Patent ID: 8758339

Claim:
An apparatus for positioning an energy delivery probe in body tissue, wherein the energy delivery probe comprises a shaft and an operative element coupled to a distal end of the shaft, the apparatus comprising: an introducer having a lumen through which the energy delivery probe may be positioned in body tissue; a conical index-key comprising a sleeve having a bore configured for being coaxially secured to the shaft of the energy delivery probe, the index-key having a plurality of radically extending key elements; and an indexer coupled to a proximal end of the introducer, the indexer having an exterior surface, an interior surface defined by a central bore, a wall thickness defined between the exterior surface and the interior surface, and a plurality of keyways extending from the interior surface towards the exterior surface and located on a respective plurality of radial lines, wherein (a) the keyways extend only partially through the wall thickness of the indexer, (b) The keyways are adapted to mate with the plurality of radically extending key elements of the index-key when the index-key is advanced distally relative to the indexer, (c) the plurality of radially extending key elements fit within the keyways of the indexer in at least two positions, and (d) the index-key is rotatable when axially translated away from the indexer.