A time-frequency approach for spike detection

Abstract

This paper presents a new time frequency based spike detection technique. As spikes are broadband events with high instantaneous energy, they tend to have a larger energy than the background at high frequencies. To detect spikes, the time frequency distribution of the signal of interest is first enhanced to attenuate the noise. Two frequency slices of the enhanced time frequency distribution are then extracted and subjected to the smoothed nonlinear energy operator (SNEO). Finally, the output of the SNEO is thresholded to localise the position of the spikes in the signal. The SNEO is employed to accentuate the spike signature in the extracted frequency slices. A spike is considered to exist in the time domain signal if a signature of the spike is detected at the same position in both frequency slices. The performance of the proposed method is evaluated using both synthetic and newborn electroencephalogram (EEG) signals.