Plug-and-Play Oxygen Auto-flow Regulator for Low Flow Oxygen Therapy: A Prototype Development

COVID-19 has exacerbated the need for viewing medical oxygen as a precious drug and thus work towards its conservation which ensures optimal supply to the patient. This paper describes the practical implementation of a ‘plug-and-play’ automatic oxygen flow-rate controller for clinical use suitable for low-flow oxygen therapy. A microcontroller based electronic controller drives the extent of opening/closing of a proportional valve in line with the clinical oxygen supply line. The controller output is based on the pulse oximeter readings and the mode of operation chosen by the caregiver. It controls the oxygen flow-rate with an accuracy of 0.1 liters per minute (LPM) around the desired flow-rate. In the automatic mode, The flow-regulator is programmed through the control algorithm to enhance oxygen conservation. To ensure patient comfort, sudden changes in flow-rate are avoided and the rate of change of flow-rate is capped at 1 LPM per minute.