JP2517882Y2 - Medical flexible wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION “Industrial field of application” The present invention relates to a medical guide wire suitable as, for example, a guide wire for inserting a catheter, a guide wire for inserting a sensor such as an ultrasonic wave, or a tube for an endoscope. Regarding

“Prior Art” Various flexible wires have been used as medical devices. For example, a guide wire for inserting a catheter, a guide wire for inserting an ultrasonic sensor or the like at the tip, and a tube for an endoscope or the like. These are mainly used as test and treatment instruments for tubular organs of the human body such as blood vessels, ureters, trachea, and esophagus.

As a guide wire for inserting a catheter, a wire as shown in FIG. 4 has been conventionally used. The guide wire for inserting the catheter has a coil 1 formed of a wire made of stainless steel, and a core wire 2 is inserted into the coil 1. In this case, the tip of the core wire 2 is processed into a taper shape to give flexibility.

However, the guide wire for catheter insertion shown in FIG. 4 cannot be used for applications such as attaching various sensors to the tip and passing lead wires etc. inside since the core wire 2 is inserted inside. . That is, since the inside is not hollow, it is limited to the use for inserting a catheter, and there is a problem that the application range is narrow.

Further, as a tube for an endoscope or the like, as shown in FIG. 5, a tube made of a metal mesh coated with a synthetic resin film 4 is used. In this case, glass fibers or the like for sending an image will be inserted inside the tube 3.

By the way, when inserting these flexible wires into a tubular organ of a human body, when the hand portion 6 of the flexible wire 5 is rotated in the direction of arrow A, for example, as shown in FIG. 6, it was inserted into the tubular organ. It is required that the tip portion 7 rotate in the same direction as the arrow B direction, that is, the rotation is transmitted. This rotation transmissibility is required to guide the tip 7 of the flexible wire 5 to an arbitrary position in the bent tubular organ, or to orient a sensor attached to the tip 7 in an arbitrary direction.

For this reason, as a flexible wire having a hollow interior, a flexible wire having a rotation transmitting property is known. This flexible wire is composed of a triple coil composed of coils 8, 9 and 10 which are sequentially wound from the inside. In this case, the winding direction of the inner coil 8 is opposite to the winding direction of the intermediate coil 9, and the winding direction of the outer coil 10 is opposite to the winding direction of the intermediate coil 9 (that is, the winding direction of the inner coil 8). Same direction).

When this flexible wire is rotated as shown by arrow C in FIG. 7, for example, the inner coil 8 contracts, the intermediate coil 9 expands, and the outer coil 10 contracts. Therefore, the coils 9 and 10 come into contact with each other, and the rotational force thereof can be transmitted to the entire flexible wire. On the contrary, when the flexible wire is rotated in the direction indicated by the arrow D in the figure, the inner coil 8 expands in diameter, the intermediate coil 9 contracts in diameter, and the outer coil 10 expands in diameter. Therefore, the coils 8 and 9 come into contact with each other, and the rotational force thereof can be transmitted to the entire flexible wire.

Therefore, according to this flexible wire, it is possible to impart flexibility and at the same time impart a rotation transmission force, and to improve operability when used as a guide wire or the like.

"Problems to be solved by the invention" In the flexible wire shown in FIG. 7, for example, an inner coil 8 is formed by winding a metal wire on a round bar-shaped core metal, and the metal wire is provided outside the coil 8. Is wound in the opposite direction to form an intermediate coil 9, and a metal wire is wound again in the opposite direction (the same direction as the coil 8) on the outside of the coil 9 to form the outer coil 10, and It is manufactured by pulling out the core metal.

By the way, generally, when a metal wire is wound around a cored bar to form a coil, spring back (spring unwinding phenomenon) occurs when the cored bar is extracted. Therefore, the diameter tends to be larger than the diameter when wound around the cored bar. This springback amount increases as D / d increases, where D is the diameter of the coil and d is the wire diameter.

However, in the conventional flexible wire shown in FIG. 7, the wires forming the coils 8, 9 and 10 all have the same wire diameter, and when the coil is formed by the above method, the diameter of the outer coil 10 is increased. Is larger than the diameter of the intermediate coil 9, and the diameter of the intermediate coil 9 is larger than the diameter of the inner coil 8. Therefore, the springback amount is
The outer coil 10 is the largest, the middle coil 9 is the second largest, and the inner coil 8 is the smallest. As a result, even if the coils 8, 9 and 10 are formed in close contact with each other, they are separated from each other by springback, which causes a reduction in the rotation transmission force.

