Dynamic braked spirometer

摘要

An improved spirometer is disclosed which permits more accurate measurement of the volume of air exhaled from the lungs of a patient. The improvement comprises flow-responsive means such as a pair of vanes disposed downstream of the rotor. The vanes cause the air flow through the spirometer to stop, almost instantaneously, with the cessation of flow into the spirometer. Thus, after the patient stops exhaling through the spirometer, the rotor stops almost immediately, permitting more accurate measurements of the volume of air exhaled.