Effect of Nebulizer Type and Position on a Ventilator Circuit on Aerosol Deposition in Lung Airway Models

Particle transport and deposition are investigated in different idealized and realistic bifurcating airway models using a computational fluid and particle dynamic study. Targeted drug delivery to the pulmonary airways primarily depends on the particle size, breathing pattern and the geometry of the airways. The aerosol characterization of nebulized albuterol delivered at a constant flowrate of 14L/min by two different nebulizers alone and placed in-line at two different positions in an adult ventilator circuit was obtained using the Next Generation Impactor. Simulations are performed using a Lagrangian particle tracking approach to model the transport of the spherical particles with diameters ranging from 0.5 to 5 microns, based on the aerodynamic particle size distribution data obtained for each operating condition. The effectiveness of the clinical treatment for each nebulizer type and position will be discussed based on the total and regional deposition fractions of the particles, and the sites of deposition. The effect of spatial distribution of the injected particles at the inlet and the presence of an endotracheal tube on the aerosol deposition and distribution will be presented.