ABSTRACT
In Chapter 7, we explored video analytics for ubiquitously monitoring human pulse patterns, gaits, and activity level. Here, we go further to address how to evaluate fatigue over time. Human fatigue is a state of capacity reduction in mental or physical performance caused by work, stress, disease, therapy, or other factors. For decades, the prevailing clinical methods for evaluating fatigue were questionnaires, which are subjective and intrusive.150 They cannot be used for real-time and continuous evaluation, or so-called online monitoring. This chapter covers two types of objective fatigue evaluation methods useful in ambient diagnostics: the vigilance clock test and fatigue facial expression recognition. The vigilance clock test is a cognition test well known to experimental psychologists but is not widely used in medical diagnosis; it is an interactive but off-line evaluation. Fatigue facial expression recognition is a video-based evaluation; it is nonintrusive and can be used for online evaluation.
