A Pulse Oximeter and a Controller Designed for Automatic Regulation of Oxygen Concentrators

Adequate, stabilized, and continuous oxygen flow is the need of the hour for subjects with long-term respiratory ailments. This requires a huge skilled medical workforce and makes manual control very difficult, posing a threat to the lives of the subjects if they encounter under or excess oxygenation resulting in hypoxemia or hyperoxemia. This work demonstrates the design and development of a printed circuit board (PCB) prototype of a pulse oximeter that could be integrated with an oxygen concentrator to obtain an automated oxygen flow rate. Thus replacing the need for manual oxygen control and providing a more efficient and economical method for oxygenation. The designed pulse oximeter can accurately measure the blood oxygen levels and heart rate by voltage signals called Photoplethysmo-gram (PPG). The PPG signals, pulsatile due to the arterial blood flow, are derived to measure the heart rate and blood oxygen levels (SpO2). All the measured parameters are then supplied to the PC via UART. A Simulink framework is implemented to show the automated control of the oxygen flow rate through the oxygen concentrator with respect to the SpO2 measured from the pulse oximeter prototype. The design and development of this prototype propose a well-founded method to integrate the pulse oximeter with an oxygen concentrator to regulate the oxygen flow rate according to the need of the subject.