Actigraphy is a technique for providing objective measurements of a person's activity levels over a given period of time. It involves wearing a small monitor to record motor activity. The device can generate a log or transmit data, and may be part of a diagnostic workup for a person with a suspected sleep disorder. Patients may receive actigraphy through a sleep clinic or sleep specialist, after a referral from a regular physician.
This device is noninvasive and less intrusive than many methods of sleep monitoring. It also allows a doctor to track activity levels over the course of the day. People with disruptions to their circadian rhythms may experience activity slumps at various points during the day, and are sometimes unaware of it, leading them to leave it off self-reporting worksheets. A doctor will use these sheets to try and narrow down a patient's activity and sleep patterns, so missing data can be a problem. At night, the actigraphy readings can show when a person wakes up and how active the person is during the night. If the person fails to remember and note the incident in a sleep journal, the log from that night will provide information.
A common location for the sensor is on the wrist, where it can be worn like a watch. Usually, the patient wears the device on the non-dominant hand. People can also wear devices on their legs or around their waists, depending on the reason for the study and their needs. Many are capable of keeping large logs, allowing a patient to wear them continuously for several days to generate a mass of useful data. Transmitting devices may be useful for sleep studies where a doctor wants to be able to monitor the patient remotely.
In addition to an actigraphy study, a doctor may request brain imaging and some other techniques to learn more about what is happening inside the patient's brain. All of this information can provide valuable insights into why someone is experiencing problems like insomnia, daytime sleepiness, or restless nights. The doctor may prescribe a variety of treatments, including medications, exercise, changes to eating schedules, and so forth, with the goal of helping the patient sleep well.
Patients who want to see the results of their actigraphy studies can ask their doctors. Charts and graphs providing basic overviews of a patient's activity levels are available and a doctor can explain the meaning of specific readings if the patient is curious.