Måling av raske øyebevegelser som et estimat av total våkentid

Søvntrykket øker med lang våkentid. Økt søvntrykk fører til økt søvnighet, kognitive funksjoner blir svekket, årvåkenhet svekkes og faren for å gjøre feil og forårsake ulykker øker. I denne studien har forskere fra Finland og Statoil ASA Norge undersøkt hvorvidt sakkades (raske øyebevegelser) målt med elektrookulografi (EOG) ambulant kan brukes som et reliabelt mål for å estimere total våkentid uten søvn. I løpet av studien gjennomgikk deltagerne flere tester, og resultatene viser at saccades målt med EOG  kan brukes som et mål for våkenhet utenfor laboratoriet.

Saccadic eye movements estimate prolonged time awake.

Kati Pettersson, Kito Müller, Aino Tietäväinen, Kristian Gould, Edward Hæggström

Studien er publisert i Journal of Sleep Research

Abstract
Prolonged time awake increases the need to sleep. Sleep pressure increases sleepiness, impairs human alertness and performance and increases the probability of human errors and accidents. Human performance and alertness during waking hours are influenced by homeostatic sleep drive and the circadian rhythm. Cognitive functions, especially attentional ones, are vulnerable to circadian rhythm and increasing sleep drive. A reliable, objective and practical metrics for estimating sleepiness could therefore be valuable. Our aim is to study whether saccades measured with electro-oculography (EOG) outside the laboratory could be used to estimate the overall time awake without sleep of a person. The number of executed saccades was measured in 11 participants during an 8-min saccade task. The saccades were recorded outside the laboratory (Naval Academy, Bergen) using EOG every sixth hour until 54 hr of time awake. Measurements were carried out on two occasions separated by 10 weeks. Five participants participated in both measurement weeks. The number of saccades decreased during sustained wakefulness. The data correlated with the three-process model of alertness; performance differed between participants but was stable within individual participants. A mathematically monotonous relation between performance in the saccade task and time awake was seen after removing the circadian rhythm component from measured eye movement data. The results imply that saccades measured with EOG can be used as a time-awake metric outside the laboratory.