A lead having an extendable and retractable fixation mechanism has a rotating
terminal
pin at the terminal end which rotates the fixation mechanism at the distal end.
As the terminal pin is rotated, the fixation mechanism is extended or retracted
from the distal end of the lead. A threaded collar allows for the fixation mechanism
to smoothly extend and retract from the lead, and allows for a 1:1 turn ratio between
the terminal pin and the fixation mechanism. A fluoroscopic ring disposed at the
distal end of the lead provides information during the implantation process.
