Wavelet transform-based mode decomposition for EEG signals under general anesthesia.

Autor:	Yamochi S; Department of Anesthesiology, Kyoto Prefectural University of Medicine, Kyoto, Japan., Yamada T; Department of Anesthesiology, Kyoto Prefectural University of Medicine, Kyoto, Japan., Obata Y; Department of Anesthesia, Yodogawa Christian Hospital, Osaka, Japan., Sudo K; Department of Anesthesiology, Kyoto Prefectural University of Medicine, Kyoto, Japan., Kinoshita M; Department of Anesthesiology, Kyoto Prefectural University of Medicine, Kyoto, Japan., Akiyama K; Department of Anesthesiology, Kindai University, Osakasayama, Osaka, Japan., Sawa T; University Hospital, Kyoto Prefectural University of Medicine, Kyoto, Japan.
Jazyk:	angličtina
Zdroj:	PeerJ [PeerJ] 2024 Nov 15; Vol. 12, pp. e18518. Date of Electronic Publication: 2024 Nov 15 (Print Publication: 2024).
DOI:	10.7717/peerj.18518
Abstrakt:	Background: Mode decomposition methods are used to extract the characteristic intrinsic mode function (IMF) from various multidimensional time series signals. We analyzed an electroencephalogram (EEG) dataset for sevoflurane anesthesia using two wavelet transform-based mode decomposition methods, comprising the empirical wavelet transform (EWT) and wavelet mode decomposition (WMD) methods, and compared the results with those from the previously reported variational mode decomposition (VMD) method. Methods: To acquire the EEG data, we used the software application EEG Analyzer, which enabled the recording of raw EEG signals via the serial interface of a bispectral index (BIS) monitor. We also created EEG mode decomposition software to perform empirical mode decomposition (EMD), VMD, EWT, and WMD operations. Results: When decomposed into six IMFs, the EWT enables narrow band separation of the low-frequency bands IMF-1 to IMF-3, in which all central frequencies are less than 10 Hz. However, in the upper IMF of the high-frequency band, which has a center frequency of ≥ 10 Hz, the dispersion within the frequency band covered was widespread among the individual patients. In WMD, a narrow band of clinical interest is specified using a bandpass filter in a Meyer wavelet filter bank within a specific mode-decomposition discipline. When compared with the VMD and EWT methods, the IMF that was decomposed via WMD was accommodated in a narrow band with only a small variance for each patient. Multiple linear regression analyses demonstrated that the frequency characteristics of the IMFs obtained from WMD best tracked the changes in the BIS upon emergence from general anesthesia. Conclusions: The WMD can be used to extract subtle frequency characteristics of EEGs that have been affected by general anesthesia, thus potentially providing better parameters for use in assessing the depth of general anesthesia. Competing Interests: The authors declare there are no competing interests. (©2024 Yamochi et al.)
Databáze:	MEDLINE
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