ABSTRACT
The use of face masks as respiratory protective equipment (RPE) is considered key to maintaining the quality of life during emergency situations, long-term care and working conditions. Face masks can reduce the virus spread and bacterial infections as well as prevent the inhalation of industrial waste gases. Individuals who wear a facial mask over a prolonged time often reported uncomfortable feelings due to breathing resistance, heat, tightness, and overall discomfort. One of the main indicators used to quantify the level of discomfort induced by RPE is the respiratory rate (RR). In fact, RR can be directly associated with RPE-related unease since the presence of facial masks might intuitively modify the breathing pattern of the users. Unfortunately, still little is known about RR and its variability in response to wearing RPE. In the last year, the massive use of face masks due to COVID-19 pandemic fosters the development of sensors to measure RR once mounted into the medical mask. Among other, fiber Bragg grating sensors (FBGs) have gained growing attention since the intrinsic advantages of small size, lightweight, high metrological properties, and safety. In the present study, a single-use FFP2 surgical mask was instrumented by a soft sensor based on FBG to perform a long-term acquisition (i.e., 20 min) of the respiratory signal during ordinary work activities at the video terminal. The promising results confirmed the high accuracy of the proposed system in the estimation of RR with a maximum discrepancy of -0.69 breaths per minute and mean absolute percentage error of 2.88 % when compared to a reference instrument. Moreover, no saturation of the sensor output occurred during the usage time.
ABSTRACT
In recent years, the market dedicated to wearable devices has undergone a strong expansion due to the increasingly development of innovative and personalized technologies for monitoring vital parameters. The COVID-19 pandemic has led the change in daily habits through the introduction of personal protective equipment (e.g., face mask) into everyday routine. The use of an instrumented face mask to monitor heart rate (HR) and respiratory rate (RR) of workers in occupational settings may be useful to better understand the physiological conditions and the presence of environmental and physical stressors.Among many methods used to estimate these two vital signs, photoplethysmography has gained broad acceptance in the scientific community. Several sites have been used to place the photoplethysmographic sensor (e.g., ear lobe and finger-tip) to estimate the above-mentioned physiological parameters. In this paper, we proposed a smart face mask (SFM) instrumented by a photoplethysmographic sensor. This configuration is particularly adequate to be used in those occupational settings which require the use of common input peripherals (e.g., mouse and keyboard) which prompt to fast movement of hands and fingers, limiting the performance of common measurement systems (e.g., smartwatches) due to motion artifacts. The proof of concept of SFM has been conducted by mimicking conditions close to the mentioned occupational settings through the use of a low computational power algorithm. The proposed system showed promising results by returning values in agreement with the reference system mimicking RR in a wide range of values. © 2021 IEEE.