New publication

Currently, optically pumped magnetometers (OPMs) achieve a sensitivity comparable to conventional magnetoencephalography (MEG) sensors. The two main advantages of OPMs compared to conventional MEG sensors are that OPMs can be placed closer to the brain and that OPMs can be attached to participants' heads. However, the OPMs that are used for MEG can only operate in an environment of nearly zero absolute magnetic field. Small head movements in the remnant magnetic field inside a magnetically shielded room (MSR) can already disable the OPMs. We developed a coil design for the compensation of the remnant magnetic field inside an MSR. In our design, coil wires are placed in wooden boards on 5 sides of a cube with a side length of 2 m. Our coils are optimized for the operation inside an MSR and shielding effects on the magnetic fields are taken into account in coil optimization. Compared to previously built bi-planar compensation coils, the coils proposed in this report are more complex in geometry and achieved smaller errors for simulated compensation fields. The proposed coils will allow for larger head movements or smaller movement artifacts in future MEG experiments compared to existing coils.

Kutschka, H., Doeller, C.F., Haueisen, J. et al.:

Magnetic field compensation coil design for magnetoencephalography. Sci Rep 11, 22650 (2021)

https://doi.org/10.1038/s41598-021-01894-z

Contact: Dr. Hermann Kutschka