catheter

Abstract

In a catheter having a curved portion at its tip, the present invention provides a means to create a desired curved shape for the curved portion without processing the various tubes that constitute the curved portion. [Solution] A catheter whose tip can be bent by the tension of a wire 30 placed inside, comprising at least a restoring portion 60 capable of exerting a restoring force against the bending movement of the catheter due to the tension of the wire 30, and provided with a plurality of stiffness adjustment portions 70 arranged at intervals along the longitudinal direction of the catheter on the restoring portion 60. Each stiffness adjustment portion 70 only needs to be capable of causing a change in the second moment of area and / or Young's modulus of the restoring portion 60, and can be configured such as providing a new separate member to the restoring portion 60, or forming a processed area such as a coating treatment or heat treatment in a part of the restoring portion 60.

Description

Technical Field

[0001] The present invention relates to a catheter, and more particularly to a catheter capable of adjusting the curved shape on the tip side of the catheter.

Background Art

[0002] In recent years, minimally invasive treatments using catheters have been actively performed on blood vessels, the heart, the urethra, and the like. For example, in the case of an electrode catheter, a wire is connected to an electrode provided at the tip, and the tip side of the catheter is curved and used by pulling this wire using an external operation unit or the like. At this time, it is considered that the tip portion of the catheter that becomes the curved portion is strongly affected by the rigidity, structure, arrangement form, etc. of various tubes that constitute the curved portion. For example, Patent Document 1 discloses that by dividing an operation wire tube through which a wire is inserted inside the curved portion into a plurality of partial wire tubes, a smooth curve shape without bending in the middle can be realized.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the catheter described in Patent Document 1, various additional operations occur, such as the process of cutting the operation wire tube to a predetermined length to manufacture the partial wire tubes, the process of managing the partial wire tubes having different lengths, and the countermeasures for fixing the partial wire tubes at a predetermined position in the catheter assembly process. Therefore, it has been one of the factors increasing the manufacturing cost.

[0005] Therefore, one of the objectives of the present invention is to provide a means for making the curved portion of a catheter having a curved portion at its tip into a desired curved shape without processing the various tubes that constitute the curved portion. [Means for solving the problem]

[0006] The present invention, made to solve the above problems, is a catheter whose tip can be bent by the tension of a wire placed inside, and which is equipped with at least a restoring part that acts to restore the bent catheter to its initial position, and the restoring part is provided with a plurality of rigidity adjustment parts arranged at intervals along the longitudinal direction of the restoring part. [Effects of the Invention]

[0007] According to the present invention, a catheter can be obtained in which the curved portion can be made into a desired curved shape without processing the various tubes that constitute the curved portion. [Brief explanation of the drawing]

[0008] [Figure 1] A schematic diagram of the catheter according to Example 1. [Figure 2] A schematic diagram showing section II in Figure 1. [Figure 3] Schematic diagram of the catheter according to Example 2. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that in some cases, components that do not affect the gist of the present invention may be omitted from the illustrations. [Examples]

[0010] <1> Overall structure (Figures 1 and 2) The catheter according to the present invention includes all types of catheters that are used by bending the tip portion of the catheter by the pulling action of a wire installed inside the catheter. Furthermore, the lumen structure inside the catheter is not particularly limited. The catheter according to this embodiment shown in Figure 1 is a single-lumen electrode catheter and comprises at least a handle portion A for the user to grasp and operate the catheter, and an insertion portion B for insertion into the human body. The details of each part are explained below.

[0011] <2> Handle section (Figure 1) Handle section A is the part that the user grasps and uses. The handle portion A is a component having various internal structures depending on the intended use of the catheter, and is not particularly limited in this invention. In the catheter shown in Figure 1, the handle portion A is provided with an operating portion A1 for performing the pulling action of the wire 30, which will be described later. In the present invention, the wire pulling mechanism by the operating unit A1 is not particularly limited, and various mechanisms such as lever type, knob type, and dial type can be employed.

