Work of breathing When there is increased gas flow resistance, the optimal respiratory rate decreases. This work (generally during the inhalation phase) is stored as potential energy which is recovered during exhalation. A pressure difference is required to overcome the frictional resistance to gas flow due to viscosity, and to provide non-elastic components of movement of the airway tissues to accommodate pulmonary volume change. Total work done against non elastic forces is 35% of total. Work is defined as a force applied over a distance. The SI unit of work is the Joule, equivalent to a force of 1 Newton exerted along a
Work of breathing narcotic effects. Standards for these conditions exist and to make useful comparisons between breathing apparatus they must be tested to the same standard. Factors which influence the work of breathing of an underwater breathing apparatus include density and viscosity of the gas, flow rates, cracking pressure (the pressure differential required to open the demand valve), and back pressure over exhaust valves. The ANSTI machine is used for automated testing of underwater breathing apparatus. Work of breathing Work of breathing (WOB) is the energy expended to inhale and exhale a breathing gas. It is usually expressed as work per unit volume,