Alternating core composite wire

Abstract

A wire having an outer shell and a core, the core including at least a first plurality of core segments that may be made of a first core material and a second plurality of core segments that may be made of a second core material different from the first core material. The first and second core segments are arranged in a periodic alternating arrangement along the length of the wire. The outer shell may be made of a metal, such as a biocompatible metal, and the core segments may be made of different materials to provide periodic material properties along the length of the wire. The wire is manufactured by inserting the core segments into the outer shell to form a wire construct, followed by subjecting the wire construct to one or more initial draws while applying a compressive force to the core segments on an upstream side of the die to maintain the core segments in contact with one another upon dense contact between the outer shell and core segments, following by closing of the outer shell onto the core segments, as the wire is pulled through a drawing die. The resulting wire may then be subjected to a plurality of finishing draws. Exemplary applications of the wire include medical devices, such as in vivo heating devices, thermally-actuated snares, in vivo positioning devices, stents, and tissue scaffolds.

1 - 15 . (canceled) 
     
     
         16 . A medical device for use in in vivo heating, comprising:
 a wire, comprising:
 an outer shell made of a biocompatible metal; and 
 a core disposed within said outer shell, said core including a plurality of first core segments made of a first material having a first electrical resistance and at least one second core segment made of a second material, said second material different from said first material and having a second electrical resistance greater than said first electrical resistance, said first core segments and said at least one second core segment arranged in a periodic alternating arrangement along a length of said wire; and 
   an insulating layer at least partially covering said wire.   
     
     
         17 . The medical device of  claim 16 , wherein at least a portion of said at least one second core segment is not covered by said insulating layer. 
     
     
         18 . The medical device of  claim 16 , wherein said first core segments are formed of a material selected from the group consisting of silver, platinum, and tantalum. 
     
     
         19 . The medical device of  claim 16 , wherein said at least one second core segment is formed of a material selected from the group consisting of stainless steel, a cobalt-nickel-chromium-tungsten-iron-manganese alloy, a nickel-titanium shape memory alloy, and a cobalt-nickel-chromium alloy. 
     
     
         20 . The medical device of  claim 16 , wherein said outer shell includes an inner diameter and said core segments each include an outer diameter equal to said inner diameter of said outer shell whereby, when viewed in section, each of said core segments completely fills said outer shell. 
     
     
         21 . The medical device of  claim 16 , wherein said at least one second core segment is disposed at a distal end of said medical device and is exposed from said layer of insulating material and twisted in an outwardly splayed fashion. 
     
     
         22 . The medical device of  claim 16 , wherein at least a portion of said wire is twisted into a double helix profile. 
     
     
         23 . The medical device of  claim 16 , further comprising a temperature measurement feedback device. 
     
     
         24 . The medical device of  claim 16 , wherein said temperature measurement feedback device is selected from a thermocouple and a thermistor, and is disposed proximate said at least one second core segment.