JPS61115550A - Catheter for catching stone - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a catheter used for capturing kidney stones and the like.

[Prior art] TiNi alloy has a remarkable shape memory effect (hereinafter referred to as "reverse transformation" of thermoelastic martensitic transformation).

(abbreviated as SME). It is also known that t simultaneously exhibits a pseudoelastic effect (hereinafter abbreviated as PE).

SME refers to the property that even if an alloy undergoes apparent plastic deformation, it completely returns to its initial shape when heated to a reverse transformation temperature (hereinafter abbreviated as Af point).

pg refers to the property that even if stress is applied at temperatures above A (Kokuboshi) and apparent plastic deformation is given, the shape completely returns to its original shape as soon as the stress is removed.

So-called shape memory alloys such as TiNi alloys and SME and PH1: are expected to be applied as temperature sensors, actuators, and energy storage materials.

On the other hand, in the conventional stone retrieval catheter, a stainless plate spring or a wire is used in the capture portion.

In clinical practice, when retrieving a stone, a catheter is inserted near the affected area, and when the catheter reaches the stone site, it is looked at with a fiberscope.

A capture jig housed inside the catheter is expanded by a spring to capture the stone. Thereafter, the captured stones are removed from the two bodies or destroyed within the two bodies using a laser or the like.

[Problem that the invention seeks to solve]

However, the shape of stones is not uniform, and conventional capturing jigs made of stainless steel or the like may not be able to capture them successfully.

[Means and effects for solving the problems] The stone retrieval catheter according to the present invention includes: a mother tube, a guide wire provided inside the 4' tube, and a guide wire disposed inside the tube. means for moving along the length of the
In the stone retrieval catheter having a means for capturing a calculus attached to the distal end of the guide wire, at least a part of the stone retrieving means is made of a T i Ni alloy exhibiting thermoelastic martensitic transformation. 'piN
A feature of the present invention is that by using i-alloy SME and pg alone or in combination, stone capture is made easy and complete.

In addition, when using a TtNt alloy SME, a current-carrying lead wire is attached to the TiN1-alloy part to be heated, or when heating is performed by radar, a V-za beam is applied to the TiNi alloy part. A conduit is installed to guide the

〔Example〕

The present invention will be described below based on examples.

Embodiment 1 FIG. 1 is a sectional view showing the structure of an embodiment of a stone retrieval catheter according to the present invention.

In Figure 1 (,), the capture part 1 is made of stainless steel tJ? eve 2
is housed inside. It is inserted into the body in this state up to the stone site. When the catheter reaches the stone site, it pushes the plate spring 4 and releases the stainless steel plate spring 1a of the capture part 1.
spontaneously expands by (1) due to the action of a spring (Fig. 1 (
b)). With the capture part 1 encasing the stone, the capture part 1
SME coil gune 1b is energized.

Or when heated above the reverse transformation temperature by Rede light,
As shown in FIG. 1(C), the stainless steel plate spring 1a is constricted to capture the calculus 5.

In this embodiment, the guide wire 3 and the stainless steel plate spring 1a of the capture section 1 were used with two three-pronged slits made of stainless steel rods. Also, SME coil spring 1b &! , 0.5
m+φ3φ3 simple helical coil spring (Ar point: 50℃)
was used. As a result, the captured stone 5 was maintained with sufficient retention force to be destroyed by the laser.

Example 2 FIG. 2 shows another example of a stone retrieval catheter using PE of TiNi alloy.

In FIG. 2(a), the capture portion 6 made of TiNi alloy is housed inside the stainless steel gib 2. In FIG. It is inserted into the body in this state up to the stone site. When the catheter reaches the stone site, the plate spring 4 is pushed to cause the capture part 6 to protrude outside the stainless steel guide f2 (Fig. 2(b)).
. Then, in the capture part 6, the PE is used to sew the calculus 6 and wrap it inside it (Fig. 2 (C) and (d)
)). Thereafter, when the leaf spring 4 is returned to its original position, the stone 5 is completely captured (FIG. 2(e)).

In this example, as shown in FIG. 2(f), TiNi
The alloy capture portion 6 is divided into three prongs and is mechanically fastened to the guide wire 3. TiNi alloy supplementary part 6
The tip is narrowed and processed to maintain flexibility. The flexible part at the tip of the capture part 6 is.

Since it has the characteristic of completely returning to its original state even if it is bent by 5 to 6 degrees, it can easily pass between the inner wall of a tube such as a blood vessel or urethra and the stone 5, and the stone After passing, the stress is relaxed, so it can act to wrap around the stone 5.

In this embodiment, the TiNi alloy that is the material of the trapping part 6 has a composition of +Tt-51at%Ni,
1=0.2rtaa, tip 0. ．． It is coated with 1 m (polyethylene V to prevent damage). ) was used. FIG. 3 shows stress strain curves of the example alloys at 0°C to 40°C.

Here, in order to further complete the capture, as shown in Fig. 2(e)
After capturing, the capturing part 6 may be heated as shown in FIG. That is,
The member that is the capture part 6 is made of a TiNi alloy exhibiting PE, but when the capture part 6 is heated in the state shown in FIG. 2(e), it is heated by SME as shown in Example-1.

The concretion 5 is tightened by the capture part 6.

Generally, when a TiNi alloy is deformed at the A1 point or higher, stress-induced martensite occurs. When this induced martensite is heated under stress, it returns to the parent phase through reverse transformation, exhibiting SME and generating a force to return to its original shape. This effect, that is, by using PE and SME together,
Stone capture is considered more complete.

〔Effect of the invention〕

As described above, according to the present invention, the stone capturing jig is made of TiNi.
By using the alloy, stones can be captured easily and reliably.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram of a catheter using 5yrE of TiNi alloy according to the present invention, and FIG. 2 is a conceptual diagram of a catheter using 5yrE of TiNi alloy according to the present invention.
A conceptual diagram of a catheter using PE alloy. FIG. 3 is a stress-strain curve diagram of a Ti-51 at% Ni alloy. 1... Capture part +1a... Stainless steel leaf spring, 1
b °°. SME: + Ilbane, 2...Stainless steel J#if
, 3... Guide wire, 4... Leaf spring for moving the guide wire. 5... Stone, 6... TiNi alloy capture part (PK leaf spring). Figure 2 Procedural amendment (voluntary) July 7, 1939

Claims (1)

[Claims] 1. A pipe, a guide wire provided inside the pipe, a means for moving the guide wire along the length of the pipe, and a means attached to the tip of the guide wire for capturing stones. A catheter for stone retrieval comprising: a TiNi alloy exhibiting thermoelastic martensitic transformation used for at least a portion of the stone retrieval means.