What’s better than a cardiac pacemaker? A cardiac pacemaker that never runs out of batteries. Because when that happens, the patient is going to have to go through surgery to get a replacement.
So to alleviate the stress and cost of having to constantly physically replace a pacemaker, researchers from the University of Bern in Switzerland have developed a pacemaker that works like a mechanical wristwatch and draws all its power from the beating of the patient’s heart.
According to Ben Coxworth at Gizmag, lead researcher and cardiologist, Rolf Vogel, first came up with the idea for a new pacemaker four years ago, and has since produced a prototype that’s based on the mechanism of an auto-winding wristwatch. Also known as a self-winding wristwatch, these nifty little devices are powered by the natural motion of the wearer’s arm, which winds the mainspring right up to capacity, and then allows it to unwind slowly, powering the rest of the watch like a tiny generator.
"In the case of the Bern device, it’s sutured onto the heart’s myocardial muscle instead of being worn on the wrist, and its spring is wound by heart contractions instead of arm movements,” says Coxworth. "When that spring unwinds, the resulting energy is buffered in a capacitor. That capacitor then powers a pacemaker, to which it is electrically wired.”
Presenting their device at the 2014 European Society of Cardiology Congress last week, the team said the system can so far produce 52 microwatts of power when attached to the heart of a live 60-kilogram pig, which is well above the requirements for a human pacemaker - about 10 microwatts.
Before they send it out to market, the team are now working on making their device smaller and more efficient in both its energy-harvesting and heart-motion-detecting capacities.