研究基于脑电分析的脑死亡判定方法,对于早期发现非脑死亡患者和避免脑死亡误判具有重要的意义。作为脑死亡判定的一个指标,近似熵被引入到对疑似脑死患者脑电信号的分析中。本研究首先将现有的静态近似熵分析法扩展到动态近似熵分析法,并用来识别昏迷患者与脑死亡者,观察患者病状变化的过程。由于在采集脑电信号的过程中存在噪声干扰,所以在动态近似熵分析之前,引入小波分析法对脑电信号进行去噪的前处理。通过对实测患者数据的分析和验证,使疑似患者的不同状态和病状变化过程得以观察和识别。结果表明:昏迷患者与脑死者的脑电信号存在特征差异,昏迷患者的动态近似熵小于脑死者的动态近似熵。
Brain death diagnosis based on EEG analysis is believed to be valuable for either reducing the risk of brain death diagnosis or preventing mistaken diagnosis.As a criterion,approximate entropy(ApEn) is used to analyze patients’EEG signals.This article applies dynamic ApEn,a method based on traditional ApEn to monitor the state of patients.Since EEG data was recorded from the real-life environment,it is necessary to introduce a pre-processing technique such as the wavelet technique to reduce the noise signals.The experimental results illustrate effectiveness of the proposed method in the EEG data analysis and well performance in evaluating the differences between coma patients and brain deaths.The dynamic complexity measure is lower for a coma patient than for a brain death.