Effect of Nasal Valve Shape on Downstream Volume, Airflow, and Pressure Drop: Importance of the Nasal Valve Revisited

Naughton, John; Lee, Andrew Y.; Ramos, Eric; Wootton, David; Stupak, Howard D.

doi:10.1177/0003489418791597

Cited by 12 publications

(3 citation statements)

References 24 publications

(32 reference statements)

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“…They also found a greater pressure drop in patients with nasal obstruction ( P < 0.05). The pressure distribution led this author to conclude that the nasal valve is a key zone for nasal obstruction, as shown elsewhere …”

Section: Resultsmentioning

confidence: 59%

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

Radulesco

Meister

Bouchet

et al. 2019

Clinical Otolaryngology

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Background: Nasal airway obstruction (nasal obstruction) is a common symptom affecting the quality of life of patients. It can be estimated by patient perception or physical measurements. Computational fluid dynamics (CFD) can be used to analyse nasal ventilation modalities. There is a lack of comparative studies investigating the correlations between CFD variables and patient perception or physical measurements.Objective of the review: Our goal was to define correlations between CFD variables and patient perception and physical measurements. We also aimed to identify the most reliable CFD variable (heat flux, WSS, total pressure, temperature…) characterising nasal breathing perception.Type of review: Systematic literature review using PRISMA guidelines. Search strategy:The selected studies were obtained from the US National Library of Medicine (PubMed) online database, MEDLINE (Ovid), Google Scholar and the Cochrane Library using a combination of MeSH terms (nose, paranasal sinus, fluid dynamics, rhinology) and non-MeSH terms (CFD, nasal airway, nasal airflow, numerical, nasal symptoms). Studies that did not incorporate objective or subjective clinical assessment were excluded. Evaluation method:We compared all results obtained by authors regarding CFD variables and assessment of nasal airway obstruction (clinical or physical). Results:To compare nasal obstruction with CFD variables, most authors use CFD-calculated nasal resistances, airflow, heat flux, wall shear stress, total pressure, velocities and streamlines. We found that heat flux appears to be the CFD variable most closely correlated with patient perception. Total pressure, wall shear stress and velocities are also useful and show good correlations. Correlations between CFD-calculated nasal resistances and patient perception are stronger after correction of the nasal cycle. Conclusions:The growing number of CFD studies on the nose has led to a better understanding of nasal obstruction. The clinical interpretation of previously unknown data, such as WSS and heat flux, is opening up new horizons in the understanding of this symptom. Heat fluxes are among the best CFD values correlated with patient perception. More studies need to be performed including temperature and humidity exchanges.

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Section: Resultsmentioning

confidence: 59%

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

Radulesco

Meister

Bouchet

et al. 2019

Clinical Otolaryngology

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“…An inlet pressure boundary condition with zero-gauge pressure was applied in the nostril. To simulate breathing during rest and exercise in the CFD method, the airflow rates passing through the nostril section were set in previous studies as 150 ml/s in the resting state for the single nasal passage and 500 ml/s in the exercise state (13,16,18,24). To provide these flow rates, the inlet pressure in the nostril was accepted as the atmospheric pressure, and the outlet pressure was adjusted.…”

Section: Methodsmentioning

confidence: 99%

Changes in nasolabial angle may alter nasal valve morphology and airflow: a computational fluid dynamics study

