scholarly journals Side asymmetry in nasal resistance correlate with nasal obstruction severity in patients with septal deformities: Computational fluid dynamics study

2020 ◽  
Vol 45 (5) ◽  
pp. 718-724
Author(s):  
Nataša Janović ◽  
Aleksandar Ćoćić ◽  
Mirjana Stamenić ◽  
Aleksa Janović ◽  
Marija Djurić
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Nasal Obstruction ◽  
Nasal Resistance ◽  
Side Asymmetry ◽  
Obstruction Severity

scholarly journals Computational Fluid Dynamics in the assessment of nasal obstruction in children

2019 ◽  
Vol 136 (2) ◽  
pp. 87-92 ◽  
Author(s):  
E. Moreddu ◽  
L. Meister ◽  
C. Philip-Alliez ◽  
J.-M. Triglia ◽  
M. Medale ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Nasal Obstruction

scholarly journals Functional relevance of computational fluid dynamics in the field of nasal obstruction: A literature review

2019 ◽  
Vol 44 (5) ◽  
pp. 801-809 ◽  
Author(s):  
Thomas Radulesco ◽  
Lionel Meister ◽  
Gilles Bouchet ◽  
Jérôme Giordano ◽  
Patrick Dessi ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Literature Review ◽  
Nasal Obstruction ◽  
Functional Relevance

scholarly journals Assessment of nasal resistance using computational fluid dynamics

2016 ◽  
Vol 2 (1) ◽  
pp. 617-621 ◽  
Author(s):  
Jan Osman ◽  
Friederike Großmann ◽  
Kay Brosien ◽  
Ulrich Kertzscher ◽  
Leonid Goubergrits ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Gold Standard ◽  
Objective Assessment ◽  
Nasal Resistance ◽  
Nasal Breathing ◽  
Current Gold Standard ◽  
Flow Parameters

AbstractAnterior rhinomanometry is the current gold standard for the objective assessment of nasal breathing by determining the nasal resistance. However, computational fluid dynamics would allow spatially and temporally well- resolved investigation of additional flow parameters. In this study, measured values of nasal resistance are compared with measured values. An unclear discrepancy between the two methods was found, suggesting further investigation.

Rhinomanometry Versus Computational Fluid Dynamics: Correlated, but Different Techniques

2020 ◽  
pp. 194589242095015
Author(s):  
Giancarlo B. Cherobin ◽  
Richard L. Voegels ◽  
Fábio R. Pinna ◽  
Eloisa M. M. S. Gebrim ◽  
Ryan S. Bailey ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Nasal Resistance ◽  
Nasal Patency ◽  
Low Correlation ◽  
Before And After ◽  
Computational Fluid Dynamics Cfd ◽  
Flow Experiments

Background Past studies reported a low correlation between rhinomanometry and computational fluid dynamics (CFD), but the source of the discrepancy was unclear. Low correlation or lack of correlation has also been reported between subjective and objective measures of nasal patency. Objective: This study investigates (1) the correlation and agreement between nasal resistance derived from CFD (RCFD) and rhinomanometry (RRMN), and (2) the correlation between objective and subjective measures of nasal patency. Methods Twenty-five patients with nasal obstruction underwent anterior rhinomanometry before and after mucosal decongestion with oxymetazoline. Subjective nasal patency was assessed with a 0-10 visual analog scale (VAS). CFD simulations were performed based on computed tomography scans obtained after mucosal decongestion. To validate the CFD methods, nasal resistance was measured in vitro (REXPERIMENT) by performing pressure-flow experiments in anatomically accurate plastic nasal replicas from 6 individuals. Results Mucosal decongestion was associated with a reduction in bilateral nasal resistance (0.34 ± 0.23 Pa.s/ml to 0.19 ± 0.24 Pa.s/ml, p = 0.003) and improved sensation of nasal airflow (bilateral VAS decreased from 5.2 ± 1.9 to 2.6 ± 1.9, p < 0.001). A statistically significant correlation was found between VAS in the most obstructed cavity and unilateral airflow before and after mucosal decongestion (r = −0.42, p = 0.003). Excellent correlation was found between RCFD and REXPERIMENT (r = 0.96, p < 0.001) with good agreement between the numerical and in vitro values (RCFD/REXPERIMENT = 0.93 ± 0.08). A weak correlation was found between RCFD and RRMN (r = 0.41, p = 0.003) with CFD underpredicting nasal resistance derived from rhinomanometry (RCFD/RRMN = 0.65 ± 0.63). A stronger correlation was found when unilateral airflow at a pressure drop of 75 Pa was used to compare CFD with rhinomanometry (r = 0.76, p < 0.001). Conclusion CFD and rhinomanometry are moderately correlated, but CFD underpredicts nasal resistance measured in vivo due in part to the assumption of rigid nasal walls. Our results confirm previous reports that subjective nasal patency correlates better with unilateral than with bilateral measurements and in the context of an intervention.

