Manufacturing method of electrode catheter and electrode catheter

Abstract

To provide a fixation method of a ring-shaped electrode to a catheter tube as a substitute for crimping fixation, and an electrode catheter obtained by the fixation method.SOLUTION: A manufacturing method of an electrode catheter includes allowing an inner tube 22 to pass through each outer tube 20 and a ring-shaped electrode 4 while the ring-shaped electrode 4 is arranged between two outer tubes 20, and thermally depositing each outer tube 20 and the inner tube 22.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing an electrode catheter and to an electrode catheter. [Background technology]

[0002] BACKGROUND ART Conventionally, an electrode catheter having an electrode on the distal end side of a tube is known (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 09-253063 Summary of the Invention [Problem to be solved by the invention]

[0004] In a typical manufacturing method for an electrode catheter, first, a catheter tube and a ring-shaped electrode with an inner diameter larger than the outer diameter of the catheter tube are prepared. Then, the catheter tube is passed through the ring-shaped electrode. When the ring-shaped electrode reaches a predetermined position on the catheter tube, it is crimped. This fixes the ring-shaped electrode to the catheter tube. By crimping the ring-shaped electrode, the outer diameter of the ring electrode and the outer diameter of the catheter tube can be made substantially equal. This eliminates the step at the boundary between the ring electrode and the catheter tube, thereby preventing adverse effects such as damage to the inner wall of a blood vessel due to this step.

[0005] However, the above-described manufacturing method has a problem in that as the outer diameter of the catheter tube becomes smaller, the deformation amount of the ring-shaped electrode increases, making the crimping process more difficult.

[0006] The present disclosure has been made in view of the above circumstances, and its purpose is to provide a method for fixing a ring-shaped electrode to a catheter tube that replaces crimping, and an electrode catheter obtained thereby. [Means for solving the problem]

[0007] One aspect of the present disclosure is a method for manufacturing an electrode catheter, which includes passing an inner tube through two outer tubes with ring electrodes disposed between them, and heat welding the outer tube and inner tube together.

[0008] Another aspect of the present disclosure is an electrode catheter. This electrode catheter includes a catheter tube and a ring-shaped electrode located on the outer circumferential surface of the catheter tube. The catheter tube has a support layer located radially inward of the ring-shaped electrode and supporting the ring-shaped electrode, and a surface layer located radially outward of the support layer. The surface layer has an exposed portion that includes the outer circumferential surface of the surface layer and is aligned with the ring-shaped electrode in the axial direction of the catheter tube, and an interposed portion that includes the inner circumferential surface of the surface layer and extends between the support layer and the exposed portion, as well as between the support layer and the ring-shaped electrode. Over at least a portion of the axial direction, at least a portion of the exposed portion that continues from the outer circumferential surface and at least a portion of the interposed portion that continues from the inner circumferential surface have different hardnesses.

[0009] Any combination of the above components, and conversion of the expression of the present disclosure into a method, device, system, etc., are also valid aspects of the present disclosure. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to provide a method for fixing a ring electrode to a catheter tube that replaces crimping, and an electrode catheter obtained thereby. [Brief explanation of the drawings]

[0011] [Figure 1]FIG. 1 is a side view of an electrode catheter according to an embodiment. [Figure 2] FIG. 1 is a cross-sectional view of a portion of an electrode catheter. [Figure 3] 3(A) and 3(B) are diagrams showing the manufacturing process of an electrode catheter. [Figure 4] 4(A) and 4(B) are diagrams showing the manufacturing process of an electrode catheter. DETAILED DESCRIPTION OF THE INVENTION

[0012] 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.

[0013] 1 is a side view of an electrode catheter 1 according to an embodiment. The electrode catheter 1 is inserted into a patient's body, for example, into the heart, through a blood vessel, and can be used for testing and treating arrhythmias and the like. The electrode catheter 1 comprises a catheter tube 2, a ring electrode 4, and a handle 6.

