Polysomnography
is
a Sleep Scoring technique or study
of sleep, performed taking multiple parameters into consideration. The purpose
of the test is to determine or eliminate the Sleep Disorders from which the subject maybe ailing. The procedure
involves the recording of various biological and physiological changes which a
person goes through while sleeping. The recordings are then subjected to comparison
with the known Sleep Disorder
readings to confirm or reject the possibilities.
The patient is called to the Sleep Clinic in the evening. After briefing him on the procedure,
he is then wired up to the machines which start recording the various changes
as soon as he falls asleep. The recordings are done through a minimum of 12
channels requiring at least 22 attachments. Some of the body functions, which
are measured during the test, are brain activity, muscle activity, eye
movements, heart rhythm, respiratory functions, etc. Once the test is over with
the person waking, the most important parameters which are analyzed include
sleep onset latency (time taken to fall asleep), sleep efficiency (the ratio
between the amount of time spent on bed and the amount of sleep), sleep stages,
breathing irregularities (if any), sleep interruptions, cardiac rhythm, leg
movements, position of the body while sleeping, and oxygen saturation.
Although the entire procedure can be conducted without any human
intervention, it is widely believed that for achieving high accuracy in
results, the presence of Sleep
Technicians and Sleep Experts is
required. The procedure, where the experts are present, is called Manual
Sleep Study Scoring.
