A mechanical connector is provided for lighting applications. The electrode layers extend beyond the periphery of the separator layers providing superior contact between the electrodes and battery terminals, eliminating the need for welding the electrode to the terminal. The second voltage reference circuit provides a second reference voltage between a terminal of the second voltage reference circuit and a second power line that is separate from the first power line. Capture of treatment event is entered into a computerized billing system along with the corresponding patient identifier. Similarly, after the screw is retreated for a preset period of time, the servomotor is stopped by automatic decompression to detect an output of the load cell. The encyclopedia-like entry can include text, graphics, links to related topics within the directory tree structure, links to related web sites external to the directory tree structure, or any combination thereof.