The goal of the thesis was to develop an individual fatigue management tool called Scextan® and designed as a software application. The development of this system involved several research and validation steps. We first describe sleep patterns of single-handed sailors, who have to manage severe sleep deprivation. Results suggested that single-handed sailors are subject to the same principles of sleep regulation as healthy adults and we choose these subjects as our mains test population. In a second step, we developed and validated the Scextan® software application. Results revealed that Scextan® is more accurate than a paper-based sleep diary. The third study was to measure fatigue in single-handed ocean race and compare the results with a mathematical prediction model of performances, which was able to predict 67% of the measured fatigue. Lastly, skippers of the 2010 "Route du Rhum" single-handed transatlantic race were offered use of Scextan®. The race winner was the only sailor to use it intensively to manage and rationallyanticipate his state of alertness. Although Scextan® is still being improved, it has already proved itself to be a valuable research tool and is on the way to becoming an individual management tool.
