Actigraphy in Sleep Disorders

Actigraphy is a method for measuring activity with computerized wristwatch like devices. During the several decades, technological advances have improved the availability of these devices, with miniaturizing their size and increasing memory capacities and detection sensitivity. Compared with polysomnography, the gold standard for evaluation of sleep, actigraphy has unique advantages which are less expensive, noninvasive, less limited in time of recording, and more conductive to repeated measures. Now, actigraphy is used increasingly in clinical practice and research for sleep and other circadian rhythm abnormalities. This paper includes the basic technology and algorithms of actigraphy, reliability and validity issues, and general consideration for applications. Also it reviews the current literatures regarding use of actigraphy in sleep disorders including insomnia, obstructive sleep apnea, and periodic limb movement disorder and other psychiatric disorders related to alteration of circadian rhythm.