A low-cost and open-hardware portable 3-electrode polysomnography device

In order to continue sleep research activities during lockdown resulting from the COVID-19 pandemic, experiments that were previously conducted in laboratories shifted to the homes of volunteers. Furthermore, for extensive data collection, it is a requirement to use a large number of portable devices. Hence in order to achieve these objectives, we developed a low-cost Polysomnographer (PSG) and open-source device capable of acquiring electroencephalographic (EEG) signals using the popular ESP32 microcontroller. The device operates based on instrumentation amplifiers. It also has a connectivity microcontroller with Wi-Fi and Bluetooth that can be used to stream EEG signals. Furthermore, this portable single-channel 3-electrode PSG device allowed us to record short naps and scored different sleep stages, such as wakefulness, non rapid eye movement (Non-REM) stage 1 (S1), S2, S3 and S4. We validated the device by comparing the obtained signals to those generated by a research-grade counterpart. The results showed a high level of accurate concordance between both devices, demonstrating the feasibility of using this approach for extensive and low-cost data collection of EEG sleep recordings.