Abstract
The forced oscillations technique (FOT) enables a non-invasive monitoring of respiratory mechanics, returning the impedance of the respiratory system (Z rs ) at chosen frequencies. Recently it has been shown that the intrabreath variations of Z rs are correlated with respiratory diseases, mainly due to the sensitivity of Z rs to morphological changes in the respiratory system. The aim of this study was to develop a morphology-based computational model able to simulate the variations of airway dimensions during normal breathing and the resulting temporal changes in Z rs . The model counts the symmetric structure of the bronchial tree, lung and thorax wall viscoelasticity, and properties of the upper airways. It takes into account the distributed character of pressure loss along the airways and flow-limiting mechanisms. Quasi-dynamic simulations are performed, and for each time instant the distributed properties of airways are recalculated to a lumped parameter net corresponding to the momentary Z rs . The implemented model enabled simulations of primary signals characterising quiet breathing and the intrabreath variations in Z rs for both the normal case and small airways constriction. The simulation results recovered the flow- and volume-dependent variations of Z rs observed in healthy subjects and their alterations associated with uniform bronchial obstruction. However, testing specific hypotheses about the manifestation of inhomogeneous lung diseases in the intrabreath FOT data involves future incorporation of structural heterogeneity into the model.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
Bates, J.H.T., Irvin, C.G., Farré, R, Hantos, Z.: Oscillation mechanics of the respiratory system. Compr. Physiol. 1(3), 1233–1272 (2011).
Kaczka, D.W., Lutchen, K.R., Hantos Z.: Emergent behavior of regional heterogeneity in the lung and its effects on respiratory impedance. J. Appl. Physiol. 110(5), 1473–1481 (2011).
Davidson, R.N., Greig, C.A., Hussain, A., et al.: Within-breath changes of airway calibre in patients with airflow obstruction by continuous measurement of respiratory impedance. Br. J. Dis. Chest 80, 335–352 (1986).
Peslin, R., Ying, Y., Gallina, C., et al.: Within-breath variations of forced oscillation resistance in healthy subjects. Eur. Respir. J. 5(1), 86–92 (1992).
Dellacà, R.L., Santus, P., Aliverti, A., et al.: Detection of expiratory flow limitation in COPD using the forced oscillation technique. Eur. Respir. J. 23(2), 232–240 (2004).
Czövek, D., Shackleton, C., Hantos, Z., Taylor, K., Kumar, A., Chacko, A., Ware, R.S., Makan, G., Radics, B., Gingl, Z., Sly, P.D.: Tidal changes in respiratory resistance are sensitive indicators of airway obstruction in children. Thorax 71(10), 907–915 (2016).
Lorx, A., Czövek, D., Gingl, Z., et al.: Airway dynamics in COPD patients by within-breath impedance tracking: effects of continuous positive airway pressure. Eur. Respir. J. 2017 Feb 15; 49(2). pii: 1601270. https://doi.org/10.1183/13993003.01270-2016. (2017).
Weibel, E. R.: Morphometry of the Human Lung, Springer, Berlin (1963).
Polak, A.G.: A forward model for maximum expiration. Comp. Biol. Med. 28(6), 613–625 (1998).
Lambert, R.K., Wilson, T.A., Hyatt, R.E., Rodarte, J.R.: A computational model for expiratory flow. J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 52(1), 44–56 (1982).
Eckel, H.E., Sittel, C., Zorowka, P., Jerke, A.: Dimensions of the laryngeal framework in adults. Surg Radiol Anat, 16(1), 31–36. (1994).
Mohsenin, V.: Gender differences in the expression of sleep-disordered breathing: role of upper airway dimensions. Chest 120(5), 1442–1447 (2001).
Persak, S.C., Sin, S., McDonough, J.M., Arens, R. Wootton, D.M.: Noninvasive estimation of pharyngeal airway resistance and compliance in children based on volume-gated dynamic MRI and computational fluid dynamics. J. Appl. Physiol. 111(6), 819–1827 (2011).
Polak, A.G., Lutchen, K.R.: Computational model for forced expiration from asymmetric normal lungs. Ann. Biomed. Eng. 31(8), 891–907 (2003).
Polak, A.G., Mroczka, J.: Nonlinear model for mechanical ventilation of human lungs. Compt. Biol. Med. 36(1), 41–58 (2006).
Morlion, B., Polak, A.G.: Simulation of lung function evolution after heart-lung transplantation using a numerical model. IEEE Trans. Biomed. Eng. 52(7), 1180–1187 (2005).
Acknowledgements
This work was supported in part by the grant no. 2016/21/B/ST7/02233 from the National Science Centre, Poland, and grant no. 105403 from the Hungarian Scientific Research Fund.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2019 Springer Nature Singapore Pte Ltd.
About this paper
Cite this paper
Polak, A.G., Hantos, Z. (2019). Simulation of Respiratory Impedance Variations During Normal Breathing Using a Morphometric Model of the Lung. In: Lhotska, L., Sukupova, L., Lacković, I., Ibbott, G.S. (eds) World Congress on Medical Physics and Biomedical Engineering 2018. IFMBE Proceedings, vol 68/1. Springer, Singapore. https://doi.org/10.1007/978-981-10-9035-6_102
Download citation
DOI: https://doi.org/10.1007/978-981-10-9035-6_102
Published:
Publisher Name: Springer, Singapore
Print ISBN: 978-981-10-9034-9
Online ISBN: 978-981-10-9035-6
eBook Packages: EngineeringEngineering (R0)