TWI552778B - Medical guidewire - Google Patents

Description

Medical guide wire

The present invention relates to a medical guide wire that is configured by attaching a coil spring to an outer circumference of a distal end side small-diameter portion of a core wire.

A guide wire for guiding a medical instrument such as a catheter to a predetermined position in a body cavity such as a blood vessel is required to have flexibility at the distal end portion.

Therefore, it is known that the outer diameter of the distal end portion of the core wire is made smaller than the outer diameter of the proximal end portion, and a coil spring is attached to the outer circumference of the distal end portion of the core wire (the distal end side small diameter portion) for the purpose of lifting A flexible guide wire of the distal end portion (for example, refer to Patent Document 1).

In order to attach the coil spring to the outer circumference of the small-diameter portion on the distal end side of the core wire, the front end portion and the rear end portion of the coil spring are usually fixed to the core wire by solder.

Recently, it has been desired to reduce the invasiveness of patients and to reduce the size of medical devices.

Along with this, the diameter of the guide wire is required to be reduced, and the inventors of the present invention are developing a guide wire having a smaller outer diameter (0.010 inch) than the conventional guide wire (0.014 inch in outer diameter).

According to the guide wire of 0.010 inches, it can contribute greatly to the miniaturization of medical devices such as catheters.

Furthermore, if based on this guide line, for example, for CTO (chronic complete The operability of the occlusion of the microchannels of the lesions is also improved.

However, the guide wire of the small diameter causes the bending rigidity (distortion resistance) to be low, and the pushability is also poor.

Based on such a problem, the inventors of the present invention have developed and proposed a guide wire for attaching a coil spring to the outer circumference of the small-diameter portion on the distal end side of the core wire, and the outer diameter of the coil on the front end side of the coil spring is 0.010 inch, coil spring The outer diameter of the coil on the end side and the outer diameter of the proximal end portion of the core wire are all guide lines of 0.014 inches (refer to Patent Document 2).

[Previous Technical Literature]

Patent Document 1: Japanese Laid-Open Patent Publication No. 2003-299739

Patent Document 2: Japanese Invention Patent No. 4345525

In the microchannel of the CTO lesion, there is a smaller aperture than 0.010 inch. In order to be inserted into such a microchannel, the guide wire (the outer diameter of the coil of the coil spring) must be smaller.

On the other hand, in the coil spring constituting the guide wire, when the outer diameter of the coil is different between the front end side and the rear end side, when a narrow portion such as a microchannel is to be inserted, stress is concentrated on a portion where the diameter of the coil changes. There will be problems that are easily distorted in this part. Moreover, the guide wire of the coil spring having a large change in the outer diameter of the coil does not have good pushability.

Also, for the guide wire, it is required to have good torque transmission (making The rotational torque on the proximal side is transmitted well to the distal side). If there is insufficient torsion transmission, the guide line is selected at the blood vessel bifurcation, and it is difficult to advance toward the blood vessel of the purpose, and the insertion workability is impaired.

However, a guide wire having a small diameter or a coil spring having a large change in the outer diameter of the coil has a tendency that the torque transmission property of the guide wire is deteriorated.

Further, it is required that the guide wire is less likely to be permanently deformed (shape retainability) even when it is bent in a blood vessel that is bent and undulated. When permanent deformation occurs in manual operation, undulations or the like due to rotation from the hand operation may cause difficulty in subsequent intravascular operation.

The present invention has been developed based on the above circumstances.

A first object of the present invention is to provide a narrow portion having a small hole diameter that cannot be inserted by using a conventional guide wire, and can be inserted, and has high bending rigidity (distortion resistance) and excellent pushability. Medical guide wire.

A second object of the present invention is to provide a medical guide wire which has excellent torque transmission property and is excellent in shape retention which is less likely to cause permanent deformation when it is bent into a undulating blood vessel.

(1) The medical guide wire according to the present invention is characterized in that it is provided with a core wire and a coil spring which is formed of Worthfield iron-based stainless steel having a tensile strength of 2,600 MPa to 3,000 MPa and has a proximal end side. Large diameter section and outer diameter ratio The distal end small diameter portion of the distal end side large diameter portion is small, and the coil spring is attached to the outer circumference of the distal end small diameter portion of the core wire in the axial direction, and is at least at the front end portion and the rear end portion. The distal end side small-diameter portion of the core wire of the coil spring is fixed to the core wire, and is wound with a tensile load of 150 gf for 10 seconds in a state of being wound one turn along the outer circumference of the rod of 3 mm in diameter. Thereafter, the warpage angle of the front end portion formed by the winding was less than 25°.

(2) The medical guide wire according to the present invention comprises a core wire and a coil spring, and the core wire is formed of Worthfield iron-based stainless steel having a tensile strength of 2,600 MPa to 3,000 MPa, and has an outer diameter of 0.012. a proximal end large diameter portion of an inch or more and a distal end small diameter portion having an outer diameter smaller than the proximal end large diameter portion, the coil spring being attached to the distal end side of the core wire along the axial direction The outer circumference of the portion is composed of a densely wound portion having a coil pitch of 1.1 to 2.0 times the coil wire diameter, and a thickly wound portion having a coil pitch of more than 2.0 times the coil wire diameter continuously continuous with the densely wound portion; The coil spring has a front end side small diameter portion having a coil outer diameter of 0.008 inches or less, and a middle diameter portion having a coil outer diameter larger than an outer diameter of a coil of the front end side small diameter portion, and has a 0.012 inch. The rear end side large diameter portion of the outer diameter of the coil which is larger than the outer diameter of the coil of the intermediate diameter portion, and a first tapered portion positioned between the distal end side small diameter portion and the intermediate diameter portion, and a second tapered portion positioned between the intermediate diameter portion and the rear end side large diameter portion, which is small by the distal end side The diameter portion, the first tapered portion, the intermediate diameter portion, and the second tapered portion constitute the tightly wound portion having a length of 5.5 mm to 110 mm, and the rear end side large diameter portion is configured as a sparsely wound portion; The distal end portion of the distal end side small diameter portion, the rear end portion of the second tapered portion, and the rear end portion of the rear end side large diameter portion are fixed by solder and then on the outer circumference of the small diameter portion on the distal end side of the core wire. The distal-side small-diameter portion of the core wire in which the coil spring is attached is fixed, and is wound by a tensile load of 150 gf for 10 seconds in a state of being wound around the outer circumference of a rod of 3 mm in diameter. The warpage angle around the front end portion (hereinafter, also referred to as "bending fatigue angle (θ)") is less than 25°.

According to such a guide wire, the coil spring constituting the guide wire has a small-diameter portion having a distal end side having a coil outer diameter of 0.008 inches or less, and a narrow portion having a small diameter that cannot be inserted by using a conventional guide wire. Since it can be inserted, it can be treated in a narrow region (for example, a microchannel having a pore diameter of 250 μm or less in a CTO lesion) which cannot be performed using a conventional guide wire.

In addition, the coil spring has a large-diameter portion on the rear end side having a coil outer diameter of 0.012 inches or more, and the small-diameter portion on the distal end side, the medium-diameter portion, and the large-diameter portion on the rear-end side are stepwise changed. Guidance of the coil spring The line is excellent in bending rigidity and excellent in pushability.

Further, the tip end portion of the distal end side small diameter portion, the rear end portion of the second tapered portion, and the rear end portion of the rear end side large diameter portion are fixed to the distal end side small diameter portion of the core wire by solder. By the outer circumference, the coil spring can be surely fixed to the distal end small-diameter portion of the core wire, and the distal end side small-diameter portion (excluding the distal end portion), the first tapered portion, the intermediate diameter portion, and the second tapered portion ( Except for the rear end portion), the outer circumference of the small-diameter portion on the distal end side of the core wire is not fixed by soldering, so that the flexibility of the densely wound portion positioned as the front end region of the coil spring can be sufficiently ensured, and Shaping is also possible in the area.

Further, since the distal end side small diameter portion, the first tapered portion, the intermediate diameter portion, and the second tapered portion constitute a tightly wound portion of the coil spring, the densely wound portion as the coil spring front end region can be revealed. Good contrast (identifiability).

Moreover, since the resistance when the guide wire is inserted into the narrow portion is different depending on the outer diameter of the coil of the coil spring, the operator can change the insertion resistance according to the stepwise change of the outer diameter of the coil. (Tactile sensation), to grasp the insertion length of the guide wire to the stenosis.

Further, the core wire is composed of high-strength Worth iron-based stainless steel having a tensile strength of 2,600 MPa to 3,000 MPa, and the bending angle (θ) of the guide wire is less than 25°, and the medical guide wire is It has excellent torque transmission property, and is hard to be permanently deformed when the blood vessel is bent and undulated, and has excellent shape retention (for example, a shape retaining property).

(3) In the medical guide wire according to the present invention, it is preferable that an outer diameter of the proximal end side large diameter portion of the core wire is 0.014 inches or more, and a coil outer diameter of the coil spring front end small diameter portion is 0.008 inches. Hereinafter, the outer diameter of the coil of the intermediate diameter portion is 0.009 to 0.011 inches, and the outer diameter of the coil of the large diameter portion of the rear end side is 0.014 inches or more.

(4) In the medical guide wire, it is preferable that a ratio of a coil outer diameter of the distal end small diameter portion to an outer diameter of the coil of the intermediate diameter portion is 0.5 to 0.9, and the first tapered portion The length is 0.5 mm to 10 mm, the ratio of the outer diameter of the coil of the large diameter portion at the rear end side to the outer diameter of the coil of the intermediate diameter portion is 1.1 to 2.3, and the length of the second tapered portion is 0.5 mm to 10 mm.

(5) In the medical guide wire according to the present invention, it is preferable that the distal end portion of the distal end side small-diameter portion is fixed to the core wire by solder containing gold, and is formed by a solder containing gold. The length of the hard straight portion is 0.1 mm to 0.5 mm.

Here, the "gold-containing solder" includes Au-Ge (gold-ruthenium) solder, Au-Si (gold-ruthenium) solder, Au-In (gold-indium) solder, and Au- Sb (gold-ruthenium) is an Au (gold) alloy solder such as solder and an Au (gold) solder (hereinafter, only the element is a solder).

In addition, the term "hard end portion of the front end" refers to a tip end portion of a coil spring (guide wire) which is infiltrated into the inside of the coil by solder, and when the tip end point is formed by solder, the front end The cusp also becomes part of the hard front part.

In addition, the term "the length of the front end hard portion" refers to the axis of the guide wire from the tip end of the guide wire to the rear end of the solder penetrating into the inside of the coil. The length of the direction.

By using solder containing gold as the solder for fixing the front end portion of the small-diameter portion of the front end side (the front end portion of the coil spring) to the core wire, the length of the hard straight portion of the front end is short (fixed by solder) The area is narrower, only 0.1mm~0.5mm, and the strength of the coil spring to the core wire can be sufficiently high enough (higher than the breaking strength of the small-diameter portion on the distal side of the core wire), even if it is inserted in the coil The core wire in the state of the spring acts as a tensile force, and there is no case where the core wire is pulled off.

Moreover, since the length of the hard straight portion of the front end is only 0.1 mm to 0.5 mm, the shaping length (the bending length of the front end) can be shortened, and as a result, the friction during the operation in the microchannel can be sufficiently reduced. resistance.

(6) In the medical guide wire, it is preferable that the solder containing gold is infiltrated in a range corresponding to one to four pitches from the tip end in the small-diameter portion on the distal end side of the coil spring. Inside the coil.

Here, for example, the penetration into the inside of the coil in a range corresponding to three pitches from the tip means that the rear end of the solder penetrating into the inside of the coil is in contact with the coil of the third turn from the tip end. There is no contact with the position of the coil of the fourth lap.

