Abstract: A demand electroventilator for monitoring and stimulating the respiration of a patient operates in a manner analogous to the operation of a demand cardiac pacemaker for monitoring and stimultating the heart when needed. The demand electroventilator has a pair of stimulating electrodes for placement on the chest of the patient and a pair of monitoring electrodes for placement on the patient's chest. The demand electroventilator also has a monitoring module connected to the monitoring electrodes, a stimulating module connected to the stimulating electrodes and a control module connected to the stimulating and monitoring modules. The monitoring module generates a signal related to the respiration of the patient which the control module interprets and causes the stimulating module to apply a train of electrical pulses having durations of 0.1 msec or less to the patient to stimulate respiration when needed.