The magnetic field intensity generated due to electrical activities in the brain is sensed by SQUID sensors located near the scalp. Multi-channel EEG system is used to measure the voltages on the scalp surface. EMSI is the estimation of the position, orientation, and strength of the active electrical sources within the brain from electrical and magnetic measurements. For accurate source localization, the measurement systems must accurately measure the field distributions with a sufficient number of samples, and the head model must accurately represent the electrical and geometrical properties of the head. Realistic head models are based on high-resolution MRI images, and state-of-the-art segmentation algorithms are used to distinguish tissues from each other. Numerical models are developed to solve the forward problem of EMSI with realistic head models. Source localization is achieved using numerous techniques to solve the inverse problem of EMSI.  Since 1996, METU BERG has focused on every aspect of EMSI.