Catheter shaft and catheter

Abstract

To restrain the whole catheter shaft from falling during a deflecting operation of a distal end.SOLUTION: A catheter shaft 20 extending in a center axis CL direction is internally provided with an operating lumen tube 23 that forms an operating lumen 26. The operating lumen tube 23 has an intermediate part 23b that is arranged to get close to an outer peripheral side from the center axis CL side of the catheter shaft 20, toward the other end side from one end side of the catheter shaft 20.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a catheter with a deflectable tip. [Background technology]

[0002] In catheters such as electrode catheters that are inserted into the heart through blood vessels, the distal end (tip) of the catheter shaft inserted into the body is deflected by pulling an operating wire (pull wire) inserted into the catheter shaft with an operating unit attached to the proximal end (base end or hand side) of the catheter shaft, which is placed outside the body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-245766 Summary of the Invention [Problem to be solved by the invention]

[0004] In a catheter that can be deflected (bent) by pulling on a control wire, when the catheter is deflected, not only the part that is to be bent (the distal end) but also the entire catheter shaft may collapse.

[0005] The present invention has been made in view of these problems, and its purpose is to provide a technique that can prevent the entire catheter shaft from collapsing during a deflection operation of the distal end. [Means for solving the problem]

[0006] In order to solve the above problems, one aspect of the present invention is a catheter shaft extending in a central axis direction. The catheter shaft includes an operating lumen tube that defines an operating lumen therein. The operating lumen tube has an inclined portion that approaches the outer periphery of the catheter shaft from the central axis side toward the other end of the catheter shaft.

[0007] Another aspect of the present invention is a catheter comprising the catheter shaft described above, a manipulation wire inserted through the manipulation lumen, and a manipulation section provided at one end of the catheter shaft for pulling the manipulation wire. [Effects of the Invention]

[0008] According to the present invention, it is possible to prevent the entire catheter shaft from collapsing during a deflection operation of the distal end. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic plan view of a catheter according to an embodiment. [Figure 2] 2 is a schematic cross-sectional view of the catheter shown in FIG. 1 taken along line AA. [Figure 3] 3 is a schematic cross-sectional view of the catheter shaft shown in FIG. 2 taken along the line B-B. [Figure 4] 3 is a schematic CC cross-sectional view of the catheter shaft shown in FIG. 2. FIG. [Figure 5] FIG. 3 is a schematic DD cross-sectional view of the catheter shaft shown in FIG. 2. [Figure 6] FIG. 10 is a schematic cross-sectional view showing a modified example of a catheter shaft. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments for carrying out the present invention will be described. The same or equivalent components will be given the same reference numerals, and redundant explanations will be omitted. In each drawing, for the sake of convenience, components will be omitted, enlarged, or reduced as appropriate. The drawings should be viewed in accordance with the orientation of the reference numerals.

[0011] FIG. 1 is a schematic plan view of a catheter 10 according to an embodiment. The catheter 10 is an electrode catheter that is inserted into the body (for example, inside the heart) through a blood vessel and is used for testing and treating arrhythmias. The catheter 10 comprises a catheter shaft 20 and an operating unit 30 attached to the base end (proximal end, rear end, hand side) of the catheter shaft 20. The catheter 10 according to the first embodiment is a single-direction type in which the tip portion can be deflected in one direction.

[0012] The catheter shaft 20 is a flexible tube that extends in the direction of its central axis and has, in order from the operating section 30 side along the central axis, a proximal region 20a, an intermediate region 20b, and a distal region 20c.

[0013] The length of the catheter shaft 20 in the central axis direction may be approximately 500 mm to 1200 mm (e.g., 1100 mm), and the outer diameter of the catheter shaft 20 may be approximately 0.6 mm to 3 mm (e.g., 2.0 mm). The lengths of the proximal region 20a, distal region 20c, and intermediate region 20b of the catheter shaft 20 may be approximately 400 mm to 1200 mm (e.g., 800 mm), approximately 100 mm to 400 mm (e.g., 150 mm), and approximately 1 mm to 100 mm (e.g., 50 mm), respectively.

[0014] A plurality of electrodes (not shown) are provided in the distal region 20c of the catheter shaft 20. These electrodes are electrically connected to a connector provided in the operation unit 30 via a conductor inserted inside the catheter shaft 20.

[0015] The operation section 30 is attached to the base end (the end of the proximal region 20a) of the catheter shaft 20, and has, in addition to the connector described above, a handle 31 and a rotating plate 32, for example.

