Assessing the effect of shipboard motion and sleep surface on sleep effectiveness

Abstract

Sleep in today's Navy is in short supply. When it is possible for Sailors and officers to sleep, that sleep should be as efficient as possible. This study sought to determine if motion affects sleep efficiency, and if sleeping surface could be used to mitigate the disturbed sleeping patterns caused by motion. To accomplish this goal, the researchers employed a motion machine driven with motion profiles from the USS Swift (HSV-2), a catamaran style vessel that may have many of the same motion characteristics as future ships. In addition, two mattress types, a standard Navy and a visco-elastic foam mattress, were compared to determine if sleep efficiency differed between the two sleeping surfaces. Twelve volunteers participated in the human-in-the-loop study. Results from the laboratory study demonstrated that motion had a significant effect on sleep efficiency. Additionally, a survey administered to each participant upon completion of the experiment found that self-reported sleep quality was better in the stationary condition. Finally, tests using activity counts and acceleration data were conducted to determine if a given mattress type was more effective at reducing the amount of shock and vibration transmitted through the motion platform. These results showed a clear advantage for the visco-elastic surface.