Method and system for locating subjects within a tracking environment

Abstract

A method and system utilize both the radio frequency (RF) and infrared (IR) parts of the electromagnetic spectrum to locate subjects (i.e. objects and persons) within a tracking environment. The system includes a battery-operated, microprocessor-based badge for each subject to be located. Each badge automatically transmits digitized infrared light signals to provide a fine determination of its subject's location. Each badge transmits RF and IR signals upon actuation of a page request/alert push button switch on its badge. An RF signal is also generated at a timed interval as a 'heartbeat' pulse. This pulse informs the host computer that the badge is both present and fully functional. The IR and RF signals are modulated or encoded with badge identification data, page request or alert notification data, and battery condition data. The system also includes ceiling or wall sensors in the form of IR and RF receivers. Each RF sensor converts the encoded RF signals into a first set of electrical signals. Each IR sensor converts encoded IR signals into a second set of electrical signals. In turn, the first and second sets of electrical signals are transmitted to a micro-processor-based collector of the system. The locating method and system are particularly useful in hospitals to determine and monitor the location of patients and/or critical equipment.