Abstract 15374: An Energy-Harvesting Leadless Pacemaker: Proof of Principle

Abstract

Introduction: Leadless pacemakers (LPM) offer several benefits over transvenous pacemakers, including lower risks of infection and vascular complications. However, their limited battery life and long-term retrieval challenges restrict their use in younger patients. Aims: We aim to extend the battery life of LPM by harvesting energy from right ventricular (RV) pressure fluctuations through a housing made of biocompatible piezoelectric materials, which can transduce pressure into voltage and thus recharge the battery. Methods: Cylindrical prototypes (n = 3) of LPM housing were fabricated using polyvinylidene fluoride (PVDF) with a thickness of 100 μm and a polyetherimide insulator wrapped around an aluminum rod, representing the LPM (1A). Our prototypes were sealed with epoxy (1B) and their dimensions (radius 9.5 mm, length 26 mm) were comparable to that of the Micra LPM (Medtronic). Prototypes were placed in a pulsatile cardiac pressure simulator (1C) and subjected to RV systolic/diastolic pressures at 1 Hz. A pressure transducer and an oscilloscope simultaneously recorded the simulator’s pressure and prototype’s transduced voltage respectively (1D). Impedance matching was performed, and an optimal resistance of 39 MΩ (1E) was identified for energy harvesting. Results: At oscillating “RV” pressures of 40 and 0 mmHg, our prototype generated 4 V (1D), corresponding to 52.5 nW of harvested power on an impedance-matched circuit. Under an assumed pacing output of 1.0 V at 0.24 ms and a pacing impedance of 500 Ω, each pacing stimulus requires 480 nW. Thus, our prototype can harvest 10.9% of the energy required to power an LPM. Conclusion: A first-generation PVDF-based energy-harvesting LPM housing can harvest approximately 10% of the power needed for pacing from RV systolic/diastolic pressures, marginally prolonging battery life. Future work will focus on increasing energy harvesting through material selection, device structure, and circuit design.