A capacitive array is housed within a polyester mat or other appropriate
nonconductive substrate material which is interconnected with a control
module. The control module supplies to the capacitive array a suitable
oscillator driver current and concurrently senses capacitance value
changes within the capacitive array induced through dielectric shifts
within the array brought about by the proximity or absence thereof of the
patient's body mass. The monitor/control module generally comprises a
power supply, a driver/sensor circuit, a calibration/comparator logic
circuit, a system interconnection integrity circuit, and an alarm
generation circuit. It may also optionally contain a nurse call relay
circuit for interconnection to a facility's nurse call system.