(7) In the medical guide wire according to the present invention, preferably, the inside of the coil spring is filled with a resin, and a resin layer formed of the resin is formed on an outer circumference of the coil spring, and the resin layer is formed on the resin layer. The surface area layer is formed with a hydrophilic resin layer, and a water-repellent resin layer is formed on the surface of the core wire.

By filling the inside of the coil spring with resin, the integral of the core wire and the coil spring can be remarkably improved, whereby the torque transmission property and the operability of the guide wire can be further improved.

In addition, since the resin layer formed of the same resin as the resin filled in the coil spring is interposed, and the hydrophilic resin layer is formed on the outer circumference of the coil spring, the lubricity by the hydrophilic resin can be stably stabilized. Appeared.

Further, by forming the water-repellent resin layer on the surface of the core wire, it is possible to prevent the patient's blood from coming into contact with the metal constituting the core wire and causing allergies, and it is possible to reliably prevent adhesion of blood or the like by the water-repellent resin layer. Moreover, lubricity with respect to other medical instruments can be exhibited.

(8) The medical guide wire according to the present invention is a medical guide wire including a core wire and a coil spring, wherein the core wire is formed of Worthfield iron-based stainless steel having a tensile strength of 2,600 MPa to 3,000 MPa. The distal end side large diameter portion and the distal end small diameter portion having an outer diameter smaller than the proximal end large diameter portion, the coil spring being attached to the distal end side small diameter portion of the core wire along the axial direction The outer circumference is fixed to the core wire at least at the front end portion and the rear end portion, and preferably, the outer diameter of the proximal end side large diameter portion of the core wire and the outer diameter of the coil spring coil are 0.012 inches or less. The front end portion of the coil spring is fixed to the core wire by solder containing gold. The length of the hard end portion formed by the gold-containing solder is 0.1 mm to 0.5 mm, and the bending fatigue angle (θ) is less than 25°.

(9) The medical guide wire according to the present invention is a medical guide wire including a core wire and a coil spring, wherein the core wire is formed of Worthfield iron-based stainless steel having a tensile strength of 2600 MPa to 3000 MPa. The distal end side large diameter portion and the distal end small diameter portion having an outer diameter smaller than the proximal end large diameter portion, the coil spring being attached to the distal end side small diameter portion of the core wire along the axial direction The outer circumference has a small-diameter portion on the distal end side, a large-diameter portion having a larger outer diameter of the coil than the small-diameter portion on the distal end side, and a small-diameter portion on the distal end side and the large-diameter portion on the rear-end side. The tapered portion is fixed to the core wire at least at the front end portion and the rear end portion, and the length of the small-diameter portion on the front end side of the coil spring is 5 mm to 100 mm, and the outer diameter of the coil is 0.012 inches or less. The front end portion is fixed to the core wire by solder containing gold, and the length of the hard end portion formed by the gold-containing solder is 0.1 mm to 0.5 mm, and the bending fatigue angle (θ) is less than 25°.

According to the medical guide wire of the present invention, it is possible to insert a narrow portion having a small hole diameter which cannot be inserted by using a conventional guide wire.

The medical guide wire of the present invention has high bending rigidity (distortion resistance) and excellent pushability.

The medical guide wire of the present invention has excellent torque transmission property, and is easily advanced toward a target blood vessel at the point of selection of a blood vessel, and has excellent insertion workability.

The medical guide wire of the present invention is less likely to be permanently deformed even if it is bent, and has excellent shape retention.

<First embodiment>

The medical guide wire of the present embodiment shown in Figs. 1 to 3 is provided with a core wire 10 and a coil spring 20; the core wire 10 is a Worth iron system having a tensile strength of 2600 MPa to 3000 MPa. The stainless steel is formed, and has a proximal-side large-diameter portion 13 having an outer diameter of 0.012 inches or more, and a distal-side small-diameter portion 11 having an outer diameter smaller than the proximal-side large-diameter portion 13, and a proximal end side. The tapered portion 12 between the large-diameter portion 13 and the distal-side small-diameter portion 11; the coil spring 20 is attached to the outer circumference of the distal-side small-diameter portion 11 of the core wire 10 in the axial direction, and has a length of 1.1 times. a densely wound portion 201 having a coil pitch of 2.0 times the coil wire diameter, and a thickly wound portion 202 continuing to the densely wound portion 201 and having a coil pitch of more than 2.0 times the coil wire diameter; and the coil spring 20 has : 21, and the ratio of the coil outer diameter (D ₂₁₎ the distal end side small-diameter portion 21 of the small-diameter portion having a distal side coil outer diameter (D ₂₁₎ 0.008 inches of the coil having a larger outer diameter (D ₂₃₎ of diameter portion 23, and has more than 0.012 inches in diameter and a coil outer diameter portion 23 (D ₂₃₎ of the larger outer coil diameter (D ₂₅₎ of the rear end side of the large-diameter And a first tapered portion 22 positioned between the distal end side small diameter portion 21 and the intermediate diameter portion 23, and a second tapered portion 24 positioned between the intermediate diameter portion 23 and the rear end side large diameter portion 25, and The front end side small diameter portion 21, the first tapered portion 22, the intermediate diameter portion 23, and the second tapered portion 24 are configured as a tightly wound portion having a length (L ₂₁ + L ₂₂ + L ₂₃ + L ₂₄ ) of 5.5 mm to 110 mm. 201, and the rear end side large diameter portion 25 is configured as a sparse winding portion 202; a front end portion of the front end side small diameter portion 21, a rear end portion of the second tapered portion 24, and a rear end of the rear end side large diameter portion 25 In part, Au-Sn (gold-tin, hereinafter only indicated by element symbols) solder 31, Au-Sn-based solder 32, and Ag-Sn (silver-tin, hereinafter only indicated by element symbols) are used. The outer circumference of the small-diameter portion 11 on the distal end side of the core wire 10 is fixed, and the distal-side small-diameter portion 11 of the core wire 10 to which the coil spring 20 is attached is wound one turn around the outer circumference of the rod having a diameter of 3 mm. In the state of the tensile load of 150 gf for 10 seconds, the warp angle of the front end portion formed by the winding (the bending fatigue angle (θ) of the permanent deformation) is a medical guide of less than 25°. line.

The guide wire of the present embodiment includes a core wire 10 and a coil spring 20.

The core wire 10 has a distal-side small-diameter portion 11 that is tapered in a direction toward the proximal direction, a tapered portion 12 that expands in the proximal direction, and a proximal-side large-diameter portion 13.

The distal-side small-diameter portion 11, the tapered portion 12, and the proximal-side large-diameter portion 13 are integrally formed of the same wire (for example, a round bar member).

The cross section of the tapered portion 12 and the proximal end large diameter portion 13 is substantially circular.

The cross section on the proximal end side of the distal side small-diameter portion 11 is substantially circular, but the distal end side of the distal-side small-diameter portion 11 can also compress the wire into a plate shape. The cross section is generally rectangular.

The core wire 10 is made of a high-strength Worthfield iron-based stainless steel (for example, SUS304 or SUS316) having a tensile strength of 2,600 MPa to 3,000 MPa.

The Worstian iron-based stainless steel having a high tensile strength of 2600 MPa to 3,000 MPa has a high elastic limit, so that it can be used as a guide wire of the present embodiment of the core wire, and it is less likely to be permanently deformed by bending.

The core wire 10 is obtained by performing wire drawing processing on a wire of a Worthfield iron-based stainless steel, and forming a wire having a predetermined wire diameter and strength, and then cutting it into a bar at a predetermined length after straight correction, and then The treatment conditions of a temperature of 300 ° C to 500 ° C and a time of 0.5 hours to 4 hours are aging treatment, thereby being produced.

Here, the "aging treatment" is performed for the purpose of eliminating (reducing) the residual stress in the portion which becomes the distal-side small-diameter portion 11, and preventing the bending of the distal end side.

If the aging treatment temperature is less than 300 ° C or exceeds 500 ° C, it is difficult to obtain a core wire 10 having a tensile strength of 2600 MPa or more, and a guide wire having a bending fatigue angle (θ) of less than 25°.

Further, if the aging treatment time is less than 0.5 hours, the residual stress cannot be sufficiently eliminated. On the other hand, even if the processing is performed for more than 4 hours, the effect equivalent to the processing time cannot be obtained.

A water-repellent resin layer (not shown) is formed on the outer peripheral surface of the core wire 10.

As the resin constituting the water-repellent resin layer, any resin which is used for medical use can be used as a water-repellent resin, and a suitable resin can be a fluorine-based resin such as PTFE.

The total length (L ₁ ) of the guide wire shown in Fig. 2 is, for example, 1500 mm to 3000 mm, and an example of a suitable one is 1780 mm.

The outer diameter (D ₁ ) of the proximal end side large diameter portion 13 of the core wire 10 is 0.012 inches (0.305 mm) or more, and preferably 0.014 inches (0.356 mm) or more, and an example of a suitable one is 0.014 inches. .

The outer diameter of the distal end small-diameter portion 11 is not particularly limited as long as it is smaller than the inner diameter of the coil spring 20, but the outer diameter (D ₁ ) of the proximal-side large-diameter portion 13 is 1/5~3/5 is better.

The distal-side small-diameter portion 11 may have a diameter that is continuously reduced toward the distal end side (hereinafter referred to as a reduced diameter), or may be a stepped diameter.

The coil spring 20 constituting the guide wire is composed of one wire and is attached to the outer circumference of the distal end small-diameter portion 11 of the core wire 10 in the axial direction.

The outer diameter (coil wire diameter) of the wire constituting the coil spring 20 is not particularly limited, but is preferably 30 μm to 90 μm, and an example of a suitable one is 50 μm.

Examples of the material of the coil spring 20 include materials excellent in X-ray contrast properties such as platinum, platinum alloy (for example, Pt/W=92/8), gold, gold-copper alloy, tungsten, and the like (X-ray non-conductive). Transmissive substance).

The coil spring 20 is composed of a distal end side small diameter portion 21, a first tapered portion 22, a middle diameter portion 23, a second tapered portion 24, and a rear end side large diameter portion 25.

The distal end side small diameter portion 21, the first tapered portion 22, the intermediate diameter portion 23, and the second tapered portion 24 constitute a tightly wound portion 201 of the coil spring 20. The densely wound portion 201 (the distal end side small diameter portion 21, the first tapered portion 22, the intermediate diameter portion 23, and the second tapered portion 24) of the coil spring 20 and the tip end point to be described later are X-ray non-transmissive regions.

The rear end side large diameter portion 25 is configured as a sparse winding portion 202 of the coil spring 20.

The coil pitch of the densely wound portion 201 on the distal end side is set to be 1.1 times to 2.0 times the coil wire diameter, and one example is 1.5 times more suitable.

If the coil pitch is 1.1 times the coil diameter of the coil, the softness of the region is impaired. On the other hand, when the coil pitch exceeds 2.0 times the coil wire diameter, good contrast properties cannot be exhibited in this region.

The coil pitch of the sparsely wound portion 202 on the rear end side is 2.0 times larger than the coil wire diameter, and it is exemplified that it is 3.0 times more suitable.

In this manner, by changing the coil pitch on the distal end side and the rear end side, it is possible to exhibit good contrast (identifiability) in the densely wound portion 201 as the distal end region.

If the entire area of the coil spring is set to the same pitch, the X-ray non-transmission area becomes longer, which leads to a decrease in the visibility.

In the second drawing, the length (L ₂ ) of the coil spring 20 is, for example, 30 mm to 800 mm, preferably 100 mm to 200 mm, and an example of a suitable one is 165 mm.

