Method for manufacturing a soft tip catheter

Abstract

A catheter and a method of manufacture of a catheter which includes a relatively rigid body and a relatively soft tip for decreasing the likelihood of injury or damage to tissue such as the wall of a blood vessel or the heart when the catheter is used as a part of an invasive medical procedure such as angiography or angioplasty. The method includes the use of a core material which is sufficiently resistant to high temperatures to allow extrusion of catheter material thereover in the process of forming the catheter. The core controls the catheter's inside diameter, and is sufficiently heat resistant to allow its use through all subsequent manufacturing process steps involving the formation of the soft tip. The method of the present invention prevents foreign material build up within the inner diameter of the catheter during processing, eliminates the need for special fusion support mandrels during fusion of the soft tip onto the catheter, and maintains the integrity of the internal diameter of the catheter and soft tip during the thermal and pressure processes of the manufacture. The invention also includes a novel method of sizing and fusing the soft tip onto the catheter including the use of a piston member about the core which can apply pressure to the material forming the soft tip at any time before, during or after the thermal heating step.