Therefore, an object of the present invention is to increase the degree of closeness of each coil and improve the rotation transmission force in a medical flexible wire including a triple coil.

[Means for Solving the Problems] In order to achieve the above object, the medical flexible wire of the present invention includes an inner coil made of metal and an intermediate coil made of the same metal, which is closely wound around the outer side of the inner coil. And an outer coil made of the same metal that is closely wound around the outer side of the intermediate coil,
In the medical flexible wire in which the intermediate coil is wound in the opposite direction to the inner coil and the outer coil, the wire diameter of the inner coil is A, the wire diameter of the intermediate coil is B, and the wire of the outer coil is When the diameter is C, A ≦ B <C or A <B ≦ C is characterized.

In a preferred aspect of the present invention, the wire diameter of each coil is A <B <C.

[Operation] In the present invention, when the wire diameter of the inner coil is A, the wire diameter of the intermediate coil is B, and the wire diameter of the outer coil is C, A ≦ B <C or A <B ≦ C. Therefore, the amount of springback when these coils are sequentially wound and formed is largest in the inner coil having a small wire diameter and smallest in the outer coil having a large wire diameter. For this reason, after the spring back, the inner coil and the outer coil come close to each other, and a force pressing the coils in the radial direction acts to further enhance the closeness.
Therefore, the frictional force between the coils can be increased and the rotation transmission force can be improved.

In the flexible wire of the present invention, the intermediate coil is wound in the opposite direction to the inner coil and the outer coil. Therefore, even if the intermediate wire is rotated in any direction on the same principle as the flexible wire shown in FIG. The rotating force can be reliably transmitted to the entire flexible wire.
In addition, since the whole is made of a coil, sufficient flexibility is obtained, and since the inside is hollow, it can be used as a guide wire for various sensors, a tube for an endoscope, and the like.

[Embodiment] FIGS. 1 and 2 show an embodiment of a medical flexible wire according to the present invention.

This medical flexible wire consists of an inner coil 11, an intermediate coil 12, and an outer coil that are lapped from the inside.
It is composed of a triple coil consisting of 13. Intermediate coil
The coil 12 is wound in the opposite direction to the coil 11 and the coil 13. For example, when the inner coil 11 and the outer coil 13 are right-handed, the intermediate coil 12 is left-handed.

In the case of this embodiment, the coils 11, 12 and 13 are formed of stainless steel square wires, but the material of the coils is not limited to stainless steel and is formed of other metal that does not adversely affect the human body. May be. Further, the wire material forming each coil 11, 12, 13 is not limited to a square wire, but may be a round wire, a flat wire, or the like.

A feature of the present invention is that, when the wire diameter of the inner coil 11 is A, the wire diameter of the intermediate coil 12 is B, and the wire diameter of the outer coil 13 is C, A ≦ B <C or A <B ≦ C, and more preferably A <B <C. Each coil 1
The wire diameter of the wire material constituting 1, 12, 13 is appropriately set depending on the application of the medical flexible wire, but usually 50
The range is up to 500 μm. When the wire diameter of the adjacent inner coil is R ₁ , the coil diameter is D _1, and the wire diameter of the outer coil is R ₂ and the coil diameter is D ₂ , then D ₁ / R ₁ ≧ D ₂ / R More preferably, it is ₂ .

3 (a), (b), and (c) show the outline of the manufacturing process of the medical flexible wire.

As shown in FIG. 3A, a stainless steel wire is wound around a round bar-shaped core metal 21 to mold the inner coil 11. This coil 11 has a coil diameter of d ₁ when wound around a cored bar 21, but when it is removed from the cored bar 21, it springs back and the coil diameter becomes d ₁ ′. Accordingly, the spring back amount is expressed by (d ₁ '-d _1).

As shown in FIG. 2B, a stainless wire is wound around the inside of the inner coil 11 in the opposite winding to form the intermediate coil 12. The coil 11 has a coil diameter of d ₂ in a wound state, but when it is removed from the cored bar 21, it springs back and the coil diameter becomes d ₂ ′. Therefore,
The springback amount is represented by (d ₂ ′ −d ₂ ).

As shown in FIG. 3C, a stainless steel wire is wound further outside the intermediate coil 12 in the opposite direction to the intermediate coil 12 (that is, in the same direction as the inner coil 11) to form the outer coil.
Mold 13. The coil 13 has a coil diameter of d ₃ in a wound state, but when it is detached from the cored bar 21, it springs back and the coil diameter becomes d ₃ ′. Accordingly, the spring back amount is expressed by (d ₃ '-d _3).

