Aerosol Deposition in the Nose As a Function of Body Size

Development of the Premature Infant Nose Throat-Model (PrINT-Model)—An Upper Airway Replica of a Premature Neonate for the Study of Aerosol Delivery

“…Furthermore, in a number of in vitro studies (4 -6,22,23) it has been pointed out, that the use of a realistic human upper airway replica would be preferable to the USP throat. The main reason, why anatomically correct upper airway models are of interest is that the upper airways act as an important trap for inhaled aerosols (10,14,16,24,25). Aerosol deposition occurs mostly in the larynx and trachea (26,27), and is determined by pharyngeal and glottal morphologic constrictions and consequent flow jets (28).…”

“…The model is derived from a CT scan and reconstructed using stereolithography. In contrast to the already existing upper airway model of Phalen et al (14), which was an extrapolated simplification of an adult nose model by reducing adult airway dimensions by 50%, this model was the first realistic upper airway model of a 9-mo-old infant to correctly represent the anatomy of the upper airways, including the laryngeal part and specifically taking into account nose breathing. The model includes the face, nasal cavity, and pharynx extending to the subglottic region.…”

“…Both mathematical and anatomical models have been developed for adults (9 -12). They show that the upper airways of adults (nose, mouth, pharynx, and larynx) are an important trap for inhaled aerosols (10,(13)(14)(15)(16).…”

Sidestream cigarette smoke deposition in surrogate nasal models

“…Therefore, the measured smoke deposition efficiency (4.5%) causes us to reject the hypothesis that cloud behavior produced enhanced smoke deposition in the hollow surrogate nasal models. Previous studies of particle deposition using our hollow models over a wide range of airflows with 0.8 and 2.02/~m diameter monodisperse polystyrene latex particles (Duke Scientific, Palo Alto, CA) indicated that our models gave deposition efficiencies that were very similar to those measured using human subjects (Phalen et al, 1989). Black and Pritchard (1984) estimated the total respiratory tract deposition efficiency of inhaled radiolabeled cigarette smoke in active cigarette smokers by studying clearance curves for the radiolabel.…”

“…These dimensions not only were realistic with respect to the anatomy ofthe human nose, but they also yielded realistic pressure-drop vs airflow rate data and realistic deposition efficiencies for monodisperse particles (Scott et ai., 1978;Phalen et al, 1989). Our adult-sized nasal models (Fig.…”