[Reducing the duration of pattern ERG recordings by "time varying filtering"].
OBJECTIVE
In 1981, de Weerd proposed the method of time varying filtering (TVF) for estimating the "true" signal of an electrophysiological response if a noise response was additionally recorded. We studied whether this method can be used to predict the average pattern ERG (PERG) of all trials from a smaller subset of trials.


METHODS
A total of 10 subjects with normal acuity participated in the experiment. Transient PERGs to reversing checkerboard patterns were recorded from both eyes using DTL electrodes. We calculated the mean deviation for partial averages of 6, 12, 20, 30, and 60 trials from the average PERG of all 120 trials. For each partial average, an additional noise response was derived by averaging the trials with alternating signs.


RESULTS
When using TVF, the number of trials could be reduced by a factor of 1.43 to yield a PERG of similar quality to classical averaging.


CONCLUSIONS
TVF allows the estimation of a "true" PERG response. This method can be used to significantly reduce the duration of PERG recordings.
Meigen
T
T
Universitäts-Augenklinik Würzburg, Josef-Schneider-Strasse 11, 97080 Würzburg. t.meigen@augenklinik.uni-wuerzburg.de
Heine
M
M
D000328:Adult; D016477:Artifacts; D004596:Electroretinography / Q000379:methods*; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D008297:Male; D008432:Mathematical Computing; D010364:Pattern Recognition, Visual / Q000502:physiology; D010775:Photic Stimulation; D012016:Reference Values; D015203:Reproducibility of Results; D012160:Retina / Q000502:physiology; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D012984:Software; D014792:Visual Acuity / Q000502:physiology