Quantification of Respiratory Muscle Performance,
ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA
Pagination or Media Count:
Quantification of respiratory muscle force, velocity and length are usually indirect measurements assessed from pressure, air flow and volume, respectively. Pressure produced by the respiratory muscles is measured at sites within the airways, rib cage and abdomen. Quantification of diaphragmatic tension is obtained by measurement of transdiaphragmatic pressure P sub di gastric minus esophageal pressures. The strength of the inspiratory muscles working in concert is the voluntary static maximum inspiratory pressure measured at the mouth, briefly sustained near functional residual capacity FRC. The inspiratory muscles velocity of shortening is quantified by measuring the inspiratory flow rate V sub I. Since the V sub I varies over the duration of inspiration T sub I, the mean inspiratory flow rate V sub IT sub I is typically used. Finally, changes in the respiratory muscles length are inferred from measurements of volume. The duration of sustained voluntary hyperpnea is inversely related to the time-pressure integral of the diaphragm T sub IT sub T.P sub diP sub di max and the mean V sub I. Thus, measurements of pressure, flow and volume yield quantitative indices of respiratory muscle performance. Keywords ExercisePhysiology.
- Anatomy and Physiology