An integrated full-head OPM-MEG system based on 128 zero-field sensors

Area of Science:

• Biophysics
• Neuroscience
• Medical Instrumentation

Background:

• Compact optically-pumped magnetometers (OPMs) offer low noise floors (10 fT/Hz^1/2).
• Dense OPM arrays are crucial for integrated, turn-key magnetoencephalography (MEG) systems.
• Evaluating OPM-MEG system performance is essential for clinical applications.

Purpose of the Study:

• To present and evaluate the HEDscan, a 128-sensor OPM MEG system.
• To assess sensor performance metrics including bandwidth, linearity, and crosstalk.
• To cross-validate the HEDscan's performance against conventional cryogenic MEG.

Main Methods:

• The HEDscan system, featuring 128 OPM sensors, was utilized.
• Sensor performance was evaluated for bandwidth, linearity, and crosstalk.
• Cross-validation studies were conducted using a Magnes 3,600 WH Biomagnetometer (cryogenic MEG).

Main Results:

• The OPM-MEG system captured high signal amplitudes during auditory paradigms.
• Short tones (1000 Hz) presented to the left ear yielded significant signal detection.
• Event-related beamformer analysis validated findings, aligning with existing literature.

Conclusions:

• The HEDscan 128-sensor OPM MEG system demonstrates robust performance.
• The system shows promise for magnetoencephalography applications.
• Cross-validation confirms the reliability of OPM-based MEG technology.