The paper investigates an adaptive feedback control system for incubator oxygen treatments which can determine the optimum oxygen concentration of the mixed gas (FiO2) that should be forced into the incubator so as to maintain the arterial oxygen partial pressure (PaO2) within normal limits for a newborn infant with respiratory problems. One of the features of the present system is that the state of respiratory distress can be estimated from the data sequence of the inputFiO2and outputtcPO2(transcutaneous oxygen pressure), and, correspondingly, the control inputFiO2can be adjusted in an adaptive manner. Validity of the control scheme is examined in simulations using the mathematical model of neonatal respiratory system and in animal experiments where we simulate hypoxia dogs by keeping them in various low-ventilation conditions.