[0016] The handle 31 is the part that the operator grasps when using the catheter 10. Various thin wires (conductor wires and operating wires) are drawn out from the inside of the catheter shaft 20 into the handle 31.

[0017] The rotating plate 32 is a member used to deflect (bend) the distal end of the catheter shaft 20. The rotating plate 32 has a protrusion 32a, and as shown in Figure 1, by pressing the protrusion 32a, the rotating plate 32 can be rotated in the direction of the arrow.

[0018] Fig. 2 is a schematic AA cross-sectional view of the catheter 10 shown in Fig. 1. That is, Fig. 2 shows a cross-section along the central axis CL of the catheter shaft 20 near the intermediate region 20b. Fig. 3 is a schematic BB cross-sectional view of the catheter shaft 20 shown in Fig. 2. That is, Fig. 3 is a cross-sectional view perpendicular to the central axis CL of the proximal region 20a of the catheter shaft 20. Fig. 4 is a schematic CC cross-sectional view of the catheter shaft 20 shown in Fig. 2. That is, Fig. 4 is a cross-sectional view perpendicular to the central axis CL of the intermediate region 20b. Fig. 5 is a schematic DD cross-sectional view of the catheter shaft 20 shown in Fig. 2. That is, Fig. 5 is a cross-sectional view perpendicular to the central axis CL of the distal region 20c of the catheter shaft 20.

[0019] As shown in FIG. 2, the catheter shaft 20 has a structure in which an inner layer 22 is provided inside an outer layer 21.

[0020] The outer layer 21 is formed in a hollow cylindrical shape. The outer layer 21 may be made of a synthetic resin such as polyolefin, polyamide, polyether block amide, or polyurethane. The thickness of the outer layer 21 may be approximately 0.4 mm to 1.5 mm (e.g., 0.8 mm), and preferably 0.6 mm to 1.2 mm. The outer layer 21 may be provided with a braid having a braided structure in which a plurality of plate-like wire members (flat wires) are intersected and woven together. The thickness of the braid may be, for example, approximately 10 μm to 200 μm (e.g., 50 μm).

[0021] The inner layer 22 is provided so as to fill the internal space formed by the outer layer 21. The inner layer 22 may be made of a resin such as polyetheretherketone (PEEK), polytetrafluoroethylene (PTFE), or perfluoroalkoxyalkane (PFA). The resin of the inner layer 22 fixes the position of the lumen tube disposed inside the catheter shaft 20.

[0022] 3 to 5, four lumen tubes 24 are disposed within the inner layer 22. The four lumen tubes 24 include a pair of lumens 24A and 24B disposed opposite each other across the central axis CL, and a pair of lumens 24C and 24D disposed opposite each other across the central axis CL. However, the number and positions of the lumen tubes 24 are not particularly limited.

[0023] Each lumen tube 24 defines a lumen 25 with a circular cross section therein. The lumen tube 24 may be made of a synthetic resin such as polyolefin, polyamide, polyether block amide, or polyurethane. The thickness of the lumen tube 24 may be approximately 10 to 200 μm (e.g., 30 μm). The inner diameter of the lumen tube 24 (the diameter of the lumen 25) may be approximately 0.2 mm to 0.6 mm (e.g., 0.4 mm).

[0024] A conducting wire (not shown) for supplying electricity to an electrode provided in the distal region 20c of the catheter shaft 20 is inserted into the lumen 25 formed by the lumen tube 24.

[0025] As shown in FIGS. 2 to 5, one operation lumen tube 23 is further disposed within the inner layer 22. The operation lumen tube 23 defines an operation lumen 26 with a circular cross section therein. The operation lumen tube 23 may be made of a synthetic resin such as polyolefin, polyamide, polyether block amide, or polyurethane. The thickness of the operation lumen tube 23 may be approximately 10 to 200 μm (e.g., 30 μm). The inner diameter of the operation lumen tube 23 (the diameter of the operation lumen 26) may be, for example, 0.2 mm to 0.35 mm (e.g., 0.25 mm).

[0026] As shown in FIG. 2, the operating lumen tube 23 includes a proximal portion 23a disposed in the proximal region 20a of the catheter shaft 20, an intermediate portion 23b disposed in the intermediate region 20b of the catheter shaft 20, and a distal portion 23c disposed in the distal region 20c of the catheter shaft 20.

