Magnetoencephalography With Optically Pumped 4He Magnetometers at Ambient Temperature
In this paper, we present the first proof of concept confirming the possibility to record magnetoencephalographic (MEG) signals with optically pumped magnetometers (OPMs) based on the parametric resonance of 4 He atoms. The main advantage of this kind of OPM is the possibility to provide a tri-axis...
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Published in | IEEE transactions on medical imaging Vol. 38; no. 1; pp. 90 - 98 |
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Main Authors | , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
New York
IEEE
01.01.2019
The Institute of Electrical and Electronics Engineers, Inc. (IEEE) |
Subjects | |
Online Access | Get full text |
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Summary: | In this paper, we present the first proof of concept confirming the possibility to record magnetoencephalographic (MEG) signals with optically pumped magnetometers (OPMs) based on the parametric resonance of 4 He atoms. The main advantage of this kind of OPM is the possibility to provide a tri-axis vector measurement of the magnetic field at room-temperature (the 4 He vapor is neither cooled nor heated). The sensor achieves a sensitivity of 210 fT/<inline-formula> <tex-math notation="LaTeX">\surd </tex-math></inline-formula>Hz in the bandwidth [2-300 Hz]. MEG simulation studies with a brain phantom were cross-validated with real MEG measurements on a healthy subject. For both studies, MEG signal was recorded consecutively with OPMs and superconducting quantum interference devices (SQUIDs) used as reference sensors. For healthy subject MEG recordings, three MEG proofs of concept were carried out: auditory evoked fields, visual evoked fields, and spontaneous activity. M100 peaks have been detected on evoked responses recorded by both OPMs and SQUIDs with no significant difference in latency. Concerning spontaneous activity, an attenuation of the signal power between 8-12 Hz (alpha band) related to eyes opening has been observed with OPM similarly to SQUID. All these results confirm that the room temperature vector 4 He OPMs can record MEG signals and provide reliable information on brain activity. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0278-0062 1558-254X |
DOI: | 10.1109/TMI.2018.2856367 |