B-AB24-02 PIEZOELECTRIC ENERGY HARVESTING FOR PACEMAKERS

Abstract

Battery depletion is the leading cause of cardiac AICD pacemaker replacement. Auto-recharging via energy harvesting (EH) is a technique that could eliminate battery replacement. Piezoelectric EH converts mechanical energy into electrical energy. Research investigating EH for implantable medical devices is limited, and most approaches require additional surgery for attachment to the epicardium. To evaluate the use of piezoelectric coatings on transvenous leads and leadless pacemakers for EH without impacting the implantation procedure. In 15 in vivo porcine hearts we tested 5 piezoelectric materials and 7 device configurations. The devices were implanted into the RV and the effects of insertion location, heart rate, and RV contractility on the piezoelectric voltage output were investigated. The animals were paced at a heart rate of 80 to 140 bpm and iv dobutamine was used to increase heart contractility. Voltage outputs and power density were shown to increase with better performing piezoelectric materials and using device designs that amplified the mechanical inputs from heart contraction and relaxation. Estimate power density for the best performing device on a lead and leadless pacemaker was 10 μW/cm3 and 5 μW/cm3, respectively. We conclude that material selection and device design affect the EH capabilities of the coatings. Power densities of the devices are approaching that of typical pacemaker batteries of 25 μW/cm3. Future studies will investigate increasing outputs using a variety of approaches including multi-layer structures, mechanical amplification, and high-performance piezoelectric materials.