143 Channel Whole-Cortex MEG System

Whole-cortex helmet-type SQUID MEG systems have been in operation in a number of laboratories since 1992, e.g. [1]. Recently, a whole-cortex integrated MEG/EEG system consisting of 143 MEG sensor Channels, 40 EEG Channels, 8 A/D and D/A Channels and 8 logical Channels was developed and operated in an unshielded environment and, more recently, in a shielded room. This paper presents the resulting noise Performance and several examples of unshielded recordings of spontaneous and evoked brain activity with response to DC.