Abstract: A registration fixture for use with a surgical navigation system for registration of medical images to a three-dimensional tracking space includes a base frame adapted to be mounted over a flat panel detector of an x-ray medical imaging device, and a side frame having optical tracking markers mounted to the base frame. The base frame includes a first set of radiopaque markers embedded therein in a first predetermined pattern and arranged on a plane, and a second set of radiopaque markers embedded therein in a second predetermined pattern also arranged on another plane, which is spaced from the first set of radiopaque markers. The side frame has a plurality of optical tracking markers and is configured to detachably mount to the base frame.

Abstract: An electrosurgical instrument includes jaws having an electrode configuration utilized to electrically modify tissue in contact with one or more electrodes. The instrument is removably connectable to an electrosurgical unit via an electrosurgical connector extending from the instrument and a receptacle on the electrosurgical unit. The electrosurgical instrument is rotatable without disrupting electrical connection to the electrodes of the jaws. One or more of the electrodes is retractable. The electrosurgical unit and instrument optimally seals and/or cuts tissue based on identifying the tissue and monitoring the modification of the tissue by the application of radio frequency energy.