Abstract: A sensing and detecting apparatus includes an elongate sensor for placement parallel to one axis of a bed. The sensor includes a first and second conductive members, the first conductive member having a resistance-per-unit-length substantially different from that of the second conductive member. One of the conductive members is electrically coupled to a source of electrical power wherein the weight of the body in the bed urges the first and second conductive members together to define an electrical path for output of a sensor signal, which varies in magnitude responsive to the position of the body along the sensor. The apparatus according to the present invention further includes an alarm circuit, with means for comparing the sensor signal to predetermined position and activity level values, and triggering an alarm or alarm signal in the event the position and or activity level values are exceeded.