Methods and systems supply uninterrupted power to a load using a backup battery module. The exemplary method also includes determining whether the virtual camera is located within a first substantially conical volume. In use, the user’s hand is held up to the side of their head, thereby placing the microphone adjacent to their mouth and the loudspeaker adjacent to their ear. The second signal line group corresponds to the isolation patterns. The first still image and the motion-compensated second still image are added or averaged with the weighting factor and a processed image is obtained. The thickness of the mattress shoulder portion is reduced relative to the thickness of the mattress back portion so that upwardly facing top surfaces of the mattress back and shoulder portions are generally coplanar.