Polysomnography is the multi-parametric test used in the study of sleep. The name is derived from Greek roots: 'Poly' (many), 'somno' (sleep), and 'graphy' (writing). Originally developed by Nathaniel Kleitman and graduate students at the University of Chicago in the 1950s, it has since been codified by the adoption in 1968 of A Manual of Standardized Terminology, Techniques, and Scoring Systems for Sleep Stages of Human Subjects, edited by Allan Rechtschaffen and Anthony Kales. (Online versions: 1. without images, 2. including later findings.)

The test entails the simultaneous recording of the electrical activity of the brain (EEG), eye movements (EOG), skeletal muscle activation (EMG), and heart rhythm (ECG). In the 1970s, respiratory airflow and respiratory effort indicators were added along with peripheral pulse oximetry following the identification of the sleep disorder Sleep apnea.

External links

• Definition of polysomnography from Dr Joseph F. Smith Medical Library
• The American Academy of Sleep Medicine
• The Association of Polysomnographic Technologists
• The Association of Polysomnographic Technologists