Towards the Emulation of the Cardiac Conduction System for Pacemaker Validation

The heart is a vital organ that relies on the orchestrated propagation of electrical stimuli to coordinate each heartbeat. Abnormalities in the heart’s electrical behaviour can be managed with a cardiac pacemaker. Recently, the closed-loop testing of pacemakers with an emulation (real-time simulation) of the heart has been proposed. This enables developers to interrogate their pacemaker design without having to engage in costly or lengthy clinical trials. Many high-fidelity heart models have been developed, but are too computationally intensive to be simulated in real-time. Heart models, designed specifically for the closed-loop testing of pacemaker logic, are too abstract to be useful for the testing of pacemaker implementations. In the context of pacemaker testing, compared to high-fidelity heart models, this article presents a more computationally efficient heart model that generates realistic piecewise continuous electrical signals. The heart model is composed of cardiac cells that are connected by paths. Our heart model is based on the Stony Brook cardiac cell model and the UPenn path model, and improves them by stabilising the activation behaviour of the cells and by capturing the piecewise continuous behaviour of electrical propagation. We provide simulation results that show our ability to faithfully model a range of arrhythmias, such as VA conduction, heart blocks, and long Q-T syndrome. Moreover, re-entrant circuits (that cause arrhythmia) can be faithfully modelled, which only the discrete-event UPenn heart model is also able to achieve.