A Probabilistic Model for Intersubject Deposition Variability of Inhaled Particles

Abstract

Experimental data on total and regional deposition of inhaled particles in the human respiratory tract show a significant amount of intersubject variability even under well-controlled breathing conditions. To explain this variability, a probabilistic lung model is proposed in which two random scaling factors are introduced to account for intersubject differences in airway dimensions, one for the tracheobronchial region and the other for the alveolar region. The calculated deposition based upon this model shows excellent agreement with experimental data, thus further supporting the view that the major cause of intersubject deposition variability in various regions is difference in airway size.