Erdogan

2023

Journal of Health Sciences and Medicine

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Aim: Nasal valve (NV) dysfunctions are a significant cause of nasal obstruction. Changes in the nasolabial angle (NLA) may also cause changes in NV morphology. The effect of changes in the 3D structure of the nasal valve region (NVR) on nasal airflow has yet to be studied sufficiently. The accuracy of computational fluid dynamics (CFD) simulation results of nasal airflow has been confirmed by in vitro tests. Therefore, this study aimed to evaluate the effect of changes in NV structure and volume on nasal airflow based on the CFD method. Material and Method: We used CT images to create a 3D structural model of the NVR. First, CT images were transferred to MIMICS® software, and the nasal air passage was modeled. A solid reference model of the NVR was then created using SolidWorks software. Five different solid 3D nasal valve models were created with nasolabial angles of 85˚ in Model 1, 90˚ in Model 2, 95˚ in Model 3, 100˚ in Model 4, and 105˚ in Model 5. To simulate breathing during rest and exercise using the CFD method, the unilateral nasal airflow rates were set at 150 ml/s and 500 ml/s, respectively. The CFD method was then used to calculate each model’s airflow properties. Finally, the volumes of the models, pressure at the NV outlet, and airflow velocity were evaluated and calculated to investigate each model’s NV airflow characteristics. Results: Our study found a significant correlation between the nasolabial angle (NLA) and NVR volume (r=-0.998, p=0.000), flow rate and velocity (r=0.984, p=0.000), velocity and maximum pressure (r=0.920, p=0.000), velocity and minimum pressure (r=-0.969, p=0.000), flow rate and maximum pressure (r=0.974, p=0.000), and flow rate and minimum pressure (r=-0.950, p=0.000). There was no correlation between NLA increase and nasal airflow velocity. We determined that the highest pressure and lowest airflow velocity values were in the upper angle region and that the lowest pressure and highest airflow velocity values were at the bottom of the NVR in all models. Conclusion: Using the CFD method, we found a decrease in NVR volume and an increase in airflow velocity with an increase in NLA. In addition, we found that the pressure values in the NVR did not change significantly with the increase in NLA.

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“…The results of studying the characteristics of the air flow in the nasal cavity, as well as the effect of the boundary layer on the mucous membrane of the nasal cavity, are the basic data for endoscopic surgery of the nasal sinuses [20,21]; planning of functional, minimally invasive surgical interventions [12,22,23], in particular septoplasty [22][23][24]; and functional−aesthetic rhinoplasty [25][26][27][28]. The influence of anatomical structures and changes in the architectonics of the nose on nasal aerodynamics [29][30][31][32][33][34][35] can be seen, in particular, in the syndrome of empty nose [30], odontogenic sinusitis [31], the shape of the nasal valve [32] and in sleep apnea syndrome [33][34][35], and the study of the characteristics of the air flow is carried out on full-scale models of the nasal cavity [36,37]. Moreover, studies of the olfactory function are relevant [38][39][40][41], especially in the diagnosis and subsequent rehabilitation of patients after COVID-19 [40].…”

Section: Actuality Of the Workmentioning

confidence: 99%

Research Active Posterior Rhinomanometry Tomography Method for Nasal Breathing Determining Violations

Аврунін

Nosova

Abdelhamid

et al. 2021

Sensors

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This study analyzes the existing methods for studying nasal breathing. The aspects of verifying the results of rhinomanometric diagnostics according to the data of spiral computed tomography are considered, and the methodological features of dynamic posterior active rhinomanometry and the main indicators of respiration are also analyzed. The possibilities of testing respiratory olfactory disorders are considered, the analysis of errors in rhinomanometric measurements is carried out. In the conclusions, practical recommendations are given that have been developed for the design and operation of tools for functional diagnostics of nasal breathing disorders. It is advisable, according to the data of dynamic rhinomanometry, to assess the functioning of the nasal valve by the shape of the air flow rate signals during forced breathing and the structures of the soft palate by the residual nasopharyngeal pressure drop. It is imperative to take into account not only the maximum coefficient of aerodynamic nose drag, but also the values of the pressure drop and air flow rate in the area of transition to the turbulent quadratic flow regime. From the point of view of the physiology of the nasal response, it is necessary to look at the dynamic change to the current mode, given the hour of the forced response, so that it will ensure the maximum possible acidity in the legend. When planning functional rhinosurgical operations, it is necessary to apply the calculation method using computed tomography, which makes it possible to predict the functional result of surgery.

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Effect of Nasal Valve Shape on Downstream Volume, Airflow, and Pressure Drop: Importance of the Nasal Valve Revisited

Cited by 12 publications

References 24 publications

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

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

Changes in nasolabial angle may alter nasal valve morphology and airflow: a computational fluid dynamics study

Research Active Posterior Rhinomanometry Tomography Method for Nasal Breathing Determining Violations

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