MAGNETOENCEPHALOGRAPHY WITH DIVERSELY ORIENTED AND MULTICOMPONENT SENSORS

Citation
B. Hochwald et A. Nehorai, MAGNETOENCEPHALOGRAPHY WITH DIVERSELY ORIENTED AND MULTICOMPONENT SENSORS, IEEE transactions on biomedical engineering, 44(1), 1997, pp. 40-50
Citations number
17
Categorie Soggetti
Engineering, Biomedical
ISSN journal
00189294
Volume
44
Issue
1
Year of publication
1997
Pages
40 - 50
Database
ISI
SICI code
0018-9294(1997)44:1<40:MWDOAM>2.0.ZU;2-U
Abstract
To locate endocranial current sources, a magnetoencephalography (MEG) system usually measures the magnetic field at many points around the s kull with an array of radial sensors, Despite the success of using rad ial components of the field, we show that using nonradial components m ay potentially also be beneficial. We demonstrate some benefits of usi ng diversely oriented and multicomponent sensors to measure the nonrad ial components, A framework is provided for analyzing the accuracy of a system that estimates the location and direction of a current dipole inside a spherical skull, The framework is then used to determine the effect on accuracy of varying the orientations of sensors in an array and, as a consequence, it is found that the radial orientations commo nly used in practice are suboptimal for locating dipoles near the arra y's tenter. A diversely oriented array that improves performance is pr esented. We show how a single multicomponent sensor can locate a dipol e, and derive a simple algorithm for locating a dipole near the sensor .