Fail safe detector in a cardiac monitor

摘要

A fail safe detector in a cardiac monitoring system provides an alarm to indicate failure of the system to respond to cardiac waveforms supplied thereto from cardiac waveform sources. A time out circuit will produce the alarm if not periodically reset by pulses produced in response to measurement of cardiac waveforms. Means are provided for sensing whether cardiac waveforms are received from the sources to provide an alternate means of triggering periodic reset signals when no waveforms are received from the sources to prevent false alarms.