排序方式: 共有6条查询结果,搜索用时 15 毫秒
1
1.
Maie Bachmann Maksim Säkki Jaan Kalda Jaanus Lass Viiu Tuulik Hiie Hinrikus 《The Environmentalist》2005,25(2-4):165-171
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. 相似文献
2.
Maie Bachmann Ruth Tomson Jaan Kalda Maksim Säkki Jaanus Lass Viiu Tuulik Hiie Hinrikus 《The Environmentalist》2007,27(4):511-517
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). 相似文献
3.
This study is aimed to clarify whether effect of low-level microwave radiation on human brain differs at different modulation
frequencies. Resting EEG recordings were done on different groups of healthy volunteers. The 450 MHz microwave radiation modulated
at 40 and 70 Hz (15 subjects) and 217 and 1,000 Hz (19 subjects) frequencies was applied. The results of our previous study
at 7, 14 and 21 Hz modulation were included into analysis. Ten cycles of the exposure (1 min off and 1 min on) at each fixed
modulation frequencies were applied. The field power density at the scalp was always 0.16 mW/cm2. Our results showed that microwave exposure increased the EEG energy at EEG frequencies lower or close to the modulation
frequency. No effect was detected at EEG frequencies higher than the modulation frequency. Statistically significant changes
were caused by exposure in the EEG alpha and beta frequency bands; no significant effect was detected in the theta band. Our
results suggest that telecommunication devices with complex spectrum of modulation frequencies like mobile phone can affect
all human EEG frequency bands. 相似文献
4.
Hiie Hinrikus Ruth Tomson Jaanus Lass Deniss Karai Jaak Kalda Viiu Tuulik 《The Environmentalist》2005,25(2-4):157-163
Summary This study is aimed to investigate dependence of nerve pulse conduction velocity on low-level microwave exposure. The changes
in fiber membrane permeability or myelin sheath, caused by microwave, should affect nerve pulse conduction velocity. Experimental
investigation was carried out for nerve pulse conduction velocity with and without applied microwave field and different orientations
of its polarization to the nerve fiber. Microwave radiation of 450 MHz was applied polarized perpendicular or parallel to
the nerve fiber. The measured field power density at the skin was 0.87 mW/cm2. Special program was developed for calculation of the nerve pulse conduction velocity in LabView environment. The right nervus
medianus motor nerve fibers of 35 young subjects were under the study. The experimental protocol included ten measurements
in every cycle of five different exposure conditions. No changes in average values of the conduction velocities discovered
in different exposure conditions. Theoretical calculations based on Hodgkin-Huxley model confirm only a weak possible effect.
The results showed that low-level microwave radiation did not cause statistically significant change in nerve pulse conduction
velocity in human motor nerve fiber. 相似文献
5.
Maie Bachmann Hiie Hinrikus Kaire Aadamsoo Ülle Võhma Jaanus Lass Jekaterina Rubljova Anna Suhhova Viiu Tuulik 《The Environmentalist》2007,27(4):505-510
This study was aimed to evaluate differences in the effect of microwave exposure on patients with depressive disorder and
healthy subjects. Our experiments were carried out on a group of depressive patients (women, 18 subjects) and comparison group
of healthy volunteers (women, 18 subjects) exposed during 30 min to 450 MHz microwave radiation modulated at 1,000 Hz frequency.
The field power density at the scalp was 0.9 mW/cm2. As a subjective criteria of microwave effect, the Brief Affect Scale (BAS) and Visual Analogue Scale (VAS) before and after
each exposure procedure were used. The analysis of EEG was performed and ratio of the EEG beta and theta power was selected
as a measure for evaluation of the microwave effect. The BAS and VAS revealed rather improvement in subjective mood score
after exposure for majority of depressive subjects (11) and no changes for others (7). The EEG analysis detected differences
between calculated parameters for exposed and sham recordings in depression as well as healthy group. Statistically significant
changes were introduced by microwave for five patients with depressive disorder and for one healthy subject. The rate of subjects
affected by microwave in depression group (28%) was five times higher compared to that rate in healthy group (5.6%). 相似文献
6.
Tuulik Varje-Riin Kumm Monika Tuulik Viiu Veraksitš Alar Päll Taavi 《Environmental geochemistry and health》2022,44(7):2101-2110
Environmental Geochemistry and Health - The effects of bath therapy are complex and result from a unique interaction between the aquatic environment and the human body functions. The effect of bath... 相似文献
1