Noun
English Wikipedia has an article on:vital signsWikipedia
vital signs pl (plural only)
(medicine) A set of measurements of a patient's condition taken regularly to assess the state of bodily functions: CSM, skin signs, lung sounds, temperature, pulse, blood pressure, and respiration.
Vital signs in medicine are temperature (rectal is most accurate), blood pressure, heart rate (pulse), respiratory rate, and oxygen saturation. Source: Internet
Vital signs indicate arousal and oxygen consumption by the brain is higher than when the sleeper is awake. citation An adult reaches REM approximately every 90 minutes, and remains in REM sleep for longer during latter half of sleep. Source: Internet