Scientists have long searched for an alternative to surgically replacing batteries in a pacemaker, which helps regulate an irregular heartbeat. A prototype draws its energy from a surprising source.
University of Michigan aerospace engineers have developed a prototype pacemaker device that is powered by vibrations from within the chest, mostly from heartbeats.
University of Michigan investigators M. Amin Karamia and Daniel J. Inman noted that previous pacemaker powering alternatives had failed. Researchers previously attempted to power a pacemaker using blood sugar or the motion of the arms and legs, but they either interfered with metabolism or required more invasive surgery. Pacemakers require very little energy to operate — only about one millionth of a watt.
The power source also could be used for implantable cardioverter defibrillators for patients at risk for sudden cardiac death as a result of a life-threatening heart arrhythmia.
During the devised method, vibrations from within the chest cavity deform a layer of piezoelectric material, which converts mechanical stress into electrical current. They found during testing that the device could maintain a heart rate ranging from seven to 700 beats per minute, considerably above and below the normal range.
Investigators determined that the amount of energy that would be generated always would be larger than the amount required to operate the pacemaker regardless of heart rate, ensuring the device would be properly powered at all times.
The device still is in early development phases and has not yet been tested on human patients, but researchers said the energy-harvesting pacemaker could offer an advantage over pacemakers currently on the market.
The study was recently published in the journal Applied Physics Letters.
In the United States, over 850,000 people are hospitalized from an arrythmia, a general term for a large group of conditions that results from abnormal electrical activity in the heart. Also known as cardiac dysrhythmias, they can cause the heart to beat too fast, too slow, or in an irregular pattern.
The conditions can range from benign to life-threatening, and in some cases can cause sudden death. Common ‘palpitations’, such as premature ventricular contractions, may be simply uncomfortable and not need treatment, but others like atrial fibrillation need treatment because they increase the risk of stroke. In many cases, arrythmias will need treatment because they can lower blood pressure to the point that a patient can faint.