Catheter

Abstract

This catheter comprises: an inner layer; a reinforcing layer arranged outside the inner layer and formed from a linear reinforcing material; and an outer layer covering the inner layer and the reinforcing layer. The reinforcing layer has, in a first section including at least a distal end of the reinforcing layer, a separation portion in which the reinforcing material is arranged with a gap from an outer surface of the inner layer, and a proximity portion in which the reinforcing material is arranged at a position closer to the outer surface of the inner layer than the separation portion, and a portion of the outer layer is arranged in the gap of the separation portion.

Description

catheter

[0001] The present disclosure relates to catheters.

[0002] Catheters used in percutaneous procedures are known. For example, Patent Document 1 discloses a catheter including a smooth layer, a reinforcing layer, and a covering layer, in which the reinforcing layer has a braided structure in the proximal section and a spiral structure in the extension section. Patent Document 2 discloses a catheter including an inner section, a reinforcing layer, and an outer section, in which a braid and a coil are used as the reinforcing layer. The smooth layer and the inner section are also referred to as the "inner layer." The covering layer and the outer section are also referred to as the "outer layer."

[0003] Patent Publication No. 2012-531224 International Publication No. 2020 / 188823 Pamphlet

[0004] In percutaneous procedures, the surgeon pushes the catheter along a curved blood vessel, so the distal end of the catheter is required to have flexibility to bend along the curved shape of the blood vessel. The catheters described in Patent Documents 1 and 2 have a structure in which a cylindrical space is provided between the outer peripheral surface of the inner layer and the inner peripheral surface of the outer layer, and a reinforcing layer is disposed in this space. Therefore, the catheters described in Patent Documents 1 and 2 have a problem in that they are low in flexibility and difficult to deliver. Furthermore, the catheters described in Patent Documents 1 and 2 have low adhesion between the inner layer and the reinforcing layer, and between the outer layer and the reinforcing layer, so there is a risk of the reinforcing layer peeling off when the catheter is bent.

[0005] The present disclosure has been made to solve at least part of the above-mentioned problems, and can be realized in the following forms.

[0006] According to one aspect of the present disclosure, there is provided a catheter comprising: an inner layer; a reinforcing layer disposed outside the inner layer, the reinforcing layer having a distal end and a proximal end and formed of a reinforcing material extending in the longitudinal direction of the catheter; and an outer layer covering the inner layer and the reinforcing layer. The reinforcing layer has, in a first section including at least the distal end of the reinforcing layer, a spaced portion where the reinforcing material is disposed with a gap from the outer surface of the inner layer, and a proximal portion where the reinforcing material is disposed closer to the outer surface of the inner layer than the spaced portion, and a part of the outer layer is disposed in the gap in the spaced portion.

[0007] FIG. 3 is an explanatory diagram illustrating the configuration of a catheter. FIG. 4 is a diagram showing the external configuration of a reinforcing layer near the boundary between the first section and the second section. FIG. 5 is a cross-sectional view of the catheter taken along line A1-A1 in FIG. 2. FIG. 6 is a cross-sectional view of the catheter taken along line A2-A2 in FIG. 2. FIG. 7 is a cross-sectional view of the catheter taken along line A3-A3 in FIG. 2. FIG. 8 is a diagram illustrating the arrangement of a separation portion. FIG. 9 is an explanatory diagram illustrating the configuration of a catheter of a second embodiment. FIG. 10 is a diagram showing a cross-section of a catheter of a third embodiment taken along line A1-A1 in FIG. 2.

[0008] <First embodiment> Fig. 1 is an explanatory diagram illustrating the configuration of a catheter 1. The catheter 1 is used in percutaneous procedures. The catheter 1 is inserted into a body lumen such as the vascular system, lymphatic system, biliary system, urinary system, respiratory system, digestive system, secretory glands, and reproductive organs. The catheter 1 includes a shaft portion 10, a distal tip 30 attached to the distal end of the shaft portion 10, and a connector 90 attached to the proximal end of the shaft portion 10. In this embodiment, a single-lumen guiding catheter is exemplified as the catheter 1.

