Development of Comprehensive Performance Standards for Underwater Breathing Apparatus

摘要

Every type of underwater breathing apparatus (UBA) imposes loads on the diver's respiratory system. It is essential for the diver's safety and performance that the UBA adheres to appropriate performance standards. These external loads can be classified as breathing resistance, elastance, hydrostatic imbalance (static lung load) and inertia. The internal loads from the diver's airway resistance, compliance and gas density add to the respiratory loads. A mathematical model was developed using data and knowledge of respiratory physiology from the scientific literature. This model allowed calculations of the effort required to overcome the external and internal loads (separately or in combination). Limits for the different external respiratory loads were set based on the respiratory model and data available from experimental studies. An effect of the diving depth on the maximum breathing resistance was confirmed and quantified. It is reasoned that the additional effort by expressed as power of breathing rather than work of breathing. Respiratory impediments acting alone.