Numerical simulation of nasal resistance using three-dimensional models of the nasal cavity and paranasal sinus

Objectives: Previously, we used a nasal cavity model to analyze the intranasal airflow dynamics and numerically calculate the nasal resistance value. Here, we created a nasal sinus model that is closer to the real human body and calculated the nasal resistance value. Moreover, we performed comparisons of the measured and simulation data. Setting: The models were healthy adult volunteers: a 35-year-old man (model 1) and a 25-year-old man (model 2), who were used as nasal cavity and paranasal sinus models. A 1.0-mm slice computed tomography (CT) was performed and a nasal sinus model was created. We compared the nasal resistance of the simulation value with that of the measured value obtained using rhinomanometry. Results: In model 1, the measured (simulation) value was 0.69 (0.48) on the right, 1.10 (0.41) on the left, and 0.42 (0.22) on both sides. In model 2, the measured (simulation) value was 0.72 (0.21) on the right, 0.32 (0.09) on the left, and 0.22 (0.06) on both sides. Conclusion: We observed a difference between the simulation and measured values, possibly because of the length of the inferior turbinate and the cross-sectional area of the choana and nasopharynx. Further experiments using additional nasal cavity and paranasal sinus models are warranted.