A low-cost PPG-based device for monitoring sleep apnea syndrome

At present, the diagnosis of sleep apnea syndrome requires patients to wear the PSG sensors all night long in hospital, which is so inconvenient and expensive that millions of sleep apnea patients can't receive diagnosis and treatment. We propose a low-cost sleep monitoring device to be used at the comfort of home based on photoplethysmography (PPG) with only single photoelectric sensor, which can simultaneously obtain oxygen saturation, pulse rate, respiration rate, heart rate variability analysis and body motions to realize the basic monitoring of circulatory, respiratory, nervous system and motor system. The device consists of two light emitting diodes, a probe-drive module, an optical - frequency converter, a microcontroller MSP430F5438A, a wireless transceiver module and a Micro SD card module. The evaluations by commercial BIOPAC systems demonstrate the feasibility of our proposed device.