Respiratory rate monitoring of video terminal operators based on fiber optic technology

Recognition of occupational stressors is a goal of primary importance to improve the psycho-physical health of workers. Many studies agree in considering the respiratory rate (RR) as a key parameter to be monitored since changes from normal physiological ranges can be closely related to states of mental and physical stress. Despite the wide availability of solutions devoted to RR detection, the utilization of light and unobtrusive wearable systems exploiting several sensing technologies is becoming more and more popular in recent years. Among others, fiber Bragg gratings (FBGs) are gaining momentum due to their valuable properties (e.g., lightness, multiplexing capability, high sensitivity etc.) which make them suitable to be integrated into garments and appropriate for RR monitoring purpose. In this work, the feasibility assessment of an FBG-based wearable system for RR detection in a static occupational scenario is presented. A chest strap instrumented with two flexible sensors based on an FBG technology was exploited to perform 40 min of RR tracking on two video terminal workers. The proposed system was able to measure the respiratory signal over a prolonged time and showed high capability to estimate RR when compared to a reference instrument, as evinced by the obtained values of mean absolute error (MAE), always <= 1 bpm.