Séminaire MEG - OPM : les capteurs MEG du futur

This seminar will give us the opportunity to show the performances of new on-scalp MEG sensors working at room temperature and also to discuss the future of the CERMEP MEG lab.

Abstract:  Magneto-Encephalo-Graphy (MEG) provides a direct measure of neuronal activity at a millisecond time scale. From these signals, one can non-invasively derive the dynamics of physiological or pathological brain activity. Conventional MEG systems (SQUID-MEG) use very low temperature to achieve the necessary sensitivity. This leads to severe experimental and economical limitations. A new generation of on-scalp MEG sensors is emerging: the optically pumped magnetometers (OPM). In OPM, an atomic gas enclosed in a glass cell is traversed by a laser beam whose modulation depends on the local magnetic field. 

The CERMEP MEG lab and the CRNL COPHY team in Lyon tested the performances of beyond the state-of-the-art OPM using Helium gas (4He-OPM). These sensors developed by the MAG4Health startup (www.mag4health.com) operate at room temperature with a large dynamic range, a large frequency bandwidth and output natively a 3D vectorial measure of the magnetic field. In this study, five 4He-OPMs were compared to a classical SQUID-MEG system. Considering that the 4He-OPMs operate at room temperature and can be placed directly on the head, our assumption was that 4He-OPMs will provide detailed recording of physiological magnetic brain activity.  Indeed, the results showed that the 4He-OPMs, despite having a lower sensitivity, showed very similar results to the classical SQUID-MEG system by taking advantages of a much closer distance to the brain.

These results demonstrate that 4He-OPMs represent a viable alternative for non-invasive recording of brain activities, paving the way for the development and democratisation of a wearable system for recording high-fidelity electromagnetic brain signals for both clinical practice and neuroscience research.

Program:

11H00-11H30: Presentation of the NEW_MEG project and of the first results obtained in epileptic patients. D. Schwartz [CERMEP / CRNL]

11H30-12H00: A new generation of OPM for high dynamic and large bandwidth MEG: the 4He OPMs - First applications in healthy volunteers. T. Gutteling [CERMEP / CRNL]

12H00-12H15: The MEG system from MAG4Health: Current system and future developments. E. Labyt [MAG4Health]

12H15-13H00: Open discussion about the future of the MEG lab of CERMEP

The flyer