Biaxially oriented multilayer polymer tube for medical devices

Abstract

A tubular extruded member particularly suitable for use in medical devices such as intravascular catheters and guide wires, wherein the extruded tubular member includes multiple layers having biaxial helical orientation in different directions. A counter-rotation extrusion process may be used to orient the layers in different biaxial helical directions. The counter-rotation extrusion process provides orientation in two different circumferential directions in addition to a longitudinal direction. By combining the dual direction or biaxial helical orientation with multiple layers, different layers of the tubular member may be tailored to have the desired mechanical properties.

What is claimed is:  
     
         1 . A medical device comprising an extruded tubular polymer member, the tubular polymer member having an inner tubular layer and an outer tubular layer, wherein the inner tubular layer has helical orientation in a first direction and the outer tubular layer has helical orientation in a second direction different from the first direction.  
     
     
         2 . A medical device as in  claim 1 , wherein the tubular polymer member is made by an extrusion process including the step of extruding the polymer member through a rotating extrusion head over a counter-rotating mandrel.  
     
     
         3 . A medical device as in  claim 1 , wherein the tubular polymer member is made by an extrusion process including the step of rotating the polymer member after passing through a counter-rotating extrusion head.  
     
     
         4 . A medical device as in  claim 1 , wherein one of the inner and outer tubular layers is formed of a relatively flexible polymeric material and the other of the inner and outer tubular layers is formed of a relatively rigid polymeric material.  
     
     
         5 . A medical device as in  claim 1 , wherein one of the inner and outer tubular layers is formed of continuous LCP fibers dispersed in a non-LCP polymer matrix.  
     
     
         6 . A medical device as in  claim 5 , wherein the LCP content of the LCP containing layer is between 0.1% and 90% by weight.  
     
     
         7 . A medical device as in  claim 5 , wherein the LCP containing layer comprises 0.05% to 50% by weight of the combined layers.  
     
     
         8 . A medical device comprising an extruded tubular polymer member formed of a relatively rigid polymeric tubular layer and a relatively flexible polymeric tubular layer, wherein the relatively rigid polymeric tubular layer has helical orientation in a first direction and the relatively flexible polymeric tubular layer has helical orientation in a second direction different from the first direction.  
     
     
         9 . A medical device as in  claim 8 , wherein the helical orientation is formed by an extrusion process including the step of extruding the polymer member through a rotating extrusion head over a counter-rotating mandrel.  
     
     
         10 . A medical device as in  claim 8 , wherein the helical orientation is formed by an extrusion process including the step of rotating the polymer member after passing through a counter-rotating extrusion head.  
     
     
         11 . A medical device comprising an extruded tubular polymer member, the tubular polymer member comprising a first extruded tubular polymer layer and a second extruded tubular polymer layer, the first extruded tubular polymer layer including continuous LCP fibers dispersed in a non-LCP thermoplastic polymer matrix, wherein the first extruded polymer layer has helical orientation in a first direction and the second extruded polymer layer has helical orientation in a second direction different from the first direction.  
     
     
         12 . A medical device as in  claim 11 , wherein the helical orientation is formed by an extrusion process including the step of extruding the polymer member through a rotating extrusion head over a counter-rotating mandrel.  
     
     
         13 . A medical device as in  claim 11 , wherein the helical orientation is formed by an extrusion process including the step of rotating the polymer member after passing through a counter-rotating extrusion head.  
     
     
         14 . A medical device as in  claim 11 , wherein the LCP content of the LCP containing layer is between 0.1% and 90% by weight.  
     
     
         15 . A medical device as in  claim 11 , wherein the LCP containing layer comprises 0.5% to 50% by weight of the combined layers.  
     
     
         16 . A method of making a medical tubular polymer member by rotating the polymer member after passing through a counter-rotating extrusion head.  
     
     
         17 . An intravascular catheter including a shaft comprising a tubular polymer member formed by the method of  claim 16 .  
     
     
         18 . An intravascular catheter including an inflatable balloon comprising a tubular polymer member formed by the method of claim  16 .