The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 07, 1995
Filed:
Nov. 22, 1991
John N Dukes, Los Altos Hills, CA (US);
J Evan Deardorff, Bedford, MA (US);
James L Miller, Westford, MA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A system and method for locating patients in a hospital using M different frequency patient transmitters and N fixed location antennas within the hospital for receiving the patient signals. The received signals for each antenna are separated from the signals received by the other N-1 antennas, and the signal strength of each signal received by each antenna is measured. The received signal strength of each antenna is processed to determine which of the antennas received the strongest signals from each of the patient transmitters. Alternatively, the approximate location within the hospital of each operating patient transmitter is determined since the antennas are in fixed locations and the layout out of the hospital is known. In other embodiments, each of the antennas have a different modulation pattern to enable identification of which of the antennas receives which signals from the patient transmitters. The M signals received by the N antennas are separated by the frequencies of the patient transmitters with each of the separated signals being a composite signal having a single frequency and modulation components from each of the N antennas. Then the signal strength of each of the separated signals is measured, and the relative contribution to the measured signal strength from each of the N antennas is determined. Finally, the relative contribution information for each patient transmitter frequency from each antenna is processed to determine which of the antennas received the strongest signals from each of the patient transmitters to locate the patient relative to particular antennas.