Satou Yuka, Ishitake Tatsuya, Ando Hideo, Nagatomi Kaori, Hoshiko Michiko, Tsuji Yoshiyasu, Tamaki Hideki, Shigemoto Akira, Kusano Midori, Mori Mihoko, Hara Kunio
Department of Environmental Medicine, Kurume University School of Medicine, Asahi-machi, Kurume, Japan.
Kurume Med J. 2009;56(1-2):17-23. doi: 10.2739/kurumemedj.56.17.
The purpose of this study was to clarify the influence of different vibration frequencies on wakefulness level. Subjects were 7 healthy male university students aged 21.9+/-1.6 years (mean). All students were non-smokers. Three exposure conditions were used (10 Hz vibration, 20 Hz vibration, and no vibration). Whole-body vertical vibration was applied to subjects sitting on a car passenger seat using a whole-body vibration shaker (CV-300, Akashi) at a single frequency (10 or 20 Hz) at an acceleration level of 0.3 ms(-2) r.m.s. for 24 min. The objective wakefulness level based on EEGs was evaluated in terms of the alpha attenuation coefficient (AAC) obtained by the Alpha Attenuation Test (AAT). As parameters of psychological stress, salivary 3-methoxy-4-hydroxyphenylglycol (MHPG) and homovanillic acid (HVA) were used. The subjective wakefulness level was evaluated using a questionnaire based on the Kwansei Gakuin Sleepiness Scale (KSS), which is a scale developed for the Japanese based on the Stanford Sleepiness Scale (SSS). The KSS score, representing the subjective wakefulness level, decreased after the exposure irrespective of the exposure condition, but the decrease was not significant. The AAC, representing the objective wakefulness level, significantly decreased only after vibration exposure (10 Hz/20 Hz) but did not differ between the two vibration frequencies. No significant changes were observed after exposure to whole-body vibration in MHPG or HVA as parameters of vibration-related stress. The AAC decreased after exposure to whole-body vibration (10 Hz/20 Hz), suggesting a decrease in the wakefulness level. However, no differences were observed in the influence of the two different vibration frequencies test.
本研究的目的是阐明不同振动频率对清醒程度的影响。研究对象为7名健康的男性大学生，年龄为21.9±1.6岁（平均年龄）。所有学生均不吸烟。采用了三种暴露条件（10赫兹振动、20赫兹振动和无振动）。使用全身振动台（CV - 300，明石）对坐在汽车乘客座椅上的受试者施加全身垂直振动，振动频率为单一频率（10或20赫兹），加速度水平为0.3米每二次方秒均方根值，持续24分钟。基于脑电图的客观清醒程度通过阿尔法衰减测试（AAT）获得的阿尔法衰减系数（AAC）进行评估。作为心理压力参数，使用了唾液3 - 甲氧基 - 4 - 羟基苯乙二醇（MHPG）和高香草酸（HVA）。主观清醒程度使用基于关西学院嗜睡量表（KSS）的问卷进行评估，该量表是在斯坦福嗜睡量表（SSS）基础上为日本人开发的。代表主观清醒程度的KSS评分在暴露后无论暴露条件如何均有所下降，但下降不显著。代表客观清醒程度的AAC仅在振动暴露（10赫兹/20赫兹）后显著下降，但两种振动频率之间没有差异。作为与振动相关压力参数的MHPG或HVA在全身振动暴露后未观察到显著变化。全身振动（10赫兹/20赫兹）暴露后AAC下降，表明清醒程度降低。然而，在两种不同振动频率测试的影响方面未观察到差异。
