Polysomnography (
PSG), a type of
sleep study, is a
multi-parametric test used in the study of
sleep and as a diagnostic tool in
sleep medicine. The test result is called a
polysomnogram, also abbreviated PSG. The name is derived from
Greek and
Latin roots: the Greek πολύς (
polus for "many, much", indicating many channels), the Latin
somnus ("sleep"), and the Greek γράφειν (
graphein, "to write").