The length (L ₂₁ ) of the distal end side small-diameter portion 21 is 0.5 mm to 100 mm, preferably 3 mm to 15 mm, and an example of a suitable one is 8.5 mm.

The length (L ₂₂ ) of the first tapered portion 22 is preferably 0.5 mm to 10 mm, and an example of a suitable one is 1.5 mm.

The length (L ₂₃ ) of the intermediate diameter portion 23 is 0.5 mm to 150 mm, preferably 10 mm to 50 mm, and an example of a suitable one is 28.5 mm.

The length (L ₂₄ ) of the second tapered portion 24 is preferably 0.5 mm to 10 mm, and an example of a suitable one is 15 mm.

The length (L ₂₅ ) of the rear end side large diameter portion 25 is, for example, 85 mm to 154.5 mm, and an example of a suitable one is 125 mm.

The length of the densely wound portion 201 of the coil spring 20, that is, the length from the distal end of the distal end side small diameter portion 21 to the rear end of the second tapered portion 24 (L ₂₁ + L ₂₂ + L ₂₃ + L ₂₄ ), It is usually set to 5.5 mm to 110 mm, preferably 10.5 mm to 80 mm, and one of the more suitable examples is 40.0 mm (8.5 mm + 1.5 mm + 28.5 mm + 1.5 mm).

By setting the length (L ₂₁ + L ₂₂ + L ₂₃ + L ₂₄ ) to 5.5 mm or more, the tip end of the small-diameter portion 21 from the distal end side to the rear end of the second tapered portion 24 can be made for almost all the microchannels. The densely wound portion 201 until now is inserted (through).

In addition, by setting the length (L ₂₁ + L ₂₂ + L ₂₃ + L ₂₄ ) to 110 mm or less, it is possible to sufficiently ensure the length of the end side large-diameter portion 25 after contributing to the improvement in bending rigidity and pushability. (L ₂₅ ).

The length (L ₃ + L ₂ ) from the tip end of the guide wire to the rear end of the coil spring 20 is, for example, 30 mm to 800 mm, and an example of a suitable one is 165.2 mm (0.2 mm + 165 mm).

The length (L ₃ + L ₂₁ + L ₂₂ + L ₂₃ + L ₂₄ ) from the distal end of the guide wire to the rear end of the second tapered portion 24 is, for example, 10 mm to 50 mm, and an example of a suitable example is 40.2. Mm (0.2 mm + 8.5 mm + 1.5 mm + 28.5 mm + 1.5 mm).

The outer diameter (D ₂₁ ) of the coil which is located at the end small-diameter portion 21 of the coil spring 20 is usually set to 0.008 inches (0.203 mm) or less, and an example of a suitable one is 0.0078 inches. By making the outer diameter (D ₂₁ ) of the coil of the distal end side small-diameter portion 21 to be 0.008 inches or less, it is possible to insert a narrow portion having a small diameter that cannot be inserted by using the conventional guide wire. A narrow region (for example, a microchannel having a pore diameter of 250 μm or less in a CTO lesion) that cannot be performed in the case of a guide wire is treated.

The outer diameter (D ₂₃ ) of the coil of the diameter portion 23 of the coil spring 20 is larger than the outer diameter (D ₂₁ ) of the coil located on the small-diameter portion 21 of the distal end side, and is preferably set to 0.009 inches to 0.011 inches (0.229). Mm~0.279mm), one of the more suitable examples is 0.010 inches (0.254mm).

By having the intermediate diameter portion 23 between the distal end side small diameter portion 21 and the rear end side large diameter portion 25, the distal end side small diameter portion 21, the intermediate diameter portion 23, the rear end side large diameter portion 25, and the coil can be obtained. The outer diameter changes stepwise, and there is no portion (a portion that is easily twisted) in which the outer diameter of the coil changes abruptly.

The outer diameter (D ₂₅ ) of the coil located at the end side large-diameter portion 25 of the coil spring 20 is larger than the outer diameter (D ₂₃ ) of the coil located in the intermediate diameter portion 23, and is usually set to 0.012 inches or more to 0.014 inches. (0.356 mm) or more is preferable, and one of the more suitable examples is 0.014 inch.

The outer diameter (D ₂₅ ) of the coil at the rear end side large diameter portion 25 is 0.012 inches or more, and the distal end side small diameter portion 21, the intermediate diameter portion 23, the rear end side large diameter portion 25, and the outer diameter of the coil are stepped. In the change of the nature, the guide wire of the embodiment of the coil spring 20 is excellent in bending rigidity and excellent in pushability.

In the coil spring 20, the ratio (D ₂₁ /D ₂₃ ) of the outer diameter of the coil of the small-diameter portion 21 of the distal end side to the outer diameter of the coil of the intermediate diameter portion 23 is 0.5 to 0.9, and the length of the first tapered portion 22 (L) ₂₂ ) It is preferably 0.5mm~10mm.

When the ratio of the outer diameter of the coil (D ₂₁ /D ₂₃ ) is less than 0.5 and/or the length of the first tapered portion 22 is less than 0.5 mm, the bending rigidity of the guide wire may be lowered and the first tapered portion may be lowered. There is distortion in the vicinity of 22, or damage to the pushability.

On the other hand, when the ratio (D ₂₁ /D ₂₃ ) exceeds 0.9 and/or the length of the first tapered portion 22 exceeds 10 mm, the diameter of the distal end small-diameter portion 21 may not be sufficiently reduced.

An example of a more suitable ratio of the outer diameter of the coil (D ₂₁ /D ₂₃ ) is 0.78 (0.0078 inch / 0.010 inch).

Further, in the coil spring 20, the ratio (D ₂₅ /D ₂₃ ) of the outer diameter of the coil at the rear end side large diameter portion 25 to the outer diameter of the coil of the intermediate diameter portion 23 is 1.1 to 2.3, and the length of the second tapered portion 24 is (L ₂₄ ) is preferably 0.5 mm to 10 mm.

When the ratio of the outer diameter of the coil of the large-diameter portion 25 on the rear end side to the outer diameter of the coil of the intermediate-diameter portion 23 (D ₂₅ /D ₂₃ ) exceeds 2.3, and/or the length of the second tapered portion 24 is less than 0.5 mm In addition, there is a fear that the bending rigidity of the guide wire is lowered to be distorted in the vicinity of the second tapered portion 24 or to impair the pushability.

On the other hand, when the ratio (D ₂₅ /D ₂₃ ) is less than 1.1 and/or the length of the second tapered portion 24 is less than 10 mm, the intermediate diameter portion 23 and the distal end portion small diameter portion may not be sufficiently obtained. 21's path to the path.

An example of a more suitable ratio of the outer diameter of the coil (D ₂₅ /D ₂₃ ) is 1.4 (0.014 inch / 0.010 inch).

In the guide wire of the present embodiment, the front end portion of the small-diameter portion 21 of the coil spring 20, the rear end portion of the second tapered portion 24, and the rear end portion of the large-diameter portion 25 of the rear end side are respectively soldered. The outer circumference of the small-diameter portion 11 on the distal end side of the core wire 10 is fixed.

As shown in FIG. 1 and FIG. 3(A), the tip end portion of the front end side small-diameter portion 21 as the tip end portion of the coil spring 20 is fixed to the core wire 10 by the Au-Sn-based solder 31. In other words, the Au-Sn-based solder 31 is infiltrated into the front end portion (the front end portion of the distal end side small-diameter portion 21) of the coil spring 20, and is surrounded by the outer circumference of the core wire 10 (the distal-side small-diameter portion 11). The front end portion of the coil spring 20 is fixed to the core wire 10 (the distal end small diameter portion 11) by contact.

As shown in FIG. 3(A), the Au-Sn-based solder 31 penetrates into the inside of the coil in a range corresponding to three pitches of the coil spring 20.

Further, in the tip end portion of the coil spring 20, a substantially hemispherical tip end point is formed by the Au-Sn-based solder 31 which does not penetrate into the coil spring 20.

Thereby, the front end hard portion of the Au-Sn-based solder 31 is formed at the tip end portion of the guide wire of the present embodiment. The hard straight portion is formed by the Au-Sn-based solder 31 which is infiltrated into the inside of the coil. And become unable to The front end portion of the coil spring 20 (the front end side small diameter portion 21) and the front end point formed by the Au-Sn-based solder 31 are formed.

The length of the hard straight portion of the front end (the length from the front end of the guide wire to the rear end of the Au-Sn-based solder 31 that penetrates into the inside of the coil) (L ₄ ) is set to 0.1 mm to 0.5 mm, preferably 0.3. Mm~0.4mm.

The fixing force of the coil spring 20 to the core wire 10 can be sufficiently ensured by the length of the front end hard straight portion being 0.1 mm or more.

Moreover, the length of the shaping (the outer length (L ₅₂ ) to be described later) can be set to 0.7 mm or less by making the length of the hard straight portion of the front end 0.5 mm or less.

In the guide wire of the present embodiment, in order to make the length of the hard portion of the front end 0.1 mm to 0.5 mm, the Au-Sn-based solder is allowed to penetrate into the range of 1 to 4 pitches corresponding to the coil spring. The inside of the coil is preferred.

The Au-Sh-based solder used in the guide wire of the present embodiment is made of, for example, an alloy of 75 mass% to 80 mass% of Au (gold) and 25 mass% to 20 mass% of Sn (tin).

By fixing the stainless steel and platinum (alloy) by using an Au-Sn-based solder, it is possible to obtain a fixed adhesion force of about 2.5 times when it is fixed by a conventionally used Ag-Sn-based solder. strength).

Therefore, even if the length of the front straight portion is 0.1 to 0.5 mm (the penetration range of the solder is 1 to 3 times the coil pitch), the fixed strength of the coil spring 20 with respect to the core 10 is still It is sufficiently high, and specifically, the tensile breaking strength of the distal-side small-diameter portion 11 of the core wire 10 can be further improved. Therefore, even if a tensile force acts between the coil spring 20 and the core wire 10, the core wire 10 can be prevented from being pulled off.

Moreover, the contrast property of the Au-Sn-based solder is superior to that of the Ag-Sn-based solder.

Further, the Au-Sn-based solder is superior to the Ag-Sn-based solder in corrosion resistance to blood and body fluids.

Further, in place of the Au-Sn-based solder, the same effect as in the case of using the Au-Sn-based solder can be achieved by using other solder containing gold.

Examples of the gold-containing solder other than the Au-Sn-based solder include Au-Ge (gold-ruthenium) solder, Au-Si (gold-ruthenium) solder, Au-In (gold-indium) solder, and Au. -Sb (gold-ruthenium) is an Au alloy solder such as solder and an Au solder.

As shown in FIG. 1 and FIG. 3(B), the boundary portion between the first tapered portion 22 and the intermediate diameter portion 23 of the coil spring 20 is not fixed to the core wire 10 by soldering.

Thereby, from the entire area of the front end side small diameter portion 21 (excluding the front end portion) to the second tapered portion 24 (excluding the rear end portion) (the front end portion of the coil spring), since there is no hard straight portion generated by the solder, The flexibility of the guide wire positioned in this area can be sufficiently ensured.

As shown in FIG. 1 and FIG. 3(C), the rear end portion of the second tapered portion 24 of the coil spring 20 is fixed to the core wire 10 by the Au-Sn-based solder 32.

In other words, the Au-Sn-based solder 32 is in contact with the outer periphery of the core wire 10 (the distal-side small-diameter portion 11) by being infiltrated into the inner end portion of the second tapered portion 24, so that the second tapered portion 24 is provided. The rear end portion is fixed to the core wire 10 (distal side small diameter portion 11).

