High Frequency Oscillations Separated by Rhythmicity in Ictal Stereo-EEG from Epileptic Patients

Abstract

This study introduces a new method for separating HFOs from background artifacts based on signal rhythmicity. EEMD is first applied on SEEG to extract IMFs, then amplitude and rhythmicity thresholds are used to extract HFOs from high frequency IMFs. The rhythmicity is represented by instant phase acceleration obtained from Hilbert transform. The results show that proposed method can achieve reliable HFOs extraction in ictal SEEG from five epileptic patients. The HFOs analysis also provides meaningful information.