https://www.instructables.com/OxiFine-Smart-Pulse-Oximeter/
OxiFine - Smart Pulse Oximeter : 7 Steps (with Pictures) - Instructables
OxiFine - Smart Pulse Oximeter: OxiFine is an open-source Pulse Oximeter device made using minimal components and the simplest design aspects. It is a modular...
smart pulsewith picturesoximeterstepsinstructables