New artifact-free electrodes for recording of biological potentials in strong electromagnetic fields

摘要

Conventional metal electrodes as used to record electrophysiological events are likely to introduce artifactual stimulation and spurious signals when the preparation to which they are attached or in which they are implanted is exposed to electromagnetic (EM) fields of high frequency. To combat these artifacts, electrodes of high linear resistance (> 100 kΩ/m) were devised for use in chronic and in acute experiments. The electrodes minimize diffractive problems and control for artifactual stimulation by eliminating spurious currents at the junction between the electrode tip and the biological preparation. Contamination of amplifier-recording circuits by demodulation artifact is prevented by proper filtration.