As shown in FIG. 1 and FIG. 3(D), the rear end portion of the rear end side large-diameter portion 25 as the rear end portion of the coil spring 20 is fixed to the core wire 10 by the Ag-Sn-based solder 33.

In other words, the Ag-Sn-based solder 33 penetrates the inside of the coil spring 20 (the rear end portion of the rear-end side large-diameter portion 25), and the core wire 10 (the distal-side small-diameter portion 11) The outer peripheral contact causes the rear end portion of the coil spring 20 to be fixed to the core wire 10 (the distal end small diameter portion 11).

In the distal-side small-diameter portion 11 of the core wire 10, the outer diameter of the portion where the large-diameter portion 25 of the coil spring 20 is fixed to the rear end is fixed to the small-diameter portion 21 of the distal end side of the coil spring 20. The outer diameter of the portion (distal end) is also large (the relative elasticity is fixed and the area is large), so that the Ag-Sn-based solder having a smaller adhesion force than the Au-Sn-based solder can be used.

As shown in FIG. 1 to FIG. 3, the guide wire of the present embodiment is filled with a hardened resin 40 inside the coil spring 20 (inside the solder does not penetrate), and the resin formed by the hardened resin 40 is formed. The layer 40A is coated on the outer circumference and the tip end point of the coil spring 20.

Further, a hydrophilic resin layer 50 is formed on the surface of the resin layer 40A.

By filling the inside of the coil spring 20 with the hardened resin 40, the integrity (interaction) of the core wire 10 and the coil spring 20 is remarkably improved. borrow In this way, the torque transmission property of the guide wire is further improved, and the rotational torque transmitted from the proximal end large diameter portion 13 of the core wire 10 is surely transmitted to the coil spring 20 integrated with the distal end small diameter portion 11.

Further, since the hydrophilic resin layer 50 is formed on the outer circumference of the coil spring 20 by the intermediate resin layer 40A (undercoat layer), the hydrophilic resin layer 50 is strongly fixed and can be produced by the hydrophilic resin. Lubricity is manifested in stability.

Here, as the cured resin 40 which is filled in the coil spring 20 and which constitutes the resin layer 40A covering the outer circumference of the coil spring 20, it has good adhesion to both the coil spring 20 and the hydrophilic resin. In particular, a photocurable resin such as urethane acrylate resin, polyurethane resin, enamel resin, epoxy resin, acrylic resin, or nylon resin may be exemplified or thermally cured. A cured product of a resin or the like.

The film thickness of the resin layer 40A that covers the outer circumference and the tip end point of the coil spring 20 is, for example, 1 μm to 100 μm, preferably 3 μm to 10 μm.

The resin constituting the hydrophilic resin layer 50 which is formed on the surface of the resin layer 40A can be used in any field of medical equipment.

The film thickness of the hydrophilic resin layer 50 is, for example, 1 μm to 30 μm, or preferably 3 μm to 19 μm.

The filling method of the curing resin 40, the method of forming the resin layer 40A, and the method of forming the laminated layer of the hydrophilic resin 50 include, for example, immersing the coil spring 20 attached to the core wire 10 in a curable resin. The curable resin is filled in the inside of the coil spring 20, and a resin layer is formed on the surface of the coil spring 20, and then thermally cured or photohardened as the hardened resin 40 (resin layer 40A), followed by the resin layer 40A. A method of coating a hydrophilic resin by a suitable means.

According to the guide wire of the present embodiment, the coil spring 20 constituting the guide wire has the distal end side small-diameter portion 21 having a coil outer diameter (D ₂₁ ) of 0.008 inches or less, and cannot be inserted by using the conventional guide wire. The narrow portion having a small aperture can also be inserted, so that it can be treated in a narrow region that cannot be performed using a conventional guide wire (for example, a microchannel having a pore diameter of 250 μm or less in a CTO lesion).

Further, the coil spring 20 has a large-diameter portion on the rear end side having a coil outer diameter (D ₂₅ ) of 0.012 inches or more, and the outer diameter of the coil is defined by the distal end side small-diameter portion 21, the intermediate-diameter portion 23, and the rear end. The side large-diameter portion 25 is stepwise changed (the outer diameter of the coil is not changed abruptly), and the guide wire of the embodiment having the coil spring 20 is provided, and the bending rigidity is high, and the pushability and the torque transmission property are also improved. Excellent.

In the coil spring 20, the ratio (D ₂₁ /D ₂₃ ) of the outer diameter of the coil of the small-diameter portion 21 on the distal end side to the outer diameter of the coil of the intermediate-diameter portion 23 is 0.5 to 0.9, and the length of the first tapered portion 22 is (L ₂₂ ) is 0.5 mm to 10 mm, and the ratio (D ₂₅ /D ₂₃ ) of the outer diameter of the coil of the large-diameter portion 25 at the rear end side to the outer diameter of the coil of the intermediate-diameter portion 23 is 1.1 to 2.3, and the second The length (L ₂₄ ) of the tapered portion 24 is 0.5 mm to 10 mm, whereby the diameter of the distal end small-diameter portion 21 is reduced (expanded treatment can be treated) and the bending rigidity, pushability, and torque transmission are improved. The effect can be matched well.

In addition, since the densely wound portion 201 of the coil spring 20 is configured by the distal end side small diameter portion 21, the first tapered portion 22, the intermediate diameter portion 23, and the second tapered portion 24, the front end region is used as the coil spring 20. The densely wound portion 201 can exhibit good contrast (identifiability).

Further, since the insertion resistance of the guide wire to the narrow portion is different depending on the outer diameter of the coil of the coil spring 20, the operator can change the insertion resistance (touch) depending on the change in the outer diameter of the coil. The length of insertion of the guide wire pair to the stenosis portion of the present embodiment is grasped.

Further, since the inside of the coil spring 20 is filled with the hardened resin 40, the integrity (interaction) between the core wire 10 and the coil spring 20 can be improved, and the torque transmission property and the operability of the guide wire can be further improved.

In addition, since the hydrophilic resin layer 50 is formed on the outer circumference of the coil spring 20 by interposing the resin layer 40A formed of the cured resin 40, the lubricity by the hydrophilic resin can be stably exhibited.

In addition, since the Au-Sn-based solder is used as the solder for fixing the distal end portion (the distal end portion of the distal end side small-diameter portion 21) of the coil spring 20 to the core wire 10, although the length of the distal rigid portion is short, only When the coil spring is 0.1 mm to 0.5 mm, the fixing strength of the coil spring to the core wire (the distal end small diameter portion 11) is sufficiently high enough, even if a tensile force acts between the coil spring 20 and the core wire 10, the core wire is not caused. 10 was pulled off.

Moreover, since the length of the hard straight portion of the front end is as short as 0.1 mm to 0.5 mm, the length of the shaping can be shortened, and as a result, the frictional resistance during the operation in the microchannel can be sufficiently reduced. In addition, it is possible to enter a narrow area that cannot be used in the case where the conventional guide wire is used. Treatment.

In the front end portion of the guide wire of the present embodiment, the Au-Sn-based solder is infiltrated into the small-diameter portion corresponding to the coil spring at the tip end portion (coil wire diameter: 50 μm, coil pitch: 75 μm, and coil outer diameter). The front end portion of the guide wire is shaped in a range of two pitches of 0.0078 inches in diameter. The front end of the guide wire has a length of 0.25 mm, and the length of the profile is 0.35 mm for the inner length (L ₅₁ ) and 0.40 mm for the outer length (L ₅₂ ).

In the front end portion of the guide wire of the present embodiment, the tip end portion of the guide wire is infiltrated with the Ag-Sn-based solder to the small-diameter portion corresponding to the coil spring (the coil wire diameter is 50 μm, the coil pitch is 75 μm, and the coil is outside the coil). The front end portion of the guide wire is shaped in a range of six pitches having a diameter of 0.010 inches. The front end of the guide wire has a length of 0.60 mm, a length of the inner length (L ₅₁ ) of 0.70 mm, and an outer length (L ₅₂ ) of 0.75 mm.

The bending fatigue angle (θ) of the guide wire of the present embodiment is less than 25°, preferably less than 10°.

Here, the "bending fatigue angle (θ)" is measured as follows. That is, as shown in Fig. 5 (1), the leading end of the guide wire G (specifically, a portion about 2 mm from the tip end including the tip end point) is fixed by the chuck C, and the guide line G is distanced. The front end is about 5 mm, and the portion from the front end of 14.5 mm (length ≒ 9.5 mm ≒ 3.14 × 3 mm) is wound around the outer circumference of the rod R having a diameter of 3 mm, and then hangs down at the rear end. (lower end) install 150g of code W to apply stretching Load. After 10 seconds, the lower method code W is unloaded, and the guide wire G loosened from the chuck C and the rod R is as shown in the figure (2), and the front end portion is produced by winding. The warp angle (the angle at which the wire is clamped before and after the winding portion) is taken as the bending fatigue angle (θ). The smaller the bending fatigue angle (θ), the more difficult it is to cause permanent deformation.

The guide line of the present embodiment in which the bending fatigue angle (θ) is less than 25° is excellent in shape retention even if it is hard to be deformed even if it is bent, and therefore it is curved and undulated by, for example, a coronary artery system. It has excellent operability when it is intravascular.

Moreover, such excellent shape retainability (difficulty in causing permanent deformation after bending) is a high tensile strength (2600 MPa to 3000 MPa) which is largely dependent on the constituent material of the core wire 10.

According to the guide wire of the present embodiment, it is possible to insert a narrow portion such as a microchannel having a small aperture which cannot be inserted by using a conventional guide wire.

The guide wire of the present embodiment has high bending rigidity (distortion resistance), excellent pushability, and good torque transmission property (the rotation force of the hand is easily transmitted to the distal end), so the blood vessel branching point is selected. It is easy to advance toward the intended blood vessel and has excellent insertion workability.

Further, when the guide wire of the present embodiment is bent in the undulating blood vessel, it is less likely to be permanently deformed even if it is bent, and has excellent shape retention.

<Second embodiment>

The guide wire as shown in Fig. 6 is provided with a core wire 10 and a coil bobbin. Spring 20B.

The core wire 10 has a distal-side small-diameter portion 11 that is tapered in a direction toward the proximal direction, a tapered portion 12 that expands in the proximal direction, and a proximal-side large-diameter portion 13.

The distal-side small-diameter portion 11, the tapered portion 12, and the proximal-side large-diameter portion 13 are integrally formed of the same wire (for example, a round bar member).

The cross section of the tapered portion 12 and the proximal end large diameter portion 13 is substantially circular.

The cross section on the proximal end side of the distal side small-diameter portion 11 is substantially circular, but the distal end side of the distal-side small-diameter portion 11 can also compress the wire into a plate shape. The cross section is generally rectangular.

The core wire 10 is made of a high-strength Worthfield iron-based stainless steel (for example, SUS304 or SUS316) having a tensile strength of 2,600 MPa to 3,000 MPa.

The Worstian iron-based stainless steel having a high tensile strength of 2600 MPa to 3,000 MPa has a high elastic limit, so that it can be used as a guide wire of the present embodiment of the core wire, and it is less likely to be permanently deformed by bending.

Further, a water-repellent resin layer is formed on the outer circumferential surface of the core wire 10.

As the resin constituting the water-repellent resin layer, any resin which is used for medical use can be used as a water-repellent resin, and a suitable resin can be a fluorine-based resin such as PTFE.

As shown in Fig. 7, the total length (L ₁ ) of the guide wire 1 is, for example, 1500 mm to 3000 mm, and one of the more suitable examples is 1780 mm.

