V, W, X, Y, Z

V, W, X, Y, Z

V

vinger-oxymetrie - meting van het zuurstofgehalte in het bloed via vingertopje

W

Wake Time - The total time scored as wakefulness in a polysomnogram occurring between "lights out" and final awakening.

White Noise - A mixture of sound waves extending over a wide frequency range that may be used to mask unwanted noise that interferes with sleep. Also called white sound.

Wilkinson Addition Test - A performance test in which the subjects add numbers for one hour. Often included in a battery of tests to measure the impact of acute or chronic sleep loss.

Withdrawal - The negative effects experienced when a person stops taking sleeping pills.

X

Nil

Y

Nil

Z

Zeitgeber - An environmental time cue that entrain biological rhythms to a specific periodicity. Known Zeitgebers are light, melatonin and physical activity. To be effective, these signals must occur when the biological clock is in a responsive phase.

zuurstofdesaturatie - sterke daling van de zuurstofgehaltes: 5% wordt afwijkend beschouwd.