[0012] <3> Insertion section (Figure 1) Insertion part B is the part that is inserted into the human body for use. The insertion section B is a flexible, elongated member, and has various outer diameters and internal structures depending on the intended use of the catheter. The catheter shown in Figure 1 is assumed to be an electrode catheter and includes a main tube 10, a wire passage tube 20, a wire 30, as well as a tip electrode 40 provided at the tip of the insertion section B, and a ring electrode 50 positioned at a predetermined interval behind the tip electrode 40. One end of the wire 30 is connected to the tip electrode 40, and the other end of the wire 30 is connected to the operating part A1 provided on the handle part A, so that the wire 30 can be pulled by the user operating the operating part A1. In the present invention, an arbitrarily long region on the tip side of the insertion portion B that is curved by the pulling operation of the wire 30 is defined as the curved portion B1.

[0013] <4>Wire-passing tube · wire (Figs. 1, 2) The wire-passing tube 20 is a member for inserting the wire 30 therethrough. Also, the wire 30 is a member for curving the curved portion B1 provided on the tip side of the catheter. In the present invention, the cross-sectional shape and material of the wire-passing tube 20 and the wire 30 are not particularly limited, and various members having flexibility can be used. Also, in the present invention, the position on the tip side of the wire-passing tube 20 is not particularly limited, and the wire 30 may be exposed from the tip of the wire-passing tube 20, or the tip of the wire may be completely covered with the wire-passing tube 20. Furthermore, in the present invention, the position on the rear end side of the wire-passing tube 20 is not particularly limited, and it may be fixed within the curved portion B1 or may be extended to the handle portion A1 side. Note that in the present invention, the wire-passing tube 20 may function as a member for protecting the wire 30 against the restoration portion 60 and the rigidity adjustment portion 70 described later. In this embodiment, as shown in Fig. 2, the wire-passing tube 20 and the wire 30 are provided at two locations for each bending direction. Each wire 30 is fixed to the tip electrode 40 provided at the tip of the insertion portion B at one end side as shown in Fig. 1, and fixed to the operation portion A1 of the handle portion A at the other end side. Thus, the wire 30 can be pushed out or pulled by the operation of the operation portion A1, and the curved portion B1 can be curved in a predetermined direction by the pulling operation of this wire 30.

[0014] <5>Restoration portion (Fig. 1) The restoration portion 60 is a member for restoring the curved portion B1 that is curved by the pulling operation of the wire 30 to its initial position. In the present invention, the shape and material of the restoration portion 60 are not particularly limited, and various members having an elastic force can be used. In this embodiment, a leaf spring is used for the restoring portion 60, and the rear end of this leaf spring is connected to the coil tube 80.

[0015] <6>Rigidity adjusting portion (Figs. 1, 2) The rigidity adjusting portion 70 is a member or part for adjusting the bending rigidity of the restoring portion 60 in order to make the bending portion B1 have a desired bending shape. In the invention, the material of the rigidity adjusting portion 70 is not particularly limited, and various members can be used. In the present invention, the "desired bending shape" refers to a bending shape suitable for the application in which the catheter according to the present invention is used, and does not simply refer to an arc shape with a regular curvature of the bending shape or a smooth curve shape without a bend in the middle.

[0016] <6.1>Configuration example of rigidity adjusting portion (Figs. 1, 2) In the present invention, the rigidity adjusting portion 70 may be a member newly added to the restoring portion 60, or may be a processed portion applied to the restoring portion 6o itself. Also, when the rigidity adjusting portion 70 is a member newly added to the restoring portion 60, the rigidity adjusting portion 70 may be fixed to the restoring portion 60 by welding or the like, or may be positioned so as to integrate the two using a shrink tube or the like not shown.

[0017] <6.2>Principle of adjusting bending rigidity Since the bending rigidity to be adjusted by the rigidity adjusting portion 70 is determined by the second moment of area and Young's modulus, when the rigidity adjusting portion 70 is provided in the form of newly adding a member to the restoring portion 60, at least the second moment of area at an arbitrary cross-section of the restoring portion 60 including the rigidity adjusting portion 70 will change. Also, when the rigidity adjusting portion 70 is provided in the form of processing the restoring portion 60 itself, the rigidity adjusting portion 70 will cause at least a change in the Young's modulus of the restoring portion 60.

