Aegis: A biofeedback adaptive alarm system using vibrotactile feedback

Aegis is a “smart” wireless-wristband alarm system that takes as input not a specific alarm time, as in traditional alarm systems, but rather a time interval specified by a user. The system then automatically chooses the optimal alarm time within that range to minimize sleep inertia in the user after waking. Worn as a wristband, Aegis continuously processes their movement readings to map their sleep stages throughout the night, and remembers the individual user´s typical sleep pattern from previous nights, combining these two sources of data to predict where in the sleep cycle the user-set time range will fall. Because sleep inertia is caused by an interruption of deep sleep, Aegis chooses its alarm time to coincide with periods of light sleep, and wakes up the user by vibrating the wristband instead of sounding an alarm, to minimize noise disturbance of roommates, spouses, and/or family members. Preliminary performance evaluation demonstrated the ability of Aegis to track sleep patterns and user satisfaction was confirmed via questionnaires and debriefing.