JPH045167Y2 - - Google Patents

Description

[Detailed description of the invention] <<Industrial application>> The present invention is used as a guide for treating diseased parts of the human body, such as the heart, by delivering medicinal solutions to the affected parts using a catheter. This invention relates to improvements in medical guide wires that are used by being inserted into the body.

《Conventional technology》 Conventionally used medical guide wire A
As shown in Fig. 7, the tube can be passed through the curved blood vessel to the desired affected area.
Its dimensions are approximately 2 mm in diameter and approximately 50 mm in length.
It is a thin filament that is approximately 70 cm long and flexible, and is constructed as shown below.

That is, as shown in the above figure, a flexible coil thin wire b formed by closely coiling a thin metal wire a around stainless steel or the like with a wire diameter of about 0.1 mm;
It has a spherical guide head part c made of a soft metal such as Sn which is fixed by welding means or the like at its distal end, and a hand part d which is fixed by welding to the base end of the same thin filament b, and the above-mentioned leading guide part A safety wire f linearly inserted through the air core e of the thin flexible coil wire b is connected between c and the hand portion d.

Therefore, when using the above conventional method, steel wire,
Since the thin metal wire a made of stainless steel wire or the like is wound into a coil strip, uneven portions a' are formed on the outer peripheral surface of the flexible thin coil wire b, and due to the characteristics of the thin metal wire a itself, blood For example, when the medical guide wire A is inserted into the blood vessel B via the indwelling needle C inserted into the blood vessel B, as shown in FIG.
It may collide with the blood vessel wall D or even damage the blood vessel B, causing pain to the patient.

Therefore, in order to resolve the above-mentioned difficulties, the 9th
As shown in the figure, it has been proposed to apply tetrafluoroethylene resin (Teflon) to the outer circumferential surface of the flexible coil thin wire b by spraying means or the like to form an outer circumferential surface coating layer g. There is.

However, when using the above improvement means,
As shown in , the thickness of the outer circumferential surface coating layer g is not uniform, and as a result, the unevenness becomes large and the sliding against the inner wall of the blood vessel becomes difficult, and the outer circumferential surface coating layer is thin. g wears quickly,
As a result, not only does the resistance within the blood vessels increase at an early stage and the slippage deteriorates, but also, as mentioned above, when tetrafluoroethylene resin is applied, due to the characteristics of the material, the slipperiness within the blood vessels is reduced. It is not so good, and there is also the disadvantage that the spraying work on the outer peripheral surface is expensive.

As mentioned above, in order to correct the uneven thickness coating of the outer peripheral surface coating layer g, it is possible to continue the spraying operation to make the entire thickness thicker.
In this case, as shown in FIG. 9b, although the thickness of the outer circumferential surface coating layer g becomes uniform, the outer circumferential surface coating layer g The synthetic resin becomes clogged, which reduces the flexibility of the thin flexible coil wire b.
There are deficiencies that result in the inability to obtain the desired flexibility.

《Problems to be solved by the invention》 In view of the problems of the above-mentioned conventional examples, the present invention does not adopt the coiled body of the thin metal wire itself as is, but instead uses the flexible coiled body as the coiled body. Instead of spraying tetrafluoroethylene resin onto the thin coiled wire b, the thin metal wire itself is first coated with polyurethane resin, and the coated thin wire of the required length is shaped into a coil. By adopting a thin coil-coated wire wrapped around the body, we can effectively utilize the good slipperiness in blood of polyurethane resin, which comes into direct contact with blood.
This makes it easier to insert into blood vessels, and by applying polyurethane resin to thin metal wires, a coating layer with a uniform thickness can be obtained, making it a highly durable product at a low cost. The purpose of this is to make it possible to provide such materials, and of course to eliminate the problem of deterioration of flexibility due to subsequent application of synthetic resin.

《Means for solving the problem》 In order to achieve the above-mentioned object, the present invention uses a coil-covered thin wire formed by coil-wound a thin metal wire coated with a polyurethane resin to a required length. , a guide head and a base portion fixedly attached to the tip and base end of the coil-coated thin filament, respectively, and the guide head and base end that are inserted through the air core of the coil-coated thin filament. It is an object of the present invention to provide a medical guide wire consisting of a safety wire and a safety wire each having a fixed end.

《Operation》 When the medical guide wire of the present invention is introduced into a blood vessel using a conventional method, the outer sheath of the coil-coated thin filament that comes into contact with blood and the inner wall of the blood vessel is made of polyurethane resin, so it has little resistance to blood. It slides easily and slides well against the inner wall of the blood vessel, making it easier to insert the coil.Furthermore, since the coil is made of coated thin wire rather than wound with thin metal wire, the coating layer of polyurethane resin is in contact with the coil, making it easier to insert the coil. Since thin filaments are formed, sufficient flexibility is exhibited when the tube is inserted into the blood vessel, and the correct insertion path within the blood vessel can be selected and inserted.

