Saccadic eye movements estimate prolonged time awake.

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.

Contrast sensitivity and the effect of 60-hour sleep deprivation.

Purpose: The study aimed to evaluate the possible influence of prolonged sleep deprivation on achromatic and chromatic (red-green and blue-yellow) contrast sensitivity (CS).

Methods: During 60-hr sleep deprivation, CS was measured in 11 naval officers every sixth hour using videographic (Vigra-C) sine-wave-generated stimuli.

Results: When comparing the CS measurements obtained in the first and last 24 hr of the study, no statistically significant mean changes of achromatic CS (2.

Improving the saccade peak velocity measurement for detecting fatigue.

The aim of the study was to compare saccadic peak velocity (SPV) values measured with video based Fitness Impairment Tester (FIT) and electro-oculography (EOG) during prolonged wakefulness. We tested different numbers of saccades and two saccade paradigms to improve the EOG measurements for detecting fatigue. The SPVs were measured from 11 fast patrol boat navigators with FIT and EOG every sixth hour until 54 h.

Effects of 60 hours of total sleep deprivation on two methods of high-speed ship navigation.

This study investigated how workload and performance in high-speed ship navigation was affected by sleep deprivation using methods based on either paper charts or electronic chart display and information systems (ECDIS). In two separate weeks, five navigators sailed 10 routes in high-fidelity simulators while undergoing progressive sleep deprivation for up to 60 h. Results showed that navigation performance was better using ECDIS, but was largely unaffected by sleep deprivation in both.

Effects of navigation method on workload and performance in simulated high-speed ship navigation.

This study examines mental workload and performance in simulated high-speed ship navigation. Two navigation methods were compared based on an electronic chart display and information system (ECDIS) and a conventional system using paper charts. Twenty naval cadets navigated in high-fidelity simulators through a 50 nautical mile course with varying levels of difficulty.

Effect of an intervention addressing working technique on the biomechanical load of the neck and shoulders among hairdressers.

The purpose of this study was to describe, and analyse the effect of an intervention on, the biomechanical workload in the neck and shoulder region of female hairdressers. Arm elevation was measured by inclinometers and muscular load of m. trapezius by electromyography.