Application of K-Means clustering algorithm based on heart rate and heart rate variability in course of simulated flight practice

AIM To based on the characteristic parameters of heart rate and heart rate variability, the K-Means clustering algorithm is used to objectively evaluate the stress state of aerospace medical students in simulated flight assessment, and a targeted teaching plan is developed to explore new teaching strategies for improving the teaching effectiveness of simulated flight practice courses.

METHODS A total of 48 aerospace medical students participated in this study. According to the K-Means clustering algorithm, they were categorized into high-stress and low-stress groups based on their HR and HRV metrics, which were recorded during two phases: resting state and landing phase of a mid-term simulated flight examination. Their performances were evaluated according to the simulated flight scores of circuit-flying and HR/HRV indexes between final and mid-term simulated flight examination to assess the teaching effectiveness.

RESULTS The HR and HRV indexes (RMSSD, LFnu, and LF/HF) during the landing phase of simulated flight were significantly different from those in the resting state. Specifically, there was an increase in heart rate (F=15.49, P<0.01), a decrease in RMSSD (F=16.81, P<0.01), and reductions in LFnu (F=61.20, P<0.01) and LF/HF (F=34.16, P<0.01), indicating that simulated flight imposed high cognitive load and stress. The simulated flight scores of circuit-flying in the final stimulated flight examination were significantly higher than that in mid-term simulated flight examination (the group of low-stress: F=16.80, P<0.01, the group of high-stress: F=67.32, P<0.01). However, the simulated flight scores of circuit-flying and HR/HRV indexes were not significant different in the final stimulated flight examination between the two groups of high-stress and low-stress (F=0.09, P=0.70), indicating that it had a similar level of simulated flight practice between the two groups.

CONCLUSION The teaching strategies based on stress states of aviation medical students can effectively improve the simulated flight performance of students in the course of simulated flight practice.