Energy caught from heartbeats could power implanted devices

Engineers have designed a device that harvests energy from the reverberation of heartbeats through the chest and converts it to electricity to run a pacemaker or an implanted defibrillator.

According to a statement, these medical machines — developed at Michigan University — send electrical signals to the heart to keep it beating in a healthy rhythm.

By taking the place of the batteries that power them today, the new energy harvester could save patients from repeated surgeries.

‘The idea is to use ambient vibrations that are typically wasted and convert them into electrical energy,’ said Amin Karami, a research fellow in the university’s department of aerospace engineering. ‘If you put your hand on top of your heart, you can feel these vibrations all over your torso.’

The researchers have yet to build a prototype device, but they have made blueprints and run simulations demonstrating that the concept would work.

In use, a miniscule piece of piezoelectric ceramic material would essentially catch heartbeat vibrations and briefly expand in response, converting mechanical stress into an electric voltage.

Karami and his colleague Daniel Inman, chair of aerospace engineering at Michigan University, have precisely engineered the ceramic layer to a shape that can harvest vibrations across a range of frequencies. They also incorporated magnets, whose additional force field can boost the electric signal that results from the vibrations.

The new device could generate 10 microwatts of power, which is about eight times the amount a pacemaker needs to operate, Karami said. It always generates more energy than the pacemaker requires and it performs at heart rates from seven to 700 beats per minute.

Karami and Inman originally designed the harvester for light unmanned aircraft, where it could generate power from wing vibrations.