JPH04236967A - Catheter guide wire - Google Patents

Abstract

PURPOSE:To provide a catheter guide wire capable of having also the softness of the top end part of the catheter while holding the rigidity of the base material part by providing a helical coil or net Ti-Ni shape memory alloy on the outside of a core material. CONSTITUTION:In the core material of a catheter guide wire, the top end part and base material part are formed of a helical or net tube 1 of a Ti-Ni shape memory alloy showing super elasticity at least at a living body internal temperature, and a core wire 3 of stainless or Ti-Ni alloy is provided only on the base material part in the inner part of the tube 1. Thus, both the rigidity of the base material part and the softness of the top end part can be possessed, and torque transmitting property is enhanced. Thus, a catheter guide wire enhanced in the softness of the top end part and the rigidity of the base material part can be obtained.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catheter guide wire, which is one of medical instruments.

0002

[Prior Art] In general, a catheter guide wire is introduced into a blood vessel by a Seldenger needle punctured from a blood vessel site, and then the Seldenger needle is removed from the guide wire, and a catheter is attached to the rear end of the guide wire. It is a medical device used to guide a catheter in advance of the catheter to a target site within a blood vessel.

[0003] As is well known, the route of a blood vessel is complicated, or a plurality of blood vessels are cross-connected. Therefore, the core material of the catheter guide wire is composed of a distal end portion having a complicated shape and a matrix portion having a linear shape. In addition, it has elasticity that allows it to absorb and release energy and reversibly deform and recover its shape when the load is removed due to deformation stress that occurs during introduction and advancement into blood vessels at the biological temperature (approximately 37°C). Because it is required to have the characteristics, SUS30 is generally used.
4. Helical springs made of SUS316 or the like, and more recently Ti-Ni shape memory alloy wires have been used.

0004

[Problems to be Solved by the Invention] However, catheter guide wires using a Ti-Ni alloy material as a core material having mere elastic properties as described above are usually designed to maintain elastic properties at least at in-vivo temperatures. There is. For this reason, there are problems with recovery from deformation within the blood vessel, torque transmission from the introduction section necessary for changing the direction of the guidewire tip upon introduction into the blood vessel, and bonding between the helical coil at the tip and the wire at the matrix section. was there.

[0005] Furthermore, because the length of the portion of the distal end that requires flexibility is constant, it is often not possible to cope with the complexity of the branching of the inserted blood vessel.

[0006]

[Means for Solving the Problems] The present invention has been proposed in view of the above-mentioned drawbacks of the conventional techniques, and provides flexibility in the distal end of a catheter guide wire while maintaining the rigidity of the substrate. The purpose of the present invention is to provide a catheter guide wire that can be used as a catheter guide wire.

[0007] In order to achieve the above object, the present invention provides a helical coil or net shape Ti--Ni shape memory alloy on the outside of the core material.

[0008]

[Example] Made of Ti-51at%Ni alloy, thickness 50
A ribbon wire with a diameter of 1.00 mm and a width of 1.00 mm was formed into a helical coil shape with an outer diameter of 0.5 mm, and superelasticity treatment was performed at 500° C. for 5 minutes. As shown in FIG. 1(A), a stainless steel wire with a wire diameter of 0.35φ and a Ti--Ni superelastic wire 3 were inserted and fixed into the tube 1 thus formed. Note that no core wire was inserted into the tip 50 mm.

FIG. 1(B) shows a tube 1 having a net-like structure,
This tube 1 is connected to the same stainless steel wire or Ti wire as described above.
- Shows the Ni-based superelastic wire 3 inserted and fixed.

Next, the results of these experiments will be shown. The entire length (approximately 2 m) was covered with a synthetic resin (polyurethane in this example). After the coating was completed, the guide wire was tested for operability using a meandering transparent tube 10 as shown in FIG. That is, the operability up to the inlet of the tube, the operability from the inlet to the distal end, and the ease of insertion into the tube 10 were conducted at a temperature of 37°C. The results are shown in Table 1.

[0011]

[Table 1]

For comparison, the test was conducted using Ti-Ni alloy core material, S
We investigated the uS alloy core material, and found that the Ti-Ni alloy core material was inserted smoothly into the tube 10 from the insertion port, and there was no permanent deformation of the guide wire even at the meandering point, and it was found that the guide wire could be easily inserted from the hand. Although the torque transmission performance was not impaired by the twisting, it took a considerable amount of time to introduce it into the meandering part, and the insertion work was difficult.

On the other hand, according to the present invention, all of them showed good results, and in particular, in the case where SuS was used for the core wire, the permanent deformation at the meandering part of SuS was suppressed by the Ti-Ni alloy superelastic net of the outer skin. Torque transferability is maintained because it is released with
Moreover, the sense of rigidity could be improved. Furthermore, a garment with a variable length of the flexible western part of the tip can be inserted into the meandering part very easily.

[0014]

Effects of the Invention According to the present invention, Ti-N is formed on the outside of the core wire.
Since the i-type shape memory alloy is arranged in a helical coil or net shape, it is possible to have both rigidity in the substrate and flexibility in the tip. Further, according to the present invention, the entire core material is a helical coil or a reticular tube, and only the substrate portion is made of a core wire of a spring material such as Ti-Ni alloy or stainless steel, so that the tip portion and the substrate portion are integrally formed. However, a catheter guide wire with improved torque transmittance, flexibility at the distal end, and rigidity at the substrate can be obtained. Furthermore, the length of the flexible portion can be controlled by arbitrarily moving the core wires constituting the matrix portion within the tube.

[Brief explanation of the drawing]

FIG. 1 (A) is a cross-sectional view showing the configuration of the helical coil and core wire of the distal end portion and substrate portion of a catheter guide wire. (B) is a cross-sectional view showing the configuration of the distal end portion and substrate portion of the catheter guide wire, a mesh tube, and a core wire.

FIG. 2 is an explanatory diagram showing an operability test.

[Explanation of symbols]

1...Ti-Ni helical coil 2...Ti-Ni helical coil 3...Core wire of Ti-Ni, SuS, etc.

Claims (2)

[Claims] 1. A catheter guide wire, characterized in that a Ti--Ni shape memory alloy is arranged in a helical coil or net shape on the outside of a core wire. 2. The core material, wherein the tip portion and the matrix portion are made of a helical coil or mesh tube of a Ti-Ni shape memory alloy that exhibits superelasticity at least at in vivo temperature, and the inside of the tube is A catheter guide wire characterized in that a core wire made of stainless steel or a Ti-Ni alloy is disposed only in the matrix portion.