Tuning Into My Heart Through Wearables: Towards a Formal Cardiac Digital Twin

Digital Twins (DTs) mimic a physical system using a digital version of the real system. While these have been explored in many domains, digital twins of human organs are yet to be created, especially those that are inspired by formal methods. To this end, we propose the first Cardiac Digital Twins (CDTs) by leveraging two key innovations from our research group. The first is a real-time model of the heart, that is based on a network of hybrid automata to represent the cardiac conduction system that mimics the rhythmic electrical activity of a normal heart. The model can be parametrised to exhibit disease states in real-time and this approach is being used by MathWorks for closed-loop validation of pacemakers in real-time. This work has raised the interest of both device manufacturers and certification agencies, especially in the USA. Our group has expertise in digital biomarkers obtained from wearables, such as Electrocardiograms (ECGs) and Photoplethysmograms (PPGs). These provide a window into the cardiac cycle and we have already shown that the two signals are strongly correlated. Hence, a second innovation is related to using wearables to personalise the real-time heart model, so that the model generates ECGs matching that of an individual in different states. Our approach paves the way for developing personalised therapies, real-time monitoring, and accurate estimation of heart rate variability.