Every year, nearly 700,000 people in the world with heart rhythm abnormalities get a pacemaker or defibrillator. The small, implanted device sends electrical pulses to urge the heart to beat normally. It’s science at its best, with one notable caveat: the devices must be replaced every five to seven years when the batteries run out. And replacement requires an expensive surgery.


But now researchers at the Department of Aerospace Engineering at the University of Michigan in Ann Arbor have come up with a prototype energy-converting device that runs on piezoelectricity — electrical energy produced from mechanical pressure, including human motion.


The device gathers energy from a beating heart and produces enough electricity from it to keep the pacemaker running, according to the study, which was released at the annual American Heart Association scientific conference on Nov. 4.


The researchers created a prototype and showed that based on a wide range of heartbeats, the device was able to generate more than 10 times the power needed for a contemporary pacemaker.


The device is about half the size of the batteries currently used in pacemakers and also contains a self-powering back-up capacitor, said M. Amin Karami, the study's lead author and a research fellow at the university.


"What we have proven is that under optimal conditions, this concept is working," Karami said, noting that the next step is to integrate the device into a pacemaker, and hopefully, commercial pacemakers to follow.


The study was paid for by the National Institute of Standards and Technology and the National Center for Advancing Translational Sciences.


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