Modeling Oculomotor Variability During Slow Cabin Decompression Using Infrared Technology

Abstract

Slow cabin decompression is highly perilous due to its gradual and thus generally inconspicuous nature. In an applied approach to studying its effects upon oculomotor performance, experienced pilots performed a simulated flight task during slow decompression inside a high-altitude chamber while an infrared-based head-mounted eye-tracker measured oculomotor and pupillary changes at approximately 5% decrements in blood oxygen saturation. Saccade angle, saccade duration, saccadic velocity, microsaccade rate, fixation duration, and pupil diameter varied systematically in response to manipulation of blood oxygen saturation level, including recovery upon return to normoxia. Changes in these oculomotor variables can serve as biomarkers for early hypoxia exposure in pilots, likely before the first subjective symptom is recognized, and can be detected with lower-resolution, non-invasive infrared technology.