We have developed a neuro-cardiovascular analyzing system for auditory evoked skin blood flow (SBF) response. Using software specially developed and designed by using Microsoft Visual Basic, Visual Basic for Applications and Cygwin, we have analyzed the heart rate (HR), electroencephalographic (EEG) changes and SBF reactions after white noise exposure. The beat-by-beat changes of mean EEG frequency (MF-EEG) and the mean EEG amplitude (MA-EEG) were analyzed by using least-square-cosine spectrum analysis Method. To verify the usefulness of the system, we recorded physiological data from 7 volunteers with a mean age of 20+/-0.9. In most cases, the HR, MF-EEG and the MA-EEG increased, on the other hand, SBF showed biphasic changes after the auditory stimuli. We suspect that biphasic changes of SBF were explained by time course changes of 1) heart rate, 2) passive vasodilation and 3) active vasoconstriction. This analysis system may be useful for evaluation of the time lag effect of auditory stimuli on neuro-cardiovascular dynamics.
