A novel, robust, and portable platform for magnetoencephalography using optically-pumped magnetometers
Holly Schofield1,2, Ryan M Hill1,2, Odile Feys3,4
1Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, United Kingdom.
Imaging Neuroscience (Cambridge, Mass.)
|November 6, 2024
Summary
A new optically-pumped magnetometer-magnetoencephalography (OPM-MEG) system offers enhanced portability and dynamic range. This advanced OPM-MEG technology provides comparable brain function measures to established systems, paving the way for next-generation medical imaging.
Area of Science:
- Biophysics
- Neuroimaging
- Medical instrumentation
Background:
- Magnetoencephalography (MEG) traditionally uses cryogenic superconducting sensors, limiting practicality and deployment.
- Optically-pumped magnetometers (OPMs) offer a cryogenic-free alternative, enabling OPM-MEG systems with potential for improved sensitivity, resolution, and subject mobility.
- Current OPM-MEG systems are nascent, with limitations in sensor and system design.
Purpose of the Study:
- To introduce a novel OPM-MEG system with miniaturized electronics, enhanced portability, and improved sensor dynamic range.
- To validate the performance of the new OPM-MEG system against an established OPM-MEG instrument.
- To demonstrate the system's capabilities in free movement scenarios and its compatibility with electroencephalography (EEG).
Main Methods:
- Development of a new OPM-MEG system featuring miniaturized, integrated electronics and enhanced sensor dynamic range.
- Comparative analysis of brain activity measurements (beta-band, gamma-band, evoked responses) against a reference OPM-MEG system.
- Testing in varying background magnetic fields (up to 8 nT) using an electromagnetic phantom.
- Evaluation of data acquisition during free subject movement, including a sit-to-stand paradigm, and simultaneous EEG recording.
- Demonstration of system portability by relocating it between laboratories.
Main Results:
- The new OPM-MEG system achieved comparable source localizations and high temporal correlations (>0.7 individual, >0.9 group) with an established system.
- The system demonstrated an improved dynamic range, functioning effectively in background fields up to 8 nT.
- Successful data acquisition was achieved during free movement tasks and simultaneous EEG recording.
- Portability was confirmed through successful relocation between different laboratory environments.
Conclusions:
- The developed OPM-MEG system represents a significant advancement in the field, addressing limitations of current OPM-MEG technology.
- The system's enhanced portability, dynamic range, and comparable performance make it a viable platform for next-generation functional medical imaging.
- This new OPM-MEG design facilitates more practical and versatile brain function assessment.
