Patent ID: 7751905

Claim:
An active fixation cardiac electrode lead comprising: an electrode lead; a housing coupled with said electrode lead; a fixation helix comprising windings movably placed in said housing at a distal end of said electrode lead so as to be extended out of said distal end of said housing and retraced into an inner space enclosed by said housing; said housing having a wall and a protrusion fixed to said wall wherein said protrusion protrudes toward a centerline of said housing into said inner space wherein said protrusion further protrudes into interspaces between said windings of said fixation helix so as to cause an axial movement of said fixation helix with respect to said housing when said fixation helix is rotated around a longitudinal axis of said fixation helix defined by said centerline and wherein said housing does not rotate and wherein said housing remains unaffected by said axial movement of said helix; said protrusion being an integral part of said wall of said housing; and, wherein said protrusion in said inner space enclosed by said housing is situated radially inward toward said centerline with respect to an indentation on an outside of said wall wherein said indentation is also an integral part of said wall and is inward toward said centerline of said housing and not outward with respect to said wall of said housing.