Abstract
Obstructive sleep apnea (OSA) is a common respiratory disorder associated with the collapse of the upper airway during sleep. OSA may cause oxygen desaturation, arousals from sleep, and daytime sleepiness, in turn affecting quality of life. There is low success rate in existing OSA surgical treatments mainly due to heterogeneity of the OSA population and poor understanding of the mechanism of the upper airway collapse in each individual. However, advancements in computational simulation have led to some detailed structural modelling of the upper airway that may help to better understand its collapse mechanism in OSA. Alternative surgical treatment methods may be critically assessed with simulation prior to clinical adoption to provide personalized treatment insight for an OSA individual. This review summarizes the current literature related to the application of fluid structure interaction simulation for OSA analysis, with a focus on pharyngeal airway deformation mechanisms, airflow characteristics, and OSA surgical treatment efficacy; it also identifies the shortcomings of current models with suggestions for future studies. It is evident that the upper airway collapse mechanism, the anatomical factors affecting the location and timing of the collapse, and the association of the upper airway anatomical features with critical pressure (Pcrit) are still lacking. Moreover, numerical simulation has been shown to be a great tool in OSA surgical treatment efficacy. Future studies incorporating the practice of virtual surgery may further support clinical decision-making.
Graphical abstract

Similar content being viewed by others
Abbreviations
- OSA:
-
Obstructive sleep apnea
- AHI:
-
Apnea–Hypopnea Index
- CT:
-
Computer tomography
- MRI:
-
Magnetic resonance imaging
- CFD:
-
Computational fluid dynamics
- FSI:
-
Fluid–structure interaction
- 2D:
-
2-Dimensional
- 3D:
-
3-Dimensional
- DNS:
-
Direct numerical simulation
- RANS:
-
Reynolds-averaged Navier–Stokes
- LES:
-
Large eddy simulation
- SST:
-
Shear stress transport
- MAS:
-
Mandibular advancement splint
- MARPE:
-
Miniscrew-assisted rapid palatal expansion
References
Eastwood PR et al (2010) Obstructive sleep apnoea: from pathogenesis to treatment: current controversies and future directions. Respirology 15:587–595
AlGhanim N, Comondore VR, Fleetham J, Marra CA, Ayas NT (2008) The economic impact of obstructive sleep apnea. Lung 186:7–12
Ho ML, Brass SD (2011) Obstructive sleep apnea. Neurol Int 3:15
Dempsey JA, Veasey SC, Morgan BJ, O’Donnell CP (2010) Pathophysiology of sleep apnea. Physiol Rev 90:47–112
Won CH, Li KK, Guilleminault C (2008) Surgical treatment of obstructive sleep apnea: upper airway and maxillomandibular surgery. Proc Am Thorac Soc 5:193–199
Sun X, Yu C, Wang Y, Liu Y (2007) Numerical simulation of soft palate movement and airflow in human upper airway by fluid-structure interaction method. Acta Mech Sin 23:359–367
Tetlow GA, Lucey AD (2006) Motions of an offset plate in viscous channel flow: a model for flutter of the soft palate. in World Congress on Medical Physics and Biomedical Engineering 2006 (eds. Magjarevic, R. & Nagel, J. H.) vol. 14 3457–3460 (Springer Berlin Heidelberg, 2007).
Chouly F, Van Hirtum A, Lagrée P-Y, Pelorson X, Payan Y (2008) Numerical and experimental study of expiratory flow in the case of major upper airway obstructions with fluid–structure interaction. J Fluids Struct 24:250–269
Tetlow GA, Lucey AD, Wang J (2008) Analogue computational modelling of upper airway dynamics. in Proc. 9th Int. Conf. Flow Induced Vibrations (FIV) (Inst. Thermodynamics, Acad. Sci., Prague, Czech Republic, Jun, 2008).
Liu Z et al (2010) Modeling and simulation of human upper airway. in 6th World Congress of Biomechanics (WCB 2010). August 1–6, 2010 Singapore (eds. Lim, C. T. & Goh, J. C. H.) vol. 31 686–689 (Springer Berlin Heidelberg, 2010).
Rasani MR, Inthavong K, Tu JY (2011) Three-dimensional fluid-structure interaction modeling of expiratory flow in the pharyngeal airway. in 5th Kuala Lumpur International Conference on Biomedical Engineering 2011 (eds. Osman, N. A. A., Abas, W. A. B. W., Wahab, A. K. A. & Ting, H.-N.) vol. 35 467–471 (Springer Berlin Heidelberg, 2011).
Cisonni J, Elliott NSJ, Lucey AD, Heil MA (2014) compound cantilevered plate model of the palate-uvula system during snoring. in 19th Australasian fluid mechanics conference vol. 8.
