Application of FIR median hybrid filters to remove blinks in electrooculograms
Marcelino Martínez, Emilio Soria‐Olivas, Rafael Magdalena‐Benedito, Antonio José Serrano-López, Joan Vila · 2007
This paper describes a comparative study of several algorithms used to remove the blink noise in the electroculogram preserving the sharp edges in the signal produced by the so-called saccadic eye movements. Median filters (MF) and several types of Fir Median Hybrid Filters (FMH) are proposed. 16 real Electrooculogram register with saccadic movements in controlled position were used to test the performance of the pre-processing filters. The filtered signals were later processed with a saccadic eye movement detector algorithm in order to detect changes in the sensibility and positive predictive value. Even though the results are preliminary, neither FMH filters nor WFMH filters produce better results than median filters, in this particular study. The highest values of sensitivity and positive predictive value are obtained by using a median filter (S=97,3%, V++=97,7%). Although the differences are not important 3-FMH and SWFMH produce slightly higher rates of saccades detection, but a reduction in computational burden is obtained by using FHM variants.