Design of Portable Functional Near-Infrared Spectroscopy-based Brain Monitoring System

In this paper, we introduce a functional nearinfrared spectroscopy-based brain-monitoring system consisting of a data acquisition board, photodiode units, and dual-wavelength near-infrared LED units. The ADS8688A analog frontend-integrated circuit-based data acquisition board provides reliable high-resolution bio-optical measurements for portable brain monitoring. Moreover, its isolated linear regulator-based low-noise power supply circuit allows maintaining low-noise measurement quality by blocking inter-circuit crosstalk. From the system evaluation via a mental arithmetic experiment, a clear decreasing trend of deoxyhemoglobin was found for the high-brain workload state during a cumulative subtraction task.