News in Science

Heartbeats may power future pacemakers

Pacemakers and defibrillators of the future may generate an extra power boost from a surprising energy source - the heart.

Using a microgenerator powered by heartbeats, a British team says their experiment produced nearly 17% of the electricity needed to run an artificial pacemaker.

They believe the next era of pacemakers could incorporate this technology and result in longer-lasting devices with more added functions to help manage the heart.

"This was a proof-of-concept study, and we provided the concept," says Dr Paul Roberts at Southampton University Hospital, Britain.

"Harvesting surplus energy might be a major transition in implantable pacemakers and defibrillators because engineers will have more energy to work with."

A pacemaker sends electrical impulses to the heart to speed up or slow cardiac rhythm, while an implantable cardioverter defibrillator signals the heart to normalise its rhythm if it gets too fast or slow.

Power hungry

The devices are incorporating evolving technology to become increasingly sophisticated, which require more power and increased battery size. This makes them uncomfortable and cosmetically less appealing, the researchers say.

"The small devices now are really very good, but power consumption must increase if we want to take them to the next level," say Roberts.

The researchers, who presented their findings at the American Heart Association meeting in New Orleans, tested a generator that helps the heart produce more than enough energy with each beat to pump blood.

The device uses two compressible bladders and a microgenerator mounted on the lead of a pacemaker or defibrillator, the wire that connects the device to the heart.

This lead is attached to the end of the right ventricle, and the bladders relay the energy from the pressure of each heartbeat to the microgenerator, which transforms it into electricity for use by the battery, the researchers said.

The researchers are now working with different materials in the microgenerator, which they believe will produce significantly more power in their next-generation device.

"While at the moment we see about 20% harvesting, we're anticipating that will be significantly more in the next iteration of the device," says Roberts.