Patent ID: 8842495

Claim:
A method for adaptively detecting movements of objects within a space, the method comprising: emitting pulsed ultrasound waves of a single frequency into the space and detecting reflections of the pulsed ultrasound waves during intervals between successive pulses; determining locations of objects within the space based on the detected ultrasound reflections; and determining real-time movements of the objects based on (i) amplitude differences between amplitudes of echoes in a current wave pulse and an average amplitude over a plurality of wave pulses and (ii) elapsed times since emission of the ultrasound reflections associated with the amplitude differences, wherein a wave pulse comprises emission of a plurality of ultrasound pulses directed at different spatial zones and determining the real-time movements comprises: for each zone, (i) calculating amplitude deviations of pulses reflected in a single spatial zone within a wave pulse by subtracting the average amplitude within the zone from the amplitudes of the echoes within the zone, and (ii) determining real-time movements within the zone based at least in part on the amplitude deviations; and calculating an average of peak-detected amplitude deviations over a plurality of echoes reflected from adjacent spatial zones in the current wave pulse, wherein the real-time movements are determined based at least in part on the average of peak-detected amplitude deviations.