The outer diameter (D ₁ ) of the proximal end side large diameter portion 13 of the core wire 10 is 0.012 inches (0.305 mm) or more, and preferably 0.014 inches (0.356 mm) or more, and an example of a suitable one is 0.014 inches. .

Further, the outer diameter (D ₁ ) of the proximal-side large-diameter portion 13 is usually 0.012 inches (0.305 mm) or less, preferably 0.010 inches (0.254 mm) or less, more preferably 0.006 inches to 0.010 inches, for example, One example is suitable for 0.010 inches.

By making the outer diameter (D ₁ ) of the proximal-side large-diameter portion 13 0.012 inches or less, it is possible to contribute to miniaturization of a medical instrument such as a catheter used together with the guide wire of the present invention, thereby achieving low invasiveness. .

The maximum outer diameter of the distal-side small-diameter portion 11 is not particularly limited as long as it is smaller than the inner diameter of the coil spring 20B, but may be the outer diameter of the proximal-side large-diameter portion 13 (D ₁ ) 1/5~3/5 or so.

The coil spring 20B constituting the guide wire 1 is attached to the outer circumference of the distal end small-diameter portion 11 of the core wire 10 in the axial direction.

The coil spring 20B is composed of one wire, and has a front end side dense winding portion 21B having a coil pitch of 1.0 to 1.8 times the coil wire diameter, and a rear end side having a coil pitch exceeding 1.8 times the coil wire diameter. The sparsely wound portion 22B is composed of a front end side densely wound portion 21B and a tip end point to be described later to constitute an X-ray non-transmissive region.

The coil pitch of the front end side densely wound portion 21B is set to be 1.0 to 1.8 times the coil wire diameter, and an example of a suitable one is 1.0 times.

The coil pitch at the rear end side densely wound portion 22B is set to be 1.8 to 2.5 times the coil wire diameter, and it is exemplified as one of the more suitable ones.

In this way, by changing the coil pitch on the distal end side and the rear end side, it is possible to exhibit good contrast (identifiability) in the distal end side densely wound portion 21B.

If the entire area of the coil spring is set to the same pitch, the X-ray non-transmission area becomes longer, which leads to a decrease in the visibility.

In Fig. 7, the length (L ₂ ) of the coil spring 20B is, for example, 30 mm to 800 mm, and an example of a suitable one is 115 mm.

The length (L ₂₁ ) of the distal end side densely wound portion 21B is, for example, 10 mm to 50 mm, and an example of a suitable one is 30 mm.

The length (L ₂₂ ) of the rear end side dense winding portion 22B is, for example, 20 mm to 750 mm, and an example of a suitable one is 85 mm.

The length (L ₃ + L ₂ ) from the tip end of the guide wire to the rear end of the coil spring 20B is, for example, 30 mm to 800 mm, and an example of a suitable one is 115.2 mm.

The length (L ₃ + L ₂₁ ) from the distal end of the guide wire to the rear end of the distal end side densely wound portion 21B is, for example, 10 mm to 50 mm, and an example of a suitable example is 30.2 mm.

The coil outer diameter (D ₂ ) of the coil spring 20B is usually set to 0.012 inches (0.305 mm) or less, preferably 0.010 inches (0.254 mm) or less, more preferably 0.006 inches to 0.010 inches, and one example is more suitable. 0.010 inches.

The microchannel is operated by making the outer diameter (D ₁ ) of the proximal end side large diameter portion 13 of the core wire 10 0.012 inches or less and the coil outer diameter (D ₂ ) of the coil spring 20B also being 0.012 inches or less. The operability at the time (for example, the lubricity of the microchannel) becomes excellent.

The outer diameter of the wire constituting the coil spring 20B is not particularly limited, but is preferably 30 μm to 90 μm, and an example of a suitable one is 60 μm. .

Examples of the material of the coil spring 20B include a material excellent in X-ray contrast properties such as platinum, a platinum alloy (for example, Pt/W=92/8), gold, a gold-copper alloy, tungsten, or a ruthenium (X-ray non-transmission). Sexual substance).

In the guide wire of the present embodiment, the front end portion, the rear end portion, and the intermediate portion (the boundary portion between the distal end side dense winding portion 21B and the rear end side sparse winding portion 22B) of the coil spring 20B are respectively made of solder. The outer circumference of the small-diameter portion 11 on the distal end side of the core wire 10 is fixed.

As shown in FIGS. 6 and 8(A), the tip end portion of the coil spring 20B is fixed to the core wire 10 by the Au-Sn-based solder 31.

In other words, the Au-Sn-based solder 31 is infiltrated into the coil spring 20B, and the coil spring 20B is made by bringing the Au-Sn-based solder 31 into contact with the outer circumference of the core wire 10 (the distal-side small-diameter portion 11). The front end portion is fixed to the core wire 10 (the distal end small diameter portion 11).

As shown in Fig. 8(A), the Au-Sn-based solder 31 penetrates into the inside of the coil in a range corresponding to the two pitches of the coil spring 20B.

Further, in the tip end portion of the coil spring 20B, the substantially hemispherical tip end point is formed by the Au-Sn-based solder 31 which does not penetrate into the coil spring 20B.

As a result, in the distal end portion of the guide wire 1 of the present embodiment, the distal end hard portion generated by the Au-Sn-based solder 31 is formed (the hard straight portion is formed by the Au-Sn-based solder 31 which is infiltrated into the inside of the coil). The front end portion of the coil spring 20B which cannot be freely bent, and the front end point formed by the Au-Sn-based solder 31 are generated.

The length of the hard front portion (the length from the tip end of the guide wire 1 to the rear end of the Au-Sn-based solder 31 penetrating inside the coil) (L ₄ ) is set to about 0.3 mm to 0.4 mm.

In the guide wire of the present invention, the length of the front straight portion is set to be 0.1 mm to 0.5 mm.

When the length of the front straight portion is less than 0.1 mm, the fixing force of the coil spring to the core wire cannot be sufficiently ensured.

On the other hand, when the length of the hard front portion exceeds 0.5 mm, the shaping length (the outer length (L ₅₂ ) to be described later) cannot be set to 0.7 mm or less.

In the guide wire of the present embodiment, in order to set the length of the hard front portion to 0.1 mm to 0.5 mm, the stitch pitch at the end portion of the coil spring is 1.0 to 1.8 times the coil wire diameter, and It is preferable that the Au-Sn-based solder is infiltrated into the inside of the coil in a range corresponding to one to three pitches of the coil spring.

The medical guide wire of the present invention has a feature of using Au-Sn-based solder as a solder for fixing the tip end portion of the coil spring to the core wire.

The Au-Sn-based solder used in the present invention is composed of, for example, an alloy of 75 mass% to 80 mass% of Au (gold) and 25 mass% to 20 mass% of Sn (tin).

By fixing the stainless steel and platinum (alloy) with Au-Sn-based solder, it is possible to obtain a fixed adhesion force (tensile strength) of about 2.5 times as compared with the conventionally used Ag-Sn-based solder. ).

Therefore, even if the length of the front straight portion is 0.1 to 0.5 mm (the penetration range of the solder is 1 to 3 times the coil pitch), the fixed strength of the coil spring 20B with respect to the core 10 is sufficient. It is high enough, specifically, the tensile breaking strength of the distal-side small-diameter portion 11 of the core wire 10 can be further increased. Therefore, even if a tensile force acts between the coil spring 20B and the core wire 10, it is possible to prevent the core wire 10 from being pulled off.

Moreover, the contrast property of the Au-Sn-based solder is superior to that of the Ag-Sn-based solder.

Further, the Au-Sn-based solder is superior to the Ag-Sn-based solder in corrosion resistance to blood and body fluids.

As shown in Fig. 6 and Fig. 8(B), the intermediate portion including the boundary region between the distal end side densely wound portion 21B and the rear end side sparsely wound portion 22B of the coil spring 20B is made of Au-Sn type solder. 32, fixed to the core 10 .

In other words, the Au-Sn-based solder 32 is infiltrated into the coil spring 20B, and the Au-Sn-based solder 32 is brought into contact with the outer circumference of the core wire 10 (the distal-side small-diameter portion 11), whereby the intermediate portion of the coil spring 20B is formed. The fixing is followed by the core wire 10 (the distal side small diameter portion 11).

Since the boundary between the distal end side densely wound portion 21B and the rear end side sparsely wound portion 22B is likely to cause stress concentration, the intermediate portion including the boundary region is fixed by fixing the Au-Sn-based solder having a large adhesion force. Then, the fixing strength of the coil spring 20B can be further improved.

As shown in FIGS. 6 and 8(C), the rear end portion of the coil spring 20B is fixed to the core wire 10 by Ag-Sn-based solder 33.

In other words, the Ag-Sn-based solder 33 is infiltrated into the coil spring 20B, and the Ag-Sn-based solder 33 is brought into contact with the outer circumference of the core wire 10 (the distal-side small-diameter portion 11), whereby the rear end of the coil spring 20B is made. The portion is fixed to the core wire 10 (the distal side small diameter portion 11).

In the distal-side small-diameter portion 11 of the core wire 10, the outer diameter of the portion to which the rear end side of the coil spring 20B is fixed is the outer diameter of the portion (distal end) fixed to the front end side of the coil spring 20B. It is also large (fixed and has a relatively large area), so that it is possible to use an Ag-Sn-based solder having a smaller adhesion force than the Au-Sn-based solder.

As shown in Fig. 6 to Fig. 8, the guide wire 1 of the present embodiment is filled with a cured resin 40 inside the coil spring 20B, and the resin layer 40A formed of the cured resin 40 is coated on the coil. The outer circumference and the front end of the spring 20B are pointed.

Further, a hydrophilic resin layer 50 is formed on the surface of the resin layer 40A.

By filling the inside of the coil spring 20B with the hardened resin 40, the core wire 10 and the coil spring 20B are integrated to remarkably increase the torque transmission property of the guide wire, and the proximal end side large diameter portion 13 of the core wire 10 is transferred. The rotational torque is surely transmitted to the distal end of the coil spring 20B integrated with the distal-side small-diameter portion 11.

Further, since the hydrophilic resin layer 50 is formed on the outer circumference of the coil spring 20B by the intermediate resin layer 40A (undercoat layer), the hydrophilic resin layer 50 is strongly fixed to be produced by the hydrophilic resin. Lubricity is manifested in stability.

Here, as the cured resin 40 which is filled in the inside of the coil spring 20B and which constitutes the resin layer 40A covering the outer periphery of the coil spring 20B, it has good adhesion to both the coil spring 20B and the hydrophilic resin. In particular, a photocurable resin such as urethane acrylate resin, polyurethane resin, enamel resin, epoxy resin, acrylic resin, or nylon resin or heat may be exemplified. A cured product of a curable resin or the like.

The film thickness of the resin layer 40A that covers the outer circumference and the tip end of the coil spring 20B is, for example, 1 μm to 100 μm, preferably 3 μm to 10 μm.

As the resin constituting the hydrophilic resin layer 50 which is formed on the surface of the resin layer 40A, any resin which can be used in the field of medical appliances can be used.

The film thickness of the hydrophilic resin layer 50 is, for example, 1 μm to 30 μm, or preferably 3 μm to 19 μm.

As a method of forming the hardening resin 40, a method of forming the resin layer 40A, and a method of forming a layer of the hydrophilic resin 50, for example, the coil spring 20B attached to the core wire 10 is immersed in a curable resin to impart curability. The resin is filled in the inside of the coil spring 20B, and a resin layer is formed on the surface of the coil spring 20B, and then is subjected to thermal hardening or photohardening as the hardening resin 40 (resin layer 40A), and then to the resin layer 40A. A method of coating a hydrophilic resin by a suitable means.

