Time domain a posteriori ´optimal filter´ for average evoked potentials

Estimating evoked potentials is a process of detecting a signal from an ensemble of sweep measurements, each of which contains a sum of signal and noise. The signal is usually detected by averaging those sweeps. In order to improve the signal detection, the authors present a time-domain a posteriori optimal filter (APOF), which is applied to the average response. This filter can be implemented online, without having to save all the sweeps and process them offline. Following the application of APOF, the mean square error of the average is usually improved. The amount of improvement increases when the signal-to-noise ratio in the average decreases. The filter is more effective when the signal and the noise have different spectra.<>