A medical electrical lead is provided that is readily manufactured using a
minimal number of parts, has a reduced size and improved reliability
during implantation and extraction. The lead includes a modular electrode
head assembly that is joined to a lead body at a butt joint. The butt
joint is stabilized in at least four possible ways: insulation tubing that
spans the joint is bonded to the electrode head assembly; two cabled
conductors extending the length of the lead body are coupled to the
electrode head assembly; an electrode head alignment peg interlocks with
and is bonded to the lead body; and a coil electrode is positioned across
the butt joint on the outer diameter of the assembly and the lead body.
The lead size is minimized by using a compact retraction stop mechanism, a
low-friction, press-fit drive shaft seal, and a small diameter coiled
conductor insulated by a thin-walled insulating tube.
