Pacemaker technology makes it possible for those with abnormal heart rhythms to live a relatively normal, healthy life. Traditional pacemakers are placed in the chest or abdomen of a patient who’s heart beat is either too fast or too slow. It uses electrical pulses to prompt the heart to beat at a normal rate, kind of like a tiny defibrillator that’s always on hand in case the heart gets out of rhythm.
But in order to overcome the heart’s faulty electrical signaling, a pacemaker needs an energy source from which to create its electrical pulses. For most pacemakers, this is supplied in the form of batteries which only have a lifespan of 5-1o years. Replacing these batteries when they wear down is a costly and uncomfortable procedure for long-term pacemaker wearers. Now, engineers at the University of Michigan have a new type of pacemaker that might eliminate the need for finite batteries.
The study, published recently in Applied Physics Letters, details the development of a device that harvests energy from the reverberation of heartbeats, powering a pacemaker with no need for batteries. Although the engineers have yet to build a working prototype, blueprints and simulations give them great confidence that the theory will work.
The patient would be implanted with a hundredth-of-an-inch thin slice of a special “piezoelectric” ceramic material would capture heartbeat vibrations and briefly expand in response. Piezoelectric materials’ are able to convert mechanical stress (which causes them to expand) into an electric voltage. By taking the place of batteries, the new energy harvester could save patients from repeated surgeries.
According to the project’s researchers, the new device could generate 10 microwatts of power, which is about eight times the amount a pacemaker needs to operate. It always generates more energy than the pacemaker requires, and it performs at heart rates from 7 to 700 beats per minute, which is well below and above the normal range.