Executive Summary : | The research project aims to develop a hybrid wearable brain-computer-interface (BCI) system by integrating Electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) for recording neurophysiological signals. EEG is popular due to its simplicity and non-invasive recording, but its poor spatial resolution limits its applications. fNIRS, on the other hand, has been explored for its relative transparency and high spectral resolution, making it possible to record brain activity with better spatial resolution than EEG. Some startups and companies, such as Artinis & Obelab, have commercialized BCI products based on hybrid technology. However, most wearable hybrid BCI systems use continuous wave signals for excitation, which only provides limited information about the brain. Researchers have shown that it is possible to extract additional information about brain activity by measuring the phase of photon propagation, which requires modulation at a frequency up to 100 MHz. The proposed BCI system combines EEG and fNIRS technologies, making it wearable and portable. Both technologies are complementary in their functionalities, providing excellent temporal resolution of neural signals and better spatial resolution. The FM-fNIRS system integrates the frequency modulation-based fNIRS system, providing information about phase change due to brain activity. The system is designed to be low-voltage and low-power, using commercial-off-the-shelf components. |