A way of using heartbeats to power pacemakers has been developed that could spare patients the ordeal of repeated surgery.
The implanted devices, which regulate heart rhythm, have saved countless lives but suffer from one serious drawback: they run on batteries.
The new system avoids the need for batteries because power is provided by energy tapped from the pumping heart.
Scientists in China have successfully tested the technology in pigs, which have a similar body design to humans.
It employs the property that certain “piezoelectric” materials have of producing an electric current when stressed.
In this case the “generator” consists of a tiny elastic structure made up of layers of material which cause electricity to flow when bent by the expanding and contracting heart.
The pig tests showed the device capable of generating currents as high as 15 microamps, enough to power a commercial pacemaker.
The team, led by Bin Yang, from the National Key Laboratory of Science and Technology in Shanghai, wrote in the journal ACS Nano: “Although several approaches of energy harvesting have been explored in this decade for powering cardiac pacemakers, the modern commercial and full-function pacemaker has never been powered effectively yet.
“Here we report an integrated strategy for directly powering a modern and full-function cardiac pacemaker which can pace the porcine heart in vivo (in a living animal) by harvesting the natural energy of a heartbeat, without using any external energy storage element.”
The scientists added: “Translating this strategy into a clinical one will exempt patients from surgical replacement, or at least less frequently.”