Real-time, model-based magnetic field correction for moving, wearable MEG.

Area of Science:

• Neuroimaging
• Biophysics
• Biomedical Engineering

Background:

• Traditional neuroimaging methods necessitate participant stillness.
• Optically pumped magnetometer magnetoencephalography (OP-MEG) offers potential for measuring neural signals during movement.
• Environmental magnetic fields and OPM operational ranges limit participant mobility.

Purpose of the Study:

• To implement real-time electromagnetic coil updates for canceling background magnetic fields in OP-MEG.
• To improve the feasibility of participant movement during OP-MEG recordings.
• To mitigate sensor saturation and enhance data quality in mobile OP-MEG.

Main Methods:

• Real-time harmonic modeling of background magnetic fields.
• On-board electromagnetic coils for homogeneous field correction (HFC).
• Testing in stationary and auditory paradigms with participant movement up to 2m.

Main Results:

• A 24 dB improvement in very low-frequency noise during stationary recordings.
• More than double the proportion of non-saturated trials during 2m movement.
• Demonstrated effective cancellation of spatially and temporally varying magnetic fields.

Conclusions:

• Real-time HFC significantly improves OP-MEG performance during participant movement.
• Model-based feedback allows correction of unmeasured field components, addressing sensor calibration issues.
• This technique enhances the practicality and reliability of mobile neuroimaging.