Abstract: A motion and proximity sensitive system for monitoring spatial relationship between mobile objects comprising two way communication between a Child Unit, affixed to the child, and a Parent Unit, carried by the parent or guardian, is disclosed. When the Child Unit senses motion and determines that it is beyond a set near field proximity to the Parent Unit, the Child Unit communicates alerts to the Parent Unit allowing the parent to trigger an alarm on the Child Unit. A second alarm function selected by the mode switch sounds an alarm automatically in response to motion beyond the set near field proximity according to an adaptive alarm sequence.

Abstract: A motion sensitive theft detector system for portable articles featuring two way communication between the theft detector unit installed in or affixed to the portable article and the control unit carried by the owner. The theft detector communicates alerts to the control unit allowing the user to screen for false alarms and to trigger an alarm at the portable article when warranted. A timing based alert suppression algorithm allows the system to be carried in its armed state without creating frequently repeated alerts at the control unit. A second alarm function selected by the mode switch sounds an alarm automatically in response to motion according to an adaptive alarm sequence. The adaptive alarm varies the alarm in response to frequency and duration of motion so that isolated movement triggers a warning but persistent motion triggers a full scale alarm.

Abstract: A motion sensitive theft detector system for portable articles featuring two way communication between the theft detector unit installed in or affixed to the portable article and the control unit carried by the owner. The theft detector communicates alerts to the control unit allowing the user to screen for false alarms and to trigger an alarm at the portable article when warranted. A second alarm function selected by the mode switch sounds an alarm automatically in response to motion according to an adaptive alarm sequence. The adaptive alarm varies the alarm in response to frequency and duration of motion so that isolated movement triggers a warning but persistent motion triggers a full scale alarm.