An EEG (electroencephalogram) recording system with carbon wire electrodes for simultaneous EEG-fMRI (functional magnetic resonance imaging) recording.
Simultaneous EEG-fMRI (Electroencephalography-functional Magnetic Resonance Imaging) recording provides a means for acquiring high temporal resolution electrophysiological data and high spatial resolution metabolic data of the brain in the same experimental runs. Carbon wire electrodes (not metallic EEG electrodes with carbon wire leads) are suitable for simultaneous EEG-fMRI recording, because they cause less RF (radio-frequency) heating and susceptibility artifacts than metallic electrodes. These characteristics are especially desirable for recording the EEG in high field MRI scanners. Carbon wire electrodes are also comfortable to wear during long recording sessions. However, carbon electrodes have high electrode-electrolyte potentials compared to widely used Ag/AgCl (silver/silver chloride) electrodes, which may cause slow voltage drifts. This paper introduces a prototype EEG recording system with carbon wire electrodes and a circuit that suppresses the slow voltage drift. The system was tested for the voltage drift, RF heating, susceptibility artifact, and impedance, and was also evaluated in a simultaneous ERP (event-related potential)-fMRI experiment.
Negishi
Michiro
M
Department of Diagnostic Radiology, School of Medicine, Yale University, New Haven, Connecticut 06520-8043, United States. michiro.negishi@yale.edu
Abildgaard
Mark
M
Laufer
Ilan
I
Nixon
Terry
T
Constable
Robert Todd
RT
D001921:Brain / Q000098:blood supply* / Q000502:physiology*; D001931:Brain Mapping; D002244:Carbon; D004566:Electrodes / Q000009:adverse effects; D004569:Electroencephalography / Q000295:instrumentation* / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D011846:Radio Waves
D002244:Carbon; D010100:Oxygen