Patent ID: 6891469

Claim:
A system for locating an object comprising: at least one transmitter for transmitting of an electromagnetic interrogation signal within each of a plurality of defined interrogation zones; at least one tag adapted for attachment to an object, the tag being responsive to said electromagnetic interrogation signal and comprising a signal receiving structure adapted to capture at least a portion of the energy of said interrogation signal, and a response generator for generating a responsive signal to announce the presence of the object within an interrogation zone; a plurality of receivers, each associated with one of the interrogation zones for detecting said responsive signal from said tag, if present, within its interrogation zone; a controller for periodically activating the at least one transmitter to conduct a census of tagged objects within the interrogation zones; a data storage device for recording the results of the census as a location inventory that identifies tagged objects as present in one of said interrogation zones; and a search processor that responds to a user initiated search for specific tagged object by first checking the data storage device for a last known location of the object in the location inventory and activating at least one of the transmitters to confirm and update the location of the tagged object based on a responsive signal from a receiver associated with the zone in which the object is located.