Patent ID: 8155759

Claim:
A flexible pacemaker lead comprising: a lead body supporting at least one flexible conductor element that provides an electrical signal path between a proximal connector element and a distal electrode, said lead body including an insulating structure that protects said at least one flexible conductor element, said insulating structure realized from a polymer blend of a thermoplastic polyurethane elastomer and an isobutylene block copolymer, wherein mole fraction of said isobutylene block copolymer as part of said polymer blend in a range between 2% and 15%, and said polymer blend has a maximum tensile strength in the range between 20 MPa and 40 MPa; wherein said isobutylene block copolymer of said polymer blend consists of a first polymer block component containing isobutylene-derived monomer units and a second polymer block component derived from a monomer component other than isobutylene; and wherein said second polymer block component comprises at least one cation-polymerizable monomer selected from the group including aliphatic olefins, alicyclic olefins, aromatic vinyl compounds, dienes, vinyl ethers, silanes, vinylcarbazole, β-pinene, acenaphthylene and like monomers.