Non-Invasive Functional-Brain-Imaging with a Novel Magnetoencephalography System

TL;DR

This paper introduces a novel non-invasive brain imaging system using optically-pumped magnetometers (OPM) that offers higher spatial resolution than traditional SQUID-based MEG systems, validated through experiments on human subjects.

Contribution

The paper presents a new OPM-based MEG system with closer sensor proximity, demonstrating improved spatial resolution over conventional SQUID systems.

Findings

Achieved sub-centimeter accuracy in localizing brain responses.

Validated system robustness through comparison with commercial MEG.

Demonstrated effective detection of somatosensory and auditory responses.

Abstract

A non-invasive functional-brain-imaging system based on optically-pumped-magnetometers (OPM) is presented. The OPM-based magnetoencephalography (MEG) system features 20 OPM channels conforming to the subject's scalp. Due to proximity (12 mm) of the OPM channels to the brain, it is anticipated that this MEG system offers an enhanced spatial resolution as it can capture finer spatial features compared to traditional MEG systems employing superconducting quantum interference device (SQUID). We have conducted two MEG experiments on three subjects: somatosensory evoked magnetic field (SEF) and auditory evoked magnetic field (AEF) using our OPM-based MEG system and a commercial SQUID-based MEG system. We have cross validated the robustness of our system by calculating the distance between the location of the equivalent current dipole (ECD) yielded by our OPM-based MEG system and the ECD location calculated by the commercial SQUID-based MEG system. We achieved sub-centimeter accuracy for both SEF and AEF responses in all three subjects.