Person support apparatuses with load cells

A person support apparatus, such as a bed, cot, stretcher, chair, or the like, includes a frame, a support surface supported by the frame, a plurality of load cells that detect weight supported on the support surface, at least one A/D converter, and a controller. The load cells output analog signals that are converted to digital by the A/D converters. The controller switches a sampling rate of the A/D converters between at least first and second rates. The outputs from the load cells are forwarded to a plurality of signal acquisition nodes that include the A/D converters. The nodes are positioned at locations that minimize the length of travel of the analog signals, thereby reducing noise interference. Shivering, occupant absence/presence, vital signs, occupant movement, and/or other parameters are detected by the load cells.