Medical guide wire, a method of making the same, an assembly of balloon catheter and guiding catheter combined with the medical guide wire, an assembly of microcatheter and guiding catheter combined with the medical guide wire
In a medical guide wire 1, a flexible core wire 2 is made of austenitic stainless steel wire treated with a solid solution procedure, and drawn with a whole cross sectional reduction ratio as 90%-97.6%. Each time when the core wire 2 is subjected to a series of mechanical procedures, the core wire 2 is heat treated repetitively at low temperature subsequent to the mechanical procedures to improve a tensile strength characteristic of the core wire 2. The core wire 2 is twisted under the low heat treatment. Effectively used is a heat generated from a synthetic layer 6 when coating the layer 6 on the helical spring body 3. This makes it possible to increase the characteristic of the tensile strength of the core wire 2 with its thermal conductivity taken into consideration. Upon improving the tensile strength of the core wire 2, optimal conditions are achieved by observing a relationship between the tensile strength and the temperature which the core wire 2 exhibits when tightly drawn as a wrought-out procedure.
