A real-time cardiac electrical model on FPGA for closed-loop test of CIED

Abnormalities in the cardiac electrical activity can be treated with cardiac implantable electronic device (CIED). Problems that occur in the closed-loop interaction between CIED and heart are difficult to detect through only open-loop testing. For the closed-loop interaction between CIED and heart model, this paper presents a frontal two-dimensional real-time heart model composed of 14861 units and 28044 paths. The model achieves a balance between computational complexity and expressive ability. The generation and conduction of excitation is simulated with Aliev-Panfilov phenomenological action potential model. With the electrophysiology, the generation of electrocardiogram (ECG) and electrogram (EGM) is based on the action potential of units. Finally, implemented on FPGA hardware platform through units grouping and pipeline technology, the heart model can generate EGM, ECG signals and conduction state snapshots in real time and respond to real-time stimulation input. The hardware framework of the heart model is scalable. The completed real-time heart model can simulate the origin of cardiac excitation and the conduction of electrical activity under normal sinus rhythm, block and premature beat conditions, which meets the real-time requirements of CIED closed-loop testing. The ECG generation process in the model can be explained with conduction state snapshots and electrophysiology.