impulse oscillometry
Also written as: IOS — Impulse Oscillometry System
A forced oscillation technique that superimposes small-amplitude pressure oscillations on tidal breathing to measure respiratory system impedance, including resistance and reactance.
Full Definition
Impulse oscillometry delivers brief, repeating pressure pulses through a mouthpiece during quiet tidal breathing and analyses the resultant oscillatory flow signals to derive frequency-dependent measures of respiratory resistance (R) and reactance (X). Key parameters include resistance at 5 Hz (R5), resistance at 20 Hz (R20), the difference R5–R20 (reflecting peripheral airway resistance), and reactance area (AX). Because it requires only tidal breathing, IOS is well suited to preschool-aged children (3–6 years). Editors should preserve the frequency subscripts (R5, R20, X5) and note that 'oscillometry' and 'oscillation technique' are not interchangeable with 'spirometry'.
Usage
Usage note: IOS is a proprietary implementation of the broader forced oscillation technique (FOT); the two terms are related but not synonymous. Preserve numeric subscripts in parameter names (R5, X5).
In Context
- "Impulse oscillometry (IOS) revealed an elevated R5–R20 difference, indicating peripheral airway obstruction." — Preschool wheeze assessment report
- "The IOS parameters were assessed before and after bronchodilator challenge to evaluate reversibility." — Pediatric allergy and respiratory clinic protocol