A system for automatic adjustment of the inspired oxygen in mechanically ventilated premature infants

Episodes of hypoxemia are often observed in ventilated preterm infants. Assistance with a transient increase in the fraction of inspired oxygen (FiO₂) is difficult and time consuming for the intensive care personnel. In order to reduce the morbidities associated with hypoxemia and oxygen toxicity, a system for closed loop control of FiO₂ (cFiO₂) was developed to respond to frequent and severe hypoxemic episodes and minimize oxygen exposure. The cFiO₂ system is based on a hybrid algorithm of rule based and differential feedback control. It automatically adjusts FiO₂ depending on the occurrence of the severity, duration, rate of change of the ensuing/resolving hypoxemia, and on the basal FiO₂ required to maintain oxygenation. In a clinical study, cFiO₂ was compared to a dedicated trained nurse managing the FiO₂ in a group of ventilated preterm infants and it was effective in limiting the duration and seventy of hypoxemia. Close loop FiO₂ control could improve the respiratory, ophthalmic and neurological outcome and facilitate the care of premature neonates.