Michael A Moura

US Patent:

45491690, Oct 22, 1985

Filed:

Dec 6, 1982

Appl. No.:

6/447302

Inventors:

Michael Moura - Fairhaven MA
Lenine Gonsalves - North Dartmouth MA
Gilbert Fain - Seekonk MA

Assignee:

Kelmar Marine Inc. - Fairhaven MA

International Classification:

G08B 108
G08B 2300

US Classification:

340539

Abstract:

A system for monitoring the security of one or more persons in a waterside environment and for providing a failure proof indication of when such person falls into the water. The system includes a portable transmitter worn about the body of the person whose security is being monitored in a location which insures its submergence when the person falls into the water. Transmissions from the portable unit, which may be either time shared or the result of an interrogation from a base station, are monitored at a base station. Continuous presence of the transmitted signal from each portable unit inhibits an alarm condition at the base station, but if the transmitted signal is not received, or is not received for a predetermined time period, the alarm condition is activated and the portable unit not transmitting is identified. The lack of a transmitted signal indicates a "man overboard" condition resulting from the transmitter being immersed in the water and transmissions thus blocked. A low battery condition is also transmitted by the portable unit and when received by the base station provides a corresponding identification of the affected portable unit allowing recharging before the battery completely fails.