Pulse oximetry is a non-invasive method for monitoring if a patient's oxygenation is unstable and Arduino user die_Diode sent us his version of a DIY Pulsoximter developed with two Arduino:
"Arduino Mega for the oximetry electronics and Arduino Uno for the graph.
The electronics includes LED Driver, Photo current transformation, patient-dependent calibration LED, Active filters, Nellcor SpO2 sensor. Adafruit OLED displays Vitalparamter. Noritake VFD display GUU-100 shows the PPG. The boards are connected to the electronics with a Protoshield."