Hollow medical wires and methods of constructing same

Abstract

The present invention provides an apparatus for performing angioplasty or vascular intervention procedures. The apparatus of the present invention comprises a catheter apparatus comprised of a superelastic hollow guidewire, a balloon member and a flexible tip. The superelastic hollow guidewire of the invention is preferably a hypotube of nitinol alloy. The use of nitinol alloy as hollow guidewire provides a catheter apparatus having high flexibility and torqueability as well as small cross sectional diameter.

What is claimed is:  
     
         1 . A medical guidewire adapted to have a medical device ride over it to a location within a patient, said guidewire comprising: 
 an elongate body having distal and proximal sections, said body being at least partially constructed using a transformational, non-linear, superelastic nickel titanium alloy material, at least said distal section of said body receiving heat treatments in the range of 300° C.-600° C. for about 10 seconds to 60 minutes such that said alloy material has recoverable strains in the range of about 1% to about 8%;    said distal section being constructed from a first nickel titanium alloy section having sufficient flexibility to navigate the guidewire through the patient;    said proximal section being constructed from a second nickel titanium alloy section having sufficient stiffness to provide the guidewire with pushability and trackability for advancing the guidewire through the patient and for riding a medical device over the guidewire; and    an occlusion device mounted on said distal section of said body.    
     
     
         2 . The medical guidewire of  claim 1 , further comprising a lumen in said body for communicating fluids from said proximal section of said body to said distal section of said body.