[0009] For ease of explanation, Figure 1 includes some parts in which the relative size ratios of the components differ from the actual ratios. Figure 1 also includes exaggerated views of some of the components. Figure 1 illustrates mutually orthogonal X, Y, and Z axes. The X axis corresponds to the longitudinal direction of the catheter 1 and each component. The X axis corresponds to the axial direction of the catheter 1 and each component. The Y axis corresponds to the height direction of the catheter 1 and each component. The Z axis corresponds to the width direction of the catheter 1 and each component. The -X axis direction is referred to as the "distal side" of the catheter 1 and each component. The +X axis direction is referred to as the "proximal side" of the catheter 1 and each component. Hereinafter, of the longitudinal ends of the catheter 1 and each component, the end located on the distal side will be referred to as the "distal end," and the other end located on the proximal side will be referred to as the "proximal end." The distal end and its vicinity will be referred to as the "distal portion," and the proximal end and its vicinity will be referred to as the "proximal end." The distal end will be inserted into the living body, and the proximal end will be manipulated by a surgeon, such as a doctor. These points are also common to Figure 2 and subsequent figures. In this embodiment, "same" and "equal" mean roughly the same, and allow for blurring due to manufacturing errors, etc. In this embodiment, "constant" also means roughly constant, and allow for blurring due to manufacturing errors, etc.

[0010] The shaft portion 10 is a cylindrical member extending in the longitudinal direction of the catheter 1. The shaft portion 10 is tubular. A lumen for inserting another medical device is formed inside the shaft portion 10. As shown in FIG. 1 , the shaft portion 10 has a first section 11 and a second section 12. The first section 11 is a section corresponding to the distal end of the shaft portion 10. The length of the first section 11 can be, for example, approximately 10 mm from the distal end of the shaft portion 10. The length of the first section 11 can be determined arbitrarily. The second section 12 is a section of the shaft portion 10 located closer to the proximal end than the first section 11. The second section 12 extends from the proximal end of the first section 11 to the proximal end of the shaft portion 10.

[0011] The distal tip 30 is an annular member disposed at the distal end of the shaft portion 10. The distal tip 30 is joined to the distal end of the shaft portion 10. An opening 1a connected to the lumen of the shaft portion 10 is provided at the distal end of the distal tip 30. The distal tip 30 can be formed from either a radiopaque resin material or a radiopaque metal material. Examples of radiopaque resin materials include a mixture of at least one of polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin, and fluororesin with a radiopaque material such as bismuth trioxide, tungsten, or barium sulfate. Examples of radiopaque metal materials include gold, platinum, tungsten, and alloys containing these elements. Forming the distal tip 30 from a radiopaque material allows the surgeon to visually confirm the distal position of the catheter 1 under X-ray images. The distal tip 30 may also be formed from a known non-radiopaque resin material.

[0012] The connector 90 is disposed at the proximal end of the shaft portion 10 and is used by the surgeon when operating the catheter 1. The connector 90 includes a main body 91 and wing portions 92. The main body 91 is a cylindrical body having an outer shape in which the outer diameter decreases from the proximal end to the distal end. The proximal end of the shaft portion 10 is inserted and fixed at the distal end of the main body 91. The proximal end of the main body 91 is provided with an opening 1b connected to the lumen of the shaft portion 10. The surgeon can insert other medical devices into the lumen of the shaft portion 10 through the opening 1b. The wing portions 92 extend from the outer surface of the main body 91 in the ±Y-axis directions. The wing portions 92 are used by the surgeon when gripping the catheter 1. The main body 91 and wing portions 92 may be integrally formed or may be formed as separate components. The connector 90 may be formed from a resin material. Examples of resin materials include polycarbonate, polyamide, polysulfone, polyurethane, polypropylene, and rigid polyvinyl chloride.

