ESTIMATION OF PULMONARY RESISTANCE BY REPETITIVE INTERRUPTION OF AIRFLOW

Abstract

Exhalation by the subject is stopped 10 times/sec by a rotating valve, which also serves as a flowmeter. Ports in the valve scan the pressure wave in the airway for components. As compared with standard methods, this technique overestimates normal resistance about 10% and underestimates high resistance about 10% (at a level of 15cm of water/1/sec). Attention is drawn to the change in resistance accompanying change in lung volume and to the use of the method in describing obstructive diseases of the lungs and airways.