Patent ID: 7637874

Claim:
A medical guide wire comprising: a flexible long core; a core elongated component, disposed to extend forwards from an end of said core, having a tapered shape; a helical coil, disposed about said core elongated component, secured by attachment of a coil distal end and a coil proximal end to said core elongated component; said helical coil including: an equiradial coil portion, having said coil proximal end, disposed at a portion of said core elongated component on a side of said core; a diameter decreasing coil portion, having said coil distal end, disposed to extend forwards from said equiradial coil portion, having a decreasing diameter, and having a length equal to or more than 25 mm; a middle connector, disposed at a distance equal to or less than 50 mm from said coil distal end, for attaching said helical coil to said core elongated component; wherein said helical coil has a coil filament with strands tightly wound in a range from said coil distal end to said middle connector, and in the tightly wound state, all strands of the coil filament are in complete contact, or there is a space between the strands equal to or less than 9% relative to a filament diameter t of the coil filament; a diameter ratio D 1 /D 2 of said diameter decreasing coil portion is equal to or more than 1.22 and equal to or less than 2.31, where D 1 is a diameter of said diameter decreasing coil portion on a side of said coil proximal end, and D 2 is a diameter of said diameter decreasing coil portion on a side of said coil distal end; said core elongated component and said helical coil satisfy a condition of d 2 ≧t, where d 2 is a diameter of a distal end of said core elongated component; wherein said middle connector is positioned on a proximal side from a point defined between said diameter decreasing coil portion and said equiradial coil portion; a first length ratio L 1 /L 2 of said helical coil is equal to or more than 1, where L 1 is a length of said diameter decreasing coil portion, and L 2 is a length of said equiradial coil portion extending to said middle connector.