[0014] The catheter tube 2 is made of a flexible tubular member, and at least the distal end is inserted into the patient's body. The catheter tube 2 is made of a known flexible material, including resins such as polyolefin, polytetrafluoroethylene, polyether block amide, polyamide, polyurethane, and silicone. The length of the catheter tube 2 is, for example, 600 mm to 1800 mm. Hereinafter, the direction in which the axis of the catheter tube 2 extends when the catheter tube 2 is straight, that is, the direction in which the distal end and proximal end are aligned, is referred to as the axial direction Ax. Furthermore, the direction parallel to the radius of the catheter tube 2 in a cross section of the catheter tube 2 perpendicular to the axial direction Ax is referred to as the radial direction D.

[0015] The ring electrodes 4 are located on the outer peripheral surface of the catheter tube 2. The electrode catheter 1 of this embodiment has, as an example, multiple, specifically five, ring electrodes 4. The number of ring electrodes 4 is not particularly limited, as long as it is one or more. The multiple ring electrodes 4 are arranged at predetermined intervals in the axial direction Ax of the catheter tube 2. The electrode catheter 1 also has a tip electrode 26 that is fitted into the tip of the catheter tube 2.

[0016] The distal end of a lead wire 14 (see FIG. 2) is connected to each ring electrode 4 and tip electrode 26. Each lead wire 14 is inserted into a lumen 8 (see FIG. 2) of the catheter tube 2 and extends to the handle 6. Preferably, the ring electrode 4 and tip electrode 26 are made of an electrically conductive metal material such as aluminum (Al), copper (Cu), stainless steel (SUS), gold (Au), or platinum (Pt).

[0017] The handle 6 is connected to the proximal end of the catheter tube 2. The handle 6 is placed outside the body when the electrode catheter 1 is in use, and is grasped or operated by the operator. An example of the handle 6 has a handle main body 62, a rotation operation part 64, and an adjustment knob 66. The handle main body 62, the rotation operation part 64, and the adjustment knob 66 are made of synthetic resin, for example, polycarbonate, acrylonitrile-butadiene-styrene copolymer (ABS), or the like.

[0018] The handle body 62 is gripped by the operator. The rotation operation unit 64 is operated by the operator when bending the distal region of the catheter tube 2. The rotation operation unit 64 is substantially disk-shaped and can rotate relative to the handle body 62 around a rotation axis perpendicular to the axial direction Ax. The proximal ends of one or more pull wires (not shown) are connected to the rotation operation unit 64. The pull wires are inserted, for example, through the lumen 8, and their distal ends are connected to the distal region of the catheter tube 2. Rotation of the rotation operation unit 64 pulls the pull wires, thereby bending the distal region of the catheter tube 2. The adjustment knob 66 is located on one surface of the rotation operation unit 64. Operating the adjustment knob 66 can fix the orientation of the rotation operation unit 64 with respect to the handle body 62. This allows the distal region of the catheter tube 2 to remain curved.

[0019] The handle body 62 has a connector (not shown). The base end of each lead wire 14 is connected to the connector. An external power supply (not shown) is electrically connected to each lead wire 14 via the connector. By applying a voltage from the power supply to each ring electrode 4 and the tip electrode 26 via each lead wire 14, it is possible to perform potential measurement, ablation, etc. at an affected area inside the body. The structure of the handle 6 and the mechanism for bending the catheter tube 2 are not particularly limited.

[0020] Next, a detailed description will be given of the structure of the catheter tube 2. Figure 2 is a cross-sectional view of a portion of the electrode catheter 1. The catheter tube 2 has a lumen 8, a support layer 10, and a surface layer 12.

[0021] The lumen 8 extends from the distal end to the proximal end of the catheter tube 2, and a conducting wire 14, a pull wire, etc. are inserted through the lumen 8. The number of lumens 8 may be one or more. The support layer 10 is tubular and is located inside the ring electrode 4 in the radial direction D of the catheter tube 2, supporting the ring electrode 4. As an example, the support layer 10 is not in direct contact with the ring electrode 4, but indirectly supports the ring electrode 4 via a surface layer 12, more specifically, an intervening portion 18, which will be described later. The surface layer 12 is tubular and is located outside the support layer 10 in the radial direction D of the catheter tube 2. In other words, the support layer 10 is covered with the surface layer 12.

