Simulation Study of Different OPM-MEG Measurement Components
Magnetoencephalography (MEG) is a neuroimaging technique that measures the magnetic fields of the brain outside of the head. In the past, the most suitable magnetometer for MEG was the superconducting quantum interference device (SQUID), but in recent years, a new type has also been used, the optica...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-04-01
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| Series: | Sensors |
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| Online Access: | https://www.mdpi.com/1424-8220/22/9/3184 |
| _version_ | 1797502909192077312 |
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| author | Urban Marhl Tilmann Sander Vojko Jazbinšek |
| author_facet | Urban Marhl Tilmann Sander Vojko Jazbinšek |
| author_sort | Urban Marhl |
| collection | DOAJ |
| description | Magnetoencephalography (MEG) is a neuroimaging technique that measures the magnetic fields of the brain outside of the head. In the past, the most suitable magnetometer for MEG was the superconducting quantum interference device (SQUID), but in recent years, a new type has also been used, the optically pumped magnetometer (OPM). OPMs can be configured to measure multiple directions of magnetic field simultaneously. This work explored whether combining multiple directions of the magnetic field lowers the source localization error of brain sources under various conditions of noise. We simulated dipolar-like sources for multiple configurations of both SQUID- and OPM-MEG systems. To test the performance of a given layout, we calculated the average signal-to-noise ratio and the root mean square of the simulated magnetic field; furthermore, we evaluated the performance of the dipole fit. The results showed that the field direction normal to the scalp yields a higher signal-to-noise ratio and that ambient noise has a much lower impact on its localization error; therefore, this is the optimal choice for source localization when only one direction of magnetic field can be measured. For a low number of OPMs, combining multiple field directions greatly improves the source localization results. Lastly, we showed that MEG sensors that can be placed closer to the brain are more suitable for localizing deeper sources. |
| first_indexed | 2024-03-10T03:42:53Z |
| format | Article |
| id | doaj.art-519dbaae1d0f4e4d98e085e7d9e6265d |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-03-10T03:42:53Z |
| publishDate | 2022-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-519dbaae1d0f4e4d98e085e7d9e6265d2023-11-23T09:14:39ZengMDPI AGSensors1424-82202022-04-01229318410.3390/s22093184Simulation Study of Different OPM-MEG Measurement ComponentsUrban Marhl0Tilmann Sander1Vojko Jazbinšek2Faculty of Natural Sciences and Mathematics, University of Maribor, Koroška cesta 160, 2000 Maribor, SloveniaPhysikalisch-Technische Bundesanstalt, Abbestraße 2, 10587 Berlin, GermanyDepartment of Physics, Institute of Mathematics, Physics and Mechanics, Jadranska ulica 19, 1000 Ljubljana, SloveniaMagnetoencephalography (MEG) is a neuroimaging technique that measures the magnetic fields of the brain outside of the head. In the past, the most suitable magnetometer for MEG was the superconducting quantum interference device (SQUID), but in recent years, a new type has also been used, the optically pumped magnetometer (OPM). OPMs can be configured to measure multiple directions of magnetic field simultaneously. This work explored whether combining multiple directions of the magnetic field lowers the source localization error of brain sources under various conditions of noise. We simulated dipolar-like sources for multiple configurations of both SQUID- and OPM-MEG systems. To test the performance of a given layout, we calculated the average signal-to-noise ratio and the root mean square of the simulated magnetic field; furthermore, we evaluated the performance of the dipole fit. The results showed that the field direction normal to the scalp yields a higher signal-to-noise ratio and that ambient noise has a much lower impact on its localization error; therefore, this is the optimal choice for source localization when only one direction of magnetic field can be measured. For a low number of OPMs, combining multiple field directions greatly improves the source localization results. Lastly, we showed that MEG sensors that can be placed closer to the brain are more suitable for localizing deeper sources.https://www.mdpi.com/1424-8220/22/9/3184magnetoencephalographyoptically pumped magnetometerssuperconducting quantum interference devicevolume conductorboundary element methodequivalent current dipole |
| spellingShingle | Urban Marhl Tilmann Sander Vojko Jazbinšek Simulation Study of Different OPM-MEG Measurement Components Sensors magnetoencephalography optically pumped magnetometers superconducting quantum interference device volume conductor boundary element method equivalent current dipole |
| title | Simulation Study of Different OPM-MEG Measurement Components |
| title_full | Simulation Study of Different OPM-MEG Measurement Components |
| title_fullStr | Simulation Study of Different OPM-MEG Measurement Components |
| title_full_unstemmed | Simulation Study of Different OPM-MEG Measurement Components |
| title_short | Simulation Study of Different OPM-MEG Measurement Components |
| title_sort | simulation study of different opm meg measurement components |
| topic | magnetoencephalography optically pumped magnetometers superconducting quantum interference device volume conductor boundary element method equivalent current dipole |
| url | https://www.mdpi.com/1424-8220/22/9/3184 |
| work_keys_str_mv | AT urbanmarhl simulationstudyofdifferentopmmegmeasurementcomponents AT tilmannsander simulationstudyofdifferentopmmegmeasurementcomponents AT vojkojazbinsek simulationstudyofdifferentopmmegmeasurementcomponents |