Schickhofer L, Semlitsch B, Mihăescu M (2016) Numerical flow simulations of a flexible plate attached to an obstacle in crossflow. in Proceedings of the 5th International Conference on Jets, Wakes and Separated Flows (ICJWSF2015) (ed. Segalini, A.) vol. 185 195–201 (Springer International Publishing)
Khalili M, Larsson M, Müller B (2016) Interaction between a simplified soft palate and compressible viscous flow. J Fluids Struct 67:85–105
Heravi F, Nazari M, Chouly F, Perrier P, Payan Y (2016) Computational fluid dynamics in the upper airway: comparison between different models and experimental data for a simplified geometry with major obstruction.
Luo H, Scholp A, Jiang JJ (2017) The finite element simulation of the upper airway of patients with moderate and severe obstructive sleep apnea hypopnea syndrome. BioMed Res Int 2017:1–5
Rasani MR, Inthavong K, Tu J (2019) A computational study of flow-induced plate flutter as potential markers for sleep apnea. CFD Lett 11:57–68
Zhu JH, Lee HP, Lim KM, Lee SJ, Teo LSL (2012) Passive movement of human soft palate during respiration: a simulation of 3D fluid/structure interaction. J Biomech 45:1992–2000
Huang R, Li X, Rong Q (2013) Control mechanism for the upper airway collapse in patients with obstructive sleep apnea syndrome: a finite element study. Sci China Life Sci 56:366–372
Rong Q, Ren S, Li Q (2013) Effect of upper airway shape on obstructive sleep apnea syndrome: numerical simulation by fluid-structure interaction method. J Mech Med Biol 13:1340009
Hami K (2021) Turbulence modeling a review for different used methods. Int J Heat Technol 39:227–234
Squires KD (2004) Detached-eddy simulation: current status and perspectives. in Direct and Large-Eddy Simulation V (eds. Friedrich, R., Geurts, B. J. & Métais, O.) vol. 9 465–480 (Springer Netherlands).
Henninger HB, Reese SP, Anderson AE, Weiss JA (2010) Validation of computational models in biomechanics. Proc Inst Mech Eng [H] 224:801–812
Zhao M, Barber T, Cistulli PA, Sutherland K, Rosengarten G (2013) Simulation of upper airway occlusion without and with mandibular advancement in obstructive sleep apnea using fluid-structure interaction. J Biomech 46:2586–2592
Bafkar O et al (2020) Impact of sleeping position, gravitational force & effective tissue stiffness on obstructive sleep apnoea. J Biomech 104:109715
Versteeg HK, Malalasekera W (2007) An introduction to computational fluid dynamics: the finite volume method. (Pearson Education Ltd,)
Lan Z, Itoi A, Takashima M, Oda M, Tomoda K (2006) Difference of pharyngeal morphology and mechanical property between OSAHS patients and normal subjects. Auris Nasus Larynx 33:433–439
Finkelstein Y et al (2014) Velopharyngeal anatomy in patients with obstructive sleep apnea versus normal subjects. J Oral Maxillofac Surg Off J Am Assoc Oral Maxillofac Surg 72:1350–1372
Pirnar J, Dolenc-Grošelj L, Fajdiga I, Žun I (2015) Computational fluid-structure interaction simulation of airflow in the human upper airway. J Biomech 48:3685–3691
Wang Y et al (2012) Fluid–structure interaction modeling of upper airways before and after nasal surgery for obstructive sleep apnea. Int J Numer Methods Biomed Eng 28:528–546
Mylavarapu G, Mihaescu M, Murugappan S, Gutmark E (2010) Fluid structure interaction analysis in human upper airways to understand sleep apnea. in 48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition (American Institute of Aeronautics and Astronautics, 2010). https://doi.org/10.2514/6.2010-1264.
Na JS, Jung H-D, Cho H-J, Choi YJ, Lee JS (2019) Computational analysis of airflow dynamics for predicting collapsible sites in the upper airways: a preliminary study. J Appl Physiol 126:330–340
Kim S-H, Chung S-K, Na Y (2015) Numerical investigation of flow-induced deformation along the human respiratory upper airway. J Mech Sci Technol 29:5267–5272
Rong Q-G, Ren S, Li Q-H (2016) Numerical study on the effect of nerve control on upper airway collapse in obstructive sleep apnea. Int J Autom Comput 13:117–124
Xu C, Brennick MJ, Dougherty L, Wootton DM (2009) Modeling upper airway collapse by a finite element model with regional tissue properties. Med Eng Phys 31:1343–1348
Huang R, Rong Q (2010) Respiration simulation of human upper airway for analysis of obstructive sleep apnea syndrome. in Life System Modeling and Intelligent Computing 588–596 (Springer).
