A dual-component solution for self-powered pacemakers: 6D kinetic motion mapping and an in-vivo validated contact-impact energy harvest

Abstract

Leadless pacemakers (LCPs) are constrained by finite battery life, requiring high-risk replacement surgeries. Harvesting energy from the heart is a promising solution but faces two key challenges: (1) the heart's ultralow-frequency motion (1-2 Hz) is inefficient for conventional harvesters, and (2) its complex 6-degree-of-freedom (6D) kinetic motion—including 3D translation and 3D rotation—varies significantly by implant site . This work presents a comprehensive solution by (1) identifying the optimal intracardiac site for energy harvesting by mapping the heart's 6D kinetic motion, and (2) developing and validating in vivo a novel harvester designed specifically to capture energy from ultralow-frequency motion.

The 6D motion analysis successfully mapped the heart's kinetic potential. According to Table 1, the left ventricular apex (Pos 6) was identified as the optimal implant site, ranking #1 overall with the highest scores for kinetic energy and "jerk" criteria. The right ventricle outflow tract (Pos 2) was the least suitable site.

The in vivo test of the contact-based piezoelectric energy harvester was successful. As shown in Table 2, at a heart rate of 125 bpm, the device generated a pulsed peak power of 11.27 mW and an RMS power of 6.95 µW per heartbeat. It successfully stored 238.2 nJ in a 0.47 µF capacitor, an energy level sufficient for pacing. We have developed a validated methodology for identifying the optimal implant location (the apex) and have proven in vivo that a novel contact-impact harvester can successfully generate supra-threshold pacing energy from the heart's motion.