The present invention relates to medical vascular catheters adapted to be inserted into a
blood vessel from an incision through the
skin of a patient for introducing other devices or fluids for diagnostic or therapeutic purposes, and particularly to an improved distal soft tip or segment attachment with a relatively stiff proximal
catheter shaft. A tubular sleeve is bonded through the application of pressure and heat to a
distal portion of the
catheter shaft and a proximal portion of the
distal segment of soft distal tip bridging the attachment junction. In the preferred method, the
catheter shaft distal end is aligned with the
distal segment or soft tip proximal end and the sleeve is fitted over the attachment junction. A heat shrink tube is fitted over the sleeve and adjoining portions of the catheter shaft and the
distal segment or distal soft tip and heat is applied. The shrinkage force of the heat shrink tube over the
assembly of the tubular sleeve overlying and bridging the attachment junction and the applied heat melts and force the materials of the tubular sleeve and the catheter shaft and the distal segment or distal soft tip together to fill interstitial spaces of the attachment junction and reduces the outer
diameter of the sleeve. The heat shrink tube is removed after the
assembly cools and solidifies. Preferably, the catheter shaft distal end and the soft tip or intermediate segment proximal end are each formed with a like plurality of ungular
cut sections that are complementary in shape to one another, whereby the ungular
cut sections are aligned with and mated together along the attachment junction.