scholarly journals Computational fluid dynamics endpoints to characterize obstructive sleep apnea syndrome in children

2014 ◽  
Vol 116 (1) ◽  
pp. 104-112 ◽  
Author(s):  
David M. Wootton ◽  
Haiyan Luo ◽  
Steven C. Persak ◽  
Sanghun Sin ◽  
Joseph M. McDonough ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Obstructive Sleep Apnea Syndrome ◽  
Sleep Apnea Syndrome ◽  
Nasal Resistance ◽  
Cfd Model ◽  
Obstructive Sleep ◽  
Apnea Syndrome

Computational fluid dynamics (CFD) analysis may quantify the severity of anatomical airway restriction in obstructive sleep apnea syndrome (OSAS) better than anatomical measurements alone. However, optimal CFD model endpoints to characterize or assess OSAS have not been determined. To model upper airway fluid dynamics using CFD and investigate the strength of correlation between various CFD endpoints, anatomical endpoints, and OSAS severity, in obese children with OSAS and controls. CFD models derived from magnetic resonance images were solved at subject-specific peak tidal inspiratory flow; pressure at the choanae was set by nasal resistance. Model endpoints included airway wall minimum pressure (Pmin), flow resistance in the pharynx (Rpharynx), and pressure drop from choanae to a minimum cross section where tonsils and adenoids constrict the pharynx ( dP TAmax). Significance of endpoints was analyzed using paired comparisons ( t-test or Wilcoxon signed rank test) and Spearman correlation. Fifteen subject pairs were analyzed. Rpharynx and dP TAmax were higher in OSAS than control and most significantly correlated to obstructive apnea-hypopnea index (oAHI), r = 0.48 and r = 0.49, respectively ( P < 0.01). Airway minimum cross-sectional correlation to oAHI was weaker ( r = −0.39); Pmin was not significantly correlated. CFD model endpoints based on pressure drops in the pharynx were more closely associated with the presence and severity of OSAS than pressures including nasal resistance, or anatomical endpoints. This study supports the usefulness of CFD to characterize anatomical restriction of the pharynx and as an additional tool to evaluate subjects with OSAS.

Frictional resistance sheds light on the multicomponent nature of nasal obstruction: A combined in vivo and computational fluid dynamics study

2013 ◽  
Vol 188 (2) ◽  
pp. 133-142 ◽  
Author(s):  
Bruno Louis ◽  
Jean-François Papon ◽  
Céline Croce ◽  
Georges Caillibotte ◽  
Gabriela Sbirlea-Apiou ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Nasal Obstruction ◽  
Frictional Resistance ◽  
Multicomponent Nature

scholarly journals Impact of Varying Types of Nasal Septal Deviation on Nasal Airflow Pattern and Warming Function: A Computational Fluid Dynamics Analysis

2019 ◽  
pp. 014556131987274 ◽  
Author(s):  
Lifeng Li ◽  
Hongrui Zang ◽  
Demin Han ◽  
Nyall R. London
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Septal Deviation ◽  
Maximal Velocity ◽  
Nasal Resistance ◽  
Nasal Airflow ◽  
Airflow Pattern ◽  
Computational Fluid Dynamics Analysis ◽  
Nasal Function ◽  
The Impact

Nasal septal deviations (NSD) have been categorized into 7 types. The effect of these different deviations on airflow pattern and warming function has not been fully investigated. The purpose of this study was to utilize a computational fluid dynamics approach to assess the impact of NSD of varying types on nasal airflow and warming function. Patients with each type of NSD were enrolled in the study, and a normal participant as the control. Using a computational fluid dynamics approach, modeling of nasal function was performed. Indices of nasal function including airflow redistribution, total nasal resistance, airflow velocity, and airflow temperature were determined. Among all types of NSD, the maximal velocity and total nasal resistance were markedly higher in type 4 and 7 deviations. The flow partition and velocity distribution were also altered in type 4 and 7 as well as type 2 and 6 deviations. Airflow in all categories of NSD was fully warmed to a similar degree. From a computational aerodynamics perspective, the type of septal deviation may contribute to altered airflow characteristics. However, warming function was similar between septal deviation types. Future studies will help to ascertain the functional importance of septal deviation types and the applicability of these computational studies.

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