Wu JZ, Dong RG, Schopper AW (2004) Analysis of effects of friction on the deformation behavior of soft tissues in unconfined compression tests. J Biomech 37:147–155
Cheng S, Gandevia SC, Green M, Sinkus R, Bilston LE (2011) Viscoelastic properties of the tongue and soft palate using MR elastography. J Biomech 44:450–454
Haddad SMH, Dhaliwal SS, Rotenberg BW, Ladak HM, Samani A (2020) Estimation of the hyperelastic parameters of fresh human oropharyngeal soft tissues using indentation testing. J Mech Behav Biomed Mater 108:103798
Pugachev A et al (2020) Application of patient‐specific simulation workflow for obstructive sleep apnea diagnosis and treatment with a mandibular advancement device. Int J Numer Methods Biomed Eng 36.
Le TB, Moghaddam MG, Woodson BT, Garcia GJM (2019) Airflow limitation in a collapsible model of the human pharynx: physical mechanisms studied with fluid-structure interaction simulations and experiments. Physiol Rep 7:e14099
Cisonni J et al (2015) Numerical simulation of pharyngeal airflow applied to obstructive sleep apnea: effect of the nasal cavity in anatomically accurate airway models. Med Biol Eng Comput 53:1129–1139
Liu Y et al (2018) Study of the upper airway of obstructive sleep apnea patient using fluid structure interaction. Respir Physiol Neurobiol 249:54–61
Mylavarapu G et al (2021) Predicting critical closing pressure in children with obstructive sleep apnea using fluid structure interaction simulations. J Appl Physiol japplphysiol.00694.2020. https://doi.org/10.1152/japplphysiol.00694.2020.
Henrik Strand Moxness M, Wülker F, Helge Skallerud B, Nordgård S (2018) Simulation of the upper airways in patients with obstructive sleep apnea and nasal obstruction: a novel finite element method: novel FE method for OSA and nasal obstruction. Laryngoscope Investig Otolaryngol 3:82–93
Huang XZ, Wang JB (1998) Practical otolaryngology. Beijing People’s Med Publ House 225–259.
Chouly F, Van Hirtum A, Lagrée P-Y, Pelorson X, Payan Y (2009) Modelling the human pharyngeal airway: validation of numerical simulations using in vitro experiments. Med Biol Eng Comput 47:49–58
Yu S et al (2014) Numerical analysis for the efficacy of nasal surgery in obstructive sleep apnea hypopnea syndrome. Acta Mech Sin 30:250–258
Jayaraju ST, Brouns M, Lacor C, De Mey J, Verbanck S (2006) Effects of tracheal stenosis on flow dynamics in upper human airways. ST Jayaraju Al-2006.
Huang C-J, Huang S-C, White SM, Mallya SM, Eldredge JD (2016) Toward numerical simulations of fluid–structure interactions for investigation of obstructive sleep apnea. Theor Comput Fluid Dyn 30:87–104
Le TB, Garcia GJM (2018) Simulating airway collapse in obstructive sleep apnea using fluid-structure interaction methodologies. in 2018 Design of Medical Devices Conference V001T08A001 (American Society of Mechanical Engineers). https://doi.org/10.1115/DMD2018-6818.
Subramaniam DR et al (2018) Biomechanics of the soft-palate in sleep apnea patients with polycystic ovarian syndrome. J Biomech 76:8–15
Yang L, Yitung C, Woosoon Y, Robert CW (2018) Study of the suture-patch device through the tongue for sleep apnea using fluid-structure interaction modeling. J Otolaryngol Rhinol 4
Wang G, Yu C, Wang Y (2018) The distributions of airflow within the upper airway and posture changes of soft palate in patients with OSAHS after nasal structural correction. Biomed Eng Appl Basis Commun 30:1850017
Hur J-S, Kim H-H, Choi J-Y, Suh S-H, Baek S-H (2017) Investigation of the effects of miniscrew-assisted rapid palatal expansion on airflow in the upper airway of an adult patient with obstructive sleep apnea syndrome using computational fluid-structure interaction analysis. Korean J Orthod 47:353
Mylavarapu G et al (2009) Validation of computational fluid dynamics methodology used for human upper airway flow simulations. J Biomech 42:1553–1559
Chang KK, Kim KB, McQuilling MW, Movahed R (2018) Fluid structure interaction simulations of the upper airway in obstructive sleep apnea patients before and after maxillomandibular advancement surgery. Am J Orthod Dentofacial Orthop 153:895–904
Acknowledgements
This study has been supported by NSERC (Natural Sciences and Engineering Research Council of Canada).
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Ashraf, W., Jacobson, N., Popplewell, N. et al. Fluid–structure interaction modelling of the upper airway with and without obstructive sleep apnea: a review. Med Biol Eng Comput 60, 1827–1849 (2022). https://doi.org/10.1007/s11517-022-02592-2
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11517-022-02592-2