| 主权项 |
1. A medical lead comprising an elongated lead body comprising a polymeric material, wherein the polymeric material consists of a silicone-urethane polymer having hydrolytic stability greater than that of a Reference Polymer X, a Reference Polymer Y, or both Reference Polymers X and Y;
wherein the silicone-urethane polymer and at least one of Reference Polymer X and Reference Polymer Y are tested under same conditions of controlled pH, temperature, inert gas, and aqueous solution according to Method of Evaluating Hydrolytic Stability to identify the silicone-urethane polymer having hydrolytic stability greater than that of Reference polymer X, Reference Polymer Y, or both Reference Polymers X and Y; wherein Reference Polymer X is a silicone polyurethane with a soft and hard segment weight ratio of 60/40, respectively, with the soft segment containing 80 wt-% PDMS (molecular weight approximately 1000 Da, n=10-11 repeat units) and 20 wt-% PTMO (poly(tetramethylene oxide), molecular weight approximately 1000 Da) and the hard 15 segment comprised of BDO (1,4-butanediol) and MDI (4,4′-methylene diphenyl diisocyanate); and wherein Reference Polymer Y is a silicone polyurethane with a soft and hard segment weight ratio of 60/40, respectively, with the soft segment containing 80 wt-% PDMS (molecular weight approximately 1000 Da, n=10-11 repeat units) and 20 wt-% PHMO (poly(hexamethylene oxide), molecular weight approximately 700 Da) and the hard segment comprised of BDO (1,4′-butanediol) and MDI (4,4′-methylene diphenyl diisocyanate). |
