Introduction of Non-linear Elasticity Models for Characterization of Shape and Deformation Statistics: Application to Isolated Adult Cardiocytes
Peter Blomgren
SDSU
Abstract:
We are exploring the viability of a novel approach to cardiocyte contractility
assessment based on biomechanical properties of the cardiac cells, energy
conservation principles, and information content measures. We define our
measure of cell contraction as being the distance between the shapes of the
contracting cell, assessed by the minimum total energy of the domain
deformation (warping) of one cell shape into another. To guarantee a meaningful
vis-a-vis correspondence between the two shapes, we employ both a data fidelity
term and a regularization term. The data fidelity term is based on nonlinear
features of the shapes while the regularization term enforces the compatibility
between the shape deformations and that of a hyper-elastic material. We tested
the proposed approach by assessing the contractile responses in isolated adult
rat cardiocytes and contrasted these measurements against two different methods
for contractility assessment in the literature. Our results show good
qualitative and quantitative agreements with these methods as far as frequency,
pacing, and overall behavior of the contractions are concerned. We hypothesize
that the proposed methodology, once appropriately developed and customized, can
provide a framework for computational cardiac cell biomechanics that can be
used to integrate both theory and experiment. For example, besides giving a
good assessment of contractile response of the cardiocyte, since the excitation
process of the cell is a closed system, this methodology can be employed in an
attempt to infer statistically significant model parameters for the
constitutive equations of the cardiocytes.