7 August 2012
4 - 5pm
Venue: Ground Floor Seminar Room (G010), UniServices House, 70 Symonds Street, Auckland
A Bioengineering research seminar by James B. Grotberg, Director, NASA Bioscience and Engineering Institute Biomedical Engineering Department, The University of Michigan
Our lab has been actively pursuing a number of problems involving multiphase flow in the lung. This talk will be a review of our efforts in surfactant and liquid delivery into the lung, airway closure, airway reopening, related aerosol deposition phenomena and alveolar dynamics. The disease settings are acute respiratory distress syndrome, asthma, cystic fibrosis, surfactant deficiency, and congestive heart failure. CFD (computational fluid dynamics) is used extensively with comparisons to our own experiments and available literature. Computations give us a way of understanding critical fluid mechanical phenomena for Newtonian and non-Newtonian fluids such as: liquid plug splitting at airway bifurcations with the influence of gravity; initiation of plug motion from a critical yield pressure drop when it has a yield stress, as in mucus; the deposition of local aerosols during airway closure and reopening on the dynamic interface of that airway; the stability of a liquid film, or bilayer film, in an airway geometry to model the serous and mucus layers during airway closure; and the combined effects of cyclic stretch and interface motion over alveolar cells. CFD also gives us insight into the levels of stresses on the epithelial cells of airways and alveoli which may cause damage, provoke the release of bioactive molecules, and initiate and sustain inflammation.