The purpose of the present study is to control human biological rhythm and life cycle by optimization of awakening timing. We developed a wearable interface for controlling awakening time named "BRAC (biological rhythm based awakening timing controller)". BRAC could estimate bio-rhythm by pulse wave from finger tip and send awake signal to user. An ordinary alarm clock operates according to set times that have to be set in advance. However, humans have a rhythm in their sleep, which affects one's sleep depth and wake-up timing. We consider the simplest way to control or reset human's bio-rhythm or life style is to optimize the awakening timing and the sleeping hours. We examined the relationship between controlling awakening timing based on autonomous nerve rhythm and equilibrium function. Our findings suggest indicate that the prototype "BRAC" could evaluate user's biological rhythm and awakes user at the time optimized for physical function of equilibrium.

The purpose of this research is to control human state and biological rhythm. The system has to be adaptive and intelligent because it must deal with human information including personal differences. As a first step to achieve the function, we try to estimate a human's state in sleep using a wearable sensor device, under less physical movement than daytime. In the next step, we try to control human biological rhythm using the method to estimate human sleep state. We consider the simplest way to control human's sleep is to control awakening timing and sleep time. The proposed system can estimate human sleep quality and rhythms, and provide stimuli based on wake up timing. The system uses only pulse wave to estimate sleep quality because the pulse wave can be measured more easily than PSG.