Verbesserung des SNR bei mehrkanaligen EEG-Ableitungen

The main problem in measurements of the focal VEP (Visual Evoked Potential) is its weak SNR (Signal-to-Noise Ratio). The most common methodfor enhancement of the SNR is the Stimulus synchronized averaging. For study ofsingle responses other ways in SNR improvement are needed. In this contribution a new method based on space-time selective measurement is introduced, which can be interpreted äs beaming a Signal source. Since the anatomical structures of sources generating the focal VEP are known in general and if the electrode positions are of sufficient density over the visual cortex, a source beamer can be realized by controlling the channels' delays.