Medical guide wire

A medical guide wire comprising:

• (a) a core wire having (i) a distal end-side small-diameter portion and (ii) a proximal end-side large-diameter portion, the proximal end-side large-diameter portion having an outside diameter that is larger than an outside diameter of the distal end-side small-diameter portion, and
• (b) a coil spring made of a single piece of wire material, the coil spring being installed on an outer periphery of the distal end-side small-diameter portion of the core wire along an axial direction throughout an entire length of the coil spring, the coil spring having (i) a coiled front end-side small-diameter portion having a coil formed by winding the wire material plural times spirally, the coil of the coiled front end-side small-diameter portion having a fixed outside diameter, (ii) a coiled rear end-side large-diameter portion having a coil formed by winding the wire material plural times spirally, the coil of the coiled rear end-side large-diameter portion having a fixed outside diameter that is larger than the fixed outside diameter of the coil of the coiled front end-side small-diameter portion, and (iii) a coiled tapered portion formed by winding the wire material plural times spirally, the coiled tapered portion being located between the front end-side small-diameter portion and the rear end-side large-diameter portion, and the coil spring being fixed to the core wire at least at a front end portion of the front end-side small-diameter portion and a rear end portion of the rear end-side large-diameter portion, wherein
• the front end-side small-diameter portion of the coil spring has a length of 5 to 100 mm, and the outside diameter of the coil thereof is at most 0.012 inch,
• the rear end-side large-diameter portion of the coil spring has a length of 85 to 154.5 mm, and the tapered portion of the coil spring has a length of 0.5 to 10 mm,
• an outside diameter of the wire material forming the coil spring is 30 to 90 μm,
• the front end portion of the front end-side small-diameter portion of the coil spring is fixed to the core wire by a Au—Sn solder,
• a length of a distal end portion stiffened by the Au—Sn solder is 0.1 to 0.5 mm,
• the coil spring is composed of a front end-side densely-coiled portion whose coil pitch is 1.0 to 1.8 times as much as the outside diameter of the wire material, and a rear end-side roughly-coiled portion whose coil pitch is 1.8 to 3.0 times as much as the wire diameter of the coil,
• the front end-side small-diameter portion and the tapered portion are formed by the front end-side densely-coiled portion of the coil spring, and the rear end-side large-diameter portion is formed by the rear end-side roughly-coiled portion of the coil spring, and
• the coil spring being fixed to the core wire at a rear end portion of the tapered portion that is an intermediate portion of the coil spring by the Au—Sn solder.

A medical guide wire comprising:

• (a) a core wire having (i) a distal end-side small-diameter portion and (ii) a proximal end-side large-diameter portion, the proximal end-side large-diameter portion having an outside diameter that is larger than an outside diameter of the distal end-side small-diameter portion, and
• (b) a coil spring made of a single piece of wire material, the coil spring being installed on an outer periphery of the distal end-side small-diameter portion of the core wire along an axial direction throughout an entire length of the coil spring, the coil spring having (i) a coiled front end-side small-diameter portion having a coil formed by winding the wire material plural times spirally, the coil of the coiled front end-side small-diameter portion having a fixed outside diameter, (ii) a coiled rear end-side large-diameter portion having a coil formed by winding the wire material plural times spirally, the coil of the coiled rear end-side large-diameter portion having a fixed outside diameter that is larger than the fixed outside diameter of the coil of the coiled front end-side small-diameter portion, and (iii) a coiled tapered portion formed by winding the wire material plural times spirally, the coiled tapered portion being located between the front end-side small-diameter portion and the rear end-side large-diameter portion, and the coil spring being fixed to the core wire at least at a front end portion of the front end-side small-diameter portion and a rear end portion of the rear end-side large-diameter portion, wherein
• the front end-side small-diameter portion of the coil spring has a length of 5 to 100 mm, and the outside diameter of the coil thereof is at most 0.012 inch,
• the rear end-side large-diameter portion of the coil spring has a length of 85 to 154.5 mm, and the tapered portion of the coil spring has a length of 0.5 to 10 mm,
• an outside diameter of the wire material forming the coil spring is 30 to 90 μm,
• the front end portion of the front end-side small-diameter portion of the coil spring is fixed to the core wire by a Au—Ge solder,
• a length of a distal end portion stiffened by the Au—Ge solder is 0.1 to 0.5 mm,
• the coil spring is composed of a front end-side densely-coiled portion whose coil pitch is 1.0 to 1.8 times as much as the outside diameter of the wire material, and a rear end-side roughly-coiled portion whose coil pitch is 1.8 to 3.0 times as much as the wire diameter of the coil,
• the front end-side small-diameter portion and the tapered portion are formed by the front end-side densely-coiled portion of the coil spring, and the rear end-side large-diameter portion is formed by the rear end-side roughly-coiled portion of the coil spring, and
• the coil spring being fixed to the core wire at a rear end portion of the tapered portion that is an intermediate portion of the coil spring by the Au—Ge solder.