[0022] The surface layer 12 has an exposed portion 16 and an interposed portion 18. The exposed portion 16 includes an outer peripheral surface 12o of the surface layer 12 and is aligned with the ring electrode 4 in the axial direction Ax of the catheter tube 2. The outer peripheral surface 12o of the surface layer 12 also forms the outer peripheral surface of the catheter tube 2. The interposed portion 18 includes an inner peripheral surface 12i of the surface layer 12 and extends between the support layer 10 and the exposed portion 16, and between the support layer 10 and the ring electrode 4. Therefore, the interposed portion 18 is located inside the exposed portion 16 in the radial direction D of the catheter tube 2. In the region where the exposed portion 16 extends, the interposed portion 18 is interposed between the support layer 10 and the exposed portion 16. In the region where the ring electrode 4 extends, the interposed portion 18 is interposed between the support layer 10 and the ring electrode 4. The support layer 10 is in contact with the inner peripheral surface of the interposed portion 18. The inner peripheral surface of the ring-shaped electrode 4 contacts the outer peripheral surface of the interposed portion 18. As an example, the boundary between the exposed portion 16 and the interposed portion 18 is located in a region aligned in the axial direction Ax with the inner peripheral surface of the ring-shaped electrode 4 or the outer peripheral surface of the interposed portion 18 in the region where the ring-shaped electrode 4 extends. In FIG. 2 , the boundary between the exposed portion 16 and the interposed portion 18 is schematically indicated by a two-dot chain line.

[0023] Preferably, the outer diameter of the exposed portion 16 is equal to the outer diameter of the ring electrode 4. In other words, the outer peripheral surfaces of the exposed portion 16 and the ring electrode 4 are substantially flush. This facilitates insertion of the catheter tube 2 into the patient's body. In the present disclosure, "equal outer diameters" means that the outer diameter X of one electrode falls within a range of ±10% of the outer diameter Y of the other electrode, i.e., Y × 90% ≦ X ≦ Y × 110% is satisfied. The outer diameter X preferably falls within a range of ±5% of the outer diameter Y, more preferably within a range of ±1%, and even more preferably ±0%. As an example, the outer diameters of the exposed portion 16 and the ring electrode 4 are average values of the outer diameters at multiple points in the axial direction Ax. The outer diameter of the exposed portion 16 is measured in a region that contacts the ring electrode 4 and has the same length as the ring electrode 4 in the axial direction Ax.

[0024] In at least a portion of the axial direction Ax, at least a portion of the exposed portion 16 continuing from the outer circumferential surface 12o and at least a portion of the interposed portion 18 continuing from the inner circumferential surface 12i have different hardnesses. That is, the surface layer 12 has different hardnesses on the outer circumferential surface 12o side and the inner circumferential surface 12i side. In this disclosure, "hardness" refers to hardness measured with a D-type hardness tester, i.e., Shore D hardness.

[0025] When the hardness of the surface layer 12 is made different between the outer peripheral surface 12o side and the inner peripheral surface 12i side, the thickness of the high-hardness and low-hardness regions can be appropriately adjusted to easily adjust the stiffness of the catheter tube 2. In particular, by making the hardness of the outer peripheral surface 12o side and the hardness of the inner peripheral surface 12i side different in the curved portion of the catheter tube 2, i.e., the tip region, it becomes possible to flexibly adjust the degree of bending of the tip region when operating the rotation operation unit 64, the operation feel of the rotation operation unit 64, etc.

[0026] Preferably, at least a portion of the intermediate portion 18 continuing from the inner circumferential surface 12i has a higher hardness than at least a portion of the exposed portion 16 continuing from the outer circumferential surface 12o. Also preferably, the support layer 10 has a higher hardness than the surface layer 12 over at least a portion in the axial direction Ax. As an example, the support layer 10 has a higher hardness than the surface layer 12 over the entire axial direction Ax. Therefore, the hardness of part or all of the catheter tube 2 increases in at least three stages from the outside to the inside in the radial direction D, namely, from the exposed portion 16, the intermediate portion 18, and the support layer 10.

