Guidewire having varying diameters and method of making

Abstract

A method of making a medical guidewire including providing a wire having a length that includes a proximal length and a distal length. The method further includes applying cold work to the distal length and not applying cold work to the proximal length, thereby imparting to the distal length a diameter that is smaller than the proximal length diameter; and applying a reducing process to the wire whereby the proximal length is reduced to have an outer diameter that is the same as the outer diameter of the distal length. The proximal length has an inner diameter and the distal length has an inner diameter that is less than the inner diameter of the proximal length.

1 .- 21 . (canceled) 
     
     
         22 . A guidewire, comprising:
 an elongated tubular member having a lumen extending from a proximal end to a distal end;   a proximal section and a distal section;   an uniform outer diameter extending along the proximal section and the distal section;   the proximal section having a first inner diameter and the distal section having a second inner diameter less than the first inner diameter; and   at least a portion of the distal section having coils.   
     
     
         23 . The guidewire of  claim 22 , wherein the coils have a rectangular cross-section. 
     
     
         24 . The guidewire of  claim 22 , wherein the proximal section is longer than the distal section. 
     
     
         25 . The guidewire of  claim 22 , wherein the distal section is more flexible than the proximal section. 
     
     
         26 . The guidewire of  claim 22 , wherein the proximal section has a length in a range from 3.94 inches to 70.87 inches and the distal section has a length in range from 0.63 inches to 3.15 inches.