<<Example>> The present invention will be described in detail with reference to the illustrated embodiment. As shown in FIGS. 1 and 2, steel wire,
A coated thin wire 3 obtained by uniformly applying a coating layer 2 of polyurethane resin to a thin metal wire 1 such as a round wire or a square wire formed of stainless steel wire or the like using a spraying method or the like is wound into a coil to a required length. Coil-covered thin filament 4 formed by
and a hemispherical guide head 5 made of Sn or the like, a base end 6 also made of the same material, and both ends fixed to the guide head 5 and the base cover 6, The safety wire 7 is inserted through the air core 4a of the coil-coated thin wire 4.

Here, as the thin metal wire 1, a round wire with a circular cross section, a square wire with a rectangular cross section, etc. can be used as shown in FIGS. 3a and 4a, and as shown in FIGS.
In each embodiment shown in FIG. b, a coating layer 2 is applied to the thin metal wire 1 so as to have a uniform thickness.
The coated thin wire 3 is formed so that the outer shape is round and square, respectively. In the embodiment shown in FIG. 5, the coating layer 2 is formed on the thin metal wire 1 which is a round wire so that the outer shape is square. I try to do this.

Therefore, if the coated thin wire 3 having a round outer shape is used as described above and the coil coated thin wire 4 is formed by using the winding core E as shown in FIG. The spiral grooves 4d are exposed and unevenness is formed, but when the rectangular coated thin wire 3 is used, there are almost no unevenness on the outer peripheral surface of the coil coated thin wire 4 as shown in FIG. , the desired results in terms of slipperiness are obtained.

Furthermore, the tip portion 4b of the coil-coated thin filament 4
However, in the illustrated example, it is engaged with a mounting groove 5a circumferentially provided on the base end side of the guide top part 5, and is fixed by adhesive means if necessary, so that the tip of the base cover part 6 The base end 4c of the coil-covered thin wire 4 is engaged and fixed in the mounting groove 6a provided around the side, and the safety wire 7 is guided by welding, gluing, or other means as is known. Top part 5, base part 6
are fixed to each.

Here, as is known, an inner core wire (not shown) is arranged in the air core 4a of the coil-coated thin wire 4 in parallel with the safety wire 7, and its base end is fixed to the base cover 6, but its tip is fixed to the base cover 6. It may be arranged to end within the air core 4a near the guide head 5.

Therefore, in order to use the above-mentioned medical guide wire, the conventional method illustrated in FIG.
First, an indwelling needle is inserted into a large blood vessel such as the femoral artery, and then the medical guidewire is inserted into the blood vessel from its guide head 5 through this indwelling needle, allowing it to be flexibly and freely inserted. The distal end portion of the medical guide wire, which is allowed to be curved in a straight line, moves smoothly along the inner wall surface of the blood vessel without colliding with the inner wall surface of the blood vessel.

<<Effects of the invention>> Since the present invention is constructed as described above, the outer circumferential surface of the coil-covered thin filament 4, which occupies most of the product, is made of polyurethane having physical properties that have low resistance in blood. Since it is made of resin, it can enter the blood smoothly and with little resistance when it comes into contact with the inner wall of the blood vessel, and it also has good chemical stability in the blood. Therefore, it is possible to provide products that have no unwanted physiological effects on the human body.

In addition, since the thin metal wire is coated with a coating layer from the beginning and then wound into a coil, it is less expensive and can be coated with a uniform thickness compared to existing technology that coats the coil with synthetic resin. It is easy to form a layer, the flexibility of the coil-coated thin wire is not inhibited by the non-uniformly applied synthetic resin, and the thin metal wire comes into contact with the coating layer. This also improves the flexibility of the coil-coated thin filament, making it possible to obtain a product that is durable and has consistent quality.

[Brief explanation of the drawing]

FIGS. 1 and 2 are partially cutaway longitudinal side views showing different embodiments of the medical guide wire according to the present invention, FIGS. 3 a, b, 4 a, b, and 5 a. ，
b is a perspective view of each end of different examples of thin metal wires and thin coated wires, respectively, which are the constituent members of the present invention; FIG. 6a,
b is a front view and a side view of the main parts showing the coiled state of the coated thin wire, FIG. 7 is a partially cutaway vertical side view showing an example of a conventional medical guide wire, and FIG. 8 is the same guide as above. FIG. 9 is an enlarged longitudinal cross-sectional side view of a main part showing a conventional example of a different type of the above wire. 1... Fine metal wire, 2... Coating layer, 3...
...Covered thin wire, 4...Coil covered thin wire, 4a...
Air core, 4b...distal end, 4c...base end, 5...
Guide head, 6...Base cover, 7...Safety wire.

Claims (1)

[Scope of utility model registration request] A coil-covered thin wire formed by coiling a coated thin metal wire coated with a polyurethane resin coating layer to a required length, and a guiding head fixed to the tip and base ends of the coil-covered thin wire, respectively. A medical guide wire comprising a safety wire that is inserted through the air core of the coil-coated thin wire and has its ends fixed to the guide head and base end, respectively.