TY - JOUR T1 - Finding optimum source-detector separation in fNIRS system with Monte Carlo simulations TT - یافتن فاصله‌ی بهینه میان منبع نور و آشکارساز در سیستم fNIRS با شبیه سازیی مونت کارلو JF - opsi JO - opsi VL - 23 IS - 0 UR - http://opsi.ir/article-1-1384-en.html Y1 - 2017 SP - 689 EP - 692 KW - fNIRS KW - Monte Carlo KW - Gray matter KW - optical parameters N2 - Functional near infrared spectroscopy (fNIRS) is a noninvasive, safe and portable optical imaging modality which can be used to study neural-related hemodynamic signals of brain by measuring concentration changes of Hb and HbO2. By investigating the optical path length of detected photons in each brain layer, optical density changes due to each layer can be measured for different source-detector separations. In this study, we obtain the sensitivity of fNIRS device to changes of absorption in cortex layer for a five-layer slab brain model and find the optimum source-detector separation. The results show that for absorption changes in cortex layer (at depth of 1 cm), the optimum distance is between 25 mm and 40 mm. M3 ER -