Tissue-stimulating electrode having sealed, low-friction extendable/retractable active fixation means

A tissue-stimulating lead comprising:

• a flexible conductor having a proximal end adapted for connection to a tissue-stimulating device and a distal end adapted for contact with desired tissue;
• a stimulating tip connected to the distal end of the conductor, said stimulating tip having a barrel therein;
• a movable carrier bobbin inserted into said barrel;
• tissue attachment means affixed to one end of said carrier bobbin, said tissue attachment means protruding from said barrel whenever said carrier bobbin assumes an extended position, and said tissue attachment means remaining inside of said barrel whenever said carrier bobbin assumes a retracted position;
• extension means for selectively applying forces to the carrier bobbin that position said carrier bobbin in its extended position, thereby facilitating the attachment of said tissue attachment means to the desired tissue;
• and
• retraction means within said stimulating tip for continuously urging the carrier bobbin back towards its retracted position;
• said retraction means helping to maintain contact between said tip electrode and the desired tissue once the desired tissue has been attached to the tissue attachment means.

A method for attaching a tissue-stimulating lead to body tissue, said tissue-stimulating lead comprising a flexible conductor having a lumen therein, and having a tip electrode attached to a distal end thereof, and further having tissue attachment means connected to said tip, internal biasing means housed within the distal end of said lead for maintaining the tissue attachment means in a non-protruding recessed position within said tip, and means for extending said tissue attachment means to a protruding position from said tip upon application of an external force, said method comprising the steps of:

• (a) positioning the tip electrode of said lead adjacent the tissue to which it is to be attached;
• (b) applying an external force to the means for extending the tissue attachment means to cause said tissue attachment means to protrude from said tip;
• (c) affixing said protruding tissue attachment means to the body tissue;
• and
• (d) removing the external force applied in step (b), whereupon said internal biasing means helps maintain the tip electrode in contact with the attached body tissue.