[0013] Fig. 2 is a diagram showing the external configuration of the reinforcing layer 50 near the boundary between the first section 11 and the second section 12. Fig. 2 shows the external appearance of only the reinforcing layer 50 in a portion PA of the shaft portion 10 that includes the boundary between the first section 11 and the second section 12. The portion PA is indicated by a dashed line in Fig. 1. Fig. 3 is a cross-sectional view of the catheter 1 taken along line A1-A1 in Fig. 2. Fig. 4 is a cross-sectional view of the catheter 1 taken along line A2-A2 in Fig. 2. Fig. 5 is a cross-sectional view of the catheter 1 taken along line A3-A3 in Fig. 2.

[0014] As shown in Figures 3 to 5, the shaft portion 10 of the catheter 1 comprises, from the inside to the outside, an inner layer 60, a reinforcing layer 50, and an outer layer 70. The inner layer 60 is a tubular body made of a resin material. The inner layer 60 is located at the innermost part of the shaft portion 10. The interior of the inner layer 60 forms the lumen 1L of the catheter 1. The inner layer 60 is provided over the entire length of the shaft portion 10 from its distal end to its proximal end. The inner layer 60 can be formed of, for example, a fluororesin such as PTFE or polyethylene. The outer layer 70 is a tubular body made of a resin material. The outer layer 70 is located at the outermost part of the shaft portion 10. The outer layer 70 covers the inner layer 60 and the reinforcing layer 50. The outer layer 70 is provided over the entire length of the shaft portion 10 from its distal end to its proximal end. The outer layer 70 can be formed of, for example, at least one of polyamide, polyamide elastomer, polyester, polyester elastomer, polyurethane, and polyurethane elastomer.

[0015] The reinforcing layer 50 is a member formed of linear reinforcing material. The reinforcing material in this embodiment includes first wires 51 and second wires 52. Hereinafter, either or both of the first wires 51 and the second wires 52 may be referred to as the "reinforcing material." The reinforcing layer 50 is disposed outside the inner layer 60. As shown in FIGS. 3 to 5 , the reinforcing layer 50 is embedded inside the outer layer 70.

[0016] As shown in FIG. 2 , the reinforcing layer 50 in the first section 11 is a multi-strand coil formed by winding the second wire 52 in multiple strands. The multiple strands can be, for example, eight strands. The reinforcing layer 50 in the first section 11 is missing the first wire 51 and is formed only by the second wire 52. As shown in FIG. 3 , in a cross section of the first section 11 of the catheter 1, some of the second wires 52 are positioned with a gap G from the outer surface 60a of the inner layer 60. The portion where the second wires 52 are positioned with a gap G from the inner layer 60 is also referred to as the "separated portion P1." In FIG. 3 , the separated portion P1 is surrounded by a dashed line. Specifically, the second wires 523, 524, 527, and 528 are positioned away from the outer surface 60a of the inner layer 60, and a gap G exists between them. In the illustrated example, the size of the gap G is constant. The size of the gap G may be different from each other in at least some of the second wires 523, 524, 527, and 528.

[0017] As shown in Figure 3, in the cross section of the first section 11 of the catheter 1, the remaining second wire rod 52 is positioned closer to the outer surface 60a of the inner layer 60 than the separated portion P1. In this embodiment, a portion of the inner surface of the second wire rod 52 is in contact with a portion of the outer surface 60a of the inner layer 60. The portion of the second wire rod 52 positioned closer to the inner layer 60 is also referred to as the "proximal portion P2." In Figure 3, the proximal portion P2 is surrounded by a two-dot chain line. Specifically, portions of the inner surfaces of the second wire rods 521, 522, 525, and 526 are in contact with a portion of the outer surface 60a of the inner layer 60.

[0018] A portion of the outer layer 70 is disposed in the gap G of the separated portion P1. In other words, in the catheter 1, the gap G between the second wire 52 and the outer surface 60a of the inner layer 60 is filled with the outer layer 70. In the example of Fig. 3, two separated portions P1 and two adjacent portions P2 are alternately provided in the circumferential direction of the catheter 1. One separated portion P1 and one adjacent portion P2 may also be alternately provided in the circumferential direction of the catheter 1.

