Abstract: In a system of communicating between a master communication device and a plurality of slave communication devices, the master determines if any of the plurality of slave devices exist within a defined geographic area and, if so sends a bit-by-bit command for the slaves to identify themselves via a unique binary identification number. To avoid collision when the slaves respond, the slaves respond to the master's command within a predetermined period of a time window providing the ID bit by bit. Responses are acknowledged by the master such that only one slave is able to respond with its compute full ID after a bit-by-bit command from the master.

Abstract: The tag includes: a tag for monitoring the security of a patient, the tag comprising,a housing having a wall, the wall having an inner surface and an outer surface,an electronic circuit located in the housing, the electronic circuit including an alarm circuit, including a capacitance measuring circuit, the capacitance measuring circuit having first and second electrodes, the first and second electrodes located adjacent the inner surface and in spaced relation from one another to form a capacitor, the alarm circuit having means for generating an alarm signal upon the capacitance measuring circuit detecting a level of capacitance corresponding to an alarm condition, whereby the outer surface of the housing is placed in contact with the patient, with the first and second electrodes capacitively coupled to the patient, but without the first and second electrodes in physical contact with the patient, the capacitance measuring circuit detects an alarm condition when the patient is no longer in contact with the oute

Abstract: The present invention provides an asset security tag comprising a housing, a transmitter transmitting radio frequency waves, the transmitter located in the housing, an electronic circuit located in the housing and coupled to the transmitter, the electronic circuit transmitting an alarm signal when the asset has been relocated to an unauthorized area, and a tag removal alarm circuit for detecting an unauthorized removal of the asset security tag from the asset and for enabling the transmitter to transmit an alarm signal upon detecting the unauthorized removal, whereby the asset security tag may be secured to an asset, and either unauthorized relocation of the asset or unauthorized removal of the tag from the asset will cause an alarm signal to be transmitted.