Assessment of Fatigue Using Wearable Sensors: A Pilot Study - 2020 Luo et al

full text:
https://www.karger.com/Article/FullText/512166

 

I suppose it's a start. Better data might be obtained by monitoring eye movements and body movements and stance and other such involuntary factors. My guess is that even when reading (hold font, lighting, etc constant, and material similar), there will be a measurable difference in how long the eye lingers on a word, how quickly the person turns the page, and so forth. Maybe pupil diameter fluctuations changes with fatigue levels too.

My mental lethargy increases abruptly 20 minutes after eating a meal of quickly-digested carbs (I assume due to increased cerebral TRP -> KYN conversion). I can be reading a book, and suddenly my eyes stop tracking the words properly and I loose track of the story. I expect that will show up as changes in eye movement or pupil diameter, and maybe in finger twitch rate or some other involuntary muscle measurements.