Four-shell ellipsoidal model employing multipole expansion in ellipsoidal coordinates.

Although the head is more closely represented as an ellipsoid than a sphere, calculation in ellipsoidal coordinates is difficult. This paper presents a four shell ellipsoidal model, employing multipole expansion in ellipsoidal coordinates, for EEG, MEG, and evoked potential applications. Computation...

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Bibliographic Details
Published in:	Medical & Biological Engineering & Computing Vol. 46; no. 9; pp. 859 - 870
Main Authors:	Blimke J, Myklebust J, Volkmer H, Merrill S, Blimke, John, Myklebust, Joel, Volkmer, Hans, Merrill, Stephen
Format:	Journal Article
Published:	Springer Nature Sep2008
Online Access:	View this record in EBSCOhost

Description
Summary:	Although the head is more closely represented as an ellipsoid than a sphere, calculation in ellipsoidal coordinates is difficult. This paper presents a four shell ellipsoidal model, employing multipole expansion in ellipsoidal coordinates, for EEG, MEG, and evoked potential applications. Computational detail and insight into efficient calculation of the Lamé functions of the first and second kind are provided to demonstrate feasibilty. The Lamé function of the second kind, derived from the Lamé function of the first kind, can be computed at higher degrees by means of partial fraction expansion.