[0019] As shown in FIG. 2 , the reinforcing layer 50 in the second section 12 has a mesh shape in which first wires 51 and second wires 52 are woven together. The specific structure of the mesh shape is not particularly limited. For example, the specific structure of the mesh shape may be a multi-strand braid structure in which multiple first wires 51 and multiple second wires 52 are braided together. The second wires 52 in the second section 12 are continuous with the second wires 52 in the spaced portion P1. For example, the second wire 521 shown in FIG. 3 and the second wires 521 shown in FIGS. 4 and 5 are a single strand extending helically in the longitudinal direction of the catheter 1. This also applies to the second wires 522 to 528.

[0020] 4 is a cross-sectional view of the catheter 1 in a portion of the second section 12 where the first wire 51 and the second wire 52 do not overlap. As shown in FIG. 4 , in the portion of the second section 12 where the first wire 51 and the second wire 52 do not overlap, the first wire 51 and the second wire 52 are alternately arranged in the circumferential direction of the catheter 1. In the illustrated example, a portion of the inner surface of the first wire 51 contacts a portion of the outer surface 60a of the inner layer 60. A portion of the inner surface of the second wire 52 contacts a portion of the outer surface 60a of the inner layer 60. The inner surface of the first wire 51 and the outer surface 60a of the inner layer 60 may be separated from each other as long as the distance between the first wire 51 and the inner layer 60 is smaller than the gap G. The inner surface of the second wire 52 and the outer surface 60a of the inner layer 60 may be separated from each other as long as the distance between the second wire 52 and the inner layer 60 is smaller than the gap G. A portion of the outer layer 70 is disposed between the first wire rod 51 and the second wire rod 52 that are adjacent to each other in the circumferential direction. For example, a portion of the outer layer 70 is disposed between the side surface of the first wire rod 511 and the side surface of the second wire rod 521. This also applies to the first wire rods 512 to 518 and the second wire rods 522 to 528.

[0021] 5 is a cross-sectional view of the catheter 1 at a portion of the second section 12 where the first wire 51 and the second wire 52 overlap. As shown in FIG. 5 , in the portion of the second section 12 where the first wire 51 and the second wire 52 overlap, the first wire 51 and the second wire 52 are arranged in a stacked state in the circumferential direction of the catheter 1. In the illustrated example, two pairs in which the second wire 52 is arranged on the inner layer 60 side and two pairs in which the first wire 51 is arranged on the inner layer 60 side are alternately arranged in the circumferential direction of the catheter 1. The pairs in which the second wire 52 is arranged on the inner layer 60 side are the pair of the first wire 511 and the second wire 521, the pair of the first wire 512 and the second wire 522, the pair of the first wire 515 and the second wire 525, and the pair of the first wire 516 and the second wire 526. The pairs in which the first wire 51 is arranged on the inner layer 60 side are a pair of the first wire 513 and the second wire 523, a pair of the first wire 514 and the second wire 524, a pair of the first wire 517 and the second wire 527, and a pair of the first wire 518 and the second wire 528. The pair in which the second wire 52 is arranged on the inner layer 60 side and the pair in which the first wire 51 is arranged on the inner layer 60 side may be alternately arranged one by one. A portion of the outer layer 70 is arranged between each pair of the first wire 51 and the second wire 52.

[0022] The first wire 51 is formed of a first metal having a first ionization tendency. In this embodiment, stainless steel is used as the first metal. That is, the first wire 51 is made of stainless steel. Instead of stainless steel, any of zinc, nickel, nickel titanium, cobalt chromium, and copper may be used as the first metal. The second wire 52 is formed of a second metal having a second ionization tendency. The second ionization tendency is smaller than the first ionization tendency. In this embodiment, tungsten is used as the second metal. That is, the second wire 52 is made of tungsten. Instead of tungsten, any of gold and platinum may be used as the second metal. By utilizing the difference between the first ionization tendency of the first wire 51 and the second ionization tendency of the second wire 52, the first wire 51 corresponding to the first section 11 can be selectively removed.

