Construction and Validation of Subject-Specific Biventricular Finite-Element Models of Healthy and Failing Swine Hearts From High-Resolution Diffusion Tensor MRI

Julius Guccione

Surgery Division of Adult Cardiothoracic Surgery, University of California San Francisco (UCSF)

Tuesday 19th November 2019

15:00:00

aula consiglio VII piano

What if physicians and surgeons could virtually analyze their patients’ health and plan therapies and surgeries using the same advanced modeling and simulation technology that the automotive, aerospace, energy and hi-tech industries rely on to test their product before they are built? As early as 1906, researchers first began suggesting the solution of continuum mechanics problems by modeling the body with a lattice of elastic bars and employing frame analysis methods. In 1941, Courant recognized piecewise polynomial interpolation over triangular subregions as a Rayleigh-Ritz solution of variational problems. Since there were no computers at the time, neither approach was practical and Courant’s work was largely forgotten until engineers had independently developed it. By 1953, structural engineers were solving matrix stiffness equations with digital computers. The widespread use of finite element methods in engineering began with the classic papers by Turner et al. and Argyris and Kelsey. The name “finite element” was coined in 1960, and the method began to be recognized as mathematically rigorous by 1963. The creation of subject-specific biventricular finite element models has been a long-term endeavor within the biomedical engineering community. Using high resolution (0.3 × 0.3 × 0.8 mm) ex-vivo data, we constructed precise fully subject-specific biventricular finite-element models of healthy and failing swine hearts. Each model includes fully subject-specific geometries, myofiber architecture and, in the case of the failing heart, fibrotic tissue distribution. Each model was calibrated using subject-specific experimental data and compared with independent in-vivo strain data obtained from echocardiography. Our methods produced highly detailed representations of swine hearts that function mechanically in a remarkably similar manner to the in-vivo subject-specific strains on a global and regional comparison. The degree of subject-specificity included in the models represents a milestone for modeling efforts that captures realism of the whole heart. This study establishes a foundation for future computational studies that can apply these validated methods to advance cardiac mechanics research. Contatto: alfio.quarteroni@polimi.it This seminar is organized within the ERC-2016-ADG Research project iHEART - An Integrated Heart Model for the simulation of the cardiac function, that has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 740132)

Julius M. Guccione, Jr., Ph.D. is Professor of Surgery, Surgery/Division of Adult Cardiothoracic Surgery at UCSF. He specializes in the realistic simulation of the efficacy of novel surgical procedures and devices for treating ischemic cardiomyopathy. Dr. Guccione graduated with a B.S. in Biomedical Engineering from Tulane University. He obtained his M.S. and Ph.D. in Bioengineering from UCSD. He completed a research fellowship in Biomedical Engineering at The Johns Hopkins University. The American Institute for Medical and Biological Engineering (AIMBE) inducted Dr. Guccione, Jr., Ph.D., to its College of Fellows in March 2019. Dr. Guccione was nominated, reviewed, and elected by peers and members of the College of Fellows for "outstanding contributions to the development, validation and dissemination of a unified foundation for cardiovascular in silico medicine."