actigraphymay

Actigraphy is a non-invasive method used to estimate a person's sleep-wake patterns. It is typically conducted using a small, wrist-worn device called an actigraph. This device contains an accelerometer that detects and records movement. When the wearer is still for an extended period, it is inferred that they are asleep. Conversely, periods of activity suggest wakefulness.

The primary applications of actigraphy lie in sleep research and the clinical assessment of sleep disorders. Researchers use it to study normal sleep architecture, the effects of lifestyle on sleep, and the impact of various conditions on sleep patterns. Clinically, it is employed to help diagnose and monitor conditions such as insomnia, circadian rhythm disorders, and sleep disturbances associated with other medical or psychiatric illnesses. Actigraphy can provide objective data that complements subjective reports from sleep diaries or questionnaires.

The data collected by an actigraph is processed by specialized software to generate a hypnogram, which is a visual representation of estimated sleep and wake periods over time. This allows for the calculation of various sleep parameters, including total sleep time, sleep efficiency, sleep onset latency, and wake after sleep onset. While actigraphy is a valuable tool, it is important to note that it estimates sleep and wakefulness based on movement, and does not directly measure physiological sleep stages like polysomnography does. Therefore, it is often used as a screening tool or in conjunction with other diagnostic methods.