Acoustic behaviour of the human maxillary sinus: The importance of the middle meatus and the ostium on resonance frequency behaviour

Abstract

This study aims to investigate the resonance frequency of the human maxillary sinus for the application of acoustically-driven drug delivery. An improved model of the classic Helmholtz resonator formula has been developed to predict the resonance frequency of a nasal cavity and maxillary sinus combination, using computational fluid dynamics (CFD). To be more specific, a 3-D CFD model of the left side of a healthy human nose, composed of a nasal cavity connected to the maxillary sinus through an ostium, has been developed to undertake direct computational acoustics for predicting the resonance frequency. The simulations of the acoustic airflow in the nasal cavity, ostium, and maxillary sinus were carried out by solving the continuity and Navier-Stokes equations. A series of experiments were conducted for validation of CFD modelling using the resonance frequency of the nasal cavity and maxillary sinus combination as a criterion. The results showed that the classic Helmholtz resonator formula overpredicted the resonance frequency of the realistic nasal cavity and maxillary combination by 50% compared to measured experimental data. However, the results of the CFD simulation demonstrated a good agreement with the experimental data, showing a difference of 10%. Further, it is shown that by accounting for the fluid mass within both the maxillary sinus and the middle meatus the resonance frequency of the nasal cavity and maxillary sinus combination can be accurately predicted.