Research

 

Pathology changes the material properties and load bearing capacity of cardiovascular soft tissues. Prediction of both progressive (hypertrophy, dilation, calcification) and catastrophic (tearing or rupture) loss of function are important for anticipatory management and the development of novel treatments.

Table indicating the large incidence of major cardiovascular diseases in the United States

By coupling computational and experimental techniques we can both generate and validate predictions of mechanical function.

Images of in vitro and in vivo data, computational methods, and model predictions.

 

Predicting Ventricular Hypertrophy

 

Predicting Growth from Mechanics: Compare the ability of published systems of equations to capture key aspects of experimentally observed growth patterns by applying in vivo changes in stretch following pressure and volume overload to a simple test-bed predicting growth.

Graphs showing experimental and model predictions of ventricular growth following pressure and volume overload.

Fast Prediction of Cardiac Growth and Remodeling: Create a compartmental model to quantitatively predict the time-course in left ventricular dilation and thickness after hemodynamic overload.

6 minutes to simulate 3 months of left ventricular remodeling using a desktop

The compartmental model predicts changes in dilation and thickening for independent studies of pressure overload, volume overload, and myocardial infarction.

Model predictions of ventricular dilation and thickening following pressure and volume overload.

 

Predicting Mechanical Failure and Dysfunction

 

Identifying Material Boundaries: Use network analysis and digital image correlation to determine the shape, size, and location of regions within a whole-tissue sample with locally similar motion. Regions where materials properties change rapidly are potential initiation locations for rupture and dysfunction.

Images showing displacement of a heterogeneous plastic sample, the sum of the normalized deformation jumps, and the segmentation identifying different regions.

 

Determining Heterogeneous Properties: The presence, arrangement, and alignment of extracellular constituents vary locally within soft tissues, causing their mechanical response to vary regionally. Our inverse technique is able to determine the heterogeneous nonlinear anisotropic material properties of whole samples.

Figure showing a sample's predicted alignment, degree of anisotropy, fiber stiffness, and fiber nonlinearity.