Simultaneous measurement of auditory brain stem potentials and EEG spectra

Compressed EEG spectra and compressed brain stem auditory potentials (BAEP) can be measured at the same time, from the same derivation, if a wide band amplifier (1 Hz-2 kHz) is used and the complete brain stem signal is sampled between two EEG sampling points. For this approach sample rates of 64 Hz for the EEG and 12,800 Hz for the BAEP were used. The auditory stimulation was repeated every 6th EEG sampling point, corresponding to a repetition rate of 10.6 Hz. Processing and presentation of the results were performed on-line, permitting continuous monitoring of the patient.