Real-time spectral intensity analysis of the EEG on a common microcomputer.

An inexpensive system for quantitative electroencephalogram (EEG) analysis over long time periods is described. This system continuously analyses EEG for intensity versus frequency content, and saves averaged 'data reduced' intensity spectra to disk at regular intervals. The method had adequate frequency resolution for EEG analysis and demonstrated useful data reduction. In the example presented 1 day of sampled EEG data (20 megabytes) were reduced to 125 kilobytes of averaged spectra, thus illustrating the utility of the system for long term EEG studies. The system uses a low cost microcomputer (IBM AT compatible) with data acquisition board and a simple multitasking program developed with Asyst software.