Though pacemakers require only small amounts of energy (about 1 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.
Aerospace engineers M. Amin Karami and Daniel J. Inman, from the University of Michigan in Ann Arbor, have developed a prototype device that could power a pacemaker using a source that is surprisingly close to the heart of the matter: vibrations in the chest cavity that are due mainly to heartbeats.
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 7 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 authors write, the amount of energy generated is always larger than the amount required to run a pacemaker, regardless of heart rate.
Though the team has yet to develop a prototype that is biocompatible, they say that the potential to package this energy harvester with pacemakers gives it an advantage over competing methods.
U-M Department of Aerospace Engineering

Loyola University Medical Center is one of the major enrollers in a landmark clinical trial that found that plugging a hole in the heart works no better than drugs in preventing strokes.
Loyola enrolled 24 patients, one of the highest patient enrollments in the multi-centre trial and more than any other Chicago-area hospital. Principal investigators at the Loyola site were stroke specialist Dr. Michael Schneck and interventional cardiologist Dr. Fred Leya.
About 1 in 4 adults has a small hole in the wall that separates the top two chambers of the heart. It’s called a patent foramen ovale (PFO). For most people, a PFO poses no problems. But in some cases, a clot can pass through the hole, migrate to the brain and trigger a stroke.
The standard treatment is medication to prevent blood clots, typically aspirin or Coumadin. A newer treatment is to plug the hole with a device delivered by a catheter. The catheter is inserted into a blood vessel at the top of the leg and guided up to the heart. When the catheter reaches the PFO, the device is deployed, opening like an umbrella to plug the hole.
The clinical trial included 909 patients who had PFOs and had previously suffered strokes or mini strokes called transient ischemic attacks (TIAs). They were randomly assigned to receive a PFO closure device plus blood thinners or drug therapy alone.
The closure device worked no better than drugs alone in preventing recurrent strokes or TIAs. Moreover, major vascular complications occurred in 3.2 percent of the closure group.
Loyola University Health System