Modular Arrays for High Precision Wearable MEG

Optically pumped magnetometers (OPMs) have the potential to deliver magnetoencephalography (MEG) signals with signal-to-noise ratios equivalent to or exceeding those of cryogenic MEG, when sensors are positioned near the scalp. OPM-based MEG can also be employed in mobile settings by incorporating lightweight, wearable sensor arrays.

Currently, personalized, rigid helmets called scannercasts remain the sole viable method for achieving high-precision on-scalp recordings during mobile MEG. However, scannercasts are costly to manufacture, necessitate pre-experiment structural imaging, and cause significant downtime during sensor transfers between scannercasts. This report introduces a solution to these challenges that preserves the benefits of scannercasts.

The authors outline a step-by-step process for building a modular, cap-based design applicable to all head sizes. Through simulations, they compare the leadfield power of their proposed array to an idealized array and a commercially available mobile solution. Additionally, they empirically validate their approach in five participants and provide a comprehensive data preparation and analysis pipeline.

By expanding the accessibility of OPM-based MEG, this design simultaneously enhances participant throughput to levels comparable with other imaging modalities. Most importantly, it eliminates the trade-off between signal quality, mobility, and practicality, effectively showcasing the distinct potential of OPM-based MEG as a tool for studying naturalistic behavior and clinical assessment with high precision.