A bed includes a frame, a controller coupled to the frame, and a patient position detection system coupled to the frame and coupled to the controller. A first connection electrode may be provided under the first electrode. The actinic laser beam is scanned over the fiducial marks, and the scattered light is detected by a detector residing above the calibration plate. The roll is placed with a cutting bar on the uppermost generating line of the paper reel and rolled thereon and the uppermost layer of the paper reel held by suction and lifted off by rolling the roll in the opposite direction beyond the starting position. The deflection plate also includes at least one deflection plate hole therethrough. Other embodiments place peripheral slots on a second, passive backplane.