Effect of 450 MHz Microwave Modulated with 217 Hz on Human EEG in Rest

Summary This study focuses on discrimination of changes, produced by low-level microwave exposure in intensity and time variability of the human EEG at rest. The power spectral density (PSD) method and nonlinear scaling analysis of the length distribution of low variability periods (LDLVP) were selected for analysis of the EEG signal. During the study, 19 healthy volunteers were exposed to a microwave (450 MHz) of 217 Hz frequency on-off modulation. The field power density at the scalp was 0.16 mW/cm². The experimental protocol consisted of ten cycles of repetitive microwave exposure. Signals from frontal, temporal, parietal and occipital EEG channels on EEG theta, alpha and beta rhythms were analysed. Exposure to microwave causes average increase of EEG activity. LDLVP analysis discriminated significant effect in time variability for 2 subjects (11%). PSD method detected significant changes in intensity for 4 subjects (21%). The effect of low-level microwave exposure is stronger on EEG beta rhythm in temporal and parietal regions of the human brain.     

基于EEG频谱特征的驾驶员疲劳监测研究

研究表明疲劳驾驶是引发交通伤亡事故的重要原因之一,因此有必要采取相应的预防措施。脑电是公认的睡眠(疲劳)金指标,因此论文提出了基于脑电频谱特征的驾驶员疲劳预测方法。采用了驾驶模拟实验中记录的三路驾驶员脑电信号,并利用驾驶员自评与专家评定两种方式相结合的方法将驾驶数据分为疲劳和清醒。针对脑电中眼电噪声很强的特点,对记录的脑电进行了自适应滤波消噪处理,结果显示可有效滤除眼电伪迹;然后根据脑电的频域特征比较突出且与疲劳相关的特点,从去噪后的脑电中提取出了的75个频谱特征;最后利用这些频谱特征,采用朴素贝叶斯分类的方法建立了驾驶员疲劳监测模型。实验结果表明,该方法能监测出驾驶员84%的疲劳状态。     

The Effects of the Level of Alertness During the Rest Period on Subsequent Performance

The aim of this study was to examine how to take an effective rest to prevent a decline in alertness at work. The relationship between alertness during the rest period and subsequent task performance were investigated. The electroencephalogram (EEG) during the rest period was classified into 3 types, and these types had a significant effect on performance after the rest period. Type 1 (increasing in theta, alpha 2, and beta 1 power) was the best one for carrying out the task, whereas performance gradually declined in Type 3 (no change in EEG activity). In the case of Type 1, the method that would relieve sleep inertia had a more positive impact on performance after the rest period.     

Diversity of Ontogenetic Pathways in Plant Populations

Population heterogeneity in cespitose, fibrous-rooted, brevirhizomatous, stoloniferous, and tap-rooted herbaceous and woody plants is described. This heterogeneity is caused by the multivariant character of plant ontogeny (i.e., its dimensional, morphological, rhythmological, and temporal multiversality), which is regarded as the main adaptation mechanism operating in plant populations because it provides for the diversity of ontogenetic pathways under different ecological conditions.     

Orientation in the intertidal salt-marsh collembolan Anurida maritima

We investigated the cues used by the intertidal insect Anurida maritima (Apterygota: Collembola) to orient to the appropriate zone in which to seek shelter during high tide. Our experiments clearly ruled out any significant role for magnetic, local topographic, slope or celestial cues. Instead, we suggest that the difference between the appearance of the up-shore and the down-shore horizon is the major cue used by the collembolans. When a mirror was used to duplicate either of the two horizons, the insects were not able to orient. The insects moved towards an artificially dark horizon (the reverse of the mirror) placed down-shore, the opposite of their usual direction of movement. The insects had an endogenous circatidal rhythm of phototactic behaviour: most of the population was always negatively phototactic, but between 2 and 7 h after low tide, a significant proportion of the population became positively phototactic. This is the first demonstration of an endogenous tidal rhythm of orientation in an insect. Received: 31 May 1999 / Received in revised form: 1 February 2000 / Accepted: 19 February 2000     

Exploring differences between self-report and electrophysiological indices of drowsy driving: A usability examination of a personal brain-computer interface device

