New publication on the design of sensor arrays of optically pumped magnetometers

New publication on the design of sensor arrays of optically pumped magnetometers.

Optically pumped magnetometers (OPMs) are widening the scopes of noninvasive neurophysiological imaging. The possibility of placing these magnetic field sensors on the scalp allows not only to acquire signals from people in movement but also to reduce the distance between the sensors and the brain, with a consequent gain in the signal-to-noise ratio. These advantages make the technique particularly attractive to characterize sources of brain activity in demanding populations, such as children and patients with epilepsy. However, the technology is currently in an early stage, presenting new design challenges around the optimal sensor arrangement and their complementarity with other techniques as electroencephalography (EEG). We present an optimal array design strategy focused on minimizing the brain source localization error. We study the complementarity between EEG and OPM-based MEG, and design optimal whole head systems based on OPMs only and a combination of OPMs and EEG electrodes for characterizing deep and superficial sources alike.

Beltrachini L, von Ellenrieder N, Eichardt R, Haueisen J:

Optimal design of on-scalp electromagnetic sensor arrays for brain source localization.
Human Brain Mapping, 42:4869-4879, 202


Whole-head OPM and hybrid OPM/EEG designs. Upper row: Spatial distribution of the equivalent uncertainty radius for the OPMs only (left), hybrid OPM/EEG (middle), and full OPM ABC 160 (right) arrays, the first two employing 100 on-scalp magnetometers. Lower row: Optimal hybrid OPM/EEG array sensor positions (left) and layout (right). EEG electrodes and OPMs are represented with blue and red dots, respectively.