Computational fluid dynamics modelling of human upper airway: A review

W M Faizal; N N N Ghazali; C Y Khor; Irfan Anjum Badruddin; M Z Zainon; Aznijar Ahmad Yazid; Norliza Binti Ibrahim; Roziana Mohd Razi

doi:10.1016/j.cmpb.2020.105627

Computational fluid dynamics modelling of human upper airway: A review

Comput Methods Programs Biomed. 2020 Nov:196:105627. doi: 10.1016/j.cmpb.2020.105627. Epub 2020 Jun 26.

Authors

W M Faizal¹, N N N Ghazali², C Y Khor³, Irfan Anjum Badruddin⁴, M Z Zainon⁵, Aznijar Ahmad Yazid⁵, Norliza Binti Ibrahim⁶, Roziana Mohd Razi⁷

Affiliations

¹ Department of Mechanical Engineering Technology, Faculty of Engineering Technology, University Malaysia Perlis, 02100 Padang Besar, Perlis, Malaysia; Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
² Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia. Electronic address: nik_nazri@um.edu.my.
³ Department of Mechanical Engineering Technology, Faculty of Engineering Technology, University Malaysia Perlis, 02100 Padang Besar, Perlis, Malaysia.
⁴ Research Center for Advanced Materials Science (RCAMS), King Khalid University, P.O. Box 9004, Abha, 61413, Asir, Kingdom Saudi Arabia; Mechanical Engineering Department, College of Engineering, King Khalid University, PO Box 394, Abha, 61421, Kingdom of Saudi Arabia. Electronic address: magami.irfan@gmail.com.
⁵ Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
⁶ Department of Oral and Maxillofacial Clinical Science, Faculty of Dentistry, University of Malaya, 50603, Kuala Lumpur, Malaysia.
⁷ Department of Paediatric Dentistry and Orthodontics, Faculty of Dentistry, University of Malaya, 50603, Kuala Lumpur, Malaysia.

Abstract

Background and objective: Human upper airway (HUA) has been widely investigated by many researchers covering various aspects, such as the effects of geometrical parameters on the pressure, velocity and airflow characteristics. Clinically significant obstruction can develop anywhere throughout the upper airway, leading to asphyxia and death; this is where recognition and treatment are essential and lifesaving. The availability of advanced computer, either hardware or software, and rapid development in numerical method have encouraged researchers to simulate the airflow characteristics and properties of HUA by using various patient conditions at different ranges of geometry and operating conditions. Computational fluid dynamics (CFD) has emerged as an efficient alternative tool to understand the airflow of HUA and in preparing patients to undergo surgery. The main objective of this article is to review the literature that deals with the CFD approach and modeling in analyzing HUA.

Methods: This review article discusses the experimental and computational methods in the study of HUA. The discussion includes computational fluid dynamics approach and steps involved in the modeling used to investigate the flow characteristics of HUA. From inception to May 2020, databases of PubMed, Embase, Scopus, the Cochrane Library, BioMed Central, and Web of Science have been utilized to conduct a thorough investigation of the literature. There had been no language restrictions in publication and study design of the database searches. A total of 117 articles relevant to the topic under investigation were thoroughly and critically reviewed to give a clear information about the subject. The article summarizes the review in the form of method of studying the HUA, CFD approach in HUA, and the application of CFD for predicting HUA obstacle, including the type of CFD commercial software are used in this research area.

Results: This review found that the human upper airway was well studied through the application of computational fluid dynamics, which had considerably enhanced the understanding of flow in HUA. In addition, it assisted in making strategic and reasonable decision regarding the adoption of treatment methods in clinical settings. The literature suggests that most studies were related to HUA simulation that considerably focused on the aspects of fluid dynamics. However, there is a literature gap in obtaining information on the effects of fluid-structure interaction (FSI). The application of FSI in HUA is still limited in the literature; as such, this could be a potential area for future researchers. Furthermore, majority of researchers present the findings of their work through the mechanism of airflow, such as that of velocity, pressure, and shear stress. This includes the use of Navier-Stokes equation via CFD to help visualize the actual mechanism of the airflow. The above-mentioned technique expresses the turbulent kinetic energy (TKE) in its result to demonstrate the real mechanism of the airflow. Apart from that, key result such as wall shear stress (WSS) can be revealed via turbulent kinetic energy (TKE) and turbulent energy dissipation (TED), where it can be suggestive of wall injury and collapsibility tissue to the HUA.

Keywords: Computational Fluid Dynamics (CFD); Fluid-structure Interaction (FSI); Human Upper Airway (HUA).

Publication types

Review

MeSH terms

Computer Simulation
Humans
Hydrodynamics*
Software
Stress, Mechanical
Trachea*