Patent ID: 8306630

Claim:
A medical device lead comprising: an insulative lead body; an outer conductive coil extending through the lead body, the outer conductive coil coupled to a first electrode at a distal end of the outer conductive coil; and an inner conductive coil extending coaxially with the outer conductive coil, the inner conductive coil coupled to a second electrode at a distal end of the inner conductive coil, the inner conductive coil including a central lumen; and a flexible core assembly disposed in the central lumen, the flexible core assembly comprised of a material that has a saturation magnetization of at least about 1.5 T and a relative permeability of greater than one, the flexible core assembly including a positioning interface configured for manipulation of the flexible core assembly such that the flexible core assembly translates through the central lumen during insertion of the flexible core assembly into the central lumen and extraction of the flexible core assembly from the central lumen, the flexible core assembly further including a reinforcement member extending axially through the flexible core assembly.