Actigrafi

Actigrafi (also known as actigraphy or actimetry) is a non-invasive method for monitoring human rest–activity cycles by measuring body movement. Devices called actigraphs or actimeters are typically worn on the wrist and contain accelerometers that record motion continuously over days to weeks. Data are processed in time epochs and analyzed with algorithms to estimate sleep and wake periods, activity levels, circadian rhythm parameters and sleep fragmentation.

Uses include sleep research, clinical assessment of insomnia, circadian rhythm disorders and hypersomnolence, as well as studies in psychiatry, neurology and pediatrics. Actigraphy is useful for long-term, real-world monitoring because it is inexpensive, unobtrusive and allows collection of habitual sleep patterns in natural settings. It is often used alongside sleep diaries and questionnaires.

Limitations include lower specificity for detecting wakefulness during sleep compared with polysomnography, sensitivity to non-sleep movements and variability across devices and scoring algorithms. Actigraphy cannot directly measure physiological signals such as brain activity or respiration and therefore cannot diagnose conditions like sleep apnea. Some devices also incorporate light sensors, heart rate or temperature to improve circadian and sleep estimates. Both medical-grade and consumer-grade actigraphs exist; clinical interpretation should consider device validation, epoch settings and algorithm choice.