A pacemaker which is based on a clockwork wristwatch, powered by the patient’s heart motion, has been invented by Swiss engineers.
The prototype of the device has been tested successfully in pigs and could mean that it will no longer be necessary for patients to undergo repeat surgery to replace the batteries of a pacemaker.
The invention is based on the idea behind a self-winding wristwatch.
Current pacemakers, used to aid the heart beat to a regular pattern, need to have their batteries replaced, on average, about every seven years. This means that patients who are often elderly have to undergo additional surgery which requires general anaesthetic and carries a high complication risk.
In England, in excess of 40000 people are fitted with pacemakers annually. These devices are necessary for patients with irregular, slow or unusually fast heart rhythms.
The new device which will be stitched directly onto the heart is based on the idea of automatic clockwork, which was developed by Swiss watchmakers during 1777. It will make use of electrical current generation from the movement of the muscle of the heart.
Automatic watches operate on a rotor, which swivels when the arm of the wearer moves. This movement causes progressive winding of a spring which then moves the mechanism of the watch.
In the pacemaker, the mechanical spring will unwind to turn an electrical micro-generator.
Adrian Zurbuchen, at the University of Bern’s cardiovascular engineering group, said batteries place a limitation on the medical implants used today. He said once they reach a specific low energy level, it becomes necessary for physicians to replace it with an accurately functioning device during a surgical procedure. This scenario not only increases cost, but also the risk of complications for patients.
Other research teams have been studying methods of getting rid of pacemaker batteries by the transmission of power through the body from an outside source, however the idea of making use of clockwork is rather innovative.
Mr Zurbuchen stated that the Swiss researchers, led by an engineer and a cardiologist, had placed their focus on concepts which have been around for more than 200 years to gain inspiration.
He said the heart is an encouraging energy source because its contractions are present for 24 hours of each day, seven days a week and are repetitive. Along with this, the automatic clockwork, which was invented in 1777, comes with a good reputation of being able to reliably get energy from movement.
The system has been successful in pigs and it regulated their heart to a consistent 130 beats per minute.
Plans are yet to be drafted to test the system in humans.
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