Sleep and wakefulness state detection in nocturnal actigraphy based on movement information.Wrist actigraphy (ACT) is a low-cost and well-established technique for long-term monitoring of human activity.  It has a special relevance in sleep studies, where its noninvasive nature makes it a valuable tool for behavioral characterization and for the detection and diagnosis of some sleep disorders.  The traditional sleep/wakefulness state estimation algorithms from the nocturnal ACT data are unbalanced from a sensitivity and specificity points of view since they tend to overestimate sleep state, with severe consequences from a diagnosis point of view. 
ACT