Hayashi Kazuko, Mukai Nobuhiro, Sawa Teiji
Department of Anesthesiology, Nantan General Hospital, Japan; Department of Anesthesiology, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto, Japan.
Department of Anesthesiology, Nantan General Hospital, Japan.
Clin Neurophysiol. 2015 Feb;126(2):404-11. doi: 10.1016/j.clinph.2014.04.019. Epub 2014 Jun 5.
The Poincaré plot is a two-dimensional state-space approach, where a timed signal is plotted against itself after a time delay, enabling determination of the dynamic nature of signals. Quantification of the Poincaré plot is a candidate for estimating anesthesia-dependent changes in the electroencephalogram (EEG).
In 20 patients, at four different states of anesthesia (0.5%, 1%, 2% and 3% sevoflurane), frontal EEG signals (10s) were used to construct Poincaré plots. The plot pattern was quantified by the standard deviation of the voltage dispersion along the line of identity (SD2), the standard deviation perpendicular to the line of identity (SD1) and their ratio (SD1/SD2), and compared using spectral EEG features.
A significant stepwise decrease in the SD1/SD2 ratio was observed with each stepwise increase in sevoflurane concentration (p<0.001 for each). From 0.5% to 3% sevoflurane anesthesia, the ratio of relative β power to δ power (β/δ) was highly correlated with SD1/SD2 (R=0.92).
The Poincaré plot of the frontal EEG can detect the significant changes in the depth of anesthesia induced by different sevoflurane concentrations.
The Poincaré plot is a useful technique for detecting the EEG changes induced by anesthesia.
庞加莱图是一种二维状态空间方法，其中一个定时信号在经过时间延迟后与自身进行绘制，从而能够确定信号的动态特性。庞加莱图的量化是估计脑电图（EEG）中麻醉相关变化的一个候选方法。
在20名患者中，在四种不同的麻醉状态（0.5%、1%、2%和3%七氟醚）下，使用额叶脑电图信号（10秒）构建庞加莱图。通过沿恒等线的电压离散度的标准差（SD2）、垂直于恒等线的标准差（SD1）及其比值（SD1/SD2）对图的模式进行量化，并与脑电图频谱特征进行比较。
随着七氟醚浓度的逐步增加，观察到SD1/SD2比值显著逐步下降（每种浓度下p<0.001）。从0.5%到3%七氟醚麻醉，相对β功率与δ功率的比值（β/δ）与SD1/SD2高度相关（R=0.92）。
额叶脑电图的庞加莱图可以检测不同七氟醚浓度引起的麻醉深度的显著变化。
庞加莱图是检测麻醉引起的脑电图变化的一种有用技术。
