Before revision: Sleep Tracking Devices and Methods Developed in the late 1950s, a polysomnograph, also known as a polysomnogram or a 'sleep study', is a test used to diagnose sleep disorders and is considered as the best and most reliable method to collect sleep data from individuals.
After revision: Devices and methods Developed in the late 1950s, a polysomnograph, also known as a polysomnogram or a 'sleep study', is a test used to diagnose sleep disorders and is considered as the best and most reliable method to collect sleep data from individuals.