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JP-2026074562-A - catheter

JP2026074562AJP 2026074562 AJP2026074562 AJP 2026074562AJP-2026074562-A

Abstract

[Problem] The objective is to provide a catheter that can suppress the occurrence of kinking while providing flexibility to the tip and rigidity to the proximal end. [Solution] The catheter 1 comprises a first coil 111 formed by spirally winding a first strand 111w, wherein the radial thickness t1 of the first strand 111w at the tip portion 111a decreases toward the tip, and a second coil 121 formed by spirally winding a second strand 121w, wherein the base portion 121a is joined to the tip portion 111a of the first coil 111 at a joint portion J, the tip extends toward the tip beyond the tip of the first coil 111, and the radial thickness t22 of the second strand 121w is smaller than the radial thickness t11 of the first strand 111w at the base portion 111b of the first coil 111. [Selection Diagram] Figure 2

Inventors

  • ジッタワット アロングコット

Assignees

  • 朝日インテック株式会社

Dates

Publication Date
20260507
Application Date
20241021

Claims (9)

  1. A first coil (111) formed by winding a first strand (111w) in a spiral shape, wherein the radial thickness (t1) of the first strand (111w) at the tip (111a) decreases toward the tip, A catheter (1, 1A, 1B, 1C, 1D, 1E) comprising: a second coil (121) formed by spirally winding a second strand (121w), the base end (121a) of the first coil (111) being joined to the tip end (111a) of the first coil (111) at a joint (J), the tip extending toward the tip side beyond the tip of the first coil (111), and the radial thickness (t22) of the second strand (121w) being smaller than the radial thickness (t11) of the first strand (111w) at the base end (111b) of the first coil (111).
  2. The catheter (1, 1A, 1C, 1D, 1E) according to claim 1, wherein the width (t21) of the second wire (121w) in the longitudinal direction is greater than the thickness (t22) of the second wire (121w) in the radial direction.
  3. The catheter (1, 1A, 1D, 1E) according to claim 2, wherein the cross-sectional shape of the second wire (121w) is rectangular.
  4. The catheter (1, 1A, 1B, 1C, 1D, 1E) according to any one of claims 1 to 3, wherein the proximal end (121a) of the second coil (121, 123, 124, 125, 126) is located on the outer circumferential surface (111g) of the tip (111a) of the first coil (111, 112, 113, 114, 115, 116).
  5. The catheter (1, 1B, 1C, 1D, 1E) according to any one of claims 1 to 4, wherein the tip portions (111a, 115a, 116a) of the first coil (111, 115, 116) have a frustoconical portion on their outer surface (111g) that tapers toward the tip.
  6. The catheter (1, 1A, 1B, 1C, 1D, 1E) according to any one of claims 1 to 5, wherein the joint (J) is formed so as to leave no gap in the area where the first coils (111, 112, 115, 116) and the second coils (121, 123, 124, 125, 126) come into contact.
  7. The device comprises outer layers (31, 35) that cover the second coils (121, 123, 124, 125, 126), The outer layers (31, 35) have tapered portions (31a, 35a) on their outer circumferential surfaces (31g) that narrow towards the tip. The catheter (1, 1A, 1B, 1C, 1D, 1E) according to any one of claims 1 to 6, wherein the proximal ends (p1, p5) of the tapered portions (31a, 35a) are located on the tip side of the joint portion (J).
  8. A catheter (1, 1A, 1B, 1C, 1D, 1E) according to any one of claims 1 to 7, comprising a reinforcing member (21) provided inside the first coil (111, 112, 113, 114, 115, 116) and extending along the longitudinal axis of the first coil (111, 112, 113, 114, 115, 116).
  9. At the tip portions (111a, 112a, 115a, 116a) of the first coil (111, 112, 115, 116), the outer surface of the first strand (111w, 112w, 115w, 116w) has a curved surface (111c, 112c, 115c, 116c) which is a part of a virtual cylindrical surface with the major axis (Z) of the first coil (111, 112, 115, 116) as its central axis. The catheter (1, 1A, 1B, 1C, 1D, 1E) according to any one of claims 1 to 8, wherein the joint (J) is formed on the curved surface (111c, 112c, 115c, 116c).

