Development of a dual wavelength 32-channel functional near-infrared spectroscopy based neuroimaging system

Advancements in the field of neuroscience is essential for our society as the fatality rate due to brain degenerative diseases is quite high. Various modalities have been in use for a long time for brain monitoring. The inexpensive, portable, and easy to operate nature of functional near-infrared spectroscopy (fNIRS) has demonstrated that it can be used to measure the concentration changes in the blood chromophores during an activity. In this paper, we have demonstrated our developed fNIRS system that is able to determine the concentration changes in oxy-hemoglobin and deoxy-hemoglobin and display them in real-time as well as record the data for future use. Our system is composed of a microcontroller, an optical probe, tri-wavelength light emitting diodes, photodiodes, a serial communication module, and a battery. To test the functionality of the system, phantom brain model was used. During the experiment, the fNIRS system showed the acquired intensity values as well as corresponding hemoglobin changes for 32 channels. The results, obtained during the testing of our system, show that the acquired signal intensity values decrease with increase in the separation between the near-infrared light transmitter and emitter.