Technology Nearly 240 Years Old Powers Battery-free Heart Pacemaker

Pacemakers have saved the lives of many heart patients, but they need batteries. When a battery runs low, the only option is to replace it surgically, which is expensive and carries the risk of medical complications.

Now a doctoral student at Switzerland's University of Bern has turned to a technology for timepieces that was developed in the 18th century and adapted it to keep pacemakers working indefinitely, without batteries.

On Aug. 31, Adrian Zurbuchen demonstrated his new device before the European Society of Cardiology (ESC) Congress 2014 in Barcelona. In place of a battery, the device is powered by the motion of the patient's heart itself.

"The heart seems to be a very promising energy source because its contractions are repetitive and present for 24 hours a day, seven days a week," Zurbuchen says. "Furthermore the automatic clockwork, invented in the year 1777, has a good reputation as a reliable technology to scavenge energy from motion."

The clockwork, invented by Swiss watchmaker Abraham-Louis Perrelet nearly 240 years ago, achieved some commercial success in the 1950s and 60s when watchmakers began promoting their "self-winding" watches, which use arm movement to keep the watch's mainspring taut.

Zurbuchen and fellow researchers created a prototype based on a commercially available watch that uses the Perrelet mechanism. They stripped it down and added a special housing with small holes allowing them to sew the device directly to the heart muscle.

When the heart contracts and expands to pump blood through a patient's body, the off-center mass of the mechanism rotates, gradually winding the mainspring, which spins an electrical micro-generator as it unwinds.

Zurbuchen's team created a prototype with an electronic circuit to store the electricity from the micro-generator in a small buffer or storage medium, then connected it to a specially crafted pacemaker. The device acquired energy from heart movement, stored the energy in the buffer and used this energy to apply electrical stimuli to the heart, just as a conventional pacemaker does.

So far, the device has worked successfully with pigs.

Zurbuchen says now is "probably a good time to look for backers," even though his team's research is still in its early stage and no human testing has yet been planned. He and his fellow researchers haven't even discussed the idea with potential industrial partners. But they say they're confident that their device will be available for heart patients in the near future.

By Andy Tully of Oilprice.com