Correlation analysis between vigilance tests and body battery

Fatigue and sleep loss are crucial factors in everyday life, as they can deeply affect human productivity and health. Fatigue assessment is really important in certain applications: having detailed information about workers’ fatigue levels may be vital in preventing possible catastrophic accidents. Monotonous activities such as highway driving may be severely affected by high levels of fatigue. For this reason, increasing the number of tools able to collect such information is really important for improving road safety and various other everyday situations. For this purpose, analyzing potential correlation between vigilance tests and body battery could provide valuable insights. In particular, vigilance tests like Psychomotor Vigilance Task (PVT) and Three Choice Vigilance Task (3CVT) are widely used in fatigue and sleep loss research fields due to their easy of use. On the other hand, Body Battery (BB) is an example of how new technologies allow for the easy collection of complex parameters that can assist in fatigue assessment. Garmin smartwatches give the opportunity to collect many vital signs useful for computing this complex parameter, providing valuable details about the body’s energy levels throughout the day. However, these smartwatches cannot provide an immediate, reliable Body Battery value, as its computation requires continuous data collection during both day and night. For this reason, two vigilance tests, Psychomotor Vigilance Task (PVT) and Three Choice Vigilance Task (3CVT), were considered to explore possible correlation with it. Having a simple tool like these tests to estimate Body Battery, even if the device was not worn in the previous days, could be crucial for assessing fatigue levels before any critical activity. To this purpose, outcome metrics of both tests were evaluated. Initially, three different versions of both PVT and 3CVT (3, 5, and 10 minutes) were tested to determine which duration was more suitable for this application. Then, once the 5 minute test demonstrated to be the best trade-off between time consumed and amount of data collected, the data collection campaign was extended to 5 subjects to understand which of the two tests could achieve the best correlation with Body Battery. At this point, Psychomotor Vigilance Task was selected for further data collection, reaching the total number of 14 subjects: 7 men and 7 female. The protocol was fine tuned step by step, and in the final phase, each subject took the test twice a day (morning and evening) for 5 days. In the end, PVT showed potential as a possible estimator of the Body Battery. However, physiological research studies, such as this one on Body Battery, require a broad and heterogeneous audience to ensure full population representativeness. In this sense, extending the data collection campaign to a larger sample could increase the robustness and validity of the results obtained in this study.