SYSTEM FOR MONITORING SLEEP EFFICIENCY

A system for monitoring sleep efficiency includes a measuring device and a data processing device. The measuring device is for measuring body temperature of a subject and for outputting temperature data associated with the body temperature. The data processing device receives the temperature data, and is programmed to process the temperature data so as to determine sleep efficiency. The processing of the temperature data includes constructing a curve of the body temperature over asleep episode, finding a saddle point of the curve occurring for a first time, treating a time instance at which the saddle point occurs as a sleep-onset time point at which the subject falls asleep, and determining the sleep efficiency according to the sleep-onset time point.