JPH04108456A - Guide wire for medical treatment - Google Patents

Abstract

PURPOSE:To obtain a J-shaped resilient part having a desired radius of the J shape by constituting a J-shaped core end of a combination of a previously molded core body and a spring body which is previously set coarser in the part for cladding the J-shaped core end than in other parts. CONSTITUTION:The spring body which is previously set coarser in the part for cladding the J-shaped core end 11c of the core body 11 than in the other parts is used as the spring body 12. Then, the coarse part of the spring body 12 does not exert a large recovering force on the J-shaped core end 11c of the core body 11 when the J-shaped core end 11c is mounted on the previously formed core body 11. The guide wire after assembly, therefore, has the radius r2 of the J shape thereof approximately equal to the radius r0 of the J shape preset in the core end 11c. The J-shaped resilient part 11c having the desired radius of the J shape is easily obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a medical guidewire for guiding a medical tube such as a catheter.

[Conventional technology] In order to guide the catheter to the target site in the blood vessel, the guide wire is made of a material with high bending elasticity to ensure that the operating force at hand is transmitted to the distal end. In addition to a main body, it also includes a flexible tip with low bending elasticity in order to be able to move smoothly through complicatedly curved and branching blood vessels.

In addition, a guide wire with a J-shaped flexible tip has a rounded J-shaped flexible part, which allows the guide wire to move smoothly through a severely curved blood vessel and prevents it from entering a branch blood vessel too quickly. .

At this time, in the conventional guide wire, a core body has a core end portion with low bending elasticity and a core body portion with high bending elasticity, and both ends of the core body are wrapped around the core body and have both ends of the core body. The main body has a large bending elasticity and the tip has a small bending elasticity.

In addition, the spring body is designed such that: (i) the tip of the guide wire has a small bending elasticity and is flexible, so that the core end of the core body is tapered to prevent the core end from penetrating into the blood vessel wall;
Over the entire length of the guidewire body and tip,
In addition to smooth uniformity, (1) it is possible to ensure resilience against bending so that the core wood body portion of the core body does not buckle due to manual operation force.

[Problems to be Solved by the Invention] However, when the conventional guidewire is constructed by combining a core body and a splinter body, as shown in FIG. 2(A),
Not only is the core end of the core body pre-bent and formed into a J-shape, but the part of the spring body that will cover the J-shape core end of the core body is also pre-bent and formed into a J-shape. ing. For this reason, it is necessary to bend the end of the spring body to the J-shaped radius and the path radius set at the core end of the core, which complicates the manufacturing process.

In the conventional guide wire, as shown in FIG. 2(A), when a full-length straight spring body is attached to a core body with a J-shaped core end formed in advance, the spring body The J-shaped radius r was preset at the end of the core because it was wrapped around the entire length band to ensure the restorability mentioned in (2) above.

is deformed to the diameter increasing side due to the large restoring force of the spring body. For this reason, the guide wire after assembly is
The J-shaped radius r is the J-shaped radius r set in advance at the above-mentioned core end. This results in a completely different result, making it difficult to obtain a J-shaped flexible portion with a desired J-shaped radius.

An object of the present invention is to easily provide a guidewire having a J-shaped flexible portion with a desired J-shaped radius using a simple component configuration.

[Means for Solving the Problems] The present invention as set forth in claim 1 provides a core body having a core end portion having a small bending elasticity and a core wood body portion having a large bending elasticity, and a core body having a core body portion having a large bending elasticity. A medical guide wire comprising a spring body whose both sides are fixed to both ends of the core body, and at least one end of which is a J-shaped flexible part, wherein at least one end of the J-shaped core end is preformed. It is constructed by a combination of a core body and a spring body that is sparsely set in advance compared to the part of the core body that covers the J-shaped core end or other parts of the core body.

In the present invention as set forth in claim 2, the ratio of the bending elasticity of the spring body portion set sparsely in advance to the other portion is 17.
30 to 3/5.

[Function] According to the present invention, a spring body is used that is sparsely set in advance compared to the part that covers the J-shaped core end of the core body or other parts. Therefore, as shown in FIG. 2(B), when this spring body is attached to a core body with a J-shaped core end formed in advance, the sparse portion of the spring body is attached to the J-shaped core end of the core body. It does not exert a large restoring force on the parts. For this reason, the J-shaped radius r2 of the assembled guide wire becomes a gap between the above-mentioned J-shaped radius r0 set in advance at the core end, and it is possible to easily obtain a J-shaped flexible portion with a desired J-shaped radius. I'll come. At this time, even if the sparse portion of the spring body exerts a slight restoring force, the J-shaped radius r of the J-shaped core end. does not change or changes only slightly. Therefore,
The J-shaped radius r2 of the J-shaped flexible portion of the assembled guidewire can be controlled extremely easily in advance at the manufacturing stage.

In addition, the spring body is set tightly in the part that does not cover the J-shaped core end of the core body, so that the main body of the guide wire has the ability to recover without buckling due to manual operation force. I can do it.

