A system is disclosed for using passive infrared technology to analyze the thermal energy in a given space, to determine whether a person is present, and if so, whether he or she is experiencing an emergency or a normal physical state. A detector mounted on the wall or ceiling collects the thermal data....http://www.google.fr/patents/US6587049?utm_source=gb-gplus-shareBrevet US6587049 - Occupant status monitor
