Feasibility of Wearable Heart Rate Sensing-Based Whole-Body Physical Fatigue Monitoring for Construction Workers

Abstract

Since construction workers are often engaged in demanding whole-body physical activities for a prolonged period of time, whole-body fatigue (WBF) is one of the most common risks at construction sites that can detrimentally impact workers’ safety, health, and productivity. To continuously and less-invasively monitor WBF, the authors proposed a wearable biosensor-based method. The method first uses a wristband which can measure the wearer’s percentage of heart rate reserve (%HRR) over time to index the intensity of physical activity. Then, the critical power model (CP) is applied to track WBF from the %HRR data. The CP is a threshold for the intensity of physical activities to determine whether an ongoing physical activity is expending anaerobic energy, which leads to the accumulation of WBF. To test the proposed monitoring method’s feasibility, the authors collected data at a construction site from 12 workers over two days. During their daily work, the workers’ heart rates were continuously measured using a wristband and their perceived WBF was periodically surveyed. The authors conducted a correlation analysis between the fatigue index calculated by the proposed method and the self-reported WBF. Results showed that the two measurements showed a statistically meaningful correlation coefficient (0.61, p-value ≈ 0). This result indicates that the proposed method is feasible to monitor WBF trends among construction workers during their ongoing work. Given that most affordable wristbands include heart rate monitoring capacities, the authors expect the proposed method is easily applicable in real construction practice.