Implantable lead

摘要

An implantable lead for use with cardiac pacemakers, defibrillators and other long term implantable electrical devices intended for sensing or tissue stimulation, having a helically wound conductor with a surrounding tubular insulating layer of elastomeric material such as silicone or polyurethane and an additional coaxial tubular exterior biocompatible layer of porous PTFE having a microstructure of nodes interconnected by fibrils. The exterior tubular layer of porous PTFE may be fitted coaxially over the elastomeric tubular layer whereby the porous PTFE tubular layer is in longitudinal compression and the fibrils within the microstructure have a bent and wavy appearance. Any portion of the length of the porous PTFE tubing in longitudinal compression allows that portion of the length of the lead wire to be extensible to a controlled extent limited by the straightening of the bent fibrils within the porous PTFE microstructure.