According to the guide wire 1 of the present embodiment, Au-Sn-based solder is used as the tip end portion of the coil spring 20B to be fixed to the core wire. Since the outer diameter of the proximal end side large diameter portion 13 of the core wire 10 is as small as 0.012 inches or less, the length of the front end hard straight portion is as short as 0.3 mm to 0.4 mm, and the coil spring is for the core wire (the distal side small diameter portion 11) The fixing strength of the fixing is also sufficiently high, and even if a tensile force acts between the coil spring 20B and the core wire 10, the core wire 10 is not pulled off.

Moreover, since the length of the hard straight portion of the front end is only 0.3 mm to 0.4 mm, the length of the shaping can be shortened, and as a result, the frictional resistance during the operation in the microchannel can be sufficiently reduced. Further, treatment can be performed in a narrow region that cannot be performed in the case where a conventional guide wire is used.

Further, since the inside of the coil spring 20B is filled with the hardened resin 40, the integrity of the core wire 10 and the coil spring 20B can be improved, and the torque transmission property and the operability of the guide wire 1 can be remarkably improved.

In addition, since the hydrophilic resin layer 50 is formed on the outer circumference of the coil spring 20B by interposing the resin layer 40A formed of the cured resin 40, the lubricity by the hydrophilic resin can be stably exhibited.

In addition, since the coil spring 20B is composed of the distal end side densely wound portion 21B and the rear end side sparsely wound portion 22B, good visibility (identifiability) can be exhibited in the distal end side densely wound portion 21B.

The bending fatigue angle (θ) of the guide wire of the present embodiment is set to less than 25°, preferably to less than 10°.

The guide line of the present embodiment in which the bending fatigue angle (θ) is less than 25° is excellent in shape retention even if it is hard to be deformed even if it is bent, and therefore it is curved and undulated by, for example, a coronary artery system. Blood Excellent operability in the tube.

Since the guide wire of the present embodiment has high bending rigidity (distortion resistance), excellent pushability, and good torque transmission property, it is easy to move toward a target blood vessel at a blood vessel branching point selection, and is excellent. Operational. Further, when the guide wire of the present embodiment is bent in the undulating blood vessel, it is less likely to be permanently deformed even if it is bent, and has excellent shape retention.

<Third embodiment>

The guide wire shown in Fig. 9 is provided with a core wire 10 and a coil spring 20C.

The core wire 10 has a distal-side small-diameter portion 11 that is tapered in a direction toward the proximal direction, a tapered portion 12 that expands in the proximal direction, and a proximal-side large-diameter portion 13.

The distal-side small-diameter portion 11, the tapered portion 12, and the proximal-side large-diameter portion 13 are integrally formed of the same wire (for example, a round bar member).

The cross section of the tapered portion 12 and the proximal end large diameter portion 13 is substantially circular.

The cross section on the proximal end side of the distal side small-diameter portion 11 is substantially circular, but the distal end side of the distal-side small-diameter portion 11 can also compress the wire into a plate shape. The cross section is generally rectangular.

The core wire 10 is made of a high-strength Worthfield iron-based stainless steel (for example, SUS304 or SUS316) having a tensile strength of 2,600 MPa to 3,000 MPa.

High strength Worthite iron with tensile strength of 2600MPa~3000MPa Since stainless steel has a high elastic limit, it can be used as a guide wire of the present embodiment of the core wire, and it is not easy to be permanently deformed by bending.

Further, a water-repellent resin layer (not shown) is formed on the outer circumferential surface of the core wire 10.

As the resin constituting the water-repellent resin layer, any resin which can be used for medical use can be used as a water-repellent resin, and a fluorine-based resin such as PTFE can be used as the suitable resin.

As shown in Fig. 10, the total length (L ₁ ) of the guide wire is, for example, 1500 mm to 3000 mm, and one of the more suitable examples is 1780 mm.

The outer diameter (D ₁ ) of the proximal end side large diameter portion 13 of the core wire 10 is preferably 0.014 inches (0.356 mm) or more, and an example of a suitable one is 0.014 inches.

The maximum outer diameter of the distal-side small-diameter portion 11 is not particularly limited as long as it is smaller than the inner diameter of the coil spring 20C, but may be the outer diameter of the proximal-side large-diameter portion 13 (D ₁ ) 1/5~3/5 is better.

The coil spring 20C constituting the guide wire 1 is composed of one wire and is attached to the outer circumference of the distal end small-diameter portion 11 of the core wire 10 in the axial direction.

The coil spring 20C is composed of a distal end side small diameter portion 21C, a tapered portion 22C, and a rear end side large diameter portion 23C.

In the present embodiment, the distal end side small diameter portion 21C and the tapered portion 22C are formed by the distal end side densely wound portion 201, and the rear end side large diameter portion 23C is composed of the rear end side sparsely wound portion 202. Further, the front end side densely wound portion 201 (the front end side small diameter portion 21C and the tapered portion 22C) and the front portion described later The tip point forms an X-ray non-transmissive area.

The coil pitch at the front end side densely wound portion 201 is set to be 1.0 to 1.8 times the coil wire diameter, and is preferably 1.3 times as appropriate as an example.

The coil pitch at the rear end side densely wound portion 202 is set to be 1.8 to 3.0 times the coil wire diameter, and is preferably 3.0 times as appropriate as an example.

In this manner, by changing the coil pitch on the distal end side and the rear end side, it is possible to exhibit good contrast (identifiability) in the distal end side densely wound portion 201.

If the entire area of the coil spring is set to the same pitch, the X-ray non-transmission area becomes longer, which leads to a decrease in the visibility.

In the tenth diagram, the length (L ₂ ) of the coil spring 20C is, for example, 30 mm to 800 mm, preferably 100 mm to 200 mm, and one of the more suitable examples is 165 mm.

The length (L ₂₁ ) of the distal end side densely wound portion 21C is, for example, 5 mm to 100 mm, preferably 10 mm to 70 mm, and an example of a suitable one is 38.5 mm.

By making the length (L ₂₁ ) of the distal end side small diameter portion 21C 5 mm or more, the distal end side small diameter portion 21C can be inserted into almost all the microchannels.

By making the length (L ₂₁ ) of the distal end side small diameter portion 21C 100 mm or less, it is possible to sufficiently ensure the length of the end side large diameter portion 23C after contributing to the improvement of the bending rigidity or the torque transmission property.

The length (L ₂₂ ) of the tapered portion 22C is, for example, 0.5 mm to 10 mm, and one of the more suitable examples is 1.5 mm.

The length (L ₂₃ ) of the rear end side large diameter portion 23C is, for example, 85 mm to 154.5 mm, and an example of a suitable one is 125 mm.

The length (L ₃ + L ₂ ) from the tip end of the guide wire to the rear end of the coil spring 20C is, for example, 30 mm to 800 mm, and an example of a suitable one is 165.2 mm.

The length (L ₃ + L ₂₁ + L ₂₂ ) from the tip end of the guide wire to the rear end of the tapered portion 22C is, for example, 10 mm to 50 mm, and an example of a suitable example is 40.2 mm.

The outer diameter (D ₂₁ ) of the coil which is located at the end small-diameter portion 21C of the coil spring 20C is usually 0.012 inches (0.305 mm) or less, preferably 0.010 inches (0.254 mm) or less, and more preferably 0.006~. 0.010 inches, one of the more suitable examples is 0.010 inches.

By making the outer diameter (D ₂₁ ) of the coil of the front end side small diameter portion 21C 0.012 inches or less, it is possible to have excellent operability (for example, lubricity in the microchannel) when the microchannel is operated.

The outer diameter (D ₂₃ ) of the coil which is located at the end side large-diameter portion 23C after the coil spring 20C is preferably 0.014 inches (0.356 mm) or more, and an example of a suitable one is 0.014 inches.

By making the outer diameter (D ₂₃ ) of the coil of the rear end side large diameter portion 23C 0.014 inches or more, it is possible to impart sufficient bending rigidity to the guide wire (push-in transferability at the time of insertion and delivery of the device after insertion) Further, the guide wire (the guide wire of the present embodiment) is excellent in torque transmission property.

The ratio (D ₂₃ /D ₂₁ ) of the outer diameter of the coil of the rear end side large diameter portion 23C and the front end side small diameter portion 21C is preferably 1.1 to 2.3, and an example of a suitable one is 1.4.

The outer diameter of the wire constituting the coil spring 20C is not particularly limited, but is preferably 30 μm to 90 μm, and an example of a suitable one is 60 μm.

Examples of the material of the coil spring 20C include a material excellent in X-ray contrast properties such as platinum, a platinum alloy (for example, Pt/W=92/8), gold, a gold-copper alloy, tungsten, or a crucible. Transmissive substance).

In the guide wire of the present embodiment, the distal end side small diameter portion 21C, the tapered portion 22C, and the rear end side large diameter portion 23C of the coil spring 20C are fixed to the distal end side small diameter portion of the core wire 10 by solder. 11 weeks outside.

As shown in FIG. 9 and FIG. 11(A), the distal end portion of the distal end side small-diameter portion 21C which is the end portion of the coil spring 20C is fixed to the core wire 10 by the Au-Sn-based solder 31.

In other words, the Au-Sn-based solder 31 is infiltrated into the front end portion (the front end portion of the front end side small-diameter portion 21C) of the coil spring 20C, and the Au-Sn-based solder 31 and the core wire 10 (distal end) are formed. The outer peripheral side of the small-diameter portion 11) is brought into contact with the front end portion of the coil spring 20C to be fixed to the core wire 10 (the distal-side small-diameter portion 11).

As shown in Fig. 11(A), the Au-Sn-based solder 31 penetrates into the inside of the coil in a range corresponding to the two pitches of the coil spring 20C.

Further, in the tip end portion of the coil spring 20C, the substantially hemispherical tip cusp is formed by the Au-Sn-based solder 31 which does not penetrate into the coil spring 20C.

Thereby, in the distal end portion of the guide wire of the present embodiment, the distal end hard portion generated by the Au-Sn-based solder 31 is formed (the hard straight portion is formed by the Au-Sn-based solder 31 which is infiltrated into the inside of the coil). The front end portion of the coil spring 20C which cannot be freely bent, and the front end point formed by the Au-Sn-based solder 31 are formed.

The length of the hard straight portion of the distal end (the length from the distal end of the guide wire 1 to the rear end of the Au-Sn-based solder 31 penetrating inside the coil) (L ₄ ) is about 0.3 mm to 0.4 mm.

In the guide wire of the present invention, the length of the front straight portion is set to be 0.1 mm to 0.5 mm.

When the length of the front straight portion is less than 0.1 mm, the fixing force of the coil spring to the core wire cannot be sufficiently ensured.

On the other hand, when the length of the hard front portion exceeds 0.5 mm, the shaping length (the outer length (L ₅₂ ) to be described later) cannot be set to 0.7 mm or less.

In the guide wire of the present embodiment, in order to set the length of the hard front portion to 0.1 mm to 0.5 mm, the stitch pitch at the end portion of the coil spring is 1.0 to 1.8 times the coil wire diameter, and It is preferable that the Au-Sn-based solder is infiltrated into the inside of the coil in a range corresponding to one to three pitches of the coil spring.

The medical guide wire of the present invention has a feature of using Au-Sn-based solder as a solder for fixing the tip end portion of the coil spring to the core wire.

The Au-Sn-based solder used in the present invention is, for example, Au ( Gold) is composed of an alloy of 75 mass% to 80 mass% and Sn (tin) of 25 mass% to 20 mass%.