IntroductionImpaired driving has resulted in numerous accidents, fatalities, and costly damage. One particularly concerning type of impairment is driver drowsiness. Despite advancements, modern vehicle safety systems remain ineffective at keeping drowsy drivers alert and aware of their state, even temporarily. Until recently the use of user-centric brain-computer interface (BCI) devices to capture electrophysiological data relating to driver drowsiness has been limited. Method: In this study, 25 participants drove on a simulated roadway under drowsy conditions. Results: Neither subjective nor electrophysiological measures differed between individuals who showed overt signs of drowsiness (prolonged eye closure) during the drive. However, the directionality and effect size estimates provided by the BCI device suggested the practicality and feasibility of its future implementation in vehicle safety systems. Practical applications: This research highlights opportunities for future BCI device research for use to assess the state of drowsy drivers in a real-world context.     

基于EEG的有限空间检修工脑疲劳特性研究

为了探究有限空间内检修工在高温高湿状态下的脑疲劳特征,采用对照与模拟有限空间作业环境相结合的方法,对作业人员脑电波变化进行监测,利用傅里叶变换对原波信号进行时频转换,提取相对频率、重心频率等特征参数。研究结果表明:在高温高湿的有限空间环境中,人体脑波功率变化幅度明显变大;在进入疲劳状态时有限空间环境的脑波功率低于对照组;高频的β波在高温高湿环境中减少的比例较大,平均下降7.1%;脑波重心频率由8 Hz降为6 Hz,平均下降11.3%,由α波变为θ波,大脑活动进入疲劳状态。说明有限空间的高温高湿环境对人体脑疲劳具有明显影响,可用于脑电智能穿戴监测设备监测工人脑疲劳状况。     

Individual changes in human EEG caused by 450 MHz microwave modulated at 40 and 70 Hz

This study was aimed to investigate the changes in the human electroencephalographic (EEG) signal caused by modulated low-level microwaves. The 450 MHz microwave exposure modulated at 40 Hz and 70 Hz frequencies was applied to a group of 15 volunteers. The field power density at the scalp was 0.16 mW/cm². Ten cycles of the exposure (1 min on and 1 min off) at both modulation frequencies were applied. Analysis of the EEG signal was performed using three different methods: nonlinear method of scaling analysis for length distribution of low variability periods (LDLVP), relative changes in EEG energy (S-parameter) and beta ratio (H-parameter). The analysis revealed significant changes caused by microwave for the whole group (H-parameter method). The exposure caused increase of the EEG beta power (S-parameter method). Statistically significant changes in EEG were detected for four subjects (26.7%) at 40 Hz modulation frequency (LDLVP method).     

modifications of ultradian and orcadian rhythms of fetal heart rate after fetal-maternal adrenal gland suppression: A double blind study

In order to verify whether fetal and maternal adrenal gland suppression induces effects on fetal behaviour, triamcinolone was administered to five healthy pregnant women at 35 weeks of gestation. Five patients of the same gestational age were used as control. Fetal heart rate (FHR) and fetal movements were recorded continuously over 2-h interval by means of cardiotocography. After 3 weeks (38 weeks of gestation) the recordings were repeated without drug administration. Cortisol, adrenocorticotropin hormone, 17 β-estradiol and unconjugated estriol were measured at the same time every 2 h in maternal peripheral plasma. At 35 weeks we found a loss of circadian rhythms of the hormones investigated and modifications of ultradian and circadian patterns of FHR in the treated group with respect to the control. No differences in hormonal and biophysical parameters were found between the two groups after the end of treatment (38 weeks). These data suggest that the inhibition of fetal and maternal adrenal glands could cause modifications of FHR patterns.     

生物节律理论在铁路行、调车安全中的应用探讨

首先对生物节律理论的涵义以及相关专业论文著作中对临界日的主要观点进行了概述。通过对生物节律理论的研究,提出了扩大范围的"72小时临界期"作为统计样本数据的依据。经过对37个样本的统计分析得出,对于铁路行、调车工种情绪高潮期是危险多发阶段,并归纳出"低低高、高高高、临低高、低高高"四类针对行、调车工种的"特别危险"级别的生物节律组合,然后使用四起一般事故作为以上分析结果的佐证。给出了生物节律在行、调车安全生产中应用的四项建议。最后,得到生物节律技术是对传统安全管理方法补充的结论。