Actigraphy

Actigraphy Doctor in Colorado

What is Actigraphy?

Actigraphy is a non-invasive method used to monitor and assess human rest and activity cycles, particularly sleep patterns. It involves wearing a small device, called an actigraph, worn like a wristwatch on the non-dominant hand that records movement over extended periods of time, ranging from several days to weeks.

How does actigraphy work?

The actigraphy contains an accelerometer that detects motion by measuring waves of movement like vibrations and how fast the movements are. By analyzing these movements, the doctor can infer sleep-wake patterns. For example, minimal movement usually indicates sleep, while increased activity suggests wakefulness. Our devices also measure light exposure, aiding in the assessment of circadian rhythms and components that may interfere with your ability to sleep. The use of actigraphy in addition to a sleep diary or log can improve the accuracy of the analysis.

How do I use an actigraph?

Secure the actigraph to your nondominant wrist (nearest the hand you don’t write with regularly or ankle). Make sure the device fits comfortably and is not too loose or too tight. It should not move up or down your skin while you are wearing it. You will be told how long to wear the device to collect data. You should wear the device continuously. If you must remove the device, please note in your actigraphy log the exact dates and time you needed to remove it. Upon completion of wearing the actigraph, Dr. Rosenthal will collect the device, evaluate the data and then will be able to review the results with you.

When is actigraphy indicated for diagnosing a sleep disorder?

 Circadian rhythm sleep disorders
 Insomnia and the effectiveness of treatment interventions, such as response to cognitive behavioral therapy for insomnia or pharmacological treatments.
 Central disorders of hypersomnolence (Narcolepsy and Idiopathic hypersomnia)

What information does actigraphy provide?

 “Sleep” and “wake” patterns based upon immobility or movement, respectively.
 Average activity counts: Average value over an entire period scored as “wake” by software algorithm. Average activity counts are provided for each 24-hour period.
 Time in bed: Total amount of time indicated as “rest” according to the sleep log. “Sleep” will only be scored when immobile and in “rest” period.
 Total sleep time: Total sleep time represents the total number of minutes scored as “sleep” within the 24-hour day.
 Light intensity: Some actigraphs measure light intensity, including three color bands of the visible spectrum. This is useful for determining how light exposure may be contributing to a sleep pattern that is delayed, advanced, irregular, non-24 hour pattern or shift work pattern.
 Sleep onset latency: This is the time elapsed between the beginning of “rest” and the beginning of “sleep” as scored by the software algorithm. The validity relies heavily on the accuracy of the self-reported actigraphy log which can vary significantly from patient to patient.

What information can be derived from actigraphy?

 Sleep efficiency: the total amount of time scored as “sleep” in an interval that has been denoted as “rest”.
 Diurnal variation: Variation in activity levels within one day as well as from day to day.
 Number of sleep periods
 Wake after sleep onset: The total number of events scored by the algorithm as “wake” during an interval that has been denoted as “rest.”