Medical guide wire

A medical guide wire comprising:

• a first core;
• a second core;
• and
• a tubular connector, wherein
• the first core has a pseudoelastic property and includes a small diameter proximal connection portion and a first core-large diameter proximal portion in order from the proximal end to the distal end,
• the tubular connector has a pseudoelastic property,
• the first core-large diameter proximal portion and the tubular connector are a Ni—Ti alloy having the transverse elastic modulus of between 17650 Mpa and 21575 Mpa when an austenite phase is exhibited,
• the second core has a strain-induced martensitic transformation phase and includes a second core-large diameter portion and a small diameter distal connection portion in order from the proximal end to the distal end,
• the second core-large diameter portion is an austenitic stainless steel wire having the transverse elastic modulus of 68500 Mpa or more,
• the small diameter proximal connection portion has a first small diameter proximal portion and a second small diameter proximal portion in order from the distal end to the proximal end,
• the outer diameter of the second small diameter proximal portion is gradually reduced from the outer diameter of the first small diameter proximal portion,
• the small diameter distal connection portion has a first small diameter distal portion and a second small diameter distal portion in order from the proximal end to the distal end,
• the outer diameter of the second small diameter distal portion is gradually reduced from the outer diameter of the first small diameter distal portion,
• the small diameter proximal connection portion is arranged inside the tubular connector at the distal end of the tubular connector and the small diameter distal connection portion is arranged inside the tubular connector at the proximal end of the tubular connector,
• the distal end of the tubular connector is in contact with a first step between the first core-large diameter proximal portion and the small diameter proximal connection portion, the first core-large diameter proximal portion having a larger outer diameter than the small diameter proximal connection portion,
• the proximal end of the tubular connector is in contact with a second step between the second core-large diameter portion and the small diameter distal connection portion, the second core-large diameter portion having a larger outer diameter than the small diameter distal connection portion, and
• when the torsional rigidity of the first core-large diameter proximal portion is defined as K1, the transverse elastic modulus of the first core-large diameter proximal portion is defined as G1, the outer diameter of a first contact position between the tubular connector and the first core-large diameter proximal portion is defined as D1, the torsional rigidity of the second core-large diameter portion is defined as K2, the transverse elastic modulus of the second core-large diameter portion is defined as G2, the outer diameter of a second contact position between the tubular connector and the second core-large diameter portion is defined as D2, the torsional rigidity of the tubular connector is defined as J1, the transverse elastic modulus of the tubular connector is defined as G3, the outer diameter of the tubular connector is defined as do, and the inner diameter of the tubular connector is defined as do1, the torsional rigidity ratio (K2/K1) of the torsional rigidity K2 of the second core-large diameter portion with respect to the torsional rigidity K1 of the first core-large diameter proximal portion satisfies the following relational expression:
• K2/K1=G2×D24/(G1×D14),
• the torsional rigidity ratio J1/K1 of the torsional rigidity J1 of the tubular connector with respect to the torsional rigidity K1 of the first core-large diameter proximal portion satisfies the following relational expression:
• J1/K1=G3×(do4−do14)/(G1×D14), and
• the torsional rigidity ratio (K2/K1) of the torsional rigidity K2 of the second core-large diameter portion with respect to the torsional rigidity K1 of the first core-large diameter proximal portion satisfies the relational expressions:
• 5.65≥(K2/K1)>(J1/K1)>1;
• and
• 4.48≥(J1/K1).