The Swiss are famous for making the best watches. Now two engineers from Switzerland have shown it’s possible to build a pacemaker that winds up like an automatic wristwatch and runs without a battery.
Their prototype, presented at a cardiology conference in Europe in late August, runs by harvesting energy from the normal beat of the human heart.
University of Bern cardiologist and engineer Rolf Vogel started working on the idea four years ago and based the first design on a commercially available automatic wristwatch, a technology first invented in 1777. He and his student, Adrian Zurbuchen, first removed all unnecessary parts to reduce its weight and size and then developed a custom housing that allowed them to suture the device directly onto the surface of the heart. From there, it just works as it would on your wrist. The motion of the heart rotates the clock mechanism, progressively winding a mechanical spring. The fully charged spring slowly unwinds and spins a tiny electrical generator.
The researchers tested their prototype system in experiments with pigs and paced the heart at 130 beats per minute without a battery. The next step is for them to integrate the device that harvests energy with an electronic circuit that stores it.
Today’s pacemakers have limited battery life, which isn’t ideal because surgery is needed to replace them. Other scientists are looking at alternatives power sources for pacemakers, such as designing body-friendly fuel cells that run on chemicals in the human system. But perhaps the movement of the heart really is the most obvious source of power.