Guidewire device and method

Abstract

The present invention is a multi-layer guidewire which has a first core metal and a secondary metal formed on the outer periphery of the core. During manufacture the composite structure is twisted providing superior mechanical properties to the finished guidewire.

What is Claimed  
     
         1 . In interventional device comprising: 
 an elongate body having a distal end and a proximal end;    a first interior core member formed from super elastic nitinol and a second layer of a metal which is not nitinol.    
     
     
         2 . The device of  claim 1  wherein said second layer material is selected from the group comprising: 
 elgiloy, MPN35, gold, platinum, silver tungsten, and stainless steel.  
 
     
     
         3 . The device of  claim 1  further comprising: 
 a distal coil mounted to the distal tip of said elongate body forming a guidewire.  
 
     
     
         4 . An interventional device according to  claim 1  having a nitinol core and a stainless steel second layer wherein said second layer represents between 5 and 25 percent of the diameter of the device.  
     
     
         5 . A method of making a guidewire comprising the steps of: 
 drawing a bimetal clad wire and subsequently twisting the wire while heating it for a fixed period of time.    
     
     
         6 . The process of  claim 5  wherein said heat range extends between 500° and 1,200° F. for between four minutes and thirty minutes.