Monitoring and signalling system including apparatus for processing

Abstract

Apparatus for a monitoring and signalling system such as a home health care system includes a plurality of sensors operative to monitor the occurrence of activities performed by an individual in his or her residence and to produce binary coded signals indicative of the occurrence of the monitored activities. Each signal comprises six successive identical messages within a one-second interval, with each message including a binary word identifying the monitoring and signalling system, the particular sensor originating the signal, and the nature of the monitored activity. Each message further includes a preamble and a pair of interwords on opposite sides of the binary word. The apparatus in accordance with the invention includes a microprocessor which operates to repetitively sample each signal originating with a sensor to determine the binary content of the signal and to extract a binary word from a message while rejecting preambles, interwords and 'glitches' (noise) present in the signal. The extracted binary word is then tested as to its satisfaction of predetermined requirements. If the binary word of one message satisfies these requirements, an interval of time is established during which a binary word of the next message is required to be extracted from the next message and also satisfy the predetermined requirements before permitting further processing of the second binary word.