Impact on Sleep Quality of Electronic Device Usage

A recent research result reports that the use of electronic devices is one of the factors affecting sleep. Polysomnography, in which EEG (Electroencephalogram), heart rates, and so on are measured, is often used to measure the state of sleep. Polysomnography burdens subjects because electrodes need to be attached to their heads and chests all night long. On the other hand, wearable devices have recently become popular as small and lightweight measurement devices worn on the body due to electronic circuit downsizing. A typical example is a wrist-watch type device, which can measure heart rates and sleep status just by being worn on the wrist. This study aims to clarify the effect of using electronic devices before bedtime on the quality of sleep through experiments. The sleep state of the subjects was measured by using a wearable device in the experiments. The measured results are compared based on the three kinds of tasks to the subject in pre-sleep time: regular books, electronic books (e-books), and electronic games (e-games). The results of statistical analysis for the measured data have shown that e-books and e-games increased the time to fall asleep and decreased sleep efficiency compared to reading regular books.