3902478 is referenced by 38 patents and cites 7 patents.

A disaster alarm consisting of the combination of a small cardiac monitor, switching and signal coder controlling a transmitter which is actuated when high or low levels of a function such as heart rate are exceeded. The signal is picked up by a receiver which in turn is connected to an alarm system which continues to operate due to self-latching circuits until re-set.Two embodiments are shown one in which alarm signals only are transmitted in a pulsed or continuous fashion rather than the cardiac signal; and the other which operates in a fail-safe mode which not only transmits an alarm signal when necessary, but periodically transmits an operating signal, the absence of which automatically causes an alarm, thus ensuring that the system cannot fail to sense an alarm signal without warning.

Disaster alarm
Application Number
Publication Number
Application Date
November 9, 1973
Publication Date
September 2, 1975
Kirk Bryan William
Raber Monte B
Cuddy Thomas Edward
Konopasek Francis
Ade Stanley G
A61B 05/04
A61B 05/452
A61B 05/464
A61B 05/00
View Original Source