MRRC has two MR compatible EEG systems for research use:
Neuroscan SynAmps2 70 channel digital EEG amplifier
This system is capable of 24 bit maximum sampling at 20000 Hz. The MRRC has built an in-house EEG cap with carbon-wire electrodes that ensure MRI transparency and safety, with attached artifact detectors that are used to remove gradient artifacts and the ballistocardiogram from the EEG signal. In addition, the center has built a front-end anti-polarization circuit that reduces low-frequency drift of the carbon-wire electrodes. The Synamps2 also contains digital TTL inputs for triggering.
Neuroscan Nu-Amps 40 channel digital EEG amplifier
This system is capable of 22 bit maximum sampling at 1000 Hz. The MRRC has built a front-end analog filters to ensure that any gradient artifacts above the 500Hz sampling rate are not aliased into lower frequencies. The analog filtering is performed prior to any digitization. The Nu-amps also contains digital TTL inputs for triggering.