A pacemaker powered by chest-cavity vibrations from heartbeats could prevent the need for repeat surgery to replace batteries.
Aerospace engineers Amin Karami and Daniel Inman from Michigan University in Ann Arbor have tested the technology, which is based on piezoelectric material, in a lab situation.
Although pacemakers require only small amounts of energy (about one millionth of a watt), their batteries have to be replaced periodically, which means multiple surgeries for patients.
Researchers have searched for ways to prolong battery life — trying to generate energy to power a pacemaker using blood sugar or the motion of the hands and legs — but these methods either interfere with metabolism or require a more drastic surgery, such as passing a wire from the limbs to the chest area.
In their method, vibrations in the chest cavity deform a layer of piezoelectric material, which is able to convert mechanical stress into electrical current. Tests indicate that the device could perform at heart rates from seven to 700 beats per minute (well below and above the normal range) and that it could deliver eight times the energy required for a pacemaker.
Furthermore, the amount of energy generated is always larger than the amount required to run a pacemaker, regardless of heart rate.
While the team has developed a prototype device of sorts, it must now prove that this is biocompatible and suitable for long periods in the human body.