[0023] In the example of Figure 4, the first wire rod 51 and the second wire rod 52 have a rectangular cross section. The shapes of the first wire rod 51 and the second wire rod 52 are not limited to this. In the example of Figure 4, in the cross section, the width of the first wire rod 51 is greater than the width of the second wire rod 52, and the height of the first wire rod 51 is greater than the height of the second wire rod. The shapes of the first wire rod 51 and the second wire rod 52 are not limited to the example shown. The width of the first wire rod 51 is the length in the longitudinal direction of the rectangular shape of the first wire rod 51. The width of the second wire rod 52 is the length in the lateral direction of the rectangular shape of the second wire rod 52.

[0024] The reinforcing layer 50 of the catheter 1 described above is fabricated, for example, by selectively removing the first wires 51 corresponding to the first section 11 from a braided body in which the first wires 51 and the second wires 52 are woven together. One example of a method for selectively removing the first wires 51 in this manner is a method that utilizes the difference between the first ionization tendency of the first wires 51 and the second ionization tendency of the second wires 52, specifically, electrolytic polishing. Another example of a method for selectively removing the first wires 51 is a method of immersing the braided body in a good solvent for the first wires 51. An example of a good solvent is hydrochloric acid. The removal method is not limited to the above and can be selected appropriately depending on the material of the reinforcing material, the manufacturing environment, and the like. The operator places the reinforcing layer 50 fabricated in this manner between a tube that will form the inner layer 60 and a tube that will form the outer layer 70, and then performs, for example, a heat treatment, to fabricate the catheter 1. The method for producing the catheter 1 is not limited to the above, and can be selected appropriately depending on the material of the tube, the manufacturing environment, etc.

[0025] The reinforcing layer 50 of the first embodiment has a multi-filament coil shape in the first section 11 and a mesh shape in the second section 12. That is, the reinforcing layer 50 has different shapes in the first section 11 and the second section 12.

[0026] In the reinforcing layer 50 of the first embodiment, the second wires 52 are deformed in the first section 11 compared to a normal multi-filament coil. This shape is obtained, for example, by removing the first wires 51 from a braided body in which the first wires 51 and the second wires 52 are woven in a mesh pattern. As a result of the deformation of the second wires 52, the amount of metal in the second wires 52 in the first section 11 can be increased compared to a normal multi-filament coil. The increased amount of metal can improve the visibility of the reinforcing layer 50 under X-ray images. The increased amount of metal can make the reinforcing layer 50 less susceptible to crushing.

[0027] FIG. 6 is a diagram illustrating the arrangement of the spaced portions P1. FIG. 6 shows imaginary lines VL1 and VL2 parallel to the axial line O of the catheter 1. The imaginary lines VL1 and VL2 are straight lines extending in a direction parallel to the longitudinal direction of the catheter 1. As shown in FIG. 6, in the first section 11, the reinforcing layer 50 includes a plurality of spaced portions P1. The spaced portions P1 located on the imaginary line VL1 are also referred to as the first spaced portion P11, the second spaced portion P12, the third spaced portion P13, and the fourth spaced portion P14. The first spaced portion P11, the second spaced portion P12, the third spaced portion P13, and the fourth spaced portion P14 are arranged side by side along the imaginary line VL1. Similarly, three spaced portions P1 are arranged on the imaginary line VL2. Furthermore, at a position approximately 180 degrees opposite the imaginary line VL1 in the circumferential direction of the catheter 1, the reinforcing layer 50 also includes a plurality of spaced-apart portions P1 arranged side by side along an imaginary line parallel to the longitudinal direction of the catheter 1. At a position approximately 180 degrees opposite the imaginary line VL2 in the circumferential direction of the catheter 1, the reinforcing layer 50 also includes a plurality of spaced-apart portions P1 arranged side by side along an imaginary line parallel to the longitudinal direction of the catheter 1.