[0027] As described above, by making the hardness of the interposed portion 18 higher than that of the exposed portion 16 and by making the hardness of the support layer 10 higher than that of the surface layer 12, the ring-shaped electrode 4 can be more stably supported from the inside. Furthermore, the shapes of the catheter tube 2 and the lumen 8 can be easily maintained. Therefore, even if the catheter tube 2 is bent and stress concentrates at the boundary between the ring-shaped electrode 4 and the catheter tube 2, damage to the catheter tube 2 can be suppressed. Furthermore, the support layer 10 can be made thinner. This allows the diameter of the lumen 8 to be increased while maintaining the outer diameter of the catheter tube 2. Therefore, the number and types of members that can be inserted into the lumen 8 can be increased. It is preferable that the hardness of the interposed portion 18 is higher than that of the exposed portion 16 throughout the entire axial direction Ax. It is also preferable that the hardness of the support layer 10 is higher than that of the surface layer 12 throughout the entire axial direction Ax. These features make it easier to achieve the above-mentioned effects.

[0028] Next, a manufacturing method of the electrode catheter 1 will be described in detail. Figures 3(A), 3(B), 4(A), and 4(B) are diagrams showing the manufacturing process of the electrode catheter 1. First, multiple outer tubes 20, one inner tube 22, and multiple ring-shaped electrodes 4 are prepared. The outer tube 20 and the inner tube 22 each have one lumen. The lumen of the inner tube 22 forms the lumen 8 of the catheter tube 2.

[0029] 3(A), with the ring-shaped electrode 4 disposed between the two outer tubes 20, an inner tube 22 is passed through the lumen of each outer tube 20 and the ring of each ring-shaped electrode 4. The inner diameters of the outer tube 20 and the ring-shaped electrode 4 are approximately equal to the outer diameter of the inner tube 22, and the outer tube 20 and the ring-shaped electrode 4 can slide relative to the inner tube 22.

[0030] As shown in Figure 1, the electrode catheter 1 of this embodiment has five ring electrodes 4. Therefore, six outer tubes 20 and five ring electrodes 4 are prepared, and an inner tube 22 is passed through the outer tubes 20 and ring electrodes 4 in an alternating arrangement. Each outer tube 20 and each ring electrode 4 is slid along the outer peripheral surface of the inner tube 22 toward the proximal end of the inner tube 22. Then, a tip electrode 26 is fitted into the tip of the inner tube 22.

[0031] The outer tube 20 located at the most proximal end of the catheter tube 2 determines the distance between the most proximal ring electrode 4 and the handle 6. The other outer tubes 20 determine the distance between two adjacent ring electrodes 4, or the distance between adjacent ring electrodes 4 and the tip electrode 26.

[0032] The distal end of the conducting wire 14 is fixed to the inner peripheral surface of each ring-shaped electrode 4 in advance by welding or the like. The inner tube 22 also has a plurality of through holes 24 connecting the outside of the inner tube 22 to the lumen 8. There is a one-to-one correspondence between each ring-shaped electrode 4 and each through hole 24. When the inner tube 22 is passed through each ring-shaped electrode 4, the proximal end of the conducting wire 14 is drawn into the lumen 8 through the corresponding through hole 24. The axial movement of the inner tube 22 of each ring-shaped electrode 4 is restricted by the outer tubes 20 on both sides at positions overlapping with the corresponding through holes 24.

[0033] The inner tube 22 is passed through the outer tube 20 and the ring-shaped electrode 4 from the tip 22a side. The tip 22a of the inner tube 22 has a pointed shape. In this embodiment, the tip 22a of the inner tube 22 has a needle-like end face that extends obliquely with respect to the axial direction Ax. This makes it easier to insert the inner tube 22 into the ring-shaped electrode 4 and the outer tube 20. The base end of the inner tube 22 may be connected to the handle 6 in advance, or may be connected to the handle 6 after the inner tube 22 and the outer tube 20 are welded together.

