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Magneto-encephalogram artifacts caused by electro-encephalogram electrodes

  • R. Murdick
  • B. J. Roth
Technical Note

Abstract

The electro-encephalogram (EEG) and magneto-encephalogram (MEG) are often measured simultaneously. By Faraday's law of induction, the changing magnetic field of the MEG can induce eddy currents in the EEG electrodes. These eddy currents produce their own magnetic field that adds to that produced by current sources in the brain, resulting in an artifact in the MEG recording. It is shown that, under typical conditions, this artifact is less than 1%, but, during measurements of high temporal frequency and high spatial resolution, the artifact can be as large as 3%.

Keywords

Magneto-encephalogram Electro-encephalogram Eddy current Electrode Artifact 

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Copyright information

© IFMBE 2003

Authors and Affiliations

  1. 1.Department of PhysicsOakland UniversityRochesterUSA

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