disclosed herein is a bio - alarm security system particularly adapted for use in banks for activating an alarm during a robbery without the need for affirmative voluntary action by an employee which might be prevented by the person committing the crime . the system includes one or more pulse rate detectors which are worn by employees , an amplifier and transmitter for transmitting the heart rate or rates to a receiving station where the heart rate signals are monitored . if abnormally fast heartbeat rates are detected such as would be caused by the stress of a robbery , an alarm is activated .