INEXPENSIVE DEVICE FOR ANALYZING AND MONITORING THE ELECTROENCEPHALOGRAM

In this paper, we present the density-modulated spectral array (DSA). The DSA is implemented by two devices. Both can fit into one standard thermal stripchart plug-in module. The first calculates the power spectrum of an EEG signal and converts the spectrum into a signal that can be displayed by the second device on the strip chart in a density-modulated format with variable line darkness and thickness. The result is similar to a voice print, and allows easy visualization of frequency distribution and changes, as well as intensity changes.