[0034] The inner tube 22 has an outer layer 28 and an inner layer 30. For example, the outer layer 28 and the inner layer 30 are fixed to each other. The outer layer 28 includes the outer peripheral surface of the inner tube 22 and contacts the inner peripheral surface of the outer tube 20. The inner layer 30 is located inside the inner tube 22 relative to the outer layer 28. In this embodiment, the inner layer 30 includes the inner peripheral surface of the inner tube 22. Although the inner tube 22 in this embodiment has a two-layer structure consisting of the outer layer 28 and the inner layer 30, the inner tube 22 may be composed of three or more layers.

[0035] Preferably, the inner layer 30 has a higher hardness than the outer layer 28 and the outer tube 20 over at least a portion of the axial direction of the inner tube 22. Also, preferably, the outer layer 28 has a higher hardness than the outer tube 20 over at least a portion of the axial direction of the inner tube 22. Preferably, the outer layer 28 has a higher hardness than the outer tube 20 in the region from the tip of the inner tube 22 to the ring electrode 4 located most proximally. Also, preferably, the outer layer 28 has a Shore D hardness that is 15 or more higher than that of the outer tube 20. This makes it easier to insert the inner tube 22 into the outer tube 20.

[0036] As an example, the inner layer 30 has a uniform hardness throughout the axial direction of the inner tube 22, and is harder than the outer layer 28 and the outer tube 20. The outer layer 28 also has a uniform hardness throughout the axial direction of the inner tube 22. Meanwhile, the outer tubes 20 have lower hardness as they are positioned closer to the distal end of the inner tube 22. The outer layer 28 has a harder hardness at least than the outer tube 20 that will be disposed in the distal region of the catheter tube 2. The axial direction of the inner tube 22 coincides with the axial direction Ax of the catheter tube 2.

[0037] Next, as shown in FIG. 3(B), heat H is applied to each outer tube 20 and each inner tube 22 to heat-weld them together. A known heat-welding device and method can be used for the heat-welding. As a result of this heat-welding, each outer tube 20 and the outer layer 28 melt and mix at their respective boundaries, forming a welded region R, as shown in FIG. 4(A). This integrates each outer tube 20 and each inner tube 22, thereby obtaining the catheter tube 2. Furthermore, the ring electrodes 4 are fixed to the catheter tube 2 by heat-welding each outer tube 20 and each inner tube 22 together.

[0038] After heat welding, the outer tube 20 and outer layer 28 become the surface layer 12. The outer peripheral surface of the outer tube 20 becomes the outer peripheral surface 12o of the surface layer 12, and the inner peripheral surface of the outer layer 28 becomes the inner peripheral surface 12i of the surface layer 12. The range from the outer peripheral surface of the outer tube 20 to the welded region R becomes the exposed portion 16, and the range from the inner peripheral surface of the inner layer 30 to the welded region R becomes the interposed portion 18. The inner layer 30 becomes the support layer 10.

[0039] Preferably, the inner layer 30 has a higher melting point than the outer layer 28 and the outer tube 20 over at least a portion of the axial direction of the inner tube 22. This makes it easier to prevent the inner layer 30 from melting during the heat welding process between the outer tube 20 and the inner tube 22. This makes it easier to maintain the shapes of the catheter tube 2 and the lumen 8. More preferably, the inner layer 30 has a higher melting point than the outer layer 28 and the outer tube 20 over the entire axial direction of the inner tube 22. This makes it easier to maintain the shapes of the catheter tube 2 and the lumen 8 over the entire axial direction Ax.

[0040] Examples of materials for the outer tube 20 include thermoplastic resins such as polyether block amides such as PEBAX (registered trademark) and polyamides such as DIAMID (registered trademark). Examples of materials for the outer layer 28 include thermoplastic resins such as polyether block amides such as PEBAX (registered trademark) and polyamides such as DIAMID (registered trademark). Examples of materials for the inner layer 30 include thermoplastic resins such as polytetrafluoroethylene (PTFE) and perfluoroalkoxyalkane (PFA). As long as the outer tube 20, outer layer 28, and inner layer 30 satisfy the above-mentioned hardness and melting point requirements, they may each be composed of only one or more of the above-mentioned resins, or may contain materials other than the above-mentioned resins.

