The Karlsruhe Heart Model KaHMo: a modular framework for numerical simulation of cardiac hemodynamics

Numerical methods are rapidly gaining importance for answering medical questions. One field in which these answer are especially valuable is cardiology. The understanding of the cardiac function on a detailed, physical level can help to improve diagnostics, prognosis and therapy for a large number of pathologies. The KaHMo (Karlsruhe Heart Model) is developed as a framework for the patient specific numerical simulation of the intraventricular flow. The framework combines different methods from several disciplines. As a means to simulate the cardiac flow in a given patient specific heart, KaHMo MRI derives the time dependent geometry of the endocardium and performs a numerical simulation of the intraventricular flow. In order to be able to predict the influence of pathological changes in e.g. the myocardium or the valves on the contraction of the heart and the flow driven by this movement, KaHMo FSI employs special Fluid-Structure-Interaction methods and a composite approach to muscular dynamics to simulate the complex interaction of non linear elastomechanics with hemodynamics. The framework is supported by additional models which include a model of the human circulatory system to derive the systemic pressure response, rheological models for the non- Newtonian behaviour of the blood as well as models for prediction of hemolysis and thrombosis risks in artificial blood pumps or ventricular assist devices. Future developments may incorporate electrodynamical models to include the possibility to predict the effect of e.g. arrythmia or therapeutical ablation on the heart function. The vision is a macroscopic holistic model of the human heart that can help to answer the ever pressing what if? questions.