[0028] Thus, in the first section 11, the reinforcing layer 50 includes a plurality of spaced portions P1 arranged side by side in a direction parallel to the longitudinal direction of the catheter 1. In other words, as shown by the dashed circle in Figure 6, the gaps G of the spaced portions P1 extend in a direction parallel to the longitudinal direction of the catheter 1.

[0029] As described above, the catheter 1 of the first embodiment has a gap P1 in which the second wire 52 serving as a reinforcing material is disposed at a gap G from the outer surface 60a of the inner layer 60, as shown in FIG. 3 . This improves the flexibility of the catheter 1 compared to a configuration without the gap G. Furthermore, because a portion of the outer layer 70 is disposed in the gap G, the adhesion between the reinforcing layer 50 and the outer layer 70 is improved compared to a configuration in which the reinforcing layer is disposed in the cylindrical space between the inner and outer layers. As a result, even if the catheter 1 is made more flexible due to the improved flexibility of the catheter 1, the improved adhesion between the reinforcing layer 50 and the outer layer 70 prevents the reinforcing layer 50 from peeling off from the outer layer 70. As a result, the flexibility and robustness of the catheter 1 can be ensured.

[0030] According to the catheter 1 of the first embodiment, flexibility and robustness of the catheter 1 can be ensured in the first section 11, which corresponds to the distal end of the catheter 1. In the second section 12, which corresponds to the proximal end of the catheter 1, the reinforcing layer 50, which is stronger than the first section 11, can transmit force applied to the proximal end of the catheter 1 to the distal end of the catheter 1. As a result, the pushability of the catheter 1 can be ensured.

[0031] 6, in the catheter 1 of the first embodiment, a plurality of separation portions P1, each having a gap G between the second wire 52 and the inner layer 60, are arranged in a direction parallel to the longitudinal direction of the catheter 1. This further improves the flexibility of the catheter 1.

[0032] According to the catheter 1 of the first embodiment, as shown in Figure 3, in the adjacent portion P2, a portion of the inner surface of the second wire 52 is in contact with a portion of the outer surface 60a of the inner layer 60, thereby improving the adhesion between the reinforcing layer 50 and the inner layer 60.

[0033] According to the catheter 1 of the first embodiment, the first wire 51 is formed of a first metal having a first ionization tendency, and the second wire 52 is formed of a second metal having a second ionization tendency. Therefore, by utilizing the difference between the first ionization tendency of the first wire 51 and the second ionization tendency of the second wire 52, a separation portion P1 having a gap G between the reinforcing layer 50 and the inner layer 60 can be easily formed by an appropriate method of removing the first wire 51 corresponding to the first section 11. An example of an appropriate method is electrolytic polishing.

[0034] According to the catheter 1 of the first embodiment, the first metal is stainless steel and the second metal is tungsten, which provides the reinforcing layer 50 with sufficient mechanical strength and also provides the catheter 1 with radiopacity.

[0035] In the catheter 1 of the first embodiment, the first wires 51 are formed from a first material, and the second wires 52 are formed from a second material different from the first material. The first material and the second material may have different good solvents. A good solvent is a solvent that has a strong dissolving power for a specific solute. In this way, for example, by immersing a braid formed by weaving the first wires 51 and the second wires 52 in a good solvent for the first wires 51, a separation portion P1 having a gap G between the reinforcing layer 50 and the inner layer 60 can be formed.

[0036] Second Embodiment Fig. 7 is an explanatory diagram illustrating the configuration of a catheter 1A of a second embodiment. The catheter 1A has the configuration described in the first embodiment, but includes a shaft portion 10A instead of the shaft portion 10. As shown in Fig. 7, the shaft portion 10A differs from the first embodiment only in the lengths of the first section 11A and the second section 12A. The first section 11A is a section from the distal end of the shaft portion 10A to the center of the shaft portion 10A in the longitudinal direction. In other words, the first section 11A includes the distal end of the shaft portion 10A and the distal side of the central section of the shaft portion 10A. The second section 12A is a section located closer to the proximal end than the first section 11A. The second section 12A includes the proximal end of the shaft portion 10A and the proximal side of the central section of the shaft portion 10A.

