Physiological Responses to Varying Workloads and Configurations of the MCU-2/P Chemical Defense Mask
Abstract
An objective of this study was to evaluate the breathing resistance characteristics of MCU-2/P and M-17 chemical defense masks during individual exposures to 8 consecutive incremental workloads. Other objectives included: evaluation of cardiorespiratory and subjective responses and testing of two commercially available blowers. Five MCU-2/P mask configurations were tested: mask without filter (MCU-OF), mask + 1 filter (MCU-1 F), mask + 2 filters (MCU- 2F), mask + 1 filter + blower A (MCU-1 F-ABA), and mask + blower B + 2 filters (MCU-ABB-2F). An M-17 mask was also tested. Each subject walked on a treadmill for 5 min at each of 8 consecutive incremental workloads (ranging from 26% to 77% of VO sub 2MAX) for a total of 40 min, while wearing each mask configuration. Variables measured included inspiratory and expiratory mask cavity pressures (IMCP and EMCP), mask cavity pressure-swing (MCPS), peak inspiratory airflow (PIAF), respiratory rate (RR), tidal volume (VT), minute volume (VE), heart rate (HR), perceived inspiratory & expiratory effort (PIE and PEE), and overall breathing discomfort (OBD). The MCU-1 F and M-1 7 masks imposed the same magnitudes of inspiratory resistance at any given workload. The highest inspiratory resistance was imposed by the MCU-1F and M-17 masks, while the lowest corresponded to the MCU-ABB-2F and MCU-2F. Either of these two masks can be expected to decrease individual tolerance to sustained physical work. The MCU-ABB-2F and the MCU-2F were the most effective methods to reduce the magnitude of inspiratory resistance at any given workload.... Breathing resistance, Protective mask, Exercise, Ventilation, Perceived effort.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1993
- Accession Number
- ADA262287
Entities
People
- F. W. Baumgardner
- Melchor J. Antunano
- Stefan H. Constable
- Yasu T. Chen