Patent ID: 7376468

Claim:
An implantable medical device for providing therapy to a body comprising: an elongate central portion having a longitudinal center of axis; at least one extendable member having a tip, the extendable member depending from the central portion and being adapted to assume a range of positions, including a contracted position, in which the tip is disposed in close proximity to the central portion, and an expanded position, in which the tip is disposed at a location distal from the central portion; at least one therapy element disposed on the extendable member for delivering therapy to the body; a linkage assembly for position adjustment of the extendable member in situ, the linkage assembly comprising a first pair of struts that are directly and pivotally linked to one another at a first point and a second pair of struts that are directly and pivotally linked to one another at a second point, the first point and the second point adapted to move towards each other to contract the extendable member, and away from one another to expand the extendable member; wherein the extendable member comprises a span having a first end and a second end that are fastened to the linkage assembly at the first point and the second point respectively, the span adapted to contract between the first point and the second point when the first point and second point are moved towards each other, and expand between the first point and the second point when the first point and the second point are moved away from each other, the span forming a paddle surface, the paddle surface having a longitudinal center of axis parallel to the longitudinal center of axis of the elongate central portion when the paddle surface is in the expanded position.