged along the circumferential direction around the central axis of the shaft (2) when viewed from the axial direction. A catheter (1) as described in item 6.

[0059] According to the catheter (1) relating to the seventh item, the shape of the tip member (4) can be adapted to the shape of each of the plurality of splines (3) contained therein, while being able to prevent other members from getting stuck between the tip member (4) and the inner circumferential surface (52) of the sheath (50).

[0060] [Item 8] The outer shape of the tip member (4) is polygonal when viewed from the central axis direction. The catheter (1) according to item 1.

[0061] According to the catheter 1 of the eighth aspect, the outer shape of the tip member 4 can be adapted to the shape of the splines 3 to be housed therein, while being able to prevent other members from getting stuck between the tip member 4 and the inner circumferential surface 52 of the sheath 50. Furthermore, when the tip member 4 is machined to have a polygonal shape as viewed from the tip side in the axial direction, this can be done relatively easily. [Explanation of symbols]

[0062] 1...catheter, 2...shaft, 3...spline, 4, 4A...tip member, 22...outer wall convex portion, 24...outer wall concave portion.

Claims

1. a shaft to be inserted into the body; a plurality of splines connected to a tip end side of the shaft; a tip member connected to a tip side of each of the plurality of splines, The outer diameter of the tip member is non-circular when viewed from the central axis direction of the shaft. catheter.

2. The catheter according to claim 1 , wherein a groove is formed on the outer surface of the tip member, the groove continuing from the distal end side to the proximal end side of the tip member.

3. the tip member accommodates tip portions of the plurality of splines, the groove is aligned along a direction in which a tip end portion of at least one of the plurality of splines extends; The catheter of claim 2.

4. The groove is located between the tip ends of adjacent splines among the plurality of splines. The catheter of claim 3.

5. The tip member has a plurality of grooves formed at different positions in a circumferential direction around the central axis of the shaft, The groove is located between the tip ends of all adjacent splines among the plurality of splines. The catheter of claim 4.

6. On the outer surface of the tip member, as viewed from the central axis direction, at least one convex portion protruding on a side away from the central axis in a radial direction around the central axis of the shaft and at least one concave portion recessed on a side approaching the central axis in the radial direction are formed. A catheter according to any one of claims 1 to 5.

7. On the outer surface of the tip member, the convex portions and the concave portions are formed so as to be alternately arranged along a circumferential direction with the central axis of the shaft as the center, as viewed from the central axis direction. The catheter of claim 6.

8. The outer shape of the tip member is polygonal when viewed from the central axis direction. The catheter of claim 1.

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