The effect of inlet flow profile and nozzle diameter on drug delivery to the maxillary sinus

Abstract

In this paper, the effect of the turbulence and swirling of the inlet flow and the diameter of the nozzle on the flow characteristics and the particles' transport/deposition patterns in a realistic combination of the nasal cavity (NC) and the maxillary sinus (MS) were examined. A computational fluid dynamics (CFD) model was developed in ANSYS® Fluent using a hybrid Reynolds averaged Navier–Stokes–large-eddy simulation algorithm. For the validation of the CFD model, the pressure distribution in the NC was compared with the experimental data available in the literature. An Eulerian–Lagrangian approach was employed for the prediction of the particle trajectories using a discrete phase model. Different inlet flow conditions were investigated, with turbulence intensities of 0.15 and 0.3, and swirl numbers of 0.6 and 0.9 applied to the inlet flow at a flow rate of 7 L/min. Monodispersed particles with a diameter of 5 µm were released into the nostril for various nozzle diameters. The results demonstrate that the nasal valve plays a key role in nasal resistance, which damps the turbulence and swirl intensities of the inlet flow. Moreover, it was found that the effect of turbulence at the inlet of the NC on drug delivery to the MS is negligible. It was also demonstrated that increasing the flow swirl at the inlet and decreasing the nozzle diameter improves the total particle deposition more than threefold due to the generation of the centrifugal force, which acts on the particles in the nostril and vestibule. The results also suggest that the drug delivery efficiency to the MS can be increased by using a swirling flow with a moderate swirl number of 0.6. It was found that decreasing the nozzle diameter can increase drug delivery to the proximity of the ostium in the middle meatus by more than 45%, which subsequently increases the drug delivery to the MS. The results can help engineers design a nebulizer to improve the efficiency of drug delivery to the maxillary sinuses.

Acoustic Aerosol Delivery: Assessing of Various Nasal Delivery Techniques and Medical Devices on Intrasinus Drug Deposition

“…The physical principle is to increase the transfer of airborne droplets from the nasal cavity to the sinus cavity through the oscillatory exchange of air across the maxillary ostium according to the Helmholtz resonator theory ( Figure 1 ). This oscillating airflow resulting from the acoustic wave allows a pressure gradient to be generated between the nasal fossae and the sinus cavity, which is a poorly ventilated area [ 11 , 12 , 13 ]. Thus, it has been previously demonstrated that the superposition of an acoustic wave on the airborne droplets produced by a nebulizer can allow, in some cases, a significant improvement of intrasinus drug deposition [ 14 , 15 , 16 , 17 ].…”

In-Plane Wave Propagation Analysis of Human Breast Lesions Using a Higher-Order Nonlocal Model and Deep Learning

“…Optimised mechanical properties lead to the smooth and robust integration of biomaterials into target tissues, reducing inflammation and enhancing the efficacy of the artificial organ or scaffold [5,7]. In drug delivery systems, acoustic analysis and fluid flow studies help researchers and clinicians gain a better understanding of therapeutic particle motion and improve drug delivery rates [8,9]. Moreover, biomechanical features are used as indicators of disease for detection purposes and in treatment monitoring to assess therapy effectiveness [10][11][12].…”

Relaxation and creep response of the alveolar lung to diagnosis and treatments for respiratory and lung disorders

“…25 In the Computational Fluid Dynamics (CFD) domain, wall behaviour is considered rigid in all types of mathematical modelling. [26][27][28][29] Therefore, the application of CFD methods to represent human body organs with viscoelastic behaviour creates an aura of ambiguity. The Fluid-Structure Interaction (FSI) method has been used to solve this problem, such that wall properties are considered in the mathematical model of the organ.…”