Benchmarking for On-Scalp MEG Sensors.

Area of Science:

• Biophysics
• Neuroscience
• Biomedical Engineering

Background:

• Magnetoencephalography (MEG) is a crucial neuroimaging technique.
• Current MEG systems utilize low-temperature superconducting quantum interference devices (SQUIDs).
• Emerging on-scalp MEG sensor technologies offer potential advantages but require rigorous validation.

Purpose of the Study:

• To introduce a standardized benchmarking protocol for evaluating novel on-scalp MEG sensor technologies.
• To quantitatively compare emerging sensors against established state-of-the-art MEG systems.
• To demonstrate the protocol's utility using a high-critical-temperature SQUID (high T_c SQUID).

Main Methods:

• A novel benchmarking protocol was established for on-scalp MEG sensor evaluation.
• A high T_c SQUID was compared with a commercial Elekta Neuromag TRIUX system.
• MEG recordings of auditory and somatosensory evoked fields (SEFs) were performed on a human subject.

Main Results:

• The protocol successfully measured signal gain for auditory-evoked fields from deeper sources.
• Unfamiliar features were observed in on-scalp sensor recordings of SEFs from shallower sources.
• Results validated the benchmarking protocol's proof of principle.

Conclusions:

• The developed protocol is a straightforward, generalizable, and human-subject-convenient method for benchmarking on-scalp MEG sensors.
• On-scalp MEG sensors show potential for extracting unique information from shallow neuromagnetic sources, difficult to obtain with current systems.
• This protocol enables magnetic sensor developers to rigorously prove the utility of their technologies in MEG recordings.