A battery-free pacemaker that harvests energy from heartbeats has been successfully tested in pigs. It uses an energy harvester wrapped around the heart that generates electricity from movement.
“Millions of patients rely on implantable medical electronic devices (IMEDs) due to powerful diagnosis and treatment capabilities,” wrote Zhong Lin Wang from the Georgia Institute of Technology in the US and colleagues in their paper. “However, batteries of IMEDs are generally bulky, rigid, and have short lifetimes.”
In tests, Wang and his colleagues found that the energy they harvested from the heart was higher than that needed for a human pacemaker. They used pigs in the tests because their hearts are about the same size as those of humans.
“The study results are very encouraging but there is a lot of work to be done before it might be used in humans,” says Tim Chico at the University of Sheffield. “The energy harvest device needed to be inserted around the heart in open-heart surgery, which is a lot more invasive than is needed for current pacemakers and would greatly limit who could have this.” Other muscles could be used instead to power the device, he says.
Pacemakers are designed to correct irregular heart rhythm. Batteries can last for 15 years, but the lifetime varies depending on how much it needs to be used.