Correlating with Local Variation in Collagen Level and Mechanical Properties of the Heart Tissues

<p>The determination of the myocardium's tissue properties is essential in constructing finite element (FE) models of the heart. To obtain accurate results, especially for functionally modeling the heart, we must determine the tissue properties in-vivo. The calculation of the heart tissue properties remains a challenging area as it is categorized as a heterogeneous, anisotropic, nonlinear soft tissue that undergoes large deformation. In this work, we tried to introduce and evaluated a finite element method to determine the mechanical properties of the cardiac tissue. The introduced method combined a finite element modeling with the experimentally obtained images from the left and right ventricles to develop a model for calculating the shear modulus, Young's modulus, and the Poisson's ratio of the ventricles leading to obtaining the constitutive matrices for each specimen. Tissue behavior was quantified under three different loading conditions: tensile loading in the x and y direction and shear loading. Statistical analysis reveals that the left ventricle demonstrates higher mechanical properties compared to the right ventricle. Additionally, the heart tissue's mechanical properties were effectively used for studying the effects of the variation in the tissue's composition, primarily collagen, on the myocardium behavior. Based on the obtained results, it was demonstrated that mechanical properties enhanced with increasing the collagen amount. The results indicated that the proposed model showed a good agreement with the previous studies and provided an ability to describe the heart tissue's behavior precisely. It offers a new approach to the study of cardiac tissue properties, as it shows the cardiac tissue's mechanical properties, including Young's modulus, shear modulus, constitutive matrices, and their correlation with the change in the microstructure of the heart tissue.</p>

Name thesis:degree_name

M.S.

Level thesis:degree_level

Masters Thesis

Year dc:date.available

2021

Author dc:creator

• Tavangar, Talayeh

Contributors dc:contributor

• Yun-Bo Yi
• Ali Azadani
• Mohammad Matin

• Cardiac tissues
• Collagen
• Finite element method
• Image processing
• Myocytes
• Ventricles
• Biological Engineering
• Biomedical Engineering and Bioengineering
• Engineering

Statement dc:rights

• <p>Copyright is held by the author. User is responsible for all copyright compliance.</p>

Language dc:language

en

Repository record dc:identifier

https://digitalcommons.du.edu/etd/2000

OAI identifier oai:identifier

oai:digitalcommons.du.edu:etd-2992