PNNL

Abstract

Advances in computational, and imaging techniques have enabled the rapid development of 3-dimensional (3-D) models of biological systems in unprecedented detail. Using these advances, 3-D models of the lungs and nasal passages of the rat and human are being developed to ultimately improve predictions of airborne pollutant dosimetry. Techniques for imaging the respiratory tract by magnetic resonance (MR) imaging were developed to improve the speed and accuracy of geometric data collection for mesh reconstruction. The MR imaging resolution is comparable to that obtained by manual measurements but at much greater speed and accuracy. Newly developed software (NWGrid) was utilized to translate imaging data from MR into 3-D mesh structures. Together, these approaches significantly reduced the time to develop a 3-D model. This more robust airway structure will ultimately facilate modeling gas or vapor exchange between the respiratory tract and vasculature as well as enable linkages of dosimetry with cell response models. The 3-D, finite volume, visco-elastic mesh structures forms the geometric basis for computational fluid dynamics modeling of inhalation, exhalation and the delivery of individual particles (or concentrations of gas or vapors) to discrete regions of the respiratory tract. The ability of these 3-D models to resolve dosimetry at such a high level of detail will require new techniques to measure regional airflows and particulate deposition for model validation.