Assessment of Two Personal Breathing Recording Devices in a Simulated Healthcare Environment.

Background: In the field of respiratory protection for healthcare workers (HCWs), few data are available on respiratory airflow rate when HCWs are performing their work activities. The objective of this study was to assess the performance of two wearable breathing recording devices in a simulated healthcare environment.

Methods: Breathing recording devices from two different manufactures "A" and "B" were assessed using 15 subjects while performing a series of simulated healthcare work activities (patient assessment; vitals; IV treatment; changing linen; carrying weight while walking; normal breathing while standing). The minute volume (MV, L/min), mean inhalation flow (MIF, L/min), peak inhalation flow (PIF, L/min), breathing frequency (f, breaths/min), and tidal volume (TV, L/min) measured by each device were analyzed. Bland-Altman method was applied to explore the variability of devices A and B. Duncan's multiple range test was used to investigate the differences among activity-specific inspiratory flow rates.

Results: The average MV, MIF and PIF reported by device A were 23, 54, and 82 L/min with 95% upper confidence intervals (CIs) of 25, 60 and 92 L/min; the mean differences of MV, MIF and PIF presented by the two units of device A were 0.9, 1.3, and 2.8 L/min, respectively. The average values and mean differences of MV, MIF and PIF found with device B were significantly higher than device A (P<0.05), showing a high variability. During non-speech activities, the PIF/MV and MIF/MV ratios were >3.14 and >2, while with speech, the ratios increased to >6 and >3. The f during speech (15 breaths/min) was significantly lower than non-speech activities (20-25 breaths/min). Among different simulated work activities, the PIF of "patient assessment" was the highest.

Conclusions: This study demonstrated a novel approach to characterize respiratory flow for healthcare workers using an innovative wearable flow recording device. Data from this investigation could be useful in the development of future respirator test standards.