Description

This disclosure relates to catheters. Catheters are known as medical devices inserted into body cavities such as blood vessels. Such catheters require both pushability and conformability to the body cavity in order to smoothly advance through complex, curved body cavities to the periphery. A catheter using double-wound wire has been proposed as a catheter that achieves both pushability and conformability to the body cavity (see, for example, Patent Document 1). In such a catheter, for example, by placing the coil portion only on a part of the outer circumference of the braided portion, flexibility is given to one part of the catheter while rigidity is given to the other parts. Japanese Patent Publication No. 2016-185206 This is a schematic longitudinal cross-sectional view showing one embodiment of the present disclosure.This is a schematic longitudinal cross-sectional view showing an enlarged portion of Figure 1.This is a partially enlarged schematic longitudinal cross-sectional view illustrating another embodiment of the present disclosure.This is a partially enlarged schematic longitudinal cross-sectional view illustrating another embodiment of the present disclosure.This is a partially enlarged schematic longitudinal cross-sectional view illustrating another embodiment of the present disclosure.This is a partially enlarged schematic longitudinal cross-sectional view illustrating another embodiment of the present disclosure.This is a partially enlarged schematic longitudinal cross-sectional view illustrating another embodiment of the present disclosure. (1) The catheter of the present disclosure comprises: a first coil formed by spirally winding a first wire, wherein the radial thickness of the first wire at the tip decreases toward the tip; and a second coil formed by spirally winding a second wire, wherein the base end is joined to the tip of the first coil at a joint, the tip extends toward the tip beyond the tip of the first coil, and the radial thickness of the second wire is smaller than the radial thickness of the first wire at the base end of the first coil. This configuration makes it possible to mitigate changes in stiffness at the tip of the first coil in the longitudinal direction. As a result, it is possible to provide flexibility to the tip of the catheter and stiffness to the proximal end while suppressing the occurrence of kinking. (2) In the catheter described in (1) above, the width of the second wire in the longitudinal direction may be greater than the thickness of the second wire in the radial direction. This configuration allows the second wire to be arranged such that it is flattened along its long axis. As a result, the outer diameter of the second coil can be reduced compared to a coil with a circular cross-sectional shape, even with the same rigidity. (3) In the catheter of (2) above, the shape of the cross-section of the second wire may be rectangular. This configuration allows the second wire to be arranged such that it is flattened along its long axis. As a result, the outer diameter of the second coil can be reduced compared to a coil with a circular cross-sectional shape, even with the same rigidity. (4) In the catheters described in (1) to (3) above, the proximal end of the second coil may be located on the outer circumferential surface of the tip of the first coil. With this configuration, the base end of the second coil can be placed over the outer circumference of the tip of the first coil, and then the first coil and the second coil can be joined together to easily form a joint. (5) In the catheters described in (1) to (4) above, the tip of the first coil may have a frustoconical portion whose outer surface is tapered toward the tip. This configuration allows for a gradual change in the rigidity of the tip of the first coil along its long axis. As a result, kinking can be more reliably suppressed. (6) In the catheters described in (1) to (5) above, the joint portion may be formed such that there is no gap in the region where the first coil and the second coil come into contact. This configuration allows for a wider contact surface between the first coil and the second coil. As a result, the first coil and the second coil can be firmly joined together. (7) The catheter according to (1) to (6) above, wherein the outer layer covers the second coil, and the outer layer has a tapered portion on its outer surface that tapers toward the tip, and the base end of the tapered portion may be located toward the tip of the joint. With this configuration, in addition to the gradual change in stiffness at the tip of the first coil in the longitudinal direction, the stiffness of the tapered outer layer can also be gradually changed along the longitudinal direction. As a result, the change in stiffness at the tip of the catheter can be effectively suppressed in multiple stages. (8) The catheters described in (1) to (7) above may be provided with a reinforcing member located inside the