Abstract:
The success of targeted drug delivery through inhalation largely depends on the efficient
deposition of aerosols across different regions of the human lung. Factors such as particle size,
airflow dynamics, lung geometry, and body posture have a significant influence on aerosol
transport and deposition. This computational fluid dynamics (CFD)-based study investigates
the combined effects of body orientation and particle size on aerosol deposition using a realistic
lung geometry reconstructed from computed tomography (CT) images and a realistic aerosol
breathing profile derived from patient data. Simulations were conducted in ANSYS Fluent
using the Discrete Phase Model (DPM) for five particle sizes (3, 5, 7, 9, and 10 µm) across
three body orientations: upright, dorsal, and lateral.
Results showed that total deposition efficiency increased with particle size, while regional
deposition varied noticeably with posture. The right lung consistently exhibited higher
deposition than the left, and the upper lobes of both lungs received the majority of particles,
particularly for larger aerosols. Although overall deposition efficiency remained similar across
orientations, regional redistribution was evident. These findings highlight how body posture
influences aerosol transport within the lungs and offer valuable insights for optimizing posture
based inhalation strategies and improving targeted drug delivery.
