Wristwatch technology leads to battery-free pacemaker
A batteryless pacemaker powered by energy from the heart and based on automatic wristwatch technology was unveiled.
The technology, developed by researchers led by Prof Rolf Vogel from the University of Bern in Switzerland, harvests energy from the motion of the heart using the 200-year-old principles used to power self-winding watches.
This means it could remove the need for operations to replace pacemaker batteries, said researcher and PhD student Adrian Zurbuchen in a statement.
‘Batteries are a limiting factor in today’s medical implants. Once they reach a critically low energy level, physicians see themselves forced to replace a correctly functioning medical device in a surgical intervention. This is an unpleasant scenario which increases costs and the risk of complications for patients.’
A traditional clockwork wristwatch is automatically wound because the rotor inside is turned whenever the watch accelerates due to the movement of the wearer’s arm. This rotation progressively winds a mechanical spring that, once fully charged, unwinds again and spins an electrical micro-generator.
To develop a pacemaker that operated in a similar way, the researchers copied the wristwatch mechanism, removing unnecessary parts to reduce weight and size and developing a custom-made housing with eyelets so it could be stitched directly onto the heart muscle tissue.
‘The heart seems to be a very promising energy source because its contractions are repetitive and present for 24 hours a day, 7 days a week,’ said Zurbuchen. ‘Furthermore the automatic clockwork, invented in the year 1777, has a good reputation as a reliable technology to scavenge energy from motion.’
To test the prototype, the researchers developed an electronic circuit to transform and store the signal into a small buffer capacity and then connected it to a custom-made cardiac pacemaker. It was then implanted into a domestic pig.
‘The next step in our prototype is to integrate both the electronic circuit for energy storage and the custom-made pacemaker directly into the harvesting device. This will eliminate the need for leads,’ said Zurbuchen.
The work was presented yesterday at the European Society of Cardiology Congress 2014 in Barcelona.
Source: The Engineer
Published: 01 Sep 2014
Category: Features, Technology & Devices
