Estimation of sleep cycle and quality based on nonlinear analysis of heart rate variability

In this paper, we propose a wake up alarm system based on human information. Now, the alarm clock we are using, operates according to time and wakes us up at the time set in advance. But human has rhythm in one's sleep cycle and the cycle affect one's sleep depth and wake-up. Moreover the waking resets human daily rhythm. Therefrom, proposed system estimates human sleep quality and rhythms, and stimulates the user at the timing easy to wake. The system uses pulse wave to estimate sleep quality because pulse wave can be measured easily than PSG . Additionally, the check system including the estimation algorithm could inform pattern and quality of his daily sleep to a user and then the user can arrange his life schedule and pays more attention based on this awareness of sleep results.