Fatigue

Abstract

The study of fatigue has increased by leaps and bounds; however, still no universal definition exists and fatigue remains a vague concept used as an umbrella term that comprises of physiological, emotional, and behavioral factors that can result in chronic physical or mental states affecting the cognitive, memory, motoric, and perceptive capacities. Biomedical engineering has faced fatigue evaluation from two different approaches: exercise‐induced fatigue (or metabolic fatigue) and central fatigue (related to the evolution of the subject condition caused by the execution of normal tasks). As metabolic fatigue is a complex mechanism usually discussed by exercise physiology, this work will center on central fatigue detection and evaluation, because of its importance within the field of human factors engineering in occupational health studies. Central fatigue has been referred to in various terms that are more or less mutually interchangeable in the research literature: loss of alertness or vigilance, fatigue, and drowsiness, although no significant difference exists among them. Research has focused on the development of objective and reliable measurement techniques able to quantify the state of human deteriorated condition, although none of the proposed methods has been yet considered to be a gold standard. This work reviews several fatigue indicators that have been reported to reflect the different dimensions resulting from this state [heart‐related measures such as the heart rate (HR) and heart rate variability (HRV), muscles activity through electromyogram (EMG) and mechanomyogram (MMG), spectral analysis of the electroencephalograph (EEG) and event‐related potential (ERP), ocular metrics, speech parameters, etc].

Effects of long and short simulated flights on the saccadic eye movement velocity of aviators

“…TOF is a leading cause of pilot fatigue [5]; thus, here we posit (pilot) fatigue as the consequence of sustained attention to the flight over a period (i.e. long vs short) of time [33] (Note, despite the distinctions between fatigue and vigilance (decrement) [34], we will use these terms interchangeably [35]).…”

International Guidelines for Environmental Education and the Connections with the Contexts of Origin

“…Contrary to the vernacular of protectionism, Orduna (2008) describes other interests that led to the creation of national parks and reserves, especially in poor countries. The author explains that, after the Second World War, there was an expansion of institutions for research, protection, and conservation of nature towards the periphery countries.…”