Bipolar screw-in lead

Abstract

An implantable active fixation lead includes an outer sheath, a protector member having a peripheral surface extending between its distal and proximal end surfaces with a helical groove formed in the peripheral surface, and a fixation helix integral with the outer sheath. The fixation helix includes a tip end engageable with body tissue and slidably engaged with the helical groove for relative translation and rotation. A longitudinal force on the lead firmly engages the protector member's distal end surface with the body tissue. With the fixation helix initially retracted proximally of the protector member's distal end surface and disengaged from the body tissue, upon application of torque to the outer sheath, the distal end surface of the protector member is moved proximally with respect to the fixation helix which, simultaneously, is extended distally beyond the distal end surface of the protector member to an extended position into engagement with the body tissue.

Dependencies are inferred from the claim text.