Magnetoencephalography System Based on Quantum Magnetic Sensors for Clinical Applications

In this paper, we present the magnetoencephalography system developed by the Institute of Applied Sciences and Intelligent Systems of the National Research Council and recently installed in a clinical environment. The system employ ultra high sensitive magnetic sensors based on superconducting quantum interference devices (SQUIDs). SQUID sensors have been realized using a standard trilayer technology that ensures good performances over time and a good signal-to-noise ratio, even at low frequencies. They exhibit a spectral density of magnetic field noise as low as 2 fT/Hz1/2. Our system consists of 163 fully-integrated SQUID magnetometers, 154 channels and 9 references, and all of the operations are performed inside a magnetically-shielded room having a shielding factor of 56 dB at 1 Hz. Preliminary measurement have demonstrated the effectiveness of the MEG system to perform useful measurements for clinical and neuroscience investigations. Such a magnetoencephalography is the first system working in a clinical environment in Italy.