The Forced Oscillation Technique (FOT) is a non-invasive method used to assess lung function by measuring airway resistance and reactance. It is especially useful for detecting early changes in lung mechanics and monitoring respiratory conditions like asthma or COPD . Tidal breathing is used to obtain measurements and hence user friendly particularly for paediatric and geriatric patients . It is likely to replace traditional Pulmonary Function Tests (PFT) in the immediate future.