Intranasal Transportation Phenomena of Medicinal Droplets

Abstract

Nebulizer treatment has been used for nasal diseases such as paranasal sinusitis, hypertrophic rhinitis and inferior concha inflammation. The effectiveness of the nebulizer treatment has been confirmed from clinical view points until now. However there are a few researches that evaluate the effect of the nebulizer treatment quantitatively, i.e., how medicinal mist transports and deposits on inflammation areas of nasal wall. Some researchers calculated intranasal transport phenomena of medicinal droplets using Computed Fluid Dynamics (CFD). However these researches analyzed a few cases. The individual difference was left out of consideration even though there were different shapes of nasal cavities and different grade of medical conditions. This study constructs three-dimensional geometry model of nasal cavities using five actual patient’s CT data. The cases undergo deviated nasal septum, hypertrophic rhinitis, chronic sinusitis and bloating inferior nasal concha tumentia. This study analyzes the characteristics of airflow and medicinal droplet for the five cases and compared each other to get further knowledge of intranasal phenomena. As a result airflow velocity and pressure drop increase in the narrowing region caused by jet effect. Inlet angle and velocity of nebulizer treatment can easily control medicinal droplet transport characteristics. In the all cases the conditions of inlet angle 25-60 degree give us good treatment condition where medicinal droplet transports wide-area of nasal cavity. Especially this study makes clear circulatory flow is formed in superior concha. The circulatory flow is able to contribute advances medicinal droplet transportation in widespread area of intranasal.