Title :
Analysis of sleep spindles in different NREM-REM cycles by means of bispectra
Author :
Romero, S. ; Mañanas, M.A. ; Lorenzo, J.L. ; Clos, S. ; Barbanoj, M.J.
Author_Institution :
Centre de Recerca en Enginyeria Biomedica, Univ. Politecnica de Catalunya, Barcelona, Spain
Abstract :
Spindles are periodic oscillations that characterize the predominant stage 2 during sleep. The aim of this paper is to study the spindle activity in different cycles of NREM-REM sleep. Higher order spectral analysis, particularly the bispectrum is used to analyze the quadratic nonlinear interaction. Ten one-second spindles from the first and the last NREM-REM cycles, with two normal subjects, are analyzed. Spindle waves are characterized using the power spectral density (PSD) function and the bispectrum to obtain: (1) differences between sleep spindles of the first and the last NREM-REM cycles, and (2) the interaction between the different components in the EEG signal. Similar results were obtained in both subjects and channels presented: no differences are observed neither in time nor in frequency domain with PSD function between spindles from the first and the last NREM-REM cycles. However, more frequency couplings were observed in the last cycle than in the first one by means of the bispectrum.
Keywords :
electroencephalography; eye; frequency-domain analysis; medical signal processing; sleep; spectral analysis; time-domain analysis; EEG signal; NREM-REM cycles; bispectra; frequency domain; higher order spectral analysis; normal subjects; one-second spindles; periodic oscillations; power spectral density function; quadratic nonlinear interaction; sleep spindles; spindle activity; spindle waves; time domain; Electrodes; Electroencephalography; Fourier transforms; Frequency domain analysis; Higher order statistics; Neurons; Signal processing; Sleep; Spectral analysis;
Conference_Titel :
Engineering in Medicine and Biology, 2002. 24th Annual Conference and the Annual Fall Meeting of the Biomedical Engineering Society EMBS/BMES Conference, 2002. Proceedings of the Second Joint
Print_ISBN :
0-7803-7612-9
DOI :
10.1109/IEMBS.2002.1134441