Visualization of particle deposition in human nasal cavities

The location and concentration of particle deposition of pollen by filtration in the human nasal cavity were visualized in a transparent silicone nasal airway model using laser-induced fluorescence (LIF) to clarify the relationship between flow and particle deposition. The model was created from a water-soluble plaster mold fabricated by a 3D printer based on X-ray computed tomography images. The working fluid was air and the tracer particles as a substitute for cedar pollen were lycopodium powder doped with fluorescent dye (Rhodamine 6G). After particle deposition, the nasal airway model was filled with an aqueous solution of glycerin that had the same refractive index as silicone. Then, LIF was applied to illuminate the deposited particles with a YAG laser sheet. Results revealed that particle deposition in the right and left cavities was highly heterogeneous and was related to the complex flow structure in the nasal cavities. .