Automatic Control of Fraction of Inspired Oxygen in Neonatal Oxygen Therapy using Fuzzy Logic Control

Abstract

Premature babies of less than 37 weeks gestation might require oxygen therapy as an integral part of treatment and respiratory support. Because of their under-developed lungs, these socalled "preemies" might contract respiratory distress syndrome (RDS). To treat RDS, neonatal oxygen therapy is administered, where controlled oxygen gas is measured as a fraction of inspired oxygen (FiO 2 ). However, exposure to high oxygen content during long treatment could cause oxygen intoxication, which might cause permanent blindness due to retinopathy of prematurity (ROP), whereas insufficient oxygen exposure could cause severe hypoxia. A doctor would use oxygen saturation (SpO 2 ) data and prescribe a dose of FiO 2 to maintain SpO 2 within a suitable range. One objective is to maintain SpO 2 within the acceptable range using FiO 2 that is as low as possible. Adjustment of FiO 2 would normally be done by nurses every 15 to 30 minutes, which might not be safe in many situations. An error in FiO 2 adjustment during a manual procedure could be as large as +/-2.5%. This paper presents a system that can determine an FiO 2 value suitable to the current SpO 2 and that automatically adjusts FiO 2 with an error clearance of +/-0.25%.

High-Flow and High-Pressure Oxygen Mixing for Ventilator System

“…Several methods have been reported. Automated Close Loop Control has been implemented in several works employing several algorithms such as PID, Fuzzy, and neuro-Fuzzy, etc [1][2][3][4].…”