Therefore, a guidewire having a J-shaped flexible portion with a desired J-shaped radius can be easily provided with a simple component configuration.

At this time, the ratio of the bending elasticity of the preset sparse part to the bending elasticity of other parts of the spring body is within the range of 1/3 to 3/5, as is clear from the results of the experiment described later. It is best to make a selection.

[Example] Fig. 1 is a schematic diagram showing a guide wire according to an embodiment of the present invention, and Fig. 2 is a schematic diagram showing a manufacturing process of the guide wire.

The guide wire 10 is composed of a stainless steel core body 11, a stainless steel spring body 12, and a plastic covering part 13 made of fluororesin or the like, and includes a straight flexible part 10B and a J-shaped flexible part 10C at both ends of a main body part 10A. ing.

Note that the J-shaped flexible portion 10C may be provided only on one side.

The core body 11 includes a core body part 11A having a relatively thick wire diameter and high bending elasticity forming the main body part 10A;
A straight core end 11B, which has a relatively small wire diameter and low bending elasticity, is formed continuously at one end of A and forms a straight flexible section 10B, and a straight core end 11B is formed continuously at one end of the core body 11A. It has a J-shaped core end portion 11C bent in a figure-5 shape with a relatively small wire diameter and low bending elasticity forming a J-shaped flexible portion 10C. Note that the straight three end portions 11B and the J-shaped core end portion 11C may be configured in a flat plate shape with a smaller cross-sectional area than the core body portion 11A. That is, the core body 11 has its straight core end portion 11B and J-shaped core end portion 11C more flexible than its core body portion 11A. Note that the core wood body portion 11A, the straight core end portion 11B, and the J-shaped core end portion 11C are the tapered portions 11D, 1
1E, the rigidity of the core body 11A and the straight core end 11B or the J-shaped core end 11C is formed to be gradual, thereby making it possible to prevent the guide wire 10 from bending. There is.

The core body 11 is inserted into the spring body 12, and the spring body is attached to a bulge portion 14.15 having a substantially hemispherical end surface joined to each end of the straight core end portion 11B and the J-shaped core end portion 11C. Each end of 12 is fixed by welding. The suffling body 12 is configured such that: (1) the outer diameters of the main body portion 10A, straight flexible portion 10B, and J-shaped flexible portion 10C of the guidewire 10 are made uniform, and the distal end of the guidewire 10 becomes tapered and penetrates into the blood vessel wall; In addition to preventing the main unit 10A from buckling due to manual operation force,
It is possible to ensure resilience against bending.

However, in the guide wire 10, ■Fig. 1 (A)
The above-mentioned core body 11 has a straight core end portion 11B and a J-shaped core end portion 11C formed in advance on both ends, as shown in FIG.
■J-shaped core end portion 11 of the core body 11 as shown in FIG. 1(B)
The spring body 12 is configured in combination with a spring body 12 that is sparsely set in advance compared to the part that covers C or other parts.

As a result of the following experiment, the ratio between the bending elasticity of the part of the spring body 12 that is preset to be sparse and the bending elasticity of other parts is preferably selected within the range of 1730 to 3/5.

That is, the tightly wound portion and the loosely wound portion of the spring body 12 were each held by a chuck. At this time, the tip of the tightly wound portion or the tip of the loosely wound portion of the spring body 12 was made to protrude lhm from the chuck. Then, the bending strength (bending elasticity equivalent value) and was measured. As a result, the bending strength of the closely wound part is about 1 to 3 g, and the bending strength of the loosely wound part is about 0.1 to 0.6 g (in other words, the ratio of bending elasticity is 1730 to 3/
5, preferably 1/20 to 1/2, it was recognized that the object of the present invention can be better achieved.

That is, if the bending elasticity ratio is less than 1/30, the loosely wound portion of the spring body 12 becomes too loose, and the guide wire 10 formed by the loosely wound portion of the spring body 12
When inserting the J-shaped flexible tip into a blood vessel, the loosely wound portion creates resistance and is not suitable.

Furthermore, if the bending elasticity ratio exceeds 375, sufficient flexibility cannot be obtained from the loosely wound portion of the spring body 12, and as a result, the loosely wound portion exerts less influence on the J-shaped core end 11C of the core body 11. It is impossible to make the restoring force sufficiently small. Therefore,
In order to better achieve the object of the present invention of easily forming a J-shaped flexible tip with a predetermined J-shaped radius in the guide wire 1o, it is preferable that the bending elasticity ratio is 375 or less.

In addition, in order to evaluate the bending elasticity that should be suitably provided to the J-shaped core end 11C of the core body 11, the core end 11C is held with a chuck, the tip of the core end 11C is made to protrude 10 mm from the chuck, and the 8IIIllllJl part from the tip side (2m11 inner part from the protruding tip of the core end 11C)
The load required to push down 5@II was measured as the bending strength (value equivalent to bending elasticity).

