Balanced, bi-planar magnetic field and field gradient coils for field compensation in wearable magnetoencephalography.

ABSTRACT: To allow wearable magnetoencephalography (MEG) recordings to be made on unconstrained subjects the spatially inhomogeneous remnant magnetic field inside the magnetically shielded room (MSR) must be nulled. Previously, a large bi-planar coil system which produces uniform fields and field gradients was used for this purpose. Its construction presented a significant challenge, six distinct coils were wound on two 1.6 × 1.6 m² planes. Here, we exploit shared coil symmetries to produce coils simultaneously optimised to generate homogenous fields and gradients. We show nulling performance comparable to that of a six-coil system is achieved with this three-coil system, decreasing the strongest field component B_x by a factor of 53, and the strongest gradient dB_x/dz

SUBMITTER: Holmes N 

PROVIDER: S-EPMC6775070 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature