Patent ID: 7715922

Claim:
An implantable lead comprising a lead body at least partially formed of a block copolymer comprising two polyethylene oxide (PEO) blocks and one polyisobutylene (PIB) block, the block copolymer being represented by the formula PEO-DI-(PIB-DI) n -PEO, the block copolymer being made by reacting two moles of a mono-functional group terminated polyethylene oxide (mPEO) with one mole of an isocyanate-terminated prepolymer, the isocyanate-terminated prepolymer being obtained by reacting n+1 moles of a diisocyanate with n moles of di-reactive group terminated polyisobutylene (diPIB), wherein n is an integer greater than zero, wherein DI represents a linkage which is the product of reacting an isocyanate group of the prepolymer with the functional group of mPEO, and is the product of reacting both isocyanate groups of the diisocyanate with the reactive groups of diPIB so as to couple multiple PIB segments together when n is greater than one.