초록 ▼

A system for monitoring a person in a secured zone is disclosed. One or more transmitters transmit a first signal into the zone. The person wears a tag that receives the first signal. The tag transmits a second signal that is responsive to the first signal. A receiver receives the second signal and

A system for monitoring a person in a secured zone is disclosed. One or more transmitters transmit a first signal into the zone. The person wears a tag that receives the first signal. The tag transmits a second signal that is responsive to the first signal. A receiver receives the second signal and provides a third signal responsive to the first signal. A controller is connected to the receiver and includes a discrimination circuit that determines if the third signal is responsive to the first signal. The controller provides an alarm signal if responsiveness is found. The responsiveness may be a constant phase relationship, and data may be transmitted by the tag at a frequency derived from the first frequency. A three loop antenna, with each loop disposed in a unique plane is described. Each unique plane is substantially perpendicular to the other unique planes, in another embodiment. The tag includes a band removal circuit that senses the skin resistivity of the patient in another embodiment. The tag may also include a chest band that senses the respiration of the patient. The tag includes a power circuit that reduces power consumption in the event the second signal is not being transmitted.

대표청구항 ▼

[ The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:] [1.] A system for monitoring a person in a secured zone comprising:at least one transmitter mounted to transmit a first signal into the zone;at least one tag to be worn on the person, w

[ The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:] [1.] A system for monitoring a person in a secured zone comprising:at least one transmitter mounted to transmit a first signal into the zone;at least one tag to be worn on the person, wherein the tag includes a receiver that receives the first signal, and a tag transmitter that transmits a second signal, wherein the second signal is responsive to, and at a fixed phase with respect to the first signal;a receiver disposed to receive the second signal and provide a third signal responsive to the first signal; anda controller connected to the receiver, wherein the controller includes a discrimination circuit that determines if the third signal is responsive to the first signal and provides an alarm signal if responsiveness is found.