近似熵在微波辐射致猕猴脑损伤检测中的应用

Application of approximate entropy in the detection of brain injury induced by microwave radiation in rhesus macaques

目的基于近似熵与相对功率谱对微波辐射后猕猴脑电图进行分析,探讨应用近似熵衡量微波辐射对脑损伤程度的可行性。方法雄性猕猴15只,根据平均功率密度不同,随机分为假辐射组、2 mW/cm2、5 mW/cm2、7 mW/cm2、11 mW/cm2微波辐射组,采用BIOPAC公司生产的MP-150多导生理记录及分析系统,分别于辐射前及辐射后即刻、1 d、3 d、7 d、14 d和30 d,对猕猴脑电图(EEG)近似熵和δ、β频段相对功率谱进行检测。结果 (1)7 mW/cm2组近似熵于辐射后即刻明显下降,11 mW/cm2组近似熵于辐射后即刻、1 d和3 d明显下降。(2)7 mW/cm2组于辐射后即刻,δ频段相对功率谱显著升高,β频段相对功率谱明显下降;11 mW/cm2组于辐射后即刻、1 d和3 d,δ频段相对功率谱显著升高,而β频段相对功率谱则明显下降。(3)2 mW/cm2和5 mW/cm2组近似熵与相对功率谱于辐射后各时间点均未见明显变化。结论 (1)7 mW/cm2和11 mW/cm2微波辐射可引起猕猴脑电生理功能损伤,且与辐射剂量相关;(2)近似熵可客观反映微波辐射对脑功能的损伤,对其进行监测和预测,可望成为一个新的评价微波对脑损伤的敏感指标。

Objective To explore the feasibility of applying approximate entropy in the evaluation of microwave radiation-induced brain damage based on approximate entropy and relative power spectral analysis of the monkey electroencephalogram after microwave exposure. Methods According to the differences of the average power density, 15 male macaques were randomly divided into five groups： sham exposure group, 2 mW/cm~, 5 mW/cm2, 7 mW/cm2, and 11 mW/cm2 microwave radiation groups. The approxi- mate entropy and relative power spectrum of ~ and beta band in the macaque electroencephalogram （EEG） were detected before the microwave irradiation and immediately, 1 d, 3 d, 7 d, 14 d and 30 d after exposure, respectively, using the MP- 150 multi-channel physiological recording and analysis system produced by BIOPAC Company. Results （1） The approximate entropy of the 7 mW/cm2 group was im- mediately decreased after the microwave irradiation, while the approximate entropy of the 11 mW/cm2 group significantly decreased immediately and in 1 d, 3 d after microwave exposure. （2）The relative power spectrum of band in the 7 mW/cm2 group was significantly increased immediately after the microwave irradiation, while its relative power spectrum of beta band was significantly decreased. The relative power spectrum of δ band in the 11 mW/cm2 group significantly increased immediately and in 1 d, 3 d after the microwave irradiation, while its relative power spectrum of beta band was significantly decreased. （3） The approximate entropy and the average power spectrum in the 2 mW/cm2 and 5 mW/cm2 groups had no sig- nificant changes after microwave exposure. Conclusions （ 1 ） The microwave radiation of the average power density of 7 mW/cm2 and 11 mW/cm2 can cause a dose related EEG dysfunctions in macaques. （2） The approximate entropy can objectively reflect the brain damage induced by microwave radiation, and its monitoring and prediction are expected to be a new sensitive indicator in the evaluation of micro- wave-induced brain injury.