Computational fluid dynamics modelling of human upper airway: A review

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.

Computational Fluid Dynamics Modeling in Respiratory Airways Obstruction: <i>Current Applications and Prospects</i>

“…Thereafter, researchers looked into the study of common aberrations such as septal deviation, septal perforations and inferior turbinate hypertrophy [26,27]. Recently, CFD has been used to model and predict the effects of surgery and therapeutic interventions [28]. The applications evaluated in this review focuses on 3-dimensional CFD analyses of obstructed upper and lower airways of the respiratory system.…”

Anatomy and Pathophysiology of Upper Airway Obstructive Sleep Apnoea: Review of the Current Literature

“…The development of non-invasive tools to diagnose OSA is a topic of ongoing research and has resulted in new and emerging technologies [46,93,94]. Huang et al [46] examined the impact of dynamic changes in tongue base thickness (TBT) in OSA during awake and sleep using DISE ultrasonography.…”

“…CFD can integrate structural analysis software using a fluid-structure interaction simulation to tackle human UA problems which involve movement, motion, and deformation of soft tissue or airway wall. This approach can be used to analyse and detect airway collapse during breathing [93]. In conjunction with CFD, MRI has been used to determine relationships between the retropalatal airway, pharyngeal length, and craniofacial structures in patients with OSA [94].…”

Turbulent Kinetic Energy of Flow During Inhale and Exhale to Characterize the Severity of Obstructive Sleep Apnea Patient

“…Computational fluid dynamics (CFD) has emerged as one of the powerful tools for attaining a deep insight into many medical disorders, including that of OSA [10]. Recently, many researchers focused on fluid mechanics in understanding the flow mechanism inside the upper airway [11].…”