Evaluating the Effect of Sinex® (0.05% Oxymetazoline) Nasal Spray on Reduction of Nasal Congestion Using Computational Fluid Dynamics

2015 ◽  
Vol 137 (8) ◽  
Author(s):  
Aravind Kishore ◽  
Lauren Blake ◽  
Chengming Wang ◽  
Shan Ba ◽  
Gary Gross
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Nasal Congestion ◽  
Nasal Resistance ◽  
Parallel Circuit ◽  
Computational Fluid Dynamics Cfd ◽  
Magnetic Resonance Imaging Mri ◽  
Circuit Analogy ◽  
Pressure Boundary Conditions ◽  
Previous Clinical Study

Computational fluid dynamics (CFD) was used to simulate air flow changes in reconstructed nasal passages based on magnetic resonance imaging (MRI) data from a previous clinical study of 0.05% Oxymetazoline (Vicks Sinex Micromist®). Total-pressure boundary conditions were uniquely applied to accommodate low patency subjects. Net nasal resistance, the primary simulation outcome, was determined using a parallel-circuit analogy and compared across treatments. Relative risk (RR) calculations show that for a 50% reduction in nasal resistance, subjects treated with Sinex® are 9.1 times more likely to achieve this after 8 hr, and 3.2 times more likely after 12 hr compared to Sham.

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 Support for Fontan Planning in Minutes, Not Hours: The Next Step in Clinical Pre-Interventional Simulations

2021 ◽  
Author(s):  
Petter Frieberg ◽  
Nicolas Aristokleous ◽  
Pia Sjöberg ◽  
Johannes Töger ◽  
Petru Liuba ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Computation Time ◽  
Left Pulmonary Artery ◽  
Cfd Modeling ◽  
Resonance Imaging ◽  
Computational Fluid Dynamics Cfd ◽  
Magnetic Resonance Imaging Mri ◽  
Cfd Method ◽  
Fontan Patients

AbstractComputational fluid dynamics (CFD) modeling may aid in planning of invasive interventions in Fontan patients. Clinical application of current CFD techniques is however limited by complexity and long computation times. Therefore, we validated a “lean” CFD method to magnetic resonance imaging (MRI) and an “established” CFD method, ultimately aiming to reduce complexity to enable predictive CFD during ongoing interventions. Fifteen Fontan patients underwent MRI for CFD modeling. The differences between lean and established approach, in hepatic and total flow percentage to the left pulmonary artery (%LPA), power loss and relative wall shear stress area were 1.5 ± 4.0%, -0.17 ± 1.1%, -0.055 ± 0.092 mW and 1.1 ± 1.4%. Compared with MRI, the lean and established method showed a bias in %LPA of -1.9 ± 3.4% and -1.8 ± 3.1%. Computation time was for the lean and established approach 3.0 ± 2.0 min and 7.0 ± 3.4 h, respectively. We conclude that the proposed lean method provides fast and reliable results for future CFD support during interventions. Graphical abstract

A Longitudinal Study of Hemodynamics in a Functional Human Hemodialysis Fistula Using 3T Magnetic Resonance Imaging-Based Computational Fluid Dynamics Analysis

2010 ◽  
Author(s):  
Yong He ◽  
Christi M. Terry ◽  
Scott A. Berceli ◽  
Alfred K. Cheung ◽  
Yan-Ting E. Shiu
Keyword(s):  
Magnetic Resonance Imaging ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Magnetic Resonance ◽  
Resonance Imaging ◽  
Computational Fluid Dynamics Analysis ◽  
Computational Fluid Dynamics Cfd ◽  
Magnetic Resonance Imaging Mri ◽  
Stage Renal Disease ◽  
End Stage

An arteriovenous fistula (AVF) is the preferred vascular access for hemodialysis in end-stage renal disease. However, 60% of AVFs fail to achieve sufficient lumen dilation to allow adequate blood flow for chronic dialysis [1]. Although hemodynamics is likely an important modulator of AVF maturation and remodeling, the AVF hemodynamic spatial distribution profiles and their relationship with AVF maturation and remodeling are unclear [2]. Based on data collected from magnetic resonance imaging (MRI) of an AVF and computational fluid dynamics (CFD) simulations, we developed a protocol for longitudinal (over time) and noninvasive monitoring of geometry and hemodynamics of human AVF.

scholarly journals Computational Fluid Dynamics (CFD) Investigation of Aerodynamic Characters inside Nasal Cavity towards Surgical Treatments for Secondary Atrophic Rhinitis

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Ya Zhang ◽  
Xudong Zhou ◽  
Miao Lou ◽  
Minjie Gong ◽  
Jingbin Zhang ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Shear Stress ◽  
Atrophic Rhinitis ◽  
Nasal Resistance ◽  
Septal Perforation ◽  
Virtual Operation ◽  
Nasal Floor ◽  
Computational Fluid Dynamics Cfd ◽  
Surgical Treatments

Purpose. To use computational fluid dynamics (CFD) technology to fundamentally understand (1) the effect of surgical treatments on nasal physiology for secondary atrophic rhinitis and (2) the priority of operations. Subjects and Methods: With the aid of medical imaging and CFD modeling, three virtual operations (nasoseptal perforation repair, cavity narrowing, and a combination of both) were performed to analyze airflow, nasal resistance, and wall shear stress. Results. Compared with the cavity-narrowing virtual operation, nasal resistance was not significantly altered by septal perforation repair virtual operation. Airflow allocation changed with more air flowing through the olfactory area and less though the nasal floor after all operations, especially the cavity-narrowing operation. Wall shear stress at the original epistaxis area and the nasal floor was reduced after the cavity-narrowing operation. Conclusions. Simulation results suggest that the cavity-narrowing operation takes priority over septal perforation repair if a staged surgery approach is adopted. If only one operation can be chosen, the cavity-narrowing operation is better than the septal perforation repair. This work shows that CFD-based modeling may aid precision medicine.

Efficiency prediction for storage chambers using computational fluid dynamics

1996 ◽  
Vol 33 (9) ◽  
pp. 163-170 ◽  
Author(s):  
Virginia R. Stovin ◽  
Adrian J. Saul
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Shear Stress ◽  
Particle Tracking ◽  
Critical Value ◽  
Complex Geometries ◽  
Bed Shear Stress ◽  
Breadth Ratio ◽  
Computational Fluid Dynamics Cfd ◽  
Simulated Flow

Research was undertaken in order to identify possible methodologies for the prediction of sedimentation in storage chambers based on computational fluid dynamics (CFD). The Fluent CFD software was used to establish a numerical model of the flow field, on which further analysis was undertaken. Sedimentation was estimated from the simulated flow fields by two different methods. The first approach used the simulation to predict the bed shear stress distribution, with deposition being assumed for areas where the bed shear stress fell below a critical value (τcd). The value of τcd had previously been determined in the laboratory. Efficiency was then calculated as a function of the proportion of the chamber bed for which deposition had been predicted. The second method used the particle tracking facility in Fluent and efficiency was calculated from the proportion of particles that remained within the chamber. The results from the two techniques for efficiency are compared to data collected in a laboratory chamber. Three further simulations were then undertaken in order to investigate the influence of length to breadth ratio on chamber performance. The methodology presented here could be applied to complex geometries and full scale installations.

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