Impulse oscillometry

Lung Physiology Workshop
IMPULSE OSCILLOMETRY

Mohd Arif Mohd Zim
Damansara Specialist Hospital 2, Kuala Lumpur, Malaysia

Impulse oscillometry is used to evaluate the lung physiology and mechanics in adults and children. It was described by Du Bois in 1956 as a tool to measure lung function using sinusoidal sound waves of single frequencies generated by a loudspeaker and passed into the lungs during tidal breathing.

The advantages of pulse oscillometry are easy to perform, provides information, which is different from spirometry, can be performed in ventilated patients and has greater sensitivity to detect peripheral airway obstruction.

IOS measures resistance (R) and reactance (X) at frequencies typically between 5 and 20 Hz.

Parameters include total airway resistance (R5), proximal airway resistance (R20), and distal airway resistance (R5-R20)