A guide is disclosed for use in performing spinal surgery to prepare across a spinal disc and adjacent vertebrae an implantation space. Electrical energization of the morphs with a DC voltage under the control of a computer provides a large range of mirror orientations and positions and the devices occupy a small planar package. A compressor is positioned within the patient body in communication with the bladders for selectively providing an air supply to the bladders to simulate a respiratory pattern. The phase detector includes an SPR qualifier that determine whether, following a state change, the Mode-S signal remains at one of the first and second states for at least a predetermined minimum time sufficient to qualify as a detector enable signal. The hierarchical representation can be used to facilitate two-way communication between an occupant and an emergency responder during an emergency event. If the unique identifier does not match the information in the neighbor list, the base station can update the neighbor list.