A closed-loop system for control of the fraction of inspired oxygen and the positive end-expiratory pressure in mechanical ventilation.

A system for automatic control of the fraction of inspired oxygen (F(IO2)), and positive end-expiratory pressure (PEEP) for patients on mechanical ventilation is presented. In this system, F(IO2) is controlled by using two interacting mechanisms; a fine control mechanism and a fast stepwise procedure used when patient's oxygen saturation level (S(pO2)) falls abruptly. The PEEP level is controlled automatically and in relation to F(IO2) to prevent hypoxemia. The system has been tested by using bench studies and computer simulations. The results show the potential of the system as an aide in effective oxygenation of patients on mechanical ventilation.