Guidewire assembly

Abstract

The guidewire assembly includes a distal tip section comprising a core wire, a mushroom shaped head fixed to a distal end of the core wire, and a coiled radiopaque wire having a distal end portion fused to the head and a proximal necked down portion which necks down to proximal end coils forming a proximal end of the coiled radiopaque wire. The proximal end coils are received on a portion of the core wire and fixed thereto by a flexible material. The method for making a guidewire assembly having increased flexibility and a secure connection between a coiled wire and a core wire comprises the steps of: forming a coiled radiopaque wire with a larger-in-diameter distal portion, a necked down middle portion, and a smaller-in-diameter proximal portion having a plurality of end coils; winding the end coils on a mandrel so that the end coils can form the proximal end portion of the coiled wire; pushing the end coils onto a tapered portion of a core wire; placing a flexible sleeve over the end coils; heat shrinking the flexible sleeve at one temperature; placing an outer sleeve over the flexible sleeve; and, heat shrinking the outer sleeve at a higher temperature to melt the flexible sleeve causing it to bond onto the tapered portion between the end coils and to the end coils.