Abstract: Apparatus for automatic stimulation of a patient having a sensor adapted to be coupled to the patient for measuring the saturation level of a predetermined gas in the blood of the patient and supplying an electrical signal representative of the measured saturation level, a computer receives the electrical signal and automatically generates a control signal when the measured saturation level falls below a predetermined value. A patient stimulator adapted to be coupled to the patient is coupled to the computer so that when a control signal is supplied by the computer to the patient stimulator a stimulant is automatically supplied to the patient.