To the top

Page Manager: Webmaster
Last update: 9/11/2012 3:13 PM

Tell a friend about this page
Print version

Localizing on-scalp MEG s… - University of Gothenburg, Sweden Till startsida
To content Read more about how we use cookies on

Localizing on-scalp MEG sensors using an array of magnetic dipole coils

Journal article
Authors C. Pfeiffer
L. M. Andersen
D. Lundqvist
M. Hamalainen
Justin F. Schneiderman
R. Oostenveld
Published in Plos One
Volume 13
Issue 5
ISSN 1932-6203
Publication year 2018
Published at Institute of Neuroscience and Physiology
Language en
Keywords atomic magnetometer, new-generation, magnetoencephalography, brain
Subject categories Biomedical Laboratory Science/Technology, Neurosciences


Accurate estimation of the neural activity underlying magnetoencephalography (MEG) signals requires co-registration i.e., determination of the position and orientation of the sensors with respect to the head. In modern MEG systems, an array of hundreds of low- T c SQUID sensors is used to localize a set of small, magnetic dipole-like (head-position indicator, HPI) coils that are attached to the subject's head. With accurate prior knowledge of the positions and orientations of the sensors with respect to one another, the HPI coils can be localized with high precision, and thereby the positions of the sensors in relation to the head. With advances in magnetic field sensing technologies, e.g., high-T-c SQUIDs and optically pumped magnetometers (OPM), that require less extreme operating temperatures than low- T-c SQUID sensors, on-scalp MEG is on the horizon. To utilize the full potential of on-scalp MEG, flexible sensor arrays are preferable. Conventional co-registration is impractical for such systems as the relative positions and orientations of the sensors to each other are subject-specific and hence not known a priori. Herein, we present a method for co-registration of on-scalp MEG sensors. We propose to invert the conventional co-registration approach and localize the sensors relative to an array of HPI coils on the subject's head. We show that given accurate prior knowledge of the positions of the HPI coils with respect to one another, the sensors can be localized with high precision. We simulated our method with realistic parameters and layouts for sensor and coil arrays. Results indicate co-registration is possible with sub-millimeter accuracy, but the performance strongly depends upon a number of factors. Accurate calibration of the coils and precise determination of the positions and orientations of the coils with respect to one another are crucial. Finally, we propose methods to tackle practical challenges to further improve the method.

Page Manager: Webmaster|Last update: 9/11/2012

The University of Gothenburg uses cookies to provide you with the best possible user experience. By continuing on this website, you approve of our use of cookies.  What are cookies?