Here, it is assumed that the wire diameter A of the inner coil 11, the wire diameter B of the intermediate coil 12, and the wire diameter C of the outer coil 13 are A <B <C. As described above, the springback amount increases as the wire diameter decreases, so each coil 11, 1
The springback amounts of 2 and 13 are (d ₁ ′ −d ₁ )> (d ₂ ′
−d ₂ )> (d ₃ ′ −d ₃ ). In this case, the springback amount also depends on the coil diameter, but since the coils are wound in layers, the effect of the difference in coil diameter is not so great.

In this way, the outer diameter of the inner coil 11 springs back to d ₁ ′. On the other hand, the inner diameter of the intermediate coil 12 is d ₁ when wound around the outer side of the inner coil 11, and therefore springs back to {d ₁ + (d ₂ ′ −d ₂ )}. Then, when the inner diameter of the intermediate coil 12 is subtracted from the outer diameter of the inner coil 11 when springed back, the following equation is obtained.

d ₁ ′ − {d ₁ + (d ₂ ′ −d ₂ )} = (d ₁ ′ −d ₁ ) − (d ₂ ′ −d ₂ )> 0 Therefore, when springing back, the inner coil 11
The outer diameter of is larger than the inner diameter of the intermediate coil 12, and the inner coil 11 is pressed against the inner circumference of the intermediate coil 12.

Similarly, the outer diameter of the intermediate coil 12 springs back to d ₂ ′. On the other hand, the inner diameter of the outer coil 13 is
Since it is d ₂ when wound around the outside of the intermediate coil 12,
It springs back to {d ₂ + (d ₃ ′ −d ₃ )}. Therefore, when the inner diameter of the outer coil 13 is subtracted from the outer diameter of the intermediate coil 12 when springed back, the following equation is obtained.

d ₂ ′ − {d ₂ + (d ₃ ′ −d ₃ )} = (d ₂ ′ −d ₂ ) − (d ₃ ′ −d ₃ )> 0 Therefore, when springback is performed, the intermediate coil 12
The outer diameter of is larger than the inner diameter of the outer coil 13, and the intermediate coil 12 is pressed against the inner circumference of the outer coil 13.

Thus, in the medical flexible wire of the present invention, the coils 11, 12, 13 are in a state of being pressed against each other,
The strong close contact improves the rotation transmission force in the twisting direction.

The medical flexible wire of the present invention can be used, for example, as a guide wire for inserting a catheter, can be used as a guide wire for inserting a sensor such as an ultrasonic wave at the tip and inserting it through a lead wire, It can also be used as a tube for an endoscope or the like. By coating a resin on the outer circumference or the inner circumference of the coil that is wound in a lap, it is possible to insert it into a tubular organ and directly inject a drug solution such as a contrast agent.

[Advantage of Invention] As described above, according to the present invention, since the closeness of each coil is increased by the springback, it is flexible, and at the same time has good rotation transmission and good operability. A flexible wire can be provided. This medical flexible wire can be used in a wide range of applications as a catheter, a guide wire for inserting various sensors, a tube for an endoscope, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial side view showing an embodiment of a medical flexible wire of the present invention, FIG. 2 is an end view of the flexible wire, and FIGS. c) is an explanatory view showing the manufacturing process of the flexible wire in order, FIG. 4 is a partial side view showing an example of a conventional guide wire, FIG. 5 is a partial side view showing a tube of a conventional endoscope, and FIG. FIG. 7 is an explanatory view showing an operating state of this kind of flexible wire, and FIG. 7 is a partial side view showing another example of the conventional flexible wire. In the figure, 11 is an inner coil, 12 is an intermediate coil, 13 is an outer coil, and A, B, and C are coil wire diameters.

Claims (2)

(57) [Scope of utility model registration request] 1. An inner coil made of metal, an intermediate coil made of the same metal, which is closely wound on the outer side of the inner coil, and an outer coil made of the same metal, which is tightly wound on the outer side of the intermediate coil. In the medical flexible wire in which the intermediate coil is wound oppositely to the inner coil and the outer coil, the wire diameter of the inner coil is A, the wire diameter of the intermediate coil is B, and A flexible medical wire, wherein A ≦ B <C or A <B ≦ C, where C is the wire diameter of the outer coil. 2. The medical flexible wire according to claim 1, wherein A <B <C.