[0041] As an example, the outer tube 20 is made of PEBAX® with a first hardness. The outer layer 28 is made of PEBAX® with a second hardness higher than the first hardness. The inner layer 30 is made of PTFE with a third hardness higher than the first and second hardnesses. The difference between the melting point of the inner layer 30 and the melting points of the outer layer 28 and the outer tube 20 is preferably 50°C or more, and more preferably 100°C or more. As an example, the melting point of the inner layer 30 is 300°C or more, and the melting points of the outer layer 28 and the outer tube 20 are 130°C to 180°C.

[0042] Through the above steps, the electrode catheter 1 is obtained as shown in Figure 4(B). In this embodiment, the ring electrode 4 is fixed to the catheter tube 2 by thermally welding the outer tube 20 to the inner tube 22. This provides a method for fixing the ring electrode 4 to the catheter tube 2 that replaces crimping. The manufacturing method of this embodiment does not involve deformation of the ring electrode 4. Therefore, even if the outer diameter of the catheter tube 2 is reduced, it is possible to avoid the problem of increased deformation of the ring electrode 4, which occurs when crimping is used, making processing more difficult.

[0043] Preferably, the outer diameter of each outer tube 20 is equal to the outer diameter of each ring electrode 4. This makes it possible to obtain an electrode catheter 1 that does not have a step at the boundary between the ring electrode 4 and the catheter tube 2, without having to crimp the ring electrode 4.

[0044] 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 changing, adding, or deleting components, are possible within the scope of the concept of the present disclosure defined in the claims. A new embodiment with design modifications will combine the effects of the combined embodiments and modifications. In the above-described embodiments, the content that allows such design modifications is emphasized by using notations such as "in this embodiment" or "in this embodiment," but design modifications are also permitted even in content without such notation. Any combination of the components included in each embodiment is also valid as an aspect of the present disclosure. Hatching on cross sections in the drawings does not limit the material of the hatched object.

[0045] The embodiments may be specified by the following items. [1st item] With the ring-shaped electrodes (4) disposed between the two outer tubes (20), an inner tube (22) is passed through each of the outer tubes (20) and the ring-shaped electrodes (4); heat welding each outer tube (20) and inner tube (22) together; A method for manufacturing an electrode catheter (1). [Second item] The inner tube (22) has an outer layer (28) in contact with the outer tube (20) and an inner layer (30) located inside the inner tube (22) relative to the outer layer (28), In at least a portion of the axial direction of the inner tube (22), the inner layer (30) has a melting point higher than that of the outer layer (28) and the outer tube (20). A method for manufacturing the electrode catheter (1) described in item 1. [3rd item] The inner tube (22) has an outer layer (28) in contact with the outer tube (20) and an inner layer (30) located inside the inner tube (22) relative to the outer layer (28), In at least a portion of the axial direction of the inner tube (22), the inner layer (30) has a higher hardness than the outer layer (28) and the outer tube (20). A method for manufacturing the electrode catheter (1) described in the first or second item. [4th item] The inner tube (22) has an outer layer (28) in contact with the outer tube (20) and an inner layer (30) located inside the inner tube (22) relative to the outer layer (28), In at least a portion of the axial direction of the inner tube (22), the outer layer (30) has a higher hardness than the outer tube (20). A method for manufacturing the electrode catheter (1) according to any one of the first to third items. [Item 5] The tip (22a) of the inner tube (22) has a pointed shape. A method for manufacturing the electrode catheter (1) according to any one of the first to fourth items. [Item 6] The outer diameter of the outer tube (20) is equal to the outer diameter of the ring electrode (4). A method for manufacturing the electrode catheter (1) according to any one of the first to fifth items. [Item 7] a catheter tube (2); a ring-shaped electrode (4) located on the outer circumferential surface of the catheter tube (2); The catheter tube (2) has a support layer (10) positioned inside the ring electrode (4) in a radial direction (D) of the catheter tube (2) and supporting the ring electrode (4), and a surface layer (12) positioned outside the support layer (10) in the radial direction (D), The surface layer (12) has an exposed portion (16) that includes an outer peripheral surface (12o) of the surface layer (12) and is aligned with the ring-shaped electrode (4) in the axial direction (Ax) of the catheter tube (2), and an interposed portion (18) that includes an inner peripheral surface (12i) of the surface layer (12) and extends between the support layer (10) and the exposed portion (16) and between the support layer (10) and the ring-shaped electrode (4); In at least a part of the axial direction (Ax), at least a part of the exposed portion (16) continuing from the outer circumferential surface (12o) and at least a part of the interposed portion (18) continuing from the inner circumferential surface (12i) have different hardnesses. Electrode catheter (1). [Item 8] At least a part of the interposed portion (18) continuing from the inner circumferential surface (12i) has a higher hardness than at least a part of the exposed portion (16) continuing from the outer circumferential surface (12o). Item 7. An electrode catheter (1). [Item 9] The support layer (10) has a higher hardness than the surface layer (12) in at least a part of the axial direction (Ax). An electrode catheter (1) according to item 7 or 8. [Item 10] The outer diameter of the exposed portion (16) is equal to the outer diameter of the ring electrode (4). An electrode catheter (1) according to any one of items 7 to 9. [Explanation of symbols]

