We employ a dry-type phantom to evaluate the performance of a diamond quantum magnetometer with a high sensitivity of about 6pT/Hz from the viewpoint of practical measurement in biomagnetic sensing. The dry phantom is supposed to represent an equivalent current dipole (ECD) generated by brain activity, emulating an encephalomagnetic field. The spatial resolution of the magnetometer is evaluated to be sufficiently higher than the length of the variation in the encephalomagnetic field distribution. The minimum detectable ECD moment is evaluated to be 0.2 nA m by averaging about 8000 measurements for a standoff distance of 2.4 mm from the ECD. We also discuss the feasibility of detecting an ECD in the measurement of an encephalomagnetic field in humans. We conclude that it is feasible to detect an encephalomagnetic field from a shallow cortex area such as the primary somatosensory cortex.
@article{arxiv.2412.18101,
title = {Performance Evaluation of a Diamond Quantum Magnetometer for Biomagnetic Sensing: A Phantom Study},
author = {Naota Sekiguchi and Yuta Kainuma and Motofumi Fushimi and Chikara Shinei and Masashi Miyakawa and Takashi Taniguchi and Tokuyuki Teraji and Hiroshi Abe and Shinobu Onoda and Takeshi Ohshima and Mutsuko Hatano and Masaki Sekino and Takayuki Iwasaki},
journal= {arXiv preprint arXiv:2412.18101},
year = {2025}
}