[0018] <6.3>Arrangement example of rigidity adjusting portion (Figs. 1, 2) In the present invention, the arrangement of the rigidity adjustment section 70 is not particularly limited. In this embodiment, as shown in Figure 1, rigidity adjustment parts 70 made of separate members (tip adjustment part 71a, rear adjustment part 72a) are provided on the front side of the tip and rear end of the restoration part 60, and rigidity adjustment parts 70 (tip adjustment part 71b in Figure 2) are also provided on the back side of the restoration part 60, resulting in a configuration in which a total of four rigidity adjustment parts 70 are added to the restoration part 60. With this configuration, the bending rigidity of the restoring section 60 around each stiffness adjustment section 70 is increased, which suppresses bending and breaking of the root and tip portions of the curved section B1. As a result, the curved section B1 can be designed to exhibit a smooth curve shape without any breaks along the way.

[0019] <6.4> Example of the shape of the rigidity adjustment part (Figure 1) In the present invention, the shape of the rigidity adjustment section 70 is not particularly limited, and plate-shaped members of equal width, plate-shaped members with varying widths and thicknesses can be used. By changing the width and thickness of the rigidity adjustment section, it is possible to cause variations in the second moment of area at any cross-section of the restoration section. In this embodiment (Figure 1), the tip adjustment section 71a has a shape in which its width decreases from the middle to the rear end of the catheter, and similarly, the rear end adjustment section 72a also has a shape in which its width decreases from the middle to the tip of the catheter.

[0020] <7> summary The catheter according to the present invention can obtain at least one of the effects described below. (1) By adjusting the bending rigidity of the restoration section according to the bending rigidity which varies depending on the changes in the material, shape, structure, etc. of the catheter components (main tube, wire tube, wire, etc.) through the configuration, arrangement, shape, number, etc. of the rigidity adjustment section, a catheter with a desired curved shape can be provided. (2) Since it is no longer necessary to process the various tubes that make up the curved section (main tube, cable tube, etc.) to adjust the curved shape or to add new assembly processes, it contributes to reducing manufacturing costs. [Examples]

[0021] A catheter according to a second embodiment of the present invention will be described with reference to Figure 3. The catheter according to this embodiment has a configuration in which, in addition to the tip-side adjustment part 70a and the rear-end-side adjustment part 70b described in Embodiment 1, the restoring part 60 is further provided with a separate rigidity adjustment part 70 (intermediate adjustment part 70c) of a different member spaced apart from these. In this embodiment, the intermediate adjustment section has a roughly diamond shape, and its width is reduced so that it tapers towards both the tip and posterior ends of the catheter. This configuration allows for more precise adjustment of the curved shape of the curved section B1. [Examples]

[0022] The catheter according to the present invention may employ any of the following embodiments or a combination thereof as the stiffness adjustment part (not shown). (Example of form 1) A form in which at least a part of the restoration part 60 is subjected to processing such as coating or heat treatment to change the second moment of area and / or Young's modulus of the processed part, thereby creating a rigidity adjustment part 70. (Example of form 2) A form in which at least a portion of the rigidity adjustment section 70, which is made of a separate member and provided on the restoration section 60, is further processed, such as by coating or heat treatment, to change the second moment of area and / or Young's modulus of the processed portion. [Explanation of Symbols]

[0023] A: Handle section A1:Operation unit B: Insertion part B1: Curved section 10: Main tube 20: Cable Tube 30: Wire 40: Tip electrode 50: Ring electrode 60: Restoration Section 70: Rigidity adjustment part 70a:Tip adjustment part 70b: Rear end adjustment section 70c: Intermediate adjustment section 80: Coil tube

Claims

1. A catheter whose tip can be bent by pulling a wire placed inside, It comprises at least a restoring part that acts to restore a curved catheter to its initial position, The restoration section is characterized by having a plurality of rigidity adjustment sections arranged at intervals along the longitudinal direction of the restoration section. catheter.

2. The aforementioned plurality of rigidity adjustment units A tip adjustment unit is positioned on the tip side of the aforementioned restoration unit, The invention is characterized by having at least a rear end adjustment section located on the rear end side of the restoration section. The catheter according to claim 1.

3. The aforementioned plurality of rigidity adjustment units The device is further characterized by having at least one intermediate adjustment section located between the tip adjustment section and the rear end adjustment section. The catheter according to claim 2.

4. The rigidity adjustment portion is characterized in that it is a heat-treated portion or a coating-treated portion relative to the restoration portion. The catheter according to claim 1.

Images