• Plamena Stoimenova Medical University of Plovdiv, Bulgaria
  • Stoilka Mandadzhieva Medical University of Plovdiv, Bulgaria
  • Blagoi Marinov Medical University of Plovdiv, Bulgaria



Forced oscillation technique, airway obstruction, heterogenous ventilatory conditions


According to the World Health Organization in 2019 chronic obstructive pulmonary disease (COPD) was the third leading cause of death worldwide, causing more than 3 million deaths whereas bronchial asthma affected more than 250 million people and caused 455 000 deaths. Both diseases are chronic obstructive conditions which need to be diagnosed early in order to prevent or slow down the complications. Consequently the world requires new effortless methods for diagnosis of airway obstructions, especially for small children and people who cannot perform the spirometry maneuver. The purpose of this report is to describe the objectives of the forced oscillation technique (FOT) and to establish its applications in the clinical practice. Studies and clinical cases regarding pulmonary function testing are summarized and analyzed. They are found in the following databases - PubMed, Google Scholar and Science Direct. Spirometry is the ‘gold standard’ for the diagnosis of airflow obstruction but it requires effort and can be difficult for patients to perform. Forced oscillation technique (FOT) on the other hand is a relatively new method that may hold the key to identifying smoking-related respiratory early alterations and childhood asthma. FOT requires tidal breathing while applying external, small amplitude oscillations in order to determine the response of the respiratory system. Therefore, it is easy for pre-school children to perform. The benefit of FOT should be taken into account for patients who cannot perform spirometry or other pulmonary function ttests. The minimal cooperation of the patient and the easy tidal breathing maneuvers make this method a great option for every pulmonologist. Compared to spirometry this technique may be more sensitive in the detection of disturbances of the peripheral airways and may be effective for the control of therapy at a long term. The Forced oscillation technique has been successfully applied in many pediatric respiratory disorders, such as asthma, cystic fibrosis, and chronic lung disease. Considering these qualities FOT may be used as an alternative of spirometry in heterogenous ventilatory disturbances of the small airways.


Download data is not yet available.


Alblooshi A. et al (2017). Is forced oscillation technique the next respiratory function test of choice in childhood asthma. World J Methodol 2017 December 26; 7(4): 129-138

Alqahtani J. et al. (2021). The clinical utility of forced oscillation technique during hospitalization in patients with exacerbation of COPD. ERJ Open Research 2021 7: 00448-2021; doi: 10.1183/23120541.00448-2021

Bhattarai P. et al. (2020). Clinical Application of Forced Oscillation Technique (FOT) in Early Detection of Airway Changes in Smokers. J. Clin. Med. 2020, 9, 2778; doi:10.3390/jcm9092778

Bickel S. et al. (2014). Impulse Oscillometry. Interpretation and Practical Applications. CHEST doi:10.1378/chest.13-1875

Boers E. et al. (2023). Global Burden of Chronic Obstructive Pulmonary Disease Through 2050. Published online 2023 Dec 7. Doi: 10.1001/jamanetworkopen.2023.46598

Cottee A. et al. (2020). Bronchodilator Response Assessed by the Forced Oscillation Technique Identifies Poor Asthma Control With Greater Sensitivity Than Spirometry. American College of Chest Physician Published by Elsevier

Delacourt C. et al. (2001). Comparison of the Forced Oscillation Technique and the Interrupter Technique for Assessing Airway Obstruction and Its Reversibility in Children. Am J Respir Crit Care Med 2001 Sep 15;164(6):965-72. doi: 10.1164/ajrccm.164.6.2010153.

Dellacà R. et al. (2004). Detection of expiratory flow limitation in COPD using the forced oscillation technique. Eur Respir J 2004 Feb;23(2):232-40. Doi: 10.1183/09031936.04.00046804.

Faria A. et al. (2009). Evaluating the forced oscillation technique in the detection of early smoking-induced respiratory changes. BioMedical Engineering OnLine 2009, doi:10.1186/1475-925X-8-22

Faria A. et al. (2010). Forced oscillation technique in the detection of smoking-induced respiratory alterations: diagnostic accuracy and comparison with spirometry. CLINICS 2010;65(12):1295-1304 doi:10.1590/S1807-59322010001200012

Kaminsky D. et al. (2004). Oscillation mechanics of the human lung periphery in asthma. J Appl Physiol 97: 1849–1858, 2004. Doi:10.1152/japplphysiol.00300.2004.

Kolsum U. et al. (2009). Impulse oscillometry in COPD: Identification of measurements related to airway obstruction, airway conductance and lung volumes. Elsevier Respiratory Medicine (2009) 103, 136-143 doi:10.1016/j.rmed.2008.07.014

Ribeiro C. et al. (2018). Forced oscillation technique for early detection of the effects of smoking and COPD: contribution of fractional-order modeling. International Journal of COPD 2018:13 3281–3295

Walker P. et al. (2018). Telemonitoring in Chronic Obstructive Pulmonary Disease (CHROMED). Am J Respir Crit Care Med Vol 198, Iss 5, pp 620–628, Sep 1, 2018 doi: 10.1164/rccm.201712-2404OC

World Health Organization – Chronic obstructive pulmonary disease (COPD)

Yaegashi M. et al. (2006). The utility of the forced oscillation technique in assessing bronchodilator responsiveness in patients with asthma. Respir Med. 2007 May;101(5):995-1000. doi: 10.1016/j.rmed.2006.09.001

Zimmermann S. et al. Day-to-day variability of forced oscillatory mechanics for early detection of acute exacerbations in COPD Eur Respir J 2020; 56: 1901739




How to Cite

Stoimenova, P., Mandadzhieva, S., & Marinov, B. (2024). FORCED OSCILLATION TECHNIQUE (FOT) – A NOVEL METHOD FOR THE DETECTION OF EARLY AIRWAY CHANGES . MEDIS – International Journal of Medical Sciences and Research, 3(1), 41–46.