Design of Multichannel Portable for Functional Near-Infrared Spectroscopy / Electroencephalography Hybrid System

Dementia is one of many brain diseases that keep growing each year. Repetitive brain assessment is needed to help doctors or/and physicians diagnose dementia. Several studies showed fNIRS and EEG gave biomarkers on the early stages of dementia. Recording both signals simultaneously give more pattern to help assess and diagnose. We developed a hybrid fNIRS-EEG portable device focused on the prefrontal cortex region with 64 fNIRS channels and 4 EEG channels. A dual-core ESP32 wrover IE with built-in WiFi is paired with ADC ADS1299 to collect both optical signals and neuro-signal simultaneously. The system is powered by 3.7 volts lithium polymer and communicates with integrated WiFi. The system has 30 Hz of fNIRS frequency sampling and 1000 Hz of EEG frequency sampling. The phantom experiment was conducted, the system has the capability to captured both optical and neuro-data simultaneously. There was no electrical difference since phantom didn’t have any electrical produced by brain activity. Future study in vivo is needed to validate the proposed system.