Development of a Sleep Monitoring System With Wearable Vital Sensor for Home Use

Abstract

Abstract:This paper describes a new sleep monitoring system for home use. The basic system consists of a wearable physiological sensor and PC software for analyzing sleep quality from user's wrist motion and heart rate variability. Different from a conventional sleep monitoring device used in a hospital, the sensor is so small and easy-to-use that a normal person can use it at home. This means that the system is useful for a sleep specialist who wants to check a patient's daily sleep pattern. The system can also be used for self-care. We have developed a wrist-watch-shaped physiological sensor that monitors user's wrist motion and pulse wave interval. We have also developed the algorithm for computing the quality of sleep from these physiological data on PC. Although sleep is a kind of brain activity and our sensor can not directly measure it, the output of our algorithm is close to medically evaluated sleep quality. We performed dozens of comparison experiments and found that its accuracy was about 73.5% on average. The value of the accuracy is enough for assessing a normal person's sleep quality.

Evaluation of Autonomic Nervous System Function During Sleep by Mindful Breathing Using a Tablet Device: Randomized Controlled Trial

“…The square root of the integral of the LF and HF power spectrum densities was calculated to suppress the variability and improve the accuracy of sleep determination. The time of sleep onset was estimated using Cole et al’s [ 33 ] method using acceleration data to determine the time of sleep onset, and the sleep stage classification was estimated based on the autonomic balance during the period when sleep was determined via acceleration data [ 34 ]. In this study, the acceleration sampling frequency of the accelerometer of the measurement device Small_System was recorded and analyzed at 125 Hz.…”

“…Sleep stages were assessed based on the relationship between autonomic activity and sleep stage and were divided into the following three stages: (1) sleep with sympathetic nerve dominance (S sleep), (2) shallow sleep with parasympathetic nerve dominance (PS sleep [shallow]), and (3) deep sleep with parasympathetic nerve dominance (PS sleep [deep]) [ 34 ]. As the sleep stages used in this study were measured using nonmedical equipment, expressions such as S sleep and PS sleep were used.…”