Habituation of sleep to road traffic noise by Actiwatch

通过腕部加速度计和睡眠测谎仪的身体运动来评估睡眠对道路交通噪声的习惯。研究对象是4名21岁的学生，他们在睡眠实验室里独立睡了17个晚上。从第5晚到第14晚，道路交通噪声整夜暴露。第5 ~ 17夜连续实验。日常生活是不受限制的。他们通常在22点睡觉，第二天早上7点左右起床。ACTIWATCH被安装在他们隐性手臂的手腕上。采样频率32Hz，灵敏度0.05G，以1分钟为单位计数。身体运动的次数是通过有功电量的总和来计算的。如果数到40或40以上，我们就认为这是觉醒。虽然小于40，但n（e-2）×0.04+n（e-1）×0.2+n(e)+n（e+1）×0.2+n（e+2）×0.04超过40，则判定为觉醒。通过该算法计算18个夜晚，ACTIWATCH【encircledR】与睡眠测谎仪的一致性平均为87%。心理肌活动无明显变化趋势。实验对象A的睡眠潜伏期在最近三天内迅速增加。睡眠测谎结果显示，受试者b的全身运动百分比与心理肌活动有显著关系。被试B、C、d在快速眼动期的身体运动显著增加，而被试A、B、d在快速眼动期的身体运动显著增加。后一事实不符合逻辑，因为肌肉张力下降。实验对象d在慢波睡眠中身体运动明显减少。从简单的角度看，用加速度计测量身体运动是监测噪声对睡眠影响的一个很好的指标。由于存在一定的个体差异，需要更多的案例来检验睡眠测谎仪的有效性。

The habituation of sleep to road traffic noise was evaluated by body movement using wrist accerelometer and also sleep polygraphy.Subjects were four 21-year old students and they slept for 17 nights independently in a sleep laboratory. From fifth to 14th nights, road traffic noise was exposed all-night long. From fifth to 17th night, consecutive experiments were conducted. The daily life is not limited. They usually go to bed at 22 o'clock and gets up around seven o'clock in the next morning. ACTIWATCH【encircledR】 was installed in the wrist of their recessive arms. The sampling frequency was 32Hz and sensitivity was 0.05G, counting for one minute as a unit. The number of body movement was calculated by the summation in the number of active electricity. If the count is 40 or over, we judged it as awakening. Though under 40, n(e-2)×0.04+n(e-1)×0.2+n(e)+n(e+1)×0.2+n(e+2)×0.04 exceeds 40, then we judged it as awakening. By this algorithm, the agreement between ACTIWATCH【encircledR】 and sleep polygraph was 87% on average by calculating 18 nights.There was no trend in activity of mental muscle. Sleep latency in subject A in the last three days increased rapidly. Body movement % for all-night long decreased significantly in subject B. There was a significant relationship between body movement % and activity of mental muscle by sleep polygraphy.A significant increase of body movement in MT was recognized in subjects B, C, D. A significant increase of body movement in REM was recognized in subjects A, B, D. The latter fact is not logical because of drop in muscle tonus. There was a significant decrease of body movement in slow wave sleep in subject D.Body movement by accerelometer seems to be a good indicator for monitoring the effect of noise on sleep from the point of simplicity. As some individual differences are existed, much more cases are needed to check the validity using sleep polygraphy.