Spatial aerosol deposition correlated to anatomic feature development in 6-year-old upper airway computational models.

The upper airways of children undergo developmental changes around age 6, yielding differences between adult and pediatric anatomies. These differences include the cricoid ring area shape, the location of narrowest constriction, and the angle of the epiglottis, all of which are expected to alter local fluid dynamic profiles and subsequent upper airway deposition and downstream aerosol delivery of inhaled therapeutics. In this work, we quantify "pediatric"-like and "adult"-like geometric and fluid dynamic features of two computed tomography (CT)-scan derived models of 6-year-old upper airways in healthy subjects and compare to an idealized model. The two CT-scan models had a mixture of "adult"- and "pediatric"-like anatomic features, with Subject B exhibiting more "pediatric"-like features than Subject A, while the idealized model exhibited entirely "adult"-like features. By computational fluid-particle dynamics, these differences in anatomical features yielded distinct local fluid profiles with altered aerosol deposition between models. Notably, the idealized model better predicted deposition characteristics of Subject A, the more "adult"-like model, including the relationship between the impaction parameter, d