Medical guide wire

1. A medical guide wire comprising a flexible line wire having a main wire portion, a core line member and a helical spring provided around a distal end of said core line member, a front end of said helical spring being fixedly interfit to a head plug provided at a tip of said core line member;

a rigid portion located on a front end of aid helical spring, said rigid portion measuring 0.5 mm or less which extends lengthwisely from a top end of said head plug to a rear end of a portion in which said helical spring is fixed to said head plug, and an intermediary location is determined on an intermediary portion of said helical spring in which an intermediary boss portion is secured to said core line member to define loosely wound portion as an elastically expandable portion from a rear end of said head plug to said intermediary location;

a clearance between line element turns of said loosely wound portion being within a range of 10-30% of a line diameter of said helical spring; and

said loosely wound portion being approximately 24 mm in length.

2. A medical guide wire comprising a flexible line wire having a main wire portion, a core member and a helical spring provide around a distal end of said core line member, a front end of said helical spring being fixedly interfit to a head plug provided a tip of said core line member;

a rigid portion located on a front end of said helical spring, said rigid portion measuring 0.5 mm or less which extends lengthwisely from a top end of said head plug to a rear end of a portion in which said helical spring is fixed to said head plug, and an intermediary location is determined on an intermediary portion of said helical spring in which an intermediary boss portion is secured to said core line member to define a loosely wound portion as an elastically expandable portion from a rear end of said head plug to said intermediary location; and

said head plug forming a spherical or semi-spherical configuration, and a right and left side portions of said head plug being undercut to form flat surface portions.

3. The medical guide wire according to claim 2 , wherein said core line member is rectangular in cross section, longer sides of which position in parallel with said flat surface portions of said head plug.

4. The medical guide wire according to claim 2 , wherein said front end of said helical spring and said head plug are produced from TIG or laser spot welding.

5. A medical guide wire comprising a flexible line wire having a main wire portion, a core member and a helical spring provided around a distal end of said core line member, a front end of said helical spring being fixedly interfit to a head plug provided at a tip of said core line member;

a rigid portion located on a front end of said helical spring, said rigid portion measuring 0.5 mm or less which extends lengthwisely from a top end of said head plug to a rear end of a portion in which said helical spring is fixed to said head plug, and an intermediary location is determined on an intermediary portion of said helical spring in which an intermediary boss portion is secured to said core line member to define a loosely wound portion as an elastically expandable portion from a rear end of said head plug to said intermediary location;

said loosely wound portion being approximately 24 mm in length; and

said head plug forming a spherical or semi-spherical configuration, and a right and left side portions of said head plug being undercut to form flat surface portions.

6. The medical guide wire according to claim 5 , wherein said core line member is rectangular in cross section, longer sides of which position in parallel with said flat surface portions of said head plug.

7. A medical guide wire comprising a flexible line wire having a main wire portion, a core member and a helical spring provided around a distal end of said core line member, a front end of said helical spring being fixedly interfit to a head plug provided at a tip of said core line member;

a rigid portion located on a front end of said helical spring, said rigid portion measuring 0.5 mm or less which extends lengthwisely from a top end of said head plug to a rear end of a portion in which said helical spring is fixed to said head plug, and an intermediary location is determined on an intermediary portion of said helical spring in which an intermediary boss portion is secured to said core line member to define a loosely wound portion as an elastically expandable portion from a rear end of said head plug to said intermediary location;

said head plug forming a spherical or semi-spherical configuration, and right and left side portions of said head plug being undercut to form flat surface portions;

said core line member being rectangular in cross section, longer sides of which position parallel with said flat surface portions of said head plug; and

said front end of said helical spring and said head plug being produced from TIG or laser spot welding.

8. A medical guide wire comprising a flexible line wire having a main wire portion, a core member and a helical spring provided around a distal end of said core line member, a front end of said helical spring being fixedly interfit to a head plug provided at a tip of said core line member;

a rigid portion located on a front end of said helical spring, said rigid portion measuring 0.5 mm or less which extends lengthwisely from a top end of said head plug to a rear end of a portion in which said helical spring is fixed to said head plug, and an intermediary location is determined on an intermediary portion of said helical spring in which an intermediary boss portion is secured to said core line member to define a loosely wound portion as an elastically expandable portion from a rear end of said head plug to said intermediary location;

said loosely wound portion being approximately 24 mm in length;

said head plug forming a spherical or semi-spherical configuration, and right and left side portions of said head plug being undercut to form flat surface portions; and

said front end of said helical spring and said head plug are produced from TIG or laser spot welding.

9. A medical guide wire comprising a flexible line wire having a main wire portion, a core member and a helical spring provided around a distal end of said core line member, a front end of said helical spring being fixedly interfit to a head plug provided at a tip of said core line member;

a rigid portion located on a front end of said helical spring, said rigid portion measuring 0.5 mm or less which extends lengthwisely from a top end of said head plug to a rear end of a portion in which said helical spring is fixed to said head plug, and an intermediary location is determined on an intermediary portion of said helical spring in which an intermediary boss portion is secured to said core line member to define a loosely wound portion as an elastically expandable portion from a rear end of said head plug to said intermediary location;

said loosely wound portion being approximately 24 mm in length;

said head plug forming a spherical or semi-spherical configuration, and left side portions of said head plug being undercut to form flat surface portions;

said core line member being rectangular in crosss section, longer sides of which position parallel with said flat surface portions of said head plug; and

said front end of said helical spring and said head plug being produced from TIG or laser spot welding.