Improved identifiability of myocardial material parameters by an energy-based cost functionReport as inadecuate




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Biomechanics and Modeling in Mechanobiology

, Volume 16, Issue 3, pp 971–988

First Online: 10 February 2017Received: 02 July 2016Accepted: 09 December 2016DOI: 10.1007-s10237-016-0865-3

Cite this article as: Nasopoulou, A., Shetty, A., Lee, J. et al. Biomech Model Mechanobiol 2017 16: 971. doi:10.1007-s10237-016-0865-3

Abstract

Myocardial stiffness is a valuable clinical biomarker for the monitoring and stratification of heart failure HF. Cardiac finite element models provide a biomechanical framework for the assessment of stiffness through the determination of the myocardial constitutive model parameters. The reported parameter intercorrelations in popular constitutive relations, however, obstruct the unique estimation of material parameters and limit the reliable translation of this stiffness metric to clinical practice. Focusing on the role of the cost function CF in parameter identifiability, we investigate the performance of a set of geometric indices based on displacements, strains, cavity volume, wall thickness and apicobasal dimension of the ventricle and a novel CF derived from energy conservation. Our results, with a commonly used transversely isotropic material model proposed by Guccione et al., demonstrate that a single geometry-based CF is unable to uniquely constrain the parameter space. The energy-based CF, conversely, isolates one of the parameters and in conjunction with one of the geometric metrics provides a unique estimation of the parameter set. This gives rise to a new methodology for estimating myocardial material parameters based on the combination of deformation and energetics analysis. The accuracy of the pipeline is demonstrated in silico, and its robustness in vivo, in a total of 8 clinical data sets 7 HF and one control. The mean identified parameters of the Guccione material law were \C 1=3000\pm 1700\,\hbox {Pa}\ and \\alpha =45\pm 25\ \b f=25\pm 14\, \b {ft}=11\pm 6\, \b {t}=9\pm 5\ for the HF cases and \C 1=1700\,\hbox {Pa}\ and \\alpha =15\ \b f=8\, \b {ft}=4\, \b {t}=3\ for the healthy case.

KeywordsParameter estimation Myocardium Patient-specific modelling Passive constitutive equations Pablo Lamata and Steven Niederer acknowledge shared senior authorship. Anastasia Nasopoulou is the single first author.





Author: Anastasia Nasopoulou - Anoop Shetty - Jack Lee - David Nordsletten - C. Aldo Rinaldi - Pablo Lamata - Steven Niederer

Source: https://link.springer.com/







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