SINGLE-SWEEP ANALYSIS USING AN AUTOREGRESSIVE WITH EXOGENOUS INPUT (ARX) MODEL

Single-sweep visual evoked potential analysis would be useful in clini cal electrophysiology practice because it would make possible the eval uation of transient phenomena, but recording single-sweep visual evoke d potentials is difficult because of the low signal-noise ratio. To in crease this ratio we used a filter based on an autoregressive with exo genous input model. We studied a group of 12 diabetic patients matched with a control group of 14 normal subjects. The model, in most cases, allowed us to extrapolate the P100 component from each single sweep o f visual evoked potential. The visual evoked potential values obtained by means of averaging were not significantly different in the groups studied, but single-sweep analysis showed different distribution of th e P100 component amplitude. The preliminary results of our study evide nced differences in the amplitude and latency distribution of normal a nd diabetic subjects, thus confirming the power of this new technique and its ability to obtain some information that is masked by the avera ging method.