[0046] 1 electrode catheter, 2 catheter tube, 4 ring electrode, 8 lumen, 10 support layer, 12 surface layer, 16 exposed portion, 18 interposition portion, 20 outer tube, 22 inner tube, 28 outer layer, 30 inner layer.

Claims

1. With the ring-shaped electrodes disposed between the two outer tubes, an inner tube is passed through each outer tube and the ring-shaped electrodes; heat welding each outer tube and the inner tube together; A method for manufacturing an electrode catheter.

2. the inner tube has an outer layer in contact with the outer tube and an inner layer located inside the inner tube relative to the outer layer, the inner layer has a melting point higher than that of the outer layer and the outer tube in at least a portion of the axial direction of the inner tube; The method for manufacturing the electrode catheter according to claim 1 .

3. the inner tube has an outer layer in contact with the outer tube and an inner layer located inside the inner tube relative to the outer layer, the inner layer has a higher hardness than the outer layer and the outer tube in at least a portion of the axial direction of the inner tube; A method for manufacturing an electrode catheter according to claim 1 or 2.

4. the inner tube has an outer layer in contact with the outer tube and an inner layer located inside the inner tube relative to the outer layer, The outer layer has a higher hardness than the outer tube in at least a portion of the inner tube in the axial direction. A method for manufacturing an electrode catheter according to claim 1 or 2.

5. The tip of the inner tube has a pointed shape. A method for manufacturing an electrode catheter according to claim 1 or 2.

6. The outer diameter of the outer tube is equal to the outer diameter of the ring-shaped electrode. A method for manufacturing an electrode catheter according to claim 1 or 2.

7. A catheter tube; a ring-shaped electrode located on the outer circumferential surface of the catheter tube, the catheter tube has a support layer positioned inside the ring electrode in a radial direction of the catheter tube and supporting the ring electrode, and a surface layer positioned outside the support layer in the radial direction, the surface layer has an exposed portion that includes an outer peripheral surface of the surface layer and is aligned with the ring-shaped electrode in the axial direction of the catheter tube, and an interposed portion that includes an inner peripheral surface of the surface layer and extends between the support layer and the exposed portion, and between the support layer and the ring-shaped electrode; In at least a part of the axial direction, at least a part of the exposed portion continuing from the outer circumferential surface and at least a part of the interposed portion continuing from the inner circumferential surface have different hardnesses. Electrode catheter.

8. At least a portion of the interposed portion continuing from the inner circumferential surface has a higher hardness than at least a portion of the exposed portion continuing from the outer circumferential surface.

8. The electrode catheter of claim 7.

9. The support layer has a higher hardness than the surface layer in at least a part of the axial direction.

9. The electrode catheter according to claim 7 or 8.

10. The outer diameter of the exposed portion is equal to the outer diameter of the ring-shaped electrode.

9. The electrode catheter according to claim 7 or 8.

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