Medical device with extruded member having helical orientation

Abstract

An elongate polymer member having molecular helical orientation formed by rotation immediately after passing through the extrusion head. The elongate polymer member is rotated downstream of the extrusion head in the molten state prior to solidification in order to impart the molecular helical orientation. Rotating the polymer member in the molten state allows the helical orientation to be imparted at the molecular level, and allows for more rotations per lineal foot of extrusion.

What is claimed is:  
     
         1 . A medical device comprising an elongate polymer member made by an extrusion process including the step of rotating the polymer member after extrusion but prior to solidification while the polymer member is still in a molten state to impart a molecular helical orientation to the polymer member.  
     
     
         2 . A medical device as in  claim 1 , wherein the elongate polymer member has a surface and a body, and wherein the molecular helical orientation extends through the surface and the body.  
     
     
         3 . A medical device as in  claim 1 , wherein the elongate polymer member is made by a co-extrusion process of two or more different polymers.  
     
     
         4 . A medical device as in  claim 3 , wherein the elongate polymer member is made by an intermittent co-extrusion process of two or more different polymers such that a proximal portion of the elongate polymer member comprises a first polymer and a distal portion of the elongate polymer member comprises a second polymer.  
     
     
         5 . A medical device as in  claim 3 , wherein the elongate polymer member is made by a continuous co-extrusion process of two or more different polymers such that the elongate polymer member comprises two or more coextending helically oriented polymers.  
     
     
         6 . A medical device as in  claim 1 , wherein the molecular helical orientation comprises 100 rotations per foot or more.  
     
     
         7 . A medical device as in  claim 6 , wherein the molecular helical orientation varies as a function of length of the elongate tubular member to impart variable flexibility.  
     
     
         8 . A medical device as in  claim 1 , wherein the medical device comprises a guidewire and the elongate polymer member forms a shaft of the guidewire.  
     
     
         9 . A medical device as in  claim 1 , wherein the medical device comprises a catheter and the elongate polymer member forms a tubular shaft of the catheter.  
     
     
         10 . A medical device as in  claim 1 , wherein the medical device comprises a balloon catheter and the elongate polymer member forms a balloon of the balloon catheter.  
     
     
         11 . A medical device as in  claim 1 , wherein the medical device comprises a balloon catheter and the elongate polymer member forms a balloon sleeve of the balloon catheter.  
     
     
         12 . A medical device as in  claim 1 , wherein the polymer member consists of a polymer having a melting temperature and a glass transition temperature.  
     
     
         13 . A medical device as in  claim 1 , wherein a first elongate polymer member is a core member of a second elongate polymer member situated around the core member.  
     
     
         14 . A medical device as in  claim 13 , wherein the second elongate polymer member is rotated in a different direction than the first elongate polymer member.  
     
     
         15 . A medical device as in  claim 1 , wherein the medical device comprises a removable core member and the elongate polymer member forms a shaft of the removable core member.  
     
     
         16 . A medical device as in  claim 15 , wherein the core member consists of a metal wire.  
     
     
         17 . A medical device as in  claim 15 , wherein the core member consists of a composite substrate disposed on the metal wire.  
     
     
         18 . A medical device as in  claim 1 , wherein the molecular helical orientation is formed by rotation immediately after extrusion thereof.