Department of Anesthesiology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
Department of Anesthesia, Yodogawa Christian Hospital, Osaka, Japan.
J Clin Monit Comput. 2022 Jun;36(3):609-621. doi: 10.1007/s10877-021-00771-4. Epub 2021 Oct 29.
The commonly used principle for measuring the depth of anesthesia involves changes in the frequency components of the electroencephalogram (EEG) under general anesthesia. Therefore, it is essential to construct an effective spectrum and spectrogram to analyze the relationship between the depth of anesthesia and the EEG frequency during general anesthesia. This paper reviews the computer programming techniques for analyzing the spectrum and spectrogram derived from a single-channel EEG recorded during general anesthesia. A periodogram is obtained by repeating a Fourier transform on EEG segments separated by short time intervals, but spectral leakage (i.e., dissociation from the true spectrum) occurs as a consequence of unnatural segmentation and noise. While offsetting the securing of the dynamic range, practical analyses of the adaptation of the window function are explained. Finally, the multitaper method, which can suppress artifacts caused by the edges of the analysis segments, suppress noise, and probabilistically infer values that are close to the real power spectral density, is explained using practical examples of the analysis. All analyses were performed and all graphs plotted using Python under Jupyter Notebook. The analyses demonstrated the effectiveness of Python-based programming under the integrated development environment Jupyter Notebook for constructing an effective spectrum and spectrogram for analyzing the relationship between the depth of anesthesia and EEG frequency analysis in general anesthesia.
用于测量麻醉深度的常用原理涉及全身麻醉下脑电图 (EEG) 的频率分量变化。因此,构建有效的频谱和频谱图以分析全身麻醉期间麻醉深度与 EEG 频率之间的关系至关重要。本文回顾了用于分析源自全身麻醉期间记录的单通道 EEG 的频谱和频谱图的计算机编程技术。通过对短时间间隔分隔的 EEG 段重复进行傅里叶变换,可以获得一个周期图,但由于不自然的分段和噪声,会发生频谱泄漏(即与真实频谱分离)。在补偿动态范围的安全性的同时,解释了窗口函数适应性的实际分析。最后,解释了多峰方法,该方法可以抑制分析段边缘引起的伪影、抑制噪声,并概率推断接近真实功率谱密度的值,并用分析的实际示例进行说明。所有分析均使用 Jupyter Notebook 下的 Python 执行,并绘制所有图形。分析表明,在集成开发环境 Jupyter Notebook 下,基于 Python 的编程在构建有效的频谱和频谱图以分析全身麻醉期间麻醉深度与 EEG 频率分析之间的关系方面是有效的。