Method For Providing An Implantable Electrical Lead Wire
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 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 intermediate carbonaceous material on at least a portion of the substrate between the substrate alloy and the elastomeric material to thereby prevent interaction of the at least one of cobalt, molybdenum, and chromium of the substrate alloy with the elastomeric material.
2 . The method of claim 1 including coating the carbonaceous material on the substrate to a thickness of about 10 nm to about 50 nm before completion of an island coalescence phase with islands of the carbonaceous material adhering to the alloy, but not to each other.
3 . The method of claim 1 including selecting the carbonaceous material from the group consisting of amorphous carbon, turbostratic carbon, diamond-like carbon, and mixtures thereof.
4 . The method of claim 1 including selecting the alloy of the substrate from the group consisting of stainless steel, ELGILOY, MP35N, and DBS/MP.
5 . The method of claim 1 including selecting the elastomeric material from silicone and polyurethane.
6 . The method of claim 1 including providing the substrate as a wire.
7 . The method of claim 6 including providing the wire having a diameter from about 0.002 inches to about 0.005 inches.
8 . The method of claim 6 including forming the wire into a helical strand having a diameter of from about 0.015 inches to about 0.030 inches.
9 . 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.
10 . The method of claim 9 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.
11 . The method of claim 9 including coating the inert material up to about 100 nm thick.
12 . The method of claim 9 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.
13 . The method of claim 9 including providing the substrate as a wire in the form of a helical strand.
14 . The method of claim 9 including selecting the alloy from the group consisting of stainless steel, ELGILOY, MP35N, and DBS/MP.
15 . The method of claim 9 including selecting the elastomeric material from silicone and polyurethane.
16 . The method of claim 9 including coating the inert material on the substrate by a process selected from the group consisting of sputtering, evaporation, laser ablation, and thermal spraying.