Determination of dominant simulated spindle frequency with different methods.
Accurate analysis of EEG sleep spindle frequency is challenging. The frequency content of true sleep spindles is not known. Therefore, simulated spindle activity was studied in the present work. Five types of simulated test signals were designed, all containing a dominant spindle represented by a 13-Hz sine wave as such or with a waxing and waning pattern accompanied by a secondary spindle activity in three test signals. Background EEG was included in four test signals, modeled either as small additional sinusoids across the spindle frequency range or as filtered Gaussian noise segments. The purpose of this study was to investigate how accurately the dominant spindle frequency of 13 Hz could be resolved with different methods in the presence of the interfering waveforms. A matching pursuit (MP) based approach, discrete Fourier transform (DFT) with Hanning windowing with and without zero padding, Hankel total least squares (HTLS) and wavelet methods were compared in the analyses. MP method provided best overall performance, followed closely by DFT with zero padding. Comparative studies like this are important to decide the method of choice in clinical sleep EEG analysis.
Huupponen
Eero
E
Institute of Signal Processing, Tampere University of Technology, Korkeakoulunkatu 1, FIN-33101, Tampere, Finland. eero.huupponen@tut.fi
De Clercq
Wim
W
Gómez-Herrero
Germán
G
Saastamoinen
Antti
A
Egiazarian
Karen
K
Värri
Alpo
A
Vanrumste
Bart
B
Vergult
Anneleen
A
Van Huffel
Sabine
S
Van Paesschen
Wim
W
Hasan
Joel
J
Himanen
Sari-Leena
SL
D000465:Algorithms; D003198:Computer Simulation; D004569:Electroencephalography / Q000706:statistics & numerical data*; D005583:Fourier Analysis; D006801:Humans; D016018:Least-Squares Analysis; D015233:Models, Statistical; D009010:Monte Carlo Method; D012890:Sleep / Q000502:physiology*