We have designed a smart, automated Pulse Oximeter which utilizes Smartphone embedded camera sensors integrated with photoplethysmography (PPG) biosensors that accurately measures heart rate (HR) and blood oxygen saturation (SpO2 level) of patients remotely. As our patient volunteer places their index finger over the rear camera sensor system (while breathing a mixture of gases with reduced O2 compared with room air), the PPG sensor measures the distension of arteries and arterioles in the subcutaneous tissue, due to blood flow with each cardiac cycle. As blood flows through the vessels, the pulse pressure is detected by illuminating the skin with the light from two inorganic light-emitting diodes-OLED (embedded in Camera sensors). The amount of light transmitted, absorbed, or reflected to a photodiode is measured, processed by our AI. A signal-processing app containing an algorithm then detects and interprets the PPG signal to determine SpO2 and HR values. Finally, an additional AI framework within the app then evaluates and displays individual biosensor readings on the Smartphone screen.
Smartphone with embedded Camera sensors integrated with photoplethysmography biosensor
(a) OLED energy structure of sensor.
(b) Current density of red (red solid line) and green (green dashed line) OLEDs and irradiance of red (red squares)
and green (green triangles) OLEDs as a function of applied voltage, the signal obtained is sufficient for resolving
the PPG waveform and provide light absorbance ratio information for arterial blood oxygenation calculation.