Requirements for Coregistration Accuracy in On-Scalp MEG

• DOI: 10.1007/s10548-018-0656-5
• Publication Date: 2018-06-22T11:54:31Z
• Authors: Rasmus Zetter; Joonas Iivanainen; Matti Stenroos; Lauri Parkkonen
• Keywords: Original Paper; Brain Mapping; Scalp; Optically-pumped magnetometer; Brain; Humans; Magnetoencephalography; Coregistration

Recent advances in magnetic sensing has made on-scalp magnetoencephalography (MEG) possible. In particular, optically-pumped magnetometers (OPMs) have reached sensitivity levels that enable their use MEG. contrast to the SQUID sensors used current MEG systems, OPMs do not require cryogenic cooling and can thus be placed within millimetres from head, enabling construction of sensor arrays conform shape an individual's head. To properly estimate location neural sources brain, one must accurately know position orientation relation With adaptable arrays, this coregistration becomes more challenging than SQUID-based systems rigid arrays. Here, we simulations quantify how needs system. The effects different types localisation errors on forward modelling source estimates obtained by minimum-norm estimation, dipole fitting, beamforming are detailed. We found generally a larger effect these affect accuracy superficial most. obtain similar or higher with RMS should $$< 4\,\hbox {mm}$$ 10^\circ$$ , respectively.