| US 7,599,735 B2 | ||
| Electrode configuration for central nervous system monitoring | ||
| Hanna E. Viertiö-Oja, Espoo (Finland); and Timothy Sampson, Helsinki (Finland) | ||
| Assigned to General Electric Company, Schenectady, N.Y. (US) | ||
| Filed on Dec. 22, 2005, as Appl. No. 11/316,374. | ||
| Prior Publication US 2007/0255164 A1, Nov. 01, 2007 | ||
| Int. Cl. A61B 5/04 (2006.01) | ||
| U.S. Cl. 600—544 [600/545; 600/546; 600/383] | 10 Claims |
| 1. A method to minimize a number of electrodes in an array to only three by positioning electrodes of the electrode array
to identify, in an electroencephalographic (EEG) signal obtained by the array, time periods that are contaminated with artifacts
resulting from eye movements of a subject, the method comprising steps of:
positioning first and second electrodes of the array on a forehead of the subject at first and second locations at which the
electrodes obtain the EEG signal including an electrooculographic (EOG) artifact, the EEG signal comprising a voltage difference
between a voltage obtained at the first electrode and a voltage obtained at the second electrode, wherein the locations of
the first and second electrodes are such that eye movement in one of a horizontal or a vertical direction will result in a
minimal overall change in the voltage difference between the first electrode and the second electrode to provide the EEG signal
in which artifacts resulting from eye movement in the one direction are minimized or eliminated;
positioning a third electrode of the array on the head of the subject at a third location to maximize voltage changes occurring
in an electrooculographic (EOG) signal as a result of eye movement in the other of the horizontal or the vertical direction
obtaining the EOG signal, wherein the EOG signal comprises a voltage difference between a voltage obtained at the third electrode
and a voltage obtained at an auxiliary electrode, wherein the auxiliary electrode is one of the electrodes in a set comprising
the first electrode and the second electrode; and
identifying time periods in which maximized voltage changes occur in the EOG signal as artifact contaminated time periods
in the EEG signal wherein the maximized voltage changes result from eye movement in the other direction.
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