Computational modeling and simulation of combined seismo- and electrocardiograms as basis for novel diagnostic tools

• Applicant: Professor Dr.-Ing. Daniel Balzani
• Subject Area: Mechanics ; Applied Mechanics, Statics and Dynamics
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 544827709

Heart simulations allow to investigate cardiac function in healthy and diseased conditions. Such simulations can for example help to unravel pathophysiological mechanisms, develop new therapeutic targets or aid in clinical diagnostics. The electrocardiogram (ECG) has been proven to be highly valuable in this context. However, it is known that the ECG sometimes fails to detect pathophysiological alterations of the heart. The seismocardiogram (SCG) is another diagnostic tool, an indirect cardiac motion measurement, which gained a lot of attention recently. Diseases restricting cardiac motion, for example heart failure, are visible in the seismocardiogram, making it a candidate to develop novel disease biomarkers. It is believed that combined SCG and ECG signals are able to diagnose a wider range of cardiac diseases, ultimately improving therapy. In this project, major goal is to develop a computational framework for the virtual analysis of combined SCG and ECG signals from heart simulations and to investigate the feasibility of using these signals in a unified approach as a diagnostic tool. To achieve this goal, we will first address important open problems in heart modeling related to cardiac motion. We will develop an improved, mathematically sound material model for cardiac tissue and include residual stresses present in the unloaded configuration by incorporating a biologically motivated, growth-based approach. Several stretch-activated ion channels from literature will be incorporated to properly account for the mechano-electrical and mechano-chemical feedback of the cells. A new materially stable formulation for cardiac tissues will be constructed, including fiber dispersion and a spatially-explicit sarcomere, into which the cell model will be integrated. Available experimental data provided by the collaboration partners will be utilized to derive atlas-based fiber orientations for the heart and analyze potential limitations of existing microstructure generators. This combination of novel extensions will enable to represent important experiments from the literature. A set of numerical studies at different idealization levels will allow a qualitative validation of the new model on structural level. Furthermore, we will develop a torso model which will be coupled to the updated heart model in order to enable the planned investigation of computed ECG and SCG signals in a more realistic virtual environment. The fundamental possibility of improved diagnostic functionality is being investigated in the sense of a feasibility study, taking into account various uncertainties and physiological variability in terms of microstructure and geometry.

• DFG Programme: Research Grants