All of the currently operating MEG systems are based on superconducting magnetometers, namely SQUIDs (superconducting quantum interference device). These sensors feature an exquisite sensitivity to pick up the weak neuromagnetic fields the bandwidth of which spans from few kHz down to almost DC (Baillet, 2017). Moreover, all MEG systems operate in a magnetic shielded room to reduce environmental magnetic noise. Recently, the development of new sensors operating at room temperature, namely Optically Pumped Magnetometers (OPMs), have open new opportunities for the widening of MEG applications. These devices, although still suffering from higher noise and limited bandwidth with respect to SQUIDs, offer the possibility to record MEG using a wearable device in a more ecological setting (Boto et al., 2018; Iivanainen et al., 2019).
