A Configurable Wireless Optical Brain Monitor Based on Internet-of-Things Services

There is an increasing interest in understanding the brain in its natural state. This recently led to the wide adoption of portable brain monitors including functional Near- Infrared Spectroscopy (fNIRS) which uses near-infrared (NIR) light to capture the brain's hemodynamic responses, also known as cerebral oxygenation. Nowadays, fNIRS is used in clinical settings of various medical fields including neurology, neuroscience, clinical psychology, and psychiatry. Compared to its counterpart, functional Magnetic Resonance Imaging (fMRI), fNIRS is portable and provides higher temporal resolution for scanning the hemodynamic response of the cortical layer of the brain. fNIRS has the potential to work as a smart wearable device to monitor a brain in an unconstrained setting. However, wearable implementation is challenging as the fNIRS system demands a complex circuit to drive NIR light sources and detect low intensity reflected light from the scalp. Also, the algorithm for the real-time controlling, configuration, data acquisition, and signal processing are complex for a wearable smart fNIRS. Currently available fNIRS systems are not intelligent, completely wearable or designed as a smart body sensor network (BSN) node. In this paper, we present our recent design of a configurable fNIRS system that acts as a BSN node controlled by a remote Graphical User Interface (GUI). The presented fNIRS system is based on an embedded board where we deployed a internet-of-things (IoT) based service-oriented architecture providing the functionality of montage configuration, fNIRS signal testing, calibration, channel selection, data collection and wireless data transmission to the GUI. This development can improve the flexibility of the fNIRS system regarding its use in natural environments where the brain functions of moving human subjects are monitored. We have experimentally evaluated working of the hardware, software, GUI and wireless data transmission, and capability of detecting hemodynamic responses.