Implantable electrical lead wire

Abstract

Implantable electrical lead wires, such as cobalt-chromium-molybdenum alloy wires, are coated with a metal, ceramic, or carbon to a thickness of about 100 nm or less to provide a non-reactive interface to polyurethane sheathing materials. Preferred is sputter coating an amorphous carbon intermediate the alloy wire and the polyurethane sheath.

1 . A deformable substrate, which comprises: 
 a) the substrate comprised of an alloy including at least one of cobalt, molybdenum, and chromium;    b) an elastomeric material at least partially covering the substrate; and    c) a coating of an inert material provided on at least a portion of the substrate covered by the elastomeric material, wherein the intermediate inert material prevents interaction of the at least one of cobalt, molybdenum, and chromium with the elastomeric material.    
     
     
         2 . The substrate of  claim 1  wherein the inert material is coated on the substrate to a thickness before completion of an island coalescence phase with islands of the inert material adhering to the alloy, but not to each other.  
     
     
         3 . The substrate of  claim 1  wherein the inert coating is up to about 100 nm thick.  
     
     
         4 . The substrate of  claim 1  wherein the inert material is selected from the group consisting of amorphous carbon, turbostratic carbon, diamond-like carbon, titanium, platinum, iridium, tantalum, palladium, niobium, gold, titanium nitride, aluminum oxide, aluminum nitride, and mixtures thereof.  
     
     
         5 . The substrate of  claim 1  comprising a wire in the form of a helical strand.  
     
     
         6 . The substrate of  claim 1  wherein the alloy of the substrate is selected from the group consisting of stainless steel, ELGILOY, MP35N, and DBS/MP.  
     
     
         7 . The substrate of  claim 1  wherein the elastomeric material is selected from silicone and polyurethane.  
     
     
         8 . An electrical lead, which comprises: 
 a) the electrical lead comprised of an alloy including at least one of cobalt, molybdenum, and chromium;    b) a sheath of an elastomeric material at least partially housing the lead;    c) an electrode at a distal end of the lead;    d) an electrical connector coupled to a proximal end of the lead; and    e) a coating of a carbonaceous material provided on at least a portion of the lead housed within the elastomeric sheath, wherein the intermediate carbonaceous material prevents interaction of the at least one of cobalt, molybdenum, and chromium with the elastomeric sheath.    
     
     
         9 . The lead of  claim 8  wherein the carbonaceous material is coated on the lead to a thickness before completion of an island coalescence phase with islands of the carbonaceous material adhering to the alloy, but not to each other.  
     
     
         10 . The lead of  claim 8  wherein the carbonaceous coating is about 10 nm to about 50 nm thick.  
     
     
         11 . The lead of  claim 8  wherein the carbonaceous material is selected from the group consisting of amorphous carbon, turbostratic carbon, diamond-like carbon, and mixtures thereof.  
     
     
         12 . The lead of  claim 8  wherein the lead comprises a helical strand.  
     
     
         13 . The lead of  claim 12  wherein the helical strand is of a wire about 0.002 inches to about 0.005 inches in diameter.  
     
     
         14 . The lead of  claim 12  wherein the helical strand in about 0.015 inches to about 0.030 inches in diameter.  
     
     
         15 . The lead of  claim 8  wherein the alloy of the lead is selected from the group consisting of stainless steel, ELGILOY, MP35N, and DBS/MP.  
     
     
         16 . The lead of  claim 8  wherein the elastomeric material is selected from silicone and polyurethane.  
     
     
         17 . An implantable electrical lead, which comprises: 
 a) a wire conductor of an alloy including at least one of cobalt, molybdenum, and chromium in the form of a helical strand;    b) an insulative sheath of polyurethane at least partially encasing the wire conductor;    c) an electrode at a distal end of the wire conductor and an electrical connector coupled to a proximal end thereof; and    d) a coating of an inert material provided on at least a portion of the wire conductor covered by the polyurethane, wherein the intermediate inert material prevents interaction of the at least one of cobalt, molybdenum, and chromium with the polyurethane.    
     
     
         18 . The lead of  claim 17  wherein the inert material is coated on the lead to a thickness before completion of an island coalescence phase with islands of the inert material adhering to the alloy, but not to each other.  
     
     
         19 . The lead of  claim 17  wherein inert coating is up to about 100 nm thick.  
     
     
         20 . The lead of  claim 17  wherein the inert material is selected from the group consisting of amorphous carbon, turbostratic carbon, diamond-like carbon, titanium, platinum, iridium, tantalum, palladium, niobium, gold, titanium nitride, aluminum oxide, aluminum nitride, and mixtures thereof.  
     
     
         21 . The lead of  claim 17  comprising a wire about 0.002 inches to about 0.005 inches in diameter as a helical strand.  
     
     
         22 . The lead of  claim 21  wherein the helical strand in about 0.015 inches to about 0.030 inches in diameter.  
     
     
         23 . The lead of  claim 21  wherein the lead is selected from stainless steel, ELGILOY, MP35N, and DBS/MP.  
     
     
         24 . The lead of  claim 21  wherein the elastomeric material is selected from silicone and polyurethane.  
     
     
         25 . A method for providing a deformable substrate, comprising the steps of: 
 a) providing the substrate comprising an alloy including at least one of cobalt, molybdenum, and chromium;    b) covering at least a portion of the substrate with an elastomeric material; and    c) coating an inert material on at least a portion of the substrate covered by the elastomeric material, the intermediate inert material preventing interaction of the at least one of cobalt, molybdenum, and chromium with the elastomeric material.    
     
     
         26 . The method of  claim 25  including coating the inert material on the substrate to a thickness before completion of an island coalescence phase with islands of the inert material adhering to the alloy, but not to each other.  
     
     
         27 . The method of  claim 25  including coating the inert material up to about 100 nm thick.  
     
     
         28 . The method of  claim 25  including selecting the inert material from the group consisting of amorphous carbon, turbostratic carbon, diamond-like carbon, titanium, platinum, iridium, tantalum, palladium, niobium, gold, titanium nitride, aluminum oxide, aluminum nitride, and mixtures thereof.  
     
     
         29 . The method of  claim 25  including providing the substrate as a wire in the form of a helical strand.  
     
     
         30 . The method of  claim 25  including selecting the alloy from the group consisting of stainless steel, ELGILOY, MP35N, and DBS/MP.  
     
     
         31 . The method of  claim 25  including selecting the elastomeric material from silicone and polyurethane.  
     
     
         32 . The method of  claim 25  including coating the inert material on the substrate by a process selected from the group consisting of sputtering, evaporation, laser ablation, and thermal spraying.