Battery-Free Pacemaker

An experimental pacemaker that’s powered by a beating heart has been successfully implanted in living pigs, bringing science one step closer to developing battery-free implantable devices. Dubbed “symbiotic pacemaker” (SPM) the new device derives power from a wafer-like piezoelectric generator that attaches to the surface of the heart and converts mechanical energy from movement into electrical energy to operate the device. A capacitor stores excess power to stimulate the heart when needed.

In one animal, which had a healthy heart, the generator was tested to see how well it harvested energy. The results indicated that the pig’s heart produced more than enough power to operate a human version of the device. In the second animal, the SPM was allowed to charge for approximately an hour. Then an irregular heartbeat was induced and the SPM was used to successfully convert the abnormal rhythm.

Although human testing is still off in the distant future, devices such as these are likely to become more widespread as researchers continue to look at other options for harvesting kinetic energy from within the body, including respiratory movement, blood flow and muscle flexion. Since replacing batteries in traditional implantable devices involves expensive surgeries every seven to ten years, the promise of battery-free operation will be well worth the effort.