Implantable endocardial lead with self-healing retractable fixation apparatus

摘要

An implantable endocardial lead with a retractable helix. A specialized stylet can be inserted into the lead at the proximal end and passed through the lead to the distal end. Located at the distal end of the lead is a piston supporting the helix. The piston is attached to a coiled trifilar conductor and has an electrode adjacent the helix. Immediately adjacent the piston proximally an additional first short coil of wire is interlocked between the wires of the trifilar conductor, providing a female thread within the conductor. The stylet has a second single strand short coil segment spot welded to the stylet adjacent a distal end thereof. The stylet is rotated to screw the second short coil segment on the stylet into the first short coil adjacent the piston.