Mechanical properties of the parenchyma of the lung are currently unknown and difficult to quantify. Creating a computer model with valid property values will allow researchers to further investigate particle mixing in the lung during inhalation and exhalation. One challenge with modeling the material of the lung is the intricate geometry of the alveolar sac. Researchers are currently trying to model particle deposition within the lung using computational fluid dynamics. However, the mechanical properties of alveolar sac structure are currently undetermined. Due to the complexity of the physical structure of an alveolar sac, it has been a challenge to model fluid-structural interactions during breathing. To assist in quantifying these interactions, computer aided finite element models are a necessity. These models will allow for calculation of the deflections and deformations of the physical structures of fluid containing membranes. The focal point of the project was to determine mechanical properties of a series of materials. There is currently no process for determining these properties and this was a major accomplishment of this research. The process of finding these properties can be applied to other materials in the future, even on a micro-scale, such as real alveolar tissue materials. These properties were applied to a series of finite element models, predicting deflection. Mechanical properties were determined by using different test specimens to collect data and fit to a Mooney Rivlin model. The results were then applied to a series of finite element models, one for each test specimen and one for a spherical boiling flask. The boiling flask tests showed promising outcome for future research, with a determined material model nearly 40% increase in accuracy from prior research. The tests were able to be replicated for a second surrogate material, showing that the process works for more than just a single material and allowing the process to be used with a new material in the future.
Library of Congress Subject Headings
Respiration--Mathematical models; Lungs--Mechanical properties--Mathematical models; Pulmonary alveoli--Models
Department, Program, or Center
Mechanical Engineering (KGCOE)
Ferrara, Joseph M., "Determination of 3-dimensional deformations of the alveolar sac during simulated breathing" (2009). Thesis. Rochester Institute of Technology. Accessed from
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