As a result, it was also recognized that the object of the present invention could be better achieved when the bending strength of the core end portion 11C was set to about 1 to 1.5 g.

The entire surface of the guide wire 10 is covered with the covering portion 13, and after using the guide wire 10 once as a guide for a catheter, immediately wipe off the blood adhering to the surface with physiological saline or the like. This allows the guidewire 10 to be reapplied to the patient.

Note that the guide wire 10 does not necessarily need to be provided with the coating section 13 described above.

If one guide wire 10 is prepared, it is possible to selectively use the straight flexible section 10B or the J-shaped flexible section 10C as the distal guide side depending on the patient, so that a single guide wire IQ can be used. Its use allows a wide range of procedures to be performed. Here, the guide wire 10 is
The bent portions of various shapes formed at the distal end of the catheter are made straight under the insertion of the relatively rigid main body 10A, and the catheter is pushed into the blood vessel by the manual operation force applied to the main body 10A. This allows for smooth guidance of the blood vessel within the blood vessel.

Further, the guide wire 10 has its tip flexible portions 10B, 10
By advancing the catheter C into the blood vessel ahead of the tip of the catheter, damage to the inner wall of the blood vessel caused by the tip of the catheter can be prevented.

When inserting a catheter into a blood vessel with severe meandering, the J-shaped flexible portion 10c is used as the tip guide side, and after guiding the tip of the catheter to the target site, the guide wire 1 is inserted.
After removing the guide wire 10 and completing the intended medical operation such as angiography, the guide wire 10 is easily inserted into the catheter from the catheter hub with the straight flexible portion 10B as the distal guide side.
This allows the catheter to be easily removed from the blood vessel.

In addition, in carrying out the present invention, the guide wire may be provided with J-shaped flexible portions having different J-shaped radii at each of both ends.

In addition, in carrying out the present invention, the constituent materials of the core body include:
Superelastic metals such as Ni-Ti alloys can also be used. Further, the above superelastic metal can also be used as a constituent material of the spring body.

Next, the operation of the above embodiment will be explained.

According to the above embodiment, as the spring body 12, the core body 1
A portion covering the J-shaped core end portion 11C of No. 1 is used, which is set in advance to be sparser than other portions. Therefore, as shown in FIG. 2(B), this spring body 12,
When the J-shaped core end 11C is attached to the preformed core 11, the sparse portions of the spring body 12 do not exert a large restoring force on the J-shaped core end 11C of the core 11. After assembly, the J-shaped radius r of the assembled guide wire 10 becomes equal to the J-shaped radius ro set in advance at the core end, and the J-shaped flexible portion 10C having the desired J-shaped radius can be easily obtained. I can do it. At this time, even if the sparse portion of the spring body 12 exerts a slight restoring force, the J-shaped core end 11C
The J-shaped radius ro does not change or changes only slightly. Therefore, the J-shaped radius r2 of the J-shaped flexible portion 10C of the guide wire 10 after assembly can be controlled extremely easily in advance at a normal stage.

Furthermore, if the spring body does not have a sparse portion, in order to obtain the desired J-shaped radius, a process of bending the spring body itself into a J-shape is required. However, in the present invention, since the linear spring body has a sparse portion (J-shaped flexible portion 10C) at one end as shown in FIG. 1(B), the above-described steps can be omitted. Furthermore, the step of forming the spring body in a sparse/dense manner can be provided during the process of manufacturing the spring body, leading to the simplification of the process.

Note that the spring body 12 is connected to the J-shaped core end 11C of the core body 11.
The guidewire 10 has a densely encapsulated area, which ensures the restorability of the guidewire 10 without buckling due to manual operation force.
It can be secured in the main body part 10A.

Therefore, with a simple component configuration, it is possible to easily provide the guide wire 10 having the J-shaped flexible portion 10C with a desired J-shaped radius.

[Effects of the Invention] As described above, according to the present invention, with the simple component configuration,
A guidewire with a J-shaped flexible portion having a desired J-shaped radius can be easily provided.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a guide wire according to an embodiment of the present invention, and FIG. 2 is a schematic diagram showing a manufacturing process of the guide wire. DESCRIPTION OF SYMBOLS 10... Guide wire, 10A... Main body part, 10C... J-shaped flexible part, 11... Core body, 11A... Core wood body part, 11C... J-shaped core end part, 12 ...Spring body.

Claims (2)

[Claims] (1) A core body having a core end portion with low bending elasticity and a core main body portion with high bending elasticity, and a spring body that covers the core body and has both side portions fixed to both ends of the core body. Consisting of
A medical guide wire in which at least one end portion is a J-shaped flexible portion includes a core body having a J-shaped core end portion preformed at at least one end portion, and a portion of the core body that encloses the J-shaped core end portion. A medical guide wire characterized in that it is configured in combination with a spring body that is sparsely set in advance compared to other parts. (2) The medical guide wire according to claim 1, wherein the ratio of bending elasticity of the spring body portion set sparsely in advance to the other portion is 1/30 to 3/5.