Forced Oscillation/Impulse Oscillometry (IOS)
This test is often used with patients too young or patients unable to perform other pulmonary testing.
It is a technique used to measure resistance of the airways using application of sine waves to the airway. It requires minimum cooperation from the patient.
IOS measures resistance, respiratory impedance, reflectance and distribution disorders. This test may be done with or without bronchodilator or with a bronchial challenge.