Contact-Based Impact Energy Harvesting from the Ultralow Frequency Intracardiac Kinetic Energy

In this study, a piezoelectric energy harvesting concept is developed for leadless pacemakers, effectively converting the ultralow frequency kinetic energy of the heart into sufficient electricity for pacing. This energy harvesting concept relies on low amplitude contact excitation in piezoelectric enclosure structures and will make perpetually self-powered intracardiac leadless pacemakers possible. This approach is a paradigm shift from conventional inertia-based power generation and extracts the optimal power by natural-frequency free-vibration excitation of the piezoelectric structure. This framework was assessed based on laboratory and in vivo tests on a living pig to demonstrate the performance of this energy generation concept. In vivo test on a living pig showed that the implanted piezoelectric energy harvester produced an 11.27 mW pulsed peak power and 238.2 nJ with 125 min –1 heart rate and a root-mean-square (RMS) power of 6.95 μW from each heartbeat, sufficient pacing energy for intracardiac leadless pacemakers.