Abstract: Functional near-infrared spectroscopy (fNIR) is a neuroimaging modality that enables continuous, noninvasive, and portable monitoring of changes in blood oxygenation and blood volume related to human brain function. FNIR can be implemented in the form of a wearable and minimally intrusive device, it has the capacity to monitor brain activity under real life conditions and in everyday environments. The principle advantage of optical technique is its noninvasive nature. It provides information about functional oxygenation and volume changes that are directly comparable to fMRI, but the apparatus is much less costly and confining. Optical technique is performed in pediatric populations much more easily than fMRI and it can be transported to the bedside for clinical evaluations. Because NIRS signals are detected several centimeters from the cortex, however, the spatial resolution of the technique is low (~1-2 cm). Spatial coverage can be increased by using arrays of emitters and detectors. Paper proposed a system for measurement of haemodynamic response from skull.