Device generates electricity from beating heart to power pacemaker
23 November 2012
An experimental device developed at Michigan University can convert energy from a beating heart
using piezoelectric crystals to provide enough electricity to power a
pacemaker and eliminate the need for batteries.
The study was presented at the American Heart Association’s
Scientific Sessions 2012.
The approach is a promising technological solution for
pacemakers, because they require only small amounts of power to
operate, said Dr M Amin Karami, lead author of the study and
research fellow in the Department of Aerospace Engineering at the
University of Michigan in Ann Arbor.
Piezoelectricity might also
power other implantable cardiac devices like defibrillators, which
also have minimal energy needs. Today’s pacemakers must be replaced
every five to seven years when their batteries run out, which is
costly and inconvenient, Karami said.
“Many of the patients are children who live with pacemakers for
many years. You can imagine how many operations they are spared if
this new technology is implemented.”
Researchers measured heartbeat-induced vibrations in the chest.
Then, they used a 'shaker' to reproduce the vibrations in the
laboratory and connected it to a prototype cardiac energy harvester
they developed. Measurements of the prototype’s performance, based
on sets of 100 simulated heartbeats at various heart rates, showed
the energy harvester performed as the scientists had predicted —
generating more than 10 times the power than modern pacemakers
The next step will be implanting the energy harvester, which is
about half the size of batteries now used in pacemakers, Karami
said. Researchers hope to integrate their technology into commercial
Two types of energy harvesters can power a typical pacemaker:
linear and nonlinear. Linear harvesters work well only at a specific
heart rate, so heart rate changes prevent them from harvesting
In contrast, a nonlinear harvester — the type used in the study —
uses magnets to enhance power production and make the harvester less
sensitive to heart rate changes. The nonlinear harvester generated
enough power from heartbeats ranging from 20 to 600 beats per minute
to continuously power a pacemaker.
Devices such as cell phones or microwave ovens would not affect
the nonlinear device, Karami said.
Video below shows Dan Inman, Chair, Department of Engineering,
Michigan University talking about harvesting the heart's energy