A pet bed and method of making the pet bed are disclosed. The bridge switching circuit has a first power switch, a second power switch, a third power switch, and a fourth power switch. The pressure supplement value for each mapped pressure value may be derived based on a prior application of the same or another map value. The system includes a metal detector, and the metal detector is suitable for the detection of a metallic object situated in the transmission area. The apertures have a horizontal extent which is less than the horizontal width of the associated set of radiation output positions.