Spherical harmonic based noise rejection and neuronal sampling with multi-axis OPMs.

ABSTRACT: In this study we explore the interference rejection and spatial sampling properties of multi-axis Optically Pumped Magnetometer (OPM) data. We use both vector spherical harmonics and eigenspectra to quantify how well an array can separate neuronal signal from environmental interference while adequately sampling the entire cortex. We found that triaxial OPMs have superb noise rejection properties allowing for very high orders of interference (L=6) to be accounted for while minimally affecting the neural space (2dB attenuation for a 60-sensor triaxial system). We show that at least 11^th order (143 spatial degrees of freedom) irregular solid harmonics or 95 eigenvectors of the lead field are needed to model the neural space for OPM data (regardless of number of axes measured). This

SUBMITTER: Tierney TM 

PROVIDER: S-EPMC10509822 | biostudies-literature | 2022 Sep

REPOSITORIES: biostudies-literature