[0027] The operating lumen 26 is formed by communication between a lumen formed by the proximal portion 23a of the operating lumen tube 23, a lumen formed by the intermediate portion 23b of the operating lumen tube 23, and a lumen formed by the distal portion 23c of the operating lumen tube 23.

[0028] The proximal portion 23a of the operating lumen tube 23 extends more proximally than the intermediate portion 23b. As shown in Figures 2 and 3, this proximal portion 23a is disposed on the central axis CL side in the radial direction of the catheter shaft 20 (the portion disposed in this manner is referred to as the "centrally disposed portion"). The extending direction of this proximal portion 23a is parallel to the direction of the central axis CL.

[0029] The distal portion 23c of the operating lumen tube 23 extends distally from the intermediate portion 23b. As shown in Figures 2 and 5, this distal portion 23c is disposed on the outer circumferential side in the radial direction of the catheter shaft 20 (the portion disposed in this manner is referred to as the "outer circumferentially disposed portion"). The extending direction of this distal portion 23c is parallel to the direction of the central axis CL.

[0030] The intermediate portion 23b of the operating lumen tube 23 extends between the proximal portion 23a and the distal portion 23c. As shown in FIG. 2, the intermediate portion 23b is disposed so as to move from the central axis CL of the catheter shaft 20 toward the outer periphery thereof as it moves from one end (proximal side) of the catheter shaft 20 toward the other end (distal side) of the catheter shaft 20 (the portion disposed in this manner is referred to as the "inclined portion"). In other words, the intermediate portion 23b of the operating lumen tube 23 is disposed at an incline with respect to the central axis CL of the catheter shaft 20. The intermediate portion 23b disposed in this manner connects the proximal portion 23a disposed on the central axis CL side and the distal portion 23c disposed on the outer periphery thereof. The intermediate portion 23b does not extend beyond the central axis CL of the catheter shaft 20. That is, the intermediate portion 23b is always located outside the central axis CL and does not cross the central axis CL.

[0031] A manipulation wire 27 for manipulating the orientation of the distal end 28 of the catheter shaft 20 is inserted through the manipulation lumen 26 of the manipulation lumen tube 23 configured as described above. The manipulation wire is also called a pull wire. The manipulation wire 27 is made of SUS wire, tungsten, Ni-Ti superelastic alloy, or the like, and its diameter may be, for example, 0.1 mm to 0.3 mm (e.g., 0.2 mm). The manipulation wire 27 may be a single wire or a stranded wire made up of multiple wires.

[0032] The distal end (tip) of the operation wire 27 is fixed to the distal portion of the catheter shaft 20 with an anchor, solder, or the like, and the proximal end (base end) is attached to the rotating plate 32 in the operation unit 30. As a result, the tension of the operation wire 27 changes in response to the rotational movement of the rotating plate 32 (operation of the rotating plate 32), allowing the operation wire 27 to be pulled along the central axis CL inside the catheter shaft 20. Therefore, when the rotating plate 32 is rotated, the distal end 28 of the catheter 10 is deflected.

[0033] According to the catheter 10 configured as described above, on the proximal side of the catheter shaft 20, the manipulation wire 27 is inserted into the centrally located portion of the manipulation lumen tube 23. On the distal side of the catheter shaft 20, the manipulation wire 27 is inserted into the outer peripheral portion of the manipulation lumen tube 23. As a result, the distal end of the manipulation wire 27 is located on the outer peripheral side of the catheter shaft 20, and therefore, when the manipulation wire 27 is pulled, the torque applied to the distal end 28 of the catheter shaft 20 can be increased and the entire catheter shaft 20 can be prevented from collapsing.

[0034] In the catheter 10 according to this embodiment, the intermediate portion 23b of the manipulation lumen tube 23 is tilted relative to the central axis CL of the catheter shaft 20, thereby changing the radial position of the manipulation lumen 26, through which the manipulation wire 27 is inserted, from the central axis CL side of the catheter shaft 20 to the outer periphery side. For example, it is possible to change the position of the catheter shaft from the central axis side to the outer periphery side by molding a catheter shaft having manipulation lumens on both the central axis side and the outer periphery side and then connecting the central axis side manipulation lumen to the outer periphery side in a post-processing step in the intermediate region of the catheter shaft. However, this increases the number of manipulation lumens and the number of post-processing steps, which may increase costs. Alternatively, it is possible to change the position of the catheter shaft from the central axis side to the outer periphery side by preparing a separate member having a passageway tilted relative to the central axis and connecting it between the proximal catheter shaft and the distal catheter shaft. However, this requires additional steps of preparing a separate member and connecting the separate members, which may increase costs. The catheter 10 according to this embodiment has a simple configuration in which the intermediate portion 23b of the operation lumen tube 23 is inclined relative to the central axis CL, which is very advantageous in terms of cost.

