Patent ID: 8109888

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; and a guide wire tip, positioned at a distal end, and having one portion of said core elongated component and said coil distal end of said helical coil attached to said core elongated component; wherein said helical coil comprises: 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; and 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 having a constant diameter with strands tightly wound in a range from said coil distal end to said middle connector; 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, and t is a filament diameter of said coil filament; and one end of said diameter decreasing coil portion nearer to said equiradial coil portion is disposed at said middle connector.