Estimation of time delay between EEG signals for epileptic focus localization: statistical error considerations.
A theoretical analysis of the variance for the time delay estimate between two EEG signals, obtained via the phase spectrum method, is presented. Explicit theoretical formulae for the variance are obtained and compared via simulations to experimentally derived results for estimate variability. The variance of the time delay estimate is inversely proportional to the frequency range of interest, to the number of data segments utilized for spectral estimation, and to the coherence between the two EEG signals. The simulations indicate that the formulae can be used even with non-gaussian and relatively narrow-band EEG-like data. A minimum-variance estimate for the time delay is also presented.
Ktonas
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Department of Electrical Engineering, University of Houston, TX 77204-4793.
Mallart
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D003198:Computer Simulation; D004569:Electroencephalography / Q000379:methods*; D004827:Epilepsy / Q000175:diagnosis*; D005583:Fourier Analysis; D006801:Humans; D008959:Models, Neurological; D013223:Statistics as Topic; D013997:Time Factors