[0035] It should be noted that the operating lumen tube 23 in the catheter shaft 20 according to this embodiment is made of the same material and is constructed as a single, seamless tube. By constructing it as a single tube in this manner, the position of the operating lumen 26 changes smoothly, and the movement of the operating wire 27 becomes smoother.

[0036] The catheter shaft 20 according to this embodiment can be produced by covering a core material corresponding to the shape of the operating lumen 26 with a lumen tube and then performing reflow molding. The reflow molding process is outlined below. (1) The core material of the operating lumen 26 is covered with a lumen tube. (2) Fix the leading and trailing ends of the core material of the operation lumen 26 and the core material of the other lumens 25 with a positioning jig. (3) Resin for the inner layer 22 is placed and reflow molded (4) Resin for the outer layer 21 is placed and reflow molded (5) Pull out the core material (6) Fixed length cut

[0037] In the above-described embodiment, a single-directional catheter 10 in which the tip portion can be deflected in one direction has been described. However, by arranging a pair of operating lumen tubes 23 symmetrically about the central axis CL of the catheter shaft 20 and inserting an operating wire 27 into each, a bidirectional catheter in which the tip portion can be deflected in both directions can be constructed.

[0038] Fig. 6 shows a modified example of a catheter shaft. The manipulation wire is not shown in Fig. 6. In the catheter shaft 60 shown in Fig. 6, the manipulation lumen tube 62 forming the manipulation lumen 64 has a first inclined portion 62a arranged from one end of the catheter shaft 60 toward the other end, from the central axis CL side to the outer periphery side of the catheter shaft 60; a second inclined portion 62b arranged from one end of the catheter shaft 60 toward the other end, from the outer periphery side to the central axis CL side of the catheter shaft 60; and a central portion 62c provided between the first inclined portion 62a and the second inclined portion 62b. The first inclined portion 62a and the second inclined portion 62b may be directly connected without providing the central portion 62c therebetween.

[0039] The above-described embodiments are merely examples. The abstract technical concepts should not be interpreted as being limited to the content of the embodiments and modified forms. The content of the embodiments and modified forms is subject to many design changes, such as changes, additions, and deletions of components. In the above-described embodiments, the content subject to such design changes is emphasized by adding the notation "embodiment." However, design changes are also permitted even in content not so notated. Hatching on cross sections in the drawings does not limit the material of the hatched object. The structures and numerical values ​​referred to in the embodiments and modified forms naturally include those that can be considered identical when manufacturing errors, etc. are taken into account. [Explanation of symbols]

[0040] 10 catheter, 20 catheter shaft, 21 outer layer, 22 inner layer, 23, 62 operating lumen tube, 24 lumen tube, 25 lumen, 26, 64 operating lumen, 27 operating wire, 28 distal end, 30 operating portion, 31 handle, 32 rotating plate.

Claims

1. A catheter shaft extending in a central axis direction, the catheter shaft includes an operating lumen tube that forms an operating lumen therein; a catheter shaft, wherein the operating lumen tube has an inclined portion that is arranged from one end side to the other end side of the catheter shaft so as to approach from the central axis side to the outer periphery side of the catheter shaft.

2. 2. The catheter shaft according to claim 1, wherein the operating lumen tube has an outer peripheral portion that extends from the inclined portion toward the other end and is positioned on the outer peripheral side in the radial direction of the catheter shaft.

3. 3. The catheter shaft according to claim 1, wherein the operating lumen tube has a centrally located portion that extends toward the one end from the inclined portion and is located toward the central axis in the radial direction of the catheter shaft.

4. 2. The catheter shaft according to claim 1, wherein the operating lumen tube has a second inclined portion that is disposed from the outer periphery of the catheter shaft toward the central axis thereof from one end toward the other end of the catheter shaft.

5. The catheter shaft of claim 1 , wherein the angled portion does not extend beyond a central axis of the catheter shaft.

6. The catheter shaft according to claim 1; an operating wire inserted through the operating lumen; an operating unit provided on the one end side of the catheter shaft for pulling the operating wire; A catheter comprising:

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