[0037] As described above, the configuration of the shaft portion 10A can be modified in various ways, and the range of the first section 11A can be modified as desired as long as it includes at least the tip end of the shaft portion 10A. The second embodiment can also achieve the same effects as the first embodiment described above.

[0038] <Third embodiment> Figure 8 is a cross-sectional view of a catheter 1B of a third embodiment taken along line A1-A1 in Figure 2. The catheter 1B has the same configuration as in the first embodiment, except that it includes an inner layer 60B instead of the inner layer 60. As shown in Figure 8, the inner layer 60B has a first inner layer 61 and a second inner layer 62.

[0039] The second inner layer 62 is a tube body formed from a resin material. The second inner layer 62 is disposed at the innermost portion of the shaft portion 10. The interior of the second inner layer 62 is the lumen 1L. The second inner layer 62 is provided over the entire length of the shaft portion 10 from the distal end to the proximal end. The first inner layer 61 is a tube body formed from a resin material. The first inner layer 61 is disposed between the second inner layer 62 and the outer layer 70. The first inner layer 61 covers the second inner layer 62. The first inner layer 61 is provided over the entire length of the shaft portion 10 from the distal end to the proximal end. The resin material forming the first inner layer 61 and the resin material forming the second inner layer 62 may be the same or different. In this embodiment, the outer surface 60a of the inner layer 60B refers to the outer surface of the first inner layer 61.

[0040] As described above, the configuration of the inner layer 60B can be modified in various ways, and the inner layer 60B may be composed of multiple layers. The number of layers of the inner layer 60B can be any number equal to or greater than 2. The third embodiment can also achieve the same effects as the first embodiment described above.

[0041] <Modifications of this embodiment> The present disclosure is not limited to the above-described embodiment, and can be implemented in various forms without departing from the gist thereof. For example, the following modifications are also possible.

[0042] [Modification 1] In the first to third embodiments described above, the configurations of the catheters 1, 1A, and 1B are illustrated. Various modifications are possible to the configurations of 1, 1A, and 1B. For example, the catheter 1 may be a microcatheter. For example, the catheter 1 may be a balloon catheter having a balloon at the tip of the shaft portion 10. For example, the catheter 1 may be any other catheter.

[0043] For example, the catheter 1 may be a multi-lumen catheter having two or more lumens. In this case, the operator may realize the multi-lumen by providing a separate tube body inside the inner layer 60. The operator may realize the multi-lumen by bundling two or more shaft portions 10 with a separate outer tube. The operator may realize the multi-lumen by using an inner layer 60 with multiple lumens pre-formed.

[0044] In the first to third embodiments, the configuration of the reinforcing layer 50 has been exemplified. The configuration of the reinforcing layer 50 can be modified in various ways. For example, FIG. 3 shows an example in which a portion of the inner surface of the second wire 52 and a portion of the outer surface 60a of the inner layer 60 are in contact with each other in the adjacent portion P2. The inner surface of the second wire 52 and the outer surface 60a of the inner layer 60 do not have to be in contact with each other in the adjacent portion P2. In this case, the size of the gap between the second wire 52 and the inner layer 60 in the adjacent portion P2 is smaller than the gap G in the separated portion P1.

[0045] 6, for example, the reinforcing layer 50 includes a plurality of spaced portions P1 arranged side by side along imaginary lines VL1 and VL2 parallel to the longitudinal direction of the catheter 1. The plurality of spaced portions P1 of the reinforcing layer 50 do not have to be arranged side by side in a direction parallel to the longitudinal direction of the catheter 1. In other words, each of the spaced portions P1 may be located at a position deviated from the imaginary lines VL1 and VL2.

