Multifunctional Microelectrode for Low-Voltage Pulsed Field Ablation in Atrial Fibrillation

Pulsed field ablation is an emerging technique for the treatment of atrial fibrillation, and it can specifically damage cardiomyocytes without destroying surrounding tissues. However, current single-function ablation electrodes apply electric pulses at thousands of volts, which is potentially harmful to the heart. In this letter, we propose a multifunctional microelectrode for low-voltage pulsed field ablation and effect evaluation. By using finite element analysis and tests on potato tissues and in vivo experiments, we show that the soft microelectrode in multiplexed array format supports two orders of magnitude reduction in ablation voltage compared with the state of the art. Meanwhile, the electrode-tissue equivalent circuit before and after irreversible electroporation is established, and we find that the ablation effect could be evaluated by impedance. In the future, the microelectrode integrated with a medical balloon can be applied to minimally invasive surgery for improving the success rate of pulsed field ablation.