Unattended and portable sleep studies are carried out only by or under the supervision of the sleep physician. There are different types of sleep studies each of which will provide different information. The information is obtained from either a paper recording polygraph or a computerized system capable of storing as well as displaying raw and unedited data. The physiological recording is visually scored by a polysomnographic technologist who is trained to monitor and document the recording according to standardized defined protocols. A qualified sleep physician is responsible for interpreting the polysomnogram.
Most patients only require a single overnight polysomnogram.
For some patients, a second study may be needed when the results are inadequate or inconsistent with the clinical symptoms or if a parasomnia under investigation does not occur. The type of study performed is determined by the sleep physician based on appropriate clinical indications as provided by the referring physician. Full PSG includes sleep staging and cardiopulmonary and limb movement monitoring. Respiratory sleep studies consist of cardiopulmonary monitoring without EEG sleep staging. EEG sleep studies include sleep staging and movement without cardiopulmonary monitoring.