Biomechanics simulations using cubic Hermite meshes with extraordinary nodes for isogeometric cardiac modeling
Date
2016-03-29
Authors
Major Professor
Advisor
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
Cubic Hermite hexahedral finite element meshes have some well-known advantages over linear tetrahedral finite element meshes in biomechanical and anatomic modeling using isogeometric analysis. These include faster convergence rates as well as the ability to easily model rule-based anatomic features such as cardiac fiber directions. However, it is not possible to create closed complex objects with only regular nodes; these objects require the presence of extraordinary nodes (nodes with 3 or >= 5 adjacent elements in 2D) in the mesh. The presence of extraordinary nodes requires new constraints on the derivatives of adjacent elements to maintain continuity. We have developed a new method that uses an ensemble coordinate frame at the nodes and a local-to-global mapping to maintain continuity. In this paper, we make use of this mapping to create cubic Hermite models of the human ventricles and a four-chamber heart. We also extend the methods to the finite element equations to perform biomechanics simulations using these meshes. The new methods are validated using simple test models and applied to anatomically accurate ventricular meshes with valve annuli to simulate complete cardiac cycle simulations.
Series Number
Journal Issue
Is Version Of
Versions
Series
Academic or Administrative Unit
Type
article
Comments
This is a manuscript of the article Published as Krishnamurthy, Adarsh, Matthew J. Gonzales, Gregory Sturgeon, W. Paul Segars, and Andrew D. McCulloch. "Biomechanics simulations using cubic Hermite meshes with extraordinary nodes for isogeometric cardiac modeling." Computer aided geometric design 43 (2016): 27-38. doi:https://doi.org/10.1016/j.cagd.2016.02.016. Copyright 2016, The Authors. CC BY-NC-ND.