Actigraphy – What is it and how does it help diagnose Sleep Disorders?
Knowing how you sleep is essential for dealing with sleep problems, and Actigraphy is a way to record it. Maximising the benefits of sleep can dramatically impact your overall well-being. However, when you encounter issues that disrupt sleep, it can cause serious problems in daily life. Many sleep disorders appear very similar on the surface. Only by recording sleep patterns and sleep quality can specialists diagnose the issue.
It is an entirely noninvasive process. An actigraphy watch is commonly worn on the non-dominant hand for two weeks. During this time, the actigraphy records your activity using a combination of light and movement sensors. This allows the actigraph to build a picture of your sleep patterns, including time and duration.
Actigraphy is essential in diagnosing sleep disorders because that data can show how sleep is affected. For instance, if data shows sleep patterns shifting later into the evening, that reveals something. What may originally have been thought to be insomnia could be some form of circadian rhythm disorder.
Collecting data like this is essential in understanding how sleep is affected, which is key to a successful diagnosis. Sleep disorders are notoriously difficult to identify as research is limited and patients are often unable to identify patterns themselves. Yet, sleep disorders differ in their causes and, as a result, their treatment. Knowing which sleep disorder you are suffering from is crucial in providing the proper treatment.
While sleep diaries can help, they can be inaccurate. Wrist actigraphy offers comprehensive data without your input. Just wear the device, and it builds the dataset your doctor needs.
What types of data does an Actigraph gather?
Actigraphy is so successful in helping diagnose sleep disorders because it records accurate data. It does this by using sensors that detect movement and sometimes light. The sensors identify when you are asleep through that movement or a lack of movement.
During this process, it builds a database of sleep patterns that includes:
- The time you fall asleep at night
- The time you wake up in the morning
- Any point where you wake up and then go back to sleep during that time
- Sleep duration – how long you were asleep
- How long it takes you to get to sleep after going to bed
- How long you are awake each day
Some actigraphy devices also contain light sensors that monitor light levels around you. They record the blue light emitted from electronic devices such as TVs, computers, and phones. This blue light can affect the production of melatonin, the hormone that triggers sleep.
With this data, Actigraphy provides insight into sleep patterns that help establish what is going on with sleep. This can eliminate some types of sleep disorders or confirm others. The benefit of this over a traditional sleep diary is that it offers more accurate data and more data in general. It is also much easier for you; all you do is put on the actigraphy watch and let it do the rest.
The device must be worn constantly throughout the actigraphy test to deliver accurate data. It should be placed on the non-dominant wrist. So, if you are right-handed, wear it on your left wrist.
Are there any disadvantages of Actigraphy?
Since actigraphy watches became widely used, some studies have been conducted on their effectiveness. In general, 15 studies released since 2004 have found the actigraphy process accurate in assessing total sleep time and identifying periods when people wake at night and eventually return to sleep.
However, one area where there is some variation depending on the person and device is estimating sleep onset delay, that is, how long it takes from going to bed to falling asleep. The best practice for diagnosing sleep disorders should always be a personal sleep diary in tandem with actigraphy. Discrepancies between the wrist actigraphy data and the sleep diary can be considered during analysis.
Actigraphy is not as accurate as polysomnography, which is conducted under laboratory conditions. Having to sleep in a laboratory under supervision offers the best data. But it is an experience that few enjoy. However, unless you have an extremely complex problem, actigraphy at home is enough for the diagnosis of a sleep disorder.
What can one expect from an Actigraphy Test?
It’s a straightforward process that works without your input. Once you receive your actigraphy watch, place it on your non-dominant wrist. Make sure it is not covered by clothing. Your medical team will give you instructions on how to use it. In addition, your doctor will set the length of the test.
You then go about your everyday life as you would every other day. The actigraphy device should be kept on at all times, where possible. However, you may have to remove it in some situations, such as swimming or playing sports. Some fully waterproof models are available now that are ideal if you swim regularly.
You may be asked to fill in a sleep diary using actigraphy, but generally, that is it. The device will record everything automatically once the period is over, whether one or two weeks, and you return the wrist actigraphy to your doctor. They can then extract the data and start analysing your sleep. That is it, and your actigraphy test is done.
Conclusion
Actigraphy is an easy, convenient and accurate way to record your sleep patterns. If you are struggling with a sleep disorder, a sleep diary is a valuable tool to help doctors identify the problem. Worn like a watch, actigraphy devices are one of the best tools to help you find a solution to your sleep problems.
Featured photo by FitNish Media on Unsplash