[0046] For example, the number of the first wires 51 and the second wires 52 included in the reinforcing layer 50 may be changed as appropriate. For example, the number of the first wires 51 and the second wires 52 may be 4, 8, 16, or 32. The number of the first wires 51 and the number of the second wires 52 included in the reinforcing layer 50 may be different.

[0047] [Modification 2] The configurations of the catheters 1, 1A, and 1B of the first to third embodiments and the configuration of the sensor-equipped catheters 1, 1A, and 1B of Modification 1 may be combined as appropriate. For example, the catheter 1A having the length of the first section 11A of the second embodiment may be provided with the inner layer 60B described in the third embodiment.

[0048] This aspect has been described above based on embodiments and modifications. The above-described embodiments of the aspect are intended to facilitate understanding of this aspect and are not intended to limit this aspect. This aspect may be modified or improved without departing from the spirit and scope of the claims, and equivalents thereof are included in this aspect. If a technical feature is not described as essential in this specification, it may be deleted as appropriate.

Claims

1. A catheter (1, 1A, 1B) comprising: an inner layer (60, 60B); a reinforcing layer (50) arranged outside the inner layer (60, 60B), the reinforcing layer (50) being formed of linear reinforcing materials (51, 52); and an outer layer (70) covering the inner layer (60, 60B) and the reinforcing layer (50), wherein the reinforcing layer (50) has, in a first section including at least the tip of the reinforcing layer (50), a spaced portion (P1) where the reinforcing materials (51, 52) are arranged with a gap from the outer surface of the inner layer (60, 60B), and a proximal portion (P2) where the reinforcing materials (51, 52) are arranged at a position closer to the outer surface of the inner layer (60, 60B) than the spaced portion (P1), A catheter (1, 1A, 1B) in which a part of the outer layer (70) is disposed in the gap of the separated portion (P1).

2. A catheter (1, 1A, 1B) according to claim 1, wherein the reinforcing layer (50) has a second section (12, 12A) closer to the base end than the first section (11, 11A), and the gap in the separation portion (P1) is a space created by the loss of a portion of the reinforcing material (51, 52) forming the reinforcing layer (50) in the second section (12, 12A).

3. A catheter (1, 1A, 1B) according to claim 2, wherein the reinforcing material (51, 52) includes a first wire (51) and a second wire (52), the reinforcing layer (50) has a mesh shape in the second section (12, 12A) in which the first wire (51) and the second wire (52) are woven together, the reinforcing layer (50) is missing the first wire (51) in the first section (11, 11A), the separated portion (P1) is a portion in which the second wire (52) is arranged with a gap from the outer surface of the inner layer (60, 60B), and the adjacent portion (P2) is a portion in which the second wire (52) is arranged closer to the outer surface of the inner layer (60, 60B) than the separated portion (P1), 4. A catheter (1, 1A, 1B) according to claim 3, wherein the first wire (51) is formed from a first metal having a first ionization tendency, and the second wire (52) is formed from a second metal having a second ionization tendency smaller than the first ionization tendency.

5. A catheter (1, 1A, 1B) according to claim 4, wherein the first metal is stainless steel and the second metal is tungsten.

6. A catheter (1, 1A, 1B) according to claim 3, wherein the first wire (51) is made of a first material, the second wire (52) is made of a second material different from the first material, and the first material and the second material have different good solvents.

7. A catheter (1, 1A, 1B) according to any one of claims 1 to 6, wherein the spaced apart portion (P1) of the reinforcing layer (50) includes a first spaced apart portion (P11) and a second spaced apart portion (P12), and the first spaced apart portion (P1) and the second spaced apart portion (P1) are arranged side by side in a direction parallel to the longitudinal direction of the catheter (1, 1A, 1B).

8. A catheter (1, 1A, 1B) according to any one of claims 1 to 6, wherein in the proximal portion (P2), a portion of the inner surface of the reinforcing material (51, 52) is in contact with a portion of the outer surface of the inner layer (60, 60B).

Images