Work of breathing 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, for example, joules/litre, or as a work rate (power), such as joules/min or equivalent units, as it is not particularly useful without a reference to volume or time. It can be calculated in terms of the pulmonary pressure multiplied by the change in pulmonary volume, or in terms of the oxygen consumption attributable to breathing. In a normal resting state the work of breathing constitutes about 5% of the total body oxygen consumption.
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,