The forced oscillation technique (FOT) is a noninvasive lung function test that applies small pressure oscillations through a mouthpiece during normal breathing to measure respiratory system impedance. It quantifies resistance and reactance across frequencies, detecting airway obstruction and peripheral (small-airway) dysfunction. FOT requires minimal patient effort, can assess bronchodilator response, and helps monitor disease in children or those unable to do spirometry.

The Forced Oscillation Technique (FOT) is a noninvasive lung function test that applies small pressure oscillations through a mouthpiece during normal breathing to measure airway resistance and reactance. It detects obstructive or small‑airway disease, requires minimal cooperation (suitable for children and frail patients), is quick and painless, and complements spirometry by assessing mechanical properties of the respiratory system.

Cost varies widely. On public health systems FOT is usually provided without direct charge to the patient. In private settings prices typically range from about £30–£200 (roughly $40–$250) depending on country and clinic. In India, private tests often cost a few hundred to a couple thousand rupees. Always check with the specific clinic or hospital for exact pricing.

FOT in PFT stands for the Forced Oscillation Technique. It’s a noninvasive test applying small pressure oscillations during normal breathing to measure respiratory system impedance — resistance and reactance. FOT detects airway obstruction, particularly small-airway dysfunction, and is useful when spirometry is difficult (young children, frail patients). It can monitor disease progression and bronchodilator response.