Development of an oxygen mask integrated arterial oxygen saturation (SaO2) monitoring system for pilot protection in advanced fighter aircraft

A smart O₂ mask that accurately tracks the vital signs of its wearer is presented. Because the sensors are integrated in the nose bridge of the standard 12-P oxygen mask, and the sensor leads can be incorporated into the microphone leads and jack coming from the mask, the system is completely blind to the pilot. The nasal sensor consists of two LEDs and a photocell mounted in adhesive tape, allowing direct, nonslip mounting on skin; it does not require arterialized blood for operation. Instead, it used two wavelengths of light at 660 and 940 nm and an integrated microprocessor-based computer program to measure arteriolar-blood pulsations. The pulsatile flow creates a transient change in the light path, modifying the amount of light received by the photocell. Thus, the oximeter combines measurement of the different light transmission characteristics of oxyhemoglobin and deoxyhemoglobin with the arterial-pulse detection principle used by plethysmographs to compute arterial oxygen saturation. The device compares accurately with blood cuvette and other methods of measuring SaO₂