An early research focus of the laboratory has been on the development of new numerical models of aerosol behavior in the human lung, particularly in the alveolar region of the lung. One of the major motivations in this research has been to develop a model that allows the study of aerosol dynamics in a region of the lung where direct collection of experimental data is not feasible in a non-invasive manner. Earlier models were one-dimensional and increased in complexity over the years with the latest contributions using either 3D models of the lung periphery that accounted for the expansion and contraction of the airspaces during breathing or models that used a multiscale approach. These studies have shown that alveolar flow can be extremely complex due to the unique time-dependent geometry of the acinus. Aerosol transport and deposition are influenced by geometric characteristics, in particular at the level of the alveolar aperture, and there are large inhomogeneities in deposition patterns within the acinar structure. Studies that included the motions of the alveolar cavities during breathing have highlighted the importance of convective exchange between the lumen and surrounding alveolar cavities, which significantly increase the number of particles depositing in these airspaces. These are important observations when one has to determine the potential effects of airborne pollutants on human health. Indeed, these results may provide a link to the mechanisms by which even low concentration of airborne pollutants can cause or exacerbate lung disease. A better understanding of the fate of aerosols in the alveolar zone of the lung as provided by these models may also be beneficial in applications such as inhalation drug therapy.
A downside of 3D models is that they typically only include a sub-region of the lung because of the prohibitive computational costs compared to simplified models. Thus, there is a need for developing multiscale strategies to link models that apply to different regions of the lung while maintaining site-specificity critical to dose-response assessments. This is the current focus of the lab.
Modeling approaches include:
- Solving one-dimensional convective-diffusive equations
- Computational fluid dynamics
- Multiscale modeling
- Darquenne C. and M. Paiva. One-dimensional simulation of aerosol transport and deposition in the human lung. J. Appl. Physiol., 77:2889-2898, 1994 (PMID:7896637)
- Darquenne, C., L. Harrington and G. K. Prisk. Alveolar duct expansion greatly enhances aerosol deposition: a three-dimensional CFD study. Phil. Trans. R. Soc. A, 367:2333-2346, 2009 (PMC2696106).
- Ma, B. and C. Darquenne. Aerosol Deposition Characteristics in Distal Acinar Airways under Cyclic Breathing Conditions. J. Appl. Physiol., 110:1271-1282, 2011. (PMC3098659)
- Oakes, J.M., A.L. Marsden, C. Grandmont, S.C. Shadden, C. Darquenne, and I.E. Vignon-Clementel. Airflow and particle deposition simulations in health and emphysema: from in-vivo to in-silico animal experiments. Ann. Biomed. Eng, 42:899-914, 2014 (PMC4092242).
- Kuprat, A., M. Jalali, T. Jan, R.A. Corley, B. Asgharian, O. Price, R.K. Singh, S. Colby and C. Darquenne. Efficient bi-directional coupling of 3D Computational Fluid-Particle Dynamics and 1D Multiple Path Particle Dosimetry lung models for multiscale modeling of aerosol dosimetry. J. Aerosol Sci., 151:105647, 2021 (https://doi.org/10.1016/j.jaerosci.2020.105647).
A full list of publications can be found on Chantal Darquenne's UCSD profile page