By fixing the stainless steel and platinum (alloy) with Au-Sn-based solder, it is possible to obtain a fixed adhesion force (tensile strength) of about 2.5 times as compared with the conventionally used Ag-Sn-based solder. ).

Therefore, even if the length of the front straight portion is 0.1 to 0.5 mm (the penetration range of the solder is 1 to 3 times the coil pitch), the fixed strength of the coil spring 20B with respect to the core 10 is sufficient. It is high enough, specifically, the tensile breaking strength of the distal-side small-diameter portion 11 of the core wire 10 can be further increased. Therefore, even if a tensile force acts between the coil spring 20C and the core wire 10, it is possible to prevent the core wire 10 from being pulled off.

Moreover, the contrast property of the Au-Sn-based solder is superior to that of the Ag-Sn-based solder.

Further, the Au-Sn-based solder is superior to the Ag-Sn-based solder in corrosion resistance to blood and body fluids.

As shown in Fig. 9 and Fig. 11(B), the rear end portion of the tapered portion 22C of the coil spring 20C is fixed to the core wire 10 by the Au-Sn-based solder 32.

In other words, the Au-Sn-based solder 32 is in contact with the outer periphery of the end portion of the tapered portion 22C and is in contact with the outer periphery of the core wire 10 (the distal-side small-diameter portion 11), whereby the rear end portion of the coil spring 20C is fixed. Next, the core wire 10 (distal side small diameter portion 11).

As shown in Fig. 9 and Fig. 11(C), as the coil spring 20C The rear end portion of the rear end side large-diameter portion 23C of the rear end portion is fixed to the core wire 10 by the Ag-Sn-based solder 33.

In other words, the Ag-Sn-based solder 33 is infiltrated into the rear end portion of the coil spring 20C (the rear end portion of the rear end side large-diameter portion 23C) and is in contact with the outer circumference of the core wire 10 (the distal-side small-diameter portion 11). Thereby, the rear end portion of the coil spring 20C is fixed to the core wire 10 (the distal end small diameter portion 11).

In the distal-side small-diameter portion 11 of the core wire 10, the outer diameter of the portion where the large-diameter portion 23C of the coil spring 20C is fixed to the rear end is fixed by the small-diameter portion 21C of the distal end side of the coil spring 20B. The outer diameter of the portion (distal end) is also large (the fixed area is relatively large), so that an Ag-Sn-based solder having a small adhesion force can be used as compared with the Au-Sn-based solder.

As shown in FIG. 9 to FIG. 11, the guide wire of the present embodiment is filled with a hardened resin 40 inside the coil spring 20C (the inside where the solder does not penetrate), and the resin formed by the hardened resin 40 is formed. The layer 40A is covered on the outer circumference and the tip end point of the coil spring 20C.

Further, a hydrophilic resin layer 50 is formed on the surface of the resin layer 40A.

By filling the inside of the coil spring 20C with the hardened resin 40, the integrity (interaction) of the core wire 10 and the coil spring 20C is remarkably improved. Thereby, the torque transmission property of the guide wire is further improved, and the rotational torque transmitted from the proximal end large diameter portion 13 of the core wire 10 is surely transmitted to the coil spring integrated with the distal end small diameter portion 11. The distal end of 20B.

Further, since the intermediate resin layer 40A (undercoat layer) forms the hydrophilic resin layer 50 on the outer circumference of the coil spring 20C, the hydrophilic resin layer 50 is provided. It is firmly fixed, and the lubricity generated by the hydrophilic resin can be stably exhibited.

Here, as the cured resin 40 that is filled in the coil spring 20C and that constitutes the resin layer 40A covering the outer circumference of the coil spring 20C, the coil spring 20C and the hydrophilic resin are provided with good adhesion. In particular, a photocurable resin such as urethane acrylate resin, polyurethane resin, enamel resin, epoxy resin, acrylic resin, or nylon resin or heat may be exemplified. A cured product of a curable resin or the like.

The film thickness of the resin layer 40A that covers the outer circumference and the tip end of the coil spring 20C is, for example, 1 μm to 100 μm, preferably 3 μm to 10 μm.

The resin constituting the hydrophilic resin layer 50 formed on the surface of the resin layer 40A can be used in any field of medical appliances.

The film thickness of the hydrophilic resin layer 50 is, for example, 1 μm to 30 μm, or preferably 3 μm to 19 μm.

As a method of forming the hardening resin 40, a method of forming the resin layer 40A, and a method of forming a layer of the hydrophilic resin 50, for example, the coil spring 20C attached to the core wire 10 is immersed in a curable resin to impart curability. The resin is filled in the inside of the coil spring 20C, and a resin layer is formed on the surface of the coil spring 20C, and then it is used as the hardening resin 40 (resin layer 40A) by heat hardening or photo hardening, and then, in the resin layer 40A. A method of coating a hydrophilic resin by a suitable means.

The outer circumference of the tapered portion 22C of the coil spring 20C is covered with a resin (the resin layer 40A and the hydrophilic resin layer 50) to form a taper shape as a guide line.

Here, the starting point of the taper is located closer to the distal end side than the front end of the tapered portion 22C (the position indicated by T _{1 of} FIG. 10), and the end point of the taper is at the ratio of the taper portion The rear end of 22C is closer to the proximal side (the position indicated by T ₂ in Fig. 10). That is, the taper angle as the shape of the guide wire is smaller than the taper angle of the tapered portion 22C so that the taper length (L ₅ ) becomes longer than the taper portion 22C (L _{22 )} ) Still long.

In this way, by coating the tapered portion 22C with the resin, the tapered shape as the guide wire is made gentler than the taper of the tapered portion 22C, and the insertion operation of the guide wire can be smoothly smoothed. Conducted.

In the tenth diagram, when the length (L ₂₂ ) of the tapered portion 22C is, for example, about 1.5 mm, the length (L ₅ ) of the tapered shape of the guide wire is preferably about 5 mm to 6 mm.

According to the guide wire of the present embodiment, the Au-Sn-based solder is used as the solder for fixing the tip end portion (the tip end portion of the distal end side small-diameter portion 21C) of the coil spring 20C to the core wire 10, so that the front end The length of the hard straight portion is as short as 0.3 mm to 0.4 mm, and the fixing strength of the coil spring to the core wire (the distal end small diameter portion 11) is sufficiently high enough, even if a tensile force acts between the coil spring 20C and the core wire 10, Nor does the core wire 10 be pulled off.

Moreover, since the length of the hard straight portion of the front end is only 0.3 mm to 0.4 mm, the shaping length can be shortened, and as a result, it can be charged. The frictional resistance during operation in the microchannel is reduced. Further, treatment can be performed in a narrow region that cannot be performed in the case where a conventional guide wire is used.

Further, by making the coil outer diameter (D ₂₁ ) of the coil end spring 20C front end side small-diameter portion 21C a small diameter of 0.012 inches or less, excellent operability (for example, in the microchannel) can be performed when the microchannel is operated. Lubricity in).

In addition, since the outer diameter (D ₁ ) of the proximal end side large diameter portion 13 of the core wire 10 and the outer diameter (D ₂₃ ) of the coil of the rear end side large diameter portion 23C are both 0.014 inches or more, the guide wire can be sufficiently provided. The bending rigidity (push-in property at the time of insertion and the delivery performance of the device after insertion) also makes the guide wire (guide wire of the present embodiment) excellent in torque transmission property.

Further, since the inside of the coil spring 20C is filled with the hardened resin 40, the integrity (interaction) of the core wire 10 and the coil spring 20C can be improved, and the torque transmission property and operability of the guide wire can be further improved.

In addition, since the hydrophilic resin layer 50 is formed on the outer circumference of the coil spring 20C by interposing the resin layer 40A formed of the cured resin 40, the lubricity by the hydrophilic resin can be stably exhibited.

In addition, the coil spring 20C is composed of a front end side dense winding portion 201 constituting the distal end side small diameter portion 21C and the tapered portion 22C, and a rear end side sparse winding portion 202 constituting the rear end side large diameter portion 23C. The distal end side small diameter portion 21C and the tapered portion 22C which are formed by the distal end side densely wound portion 201 can exhibit good contrast (identifiability).

The bending fatigue angle (θ) of the guide wire of the present embodiment is set to less than 25°, preferably to less than 10°.

The guide line of the present embodiment in which the bending fatigue angle (θ) is less than 25° is excellent in shape retention even if it is hard to be deformed even if it is bent, and therefore it is curved and undulated by, for example, a coronary artery system. Excellent operability in the blood vessels.

Since the guide wire of the present embodiment has high bending rigidity (distortion resistance), excellent pushability, and good torque transmission property, it is easy to move toward a target blood vessel at a blood vessel branching point selection, and is excellent. Operational. Further, when the guide wire of the present embodiment is bent in the undulating blood vessel, it is less likely to be permanently deformed even if it is bent, and has excellent shape retention.

Example <Example 1>

Six guide structures as shown in Figs. 1 to 3 were produced, and the guide wire of the present invention of the coil spring 20 was attached to the distal end small-diameter portion 11 of the core wire 10 (core wire covered with PTFE). The core wire 10 is composed of a Worthfield iron-based stainless steel (SUS304) having a tensile strength of 2800 MPa and an aging treatment at 300 to 500 ° C for 0.5 to 4 hours, and has a shape (size) to be described later.

(1) proximal side large diameter portion 13:

‧Outer diameter: 0.014 inches (0.356mm)

‧ Length: 1665mm

(2) Cone 12:

‧Maximum outer diameter: 0.014 inches

‧Minimum outer diameter: 0.008 inches

‧ Length: 170mm

(3) distal side small diameter portion 11:

‧Continuous tapered shape

‧Maximum outer diameter: 0.008 inches

‧Minimum outer diameter: 0.0017 inches

‧ Length: 165mm

Here, the coil spring 20 is formed of a platinum wire having an outer diameter (coil wire diameter) of 50 μm, and the outer diameter (D ₂₁ ) of the small-diameter portion 21 of the distal end side is 0.0078 inches and length (L ₂₁ ). 8.5 mm, the length (L ₂₂ ) of the first tapered portion 22 is 1.5 mm, the outer diameter (D ₂₃ ) of the coil of the intermediate diameter portion 23 is 0.010 inches, the length (L ₂₃ ) is 28.5 mm, and the length of the second tapered portion 24 is 8.5 mm. (L ₂₄ ) is 1.5 mm, and the outer diameter (D ₂₅ ) of the coil at the rear end side large diameter portion 25 is 0.014 inches, the length (L ₂₅ ) is 125 mm, and the small-diameter portion 21 of the distal end side, the first tapered portion 22, and the middle The coil pitch of the densely wound portion 201 formed by the diameter portion 23 and the second tapered portion 24 is 75 μm (1.5 times the coil wire diameter, the coil separation distance is 25 μm), and the thick portion formed by the rear end side large diameter portion 25 is thick. The coil pitch of the wound portion 202 is 150 μm (three times the coil wire diameter and the coil separation distance is 100 μm).

Further, the front end portion of the small-diameter portion 21 of the coil spring 20 and the rear end portion of the second tapered portion are fixed to the core wire 10 by Au-Sn-based solder, and the rear end portion of the large-diameter portion 25 at the rear end side. Is using Ag-Sn welding The material is fixed to be attached to the core wire 10.

In each of the six guide lines, the number of pitches (in the first table, abbreviated as "the number of pitches" in the first table) corresponding to the area (length) in which the solder penetrates into the coil is set to any one of 1 to 4. . The length of the hard end portion of the front end thus formed is as shown in Table 1.

