Performance of Signal Space Separation Depending on Sensor Array Arrangement in Biomagnetic Measurements


Article Preview

Signal source separation (SSS) has widely been adopted for magnetoencephalography (MEG) to reduce external magnetic noise interference. The basic idea of SSS is based on decomposing measured fields into spherical harmonic bases. Due to the feature, the performance of SSS strongly depends on the shape of a measuring sensor array. In this article, we show the noise reduction performances in several different shapes of the sensor and array and demonstrate SSS is only effective for a non-spherical sensor array or for a gradiometric arrangement.



Key Engineering Materials (Volumes 480-481)

Edited by:

Yanwen Wu




K. W. Kim et al., "Performance of Signal Space Separation Depending on Sensor Array Arrangement in Biomagnetic Measurements", Key Engineering Materials, Vols. 480-481, pp. 1418-1425, 2011

Online since:

June 2011




[1] Clarke and A. Barginski: The SQUID Handbook, Fundamentals and Technology of SQUID's and SQUID Systems (Wiley, New York 2004).


[2] M. Hämäläinen, R. Hari, R. J. Ilmoniemi, J. Knuutila, and O. V. Lounasmaa : Magnetoencephalography—Theory, instrumentation, and applications to noninvasive studies of the working human brain. Rev. Mod. Phys Vol. 65 ( 1993).


[3] S. Taulu, M. Kajola, and J. Simola: Suppression of interference and artifacts by the signal space separation method. Brain Topograph Vol. 16 (2004), p.269–275.


[4] I. Kominis, T. Kornack, J. Allred, and M. Romalis: A subfemtotesla multichannel atomic magnetometer. Nature Vol. 422 (2003), p.596–599.


[5] H. Xia, A. B. Baranga, D. Hoffman, and M. V. Romalis: Magnetoencephalography with an atomic magnetometer. Appl. Phys. Lett. 89, 211104, (2006).


[6] K. Kim, H. Xia, S. K. Lee and M. V. Romalis: Development of a Wide-coverage Atomic Brain Magnetometer System. International Conference on Biomagnetism, Sapporo, Japan, 232 (2008).

[7] K. Kim, W. K. Lee, I. S. Kim, and H. S. Moon: Atomic Vector Gradiometer System Using Cesium Vapor Cells for Magnetocardiography: Perspective on Practical Application, IEEE Trans. Instru. Meas. Vol. 56(2) (2007), pp.458-462.