UC Irvine

Cardiac pacemakers have evolved over the years from the original version with external leads to the miniaturized leadless version that is implanted completely inside the ventricle. The leadless pacemakers offer advantages in simpler surgical procedures, easier device operation, and better patient comfort. However, the reduced size of the pacemaker substantially restricts battery capacity, reducing the battery life from 13-16 years to as few as 5-8 years. The reduced battery longevity often requires the patient to return for a pacemaker replacement surgery. This could result in increased medical cost, inconvenience, and potential risk to the patients. To address this issue, many researchers have examined different methods of harvesting energy for the pacemaker, mainly focusing on piezoelectric energy conversion. The results, however, were not promising due to the low energy conversion efficiency and potential material failure of the brittle piezoelectric materials.This thesis is aimed at exploring an alternative solution based on electromagnetic induction to convert mechanical energy generated at each systolic and diastolic cycle into electricity. The human heart is an inexhaustible mechanical energy source that is constant and consistent in its mechanical motion. Taking this into our advantage, the research aimed at utilizing the heart’s own mechanical motion to generate electrical energy to power the pacemaker. During the course of the research, multiple design iterations, experimenting with solid magnet cores, ferrofluid, and finally, the concentric double ring magnet design were developed. Many proof-of-concept testing and feasibility testing have been conducted to prove the viability of the design and the structural materials. The research will continue with more simulation testing on the materials and electrical circuit design for signal amplification and storage.