Method and apparatus for tracking a patient
First Claim
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; and
a 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.
1 Assignment
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Accused Products
Abstract
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.
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Citations
24 Claims
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1. A system for monitoring a person in a secured zone comprising:
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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; and a 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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A system for monitoring a person in a secured zone comprising:
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at least one transmitter means for transmitting a first signal into the zone; at least one tag to be worn on the person, wherein the tag includes a receiver means for receiving the first signal, and a tag transmitter means for transmitting a second signal into the zone, wherein the second signal is responsive to, and at a fixed phase with respect to, the first signal; a receiver means for receiving the second signal and providing a third signal responsive to the first signal; and a controller connected to the receiver means, wherein the controller includes a discrimination means for determining if the third signal is responsive to the first signal and for providing an alarm signal if responsiveness is found. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17)
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18. A method for monitoring a person wearing a tag in a secured zone comprising the steps of:
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transmitting a first signal into the zone; receiving the first signal at the tag; transmitting a second signal from the tag, wherein the second signal is responsive to, and at a fixed phase with respect to, the first signal; receiving the second signal and providing a third signal responsive to the first signal; and determining if the third signal is responsive to the first signal and providing an alarm signal if responsiveness is found. - View Dependent Claims (19, 20, 21, 22, 23, 24)
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Specification