Further, after the coil spring is attached to the core wire, a resin (urethane acrylate resin) is filled in the inside of the coil spring, and a resin layer formed of a cured resin is formed on the outer circumference of the coil spring, and the resin is formed on the resin. The layer surface area layer is formed with a hydrophilic resin layer composed of polyethylene oxide.

<Comparative Example 1>

The coil spring is formed of a platinum wire having an outer diameter of 50 μm, a coil outer diameter of 0.0078 inches, a length of 38.5 mm, a front end side small diameter portion, and a length of the front end side small diameter portion of 1.5 mm. a tapered portion and a coil having a large diameter portion of a rear end side having a coil outer diameter of 0.014 inches and a length of 125 mm continuous in the tapered portion, and a coil located at a densely wound portion composed of a small-diameter portion and a tapered portion at the distal end side The pitch is 75 μm, and the coil pitch of the thick winding portion composed of the large-diameter portion on the rear end side is 150 μm, and the front end portion of the small-diameter portion of the coil spring and the tapered portion are used by Au-Sn-based solder. The rear end portion is fixed to the core wire, and the rear end portion of the large-diameter portion of the rear end side is fixed to the core wire by using Ag-Sn-based solder. Except for the above, the rest is the same as in the first embodiment, and the small-diameter portion from the front end side is used. And a coil spring composed of a tapered portion and a large diameter portion at the rear end side is attached to the distal end of the core wire Six smaller guide lines were produced by the side small diameter portion.

<Comparative Example 2>

The core wire was made in the same manner as in Example 1 except that Worstian iron-based stainless steel (SUS304) having a tensile strength of 2400 MPa was used, and six comparative guide wires were produced.

(2) Front end load of the guide line:

For each of the guide wires obtained in the first embodiment and the comparative example 1, when the tip end point was brought into contact with the electronic balance, the portion 10 mm from the tip end was deflected (the amount of deflection: 0.5 mm). The maximum load. The maximum load (described as "front end load" in the first table) can be regarded as a front end portion of the guide wire and has good bending rigidity and flexibility as long as it is in the range of 0.5 to 1.0 gf. The results are shown in the first table described later.

(3) The minimum shaping length and fixed adhesion of the guide wire:

For each of the guide lines obtained in Example 1 and Comparative Example 1, the minimum shaping length (the minimum length that can be bent) was measured.

The measurement of the minimum shaping length is performed on the inner length (L51) and the outer length (L52) as shown in Fig. 4.

Further, a tensile force was applied between the coil spring and the core wire, and the fracture site was observed to evaluate the fixed adhesion. The evaluation criterion is that the occurrence of the fracture at the small-diameter portion on the distal end side of the core wire is "○", at the coil spring or the distal end. The case where peeling occurs between the small-diameter portion and the solder is "x". Even if there is only one "X", it cannot be used as a product. The result is displayed together in the first table to be described later.

(4) Bending fatigue angle (θ):

For each of the guide lines obtained by the first embodiment and the comparative example 1, When the bending fatigue angle (θ) measured by the above method was measured, the bending fatigue angle (θ) with respect to the guide wire (6) in Comparative Example 2 was 26° to 30°, which was the same in Example 1. The bending fatigue angle (θ) of the lead wires (6) is small from 7° to 10°, and is excellent in shape retention which is less likely to cause permanent deformation.

(5) Torque transmission:

Each of the guide wires obtained in the first embodiment and the comparative example 1 is inserted into the jig of the simulated human coronary artery shown in Fig. 12, and the proximal end of the guide wire is made by the motor (hand-operating side) The torsional rotation was performed at a predetermined hand-operated side angle of 720 degrees, and the front end rotation angle (twist angle) at the distal end (front end) of the guide wire was investigated. The result is shown in Fig. 13. The closer to the theoretical straight line shown in Fig. 13, the better the torque transmission property and the more excellent the workability. When the torque transmission property is good, the rotational force on the hand-operated side can be easily transmitted to the distal end, and at the point of selection of the blood vessel, it is easy to advance toward the intended blood vessel, and the insertion workability can be improved.

10‧‧‧core

11‧‧‧ distal side small diameter section

12‧‧‧ Cone

13‧‧‧ proximal side large diameter

20‧‧‧ coil spring

21‧‧‧ Front side small diameter section

22‧‧‧1st cone

23‧‧‧Medium Department

24‧‧‧2nd taper

25‧‧‧Back side large diameter section

201‧‧‧Small winding part

202‧‧‧Sparse winding part

31‧‧‧Au-Sn solder

32‧‧‧Au-Sn solder

33‧‧‧Ag-Sn solder

40‧‧‧ hardened resin

40A‧‧‧ resin layer

50‧‧‧Hydrophilic resin layer

Fig. 1 is a side elevational view showing a part of the first embodiment of the guide wire of the present invention.

Fig. 2 is a side view (a view for explaining the size) showing a part of the first embodiment of the guide wire of the present invention.

Figure 3 is a partial enlarged view of Fig. 1, (A) is a detailed view of Part A, (B) is a detailed view of Part B, and (C) is a detailed view of Part C, (D) ) is a detailed picture of part D.

Fig. 4 is a side view showing a state in which the front end portion of the guide wire is shaped.

Fig. 5 is an explanatory diagram of a method of measuring the bending fatigue angle (θ) of the guide wire.

Fig. 6 is a side view showing a part of the second embodiment showing the guide wire of the present invention.

Fig. 7 is a side view (a view for explaining the size) showing a part of the second embodiment of the guide wire of the present invention.

Fig. 8 is a partial enlarged view of Fig. 6, (A) is a detailed view of Part A, (B) is a detailed view of Part B, (C) is a detailed view of Part C, and (D) is a detailed view of Part D.

Fig. 9 is a partially cutaway side view showing a third embodiment of the guide wire of the present invention.

Fig. 10 is a partially cutaway side view showing the third embodiment of the guide wire of the present invention (a view for explaining the dimensions).

Fig. 11 is a partial enlarged view of Fig. 9, (A) is a detailed view of Part A, (B) is a detailed view of Part B, and (C) is a detailed view of Part C.

Fig. 12 is an explanatory view showing a simulation device for testing the torque transmission property of the guide wire.

Fig. 13 is a graph showing the torque transmission property of the guide wire.

10‧‧‧core

11‧‧‧ distal side small diameter section

12‧‧‧ Cone

13‧‧‧ proximal side large diameter

20‧‧‧ coil spring

21‧‧‧ Front side small diameter section

22‧‧‧1st cone

23‧‧‧Medium Department

24‧‧‧2nd taper

25‧‧‧Back side large diameter section

201‧‧‧Small winding part

202‧‧‧Sparse winding part

31‧‧‧Au-Sn solder

32‧‧‧Au-Sn solder

33‧‧‧Ag-Sn solder

40‧‧‧ hardened resin

40A‧‧‧ resin layer

50‧‧‧Hydrophilic resin layer

Claims (7)

A medical guide wire comprising: a core wire and a coil spring formed of a Worstian iron-based stainless steel having a tensile strength of 2600 MPa to 3000 MPa, and having a proximal end side large diameter portion, and a distal end small-diameter portion having an outer diameter smaller than the proximal-side large-diameter portion, the coil spring being attached to an outer circumference of the distal-side small-diameter portion of the core wire along the axial direction, and at least at the front end portion and the rear portion The end portion is fixed to the core wire, and the coil spring has a front end side small diameter portion having a coil outer diameter of 0.008 inches (0.203 mm) or less, and a coil outer diameter larger than the front end side small diameter portion. a middle diameter portion of the outer diameter of the coil, and a rear end side large diameter portion having a coil outer diameter of 0.012 inch (0.305 mm) or more and larger than the outer diameter of the coil of the intermediate diameter portion, and a small diameter at the front end side a first tapered portion between the portion and the intermediate diameter portion, and a second tapered portion positioned between the intermediate diameter portion and the rear end large diameter portion, and a distal end side of the core wire of the coil spring is fixed The small diameter portion is wound one turn around the outer circumference of the rod having a diameter of 3 mm. Next, when the load was applied at a tensile load of 150 gf for 10 seconds, the warpage angle of the front end portion formed by the winding was less than 25°. The medical guide wire according to the first aspect of the invention, comprising a core wire and a coil spring, wherein the core wire is formed of a Worthfield iron-based stainless steel having a tensile strength of 2600 MPa to 3000 MPa, and has an outer diameter. a proximal side large diameter portion of 0.012 inches or more and a distal end small diameter portion having an outer diameter smaller than the proximal end large diameter portion, the coil spring being attached to the distal end side of the core wire along the axial direction The outer circumference of the small diameter portion is composed of a densely wound portion having a coil pitch of 1.1 to 2.0 times the coil wire diameter, and a thickly wound portion having a coil pitch of more than 2.0 times the coil wire diameter continuously continuous with the densely wound portion. The coil spring has a small-diameter portion having a distal end side having a coil outer diameter of 0.008 inches or less, and a middle diameter portion having a coil outer diameter larger than an outer diameter of a coil of the distal end side small-diameter portion, and a rear end side large diameter portion of a coil outer diameter of 0.012 inches or more and larger than an outer diameter of a coil of the intermediate diameter portion, and a first tapered portion positioned between the distal end side small diameter portion and the intermediate diameter portion, and Positioned on the above-mentioned middle diameter portion and the rear end side The second tapered portion between the portions is formed by the distal end side small diameter portion, the first tapered portion, the intermediate diameter portion, and the second tapered portion, and the densely wound portion having a length of 5.5 mm to 110 mm is formed by The rear end side large diameter portion is configured as a sparsely wound portion; the front end portion of the front end side small diameter portion and the rear end portion of the second tapered portion And the rear end portion of the large-diameter portion of the rear end side is fixed by solder and then on the outer circumference of the small-diameter portion on the distal end side of the core wire, and the distal end side of the core wire to which the coil spring is attached is fixed The diameter portion was wound under a tensile load of 150 gf for 10 seconds in a state where the outer circumference of the rod having a diameter of 3 mm was wound once, and the angle of warpage of the front end portion formed by the winding was less than 25°. The medical guide wire according to the second aspect of the invention, wherein the outer diameter of the proximal end side large diameter portion of the core wire is 0.014 inches or more, and the coil outer diameter of the small end portion of the coil spring front end side is 0.008 inches or less. The outer diameter of the coil of the intermediate diameter portion is 0.009 to 0.011 inches, and the outer diameter of the coil of the large diameter portion of the rear end side is 0.014 inches or more. The medical guide wire according to the third aspect of the invention, wherein a ratio of a coil outer diameter of the distal end small diameter portion to an outer diameter of the coil of the intermediate diameter portion is 0.5 to 0.9, and a length of the first tapered portion The ratio of the outer diameter of the coil of the large diameter portion of the rear end side to the outer diameter of the coil of the intermediate diameter portion is 1.1 to 2.3, and the length of the second tapered portion is 0.5 mm to 10 mm. The medical guide wire according to any one of claims 1 to 4, wherein the distal end portion of the distal end side small diameter portion is fixed to the core wire by a solder containing gold, and is contained in gold. The length of the hard portion of the front end formed by the solder is 0.1mm~0.5mm. According to the medical guide wire of the fifth aspect of the invention, in the small-diameter portion on the distal end side of the coil spring, the solder containing gold is infiltrated in a range corresponding to one to four pitches from the tip end. Inside the coil. The medical guide wire according to any one of claims 1 to 4, wherein the inside of the coil spring is filled with a resin, and a resin layer formed of the resin is formed on an outer circumference of the coil spring. A hydrophilic resin layer is formed on the surface layer of the resin layer, and a water-repellent resin layer is formed on the surface of the core wire.