Cardiac digital twins hold great promise for personalized medicine, but they currently depend on complex constitutive models of tissue mechanics that are often over-parameterized for the clinical context. To address this, we introduce CHESRA (Cardiac Hyperelastic Evolutionary Symbolic Regression Algorithm), a physics-informed machine learning framework that automatically derives simple strain energy functions from multiple experimental data sources. Using a normalizing loss function, CHESRA identified two new functions with only three and four parameters, respectively. These functions achieve high data fitting accuracy in experimental scenarios while enabling more consistent parameter estimation than state-of-the-art approaches, both in tissue benchmarks and 3D simulations. By combining biophysical constraints with data-driven discovery, CHESRA demonstrates how physics-informed learning can generate accurate, personalizable models for advancing cardiac digital twins and clinical decision-making.
@article{arxiv.2508.09772,
title = {Physics-Informed Symbolic Regression for Elasticity Modeling in Cardiac Digital Twins},
author = {Sophia Ohnemus and Kristin Fullerton and Leto L. Riebel and Mary M. Maleckar and Andrew D. McCulloch and Viviane Timmermann and Gabriel Balaban},
journal= {arXiv preprint arXiv:2508.09772},
year = {2026}
}