Abstract
Biomagnetic field measurement is widely used the magnetic field perpendicular to the scalp. There are problems of separating multiple sources overlapping in time when many distinct areas are active. We developed a three-dimensional (3-D) second-order gradiometer connected to three SQUIDs for vector measurement of the MEG (magnetoencephalogram). This SQUID magnetometer can detect magnetic field components perpendicular (Br) and tangential (Bθ, Bφ) to the scalp simultaneously. Magnetic field distribution of tangential component can provide information about new constraint conditions for inverse problem by visual inspection. This paper presents example of a 3-D vector measurement of MEG.
