The modern society is affecting sleep time caused by excessive use of smart phones and electronic devices. Increased stress from lack of sleep negatively affects life by reducing the quality of sleep and reducing the efficiency of daily life. As the number of patients visiting due to sleep problems increases regardless of gender and age, interest in sleep is increasing. Sleeping pills, the most effective and quickest way to treat sleep, are under debate over dietary disorders or mortality, and people have tried to find alternatives to sleeping pills as well as the emergence of a well-being culture. Through these efforts, the scale of the sleeping industry is growing.
By combining the most important bed and sound wave vibration in the sleep environment, we wanted to find out about sleep induction using the physiological signals EEG and HRV. Bed related to sleep induction exists smart bed with fever or lighting, recliner function, and sonic vibrator is used for exercise and rehabilitation purposes. Although smart beds with sonic vibration bed exist, it seems novel to find out the sleep-inducing effects of full-body vibration class beds because they have the purpose of massage functions. In this study, men and women in their 20s were divided into poor sleeper(PS) and good sleeper(GS) groups using PSQI, a sleep quality assessment tool, to identify the decrease of brain wave alpha wave and increase of theta wave and the rate of west wave upon entering sleep, and to see the effects of mental and physical stability, heart rate variability was also observed. The subjects were measured EEG and HRV for 20 minutes in a regular bed, then rested for 5 minutes, followed by 396Hz of sonic vibration for 10 minutes in a smart bed, then remeasured EEG and HRV for 20 minutes.
In the eight attached brain waves channels (F3, F4, C3, C4, P3, P4, P4, O1 and O2), the brain wave changes in PS Group and GS group showed an increase in the theta wave relative power spectrum and a decrease in the alpha wave relative spectrum in both groups. It showed the effect of inducing sleep through full-body vibration stimulation. In addition, when each group observed changes by cutting C4 in minutes, where brain waves are commonly observed during awakening or entering sleep, GS Group showed higher theta and lower alpha waves after full-body vibration than PS group. The PS group showed a tendency for the theta to start lower than before the stimulus but to increase, while the alpha wave tended to decrease after the stimulus, although the start before and after the stimulus was the same. Slow wave ratio has increased for all GS groups except for some channels in the PS group. Each figure in the PS group was higher than that of GS Group. GS group has no difficulty in entering sleep, so the difference in the ratio of west waves before and after sound wave stimulation is not significant. PS groups have difficulties until entering sleep, so it is judged that the difference in the ratio of theta waves before and after sonic vibration stimulation is large, so the ratio of theta waves in PS groups is more efficient than GS groups. Heart rate variability was stable in other analyses except for the tendency for NN50 and pNN50 to decrease in the time band analysis, but was not significant. The full-body vibration stimulation of the sonic vibrator class was shown to be effective in inducing sleep. However, it seems difficult to achieve a clear effect on patients with sleep problems.