Considerations for Patients with Pacemakers: Heart-powered Generators, Danger from Headphone Magnets

Patients who rely on heart-supporting devices (pacemakers, implanted defibrillators) have some things to consider about the way they live their lives that don’t apply to everyone else. One such consideration is how long the devices they rely on will last before needing to be replaced.

 

The next generation of pacemakers might very well last considerably longer than those now available, American Heart Association said Monday in a report about recent research into powering such devices using energy from the patient’s beating heart itself.

 

In an experimental study, a micro-generator was powered by heartbeats, and was able to produce nearly 17 percent of the electricity needed to run a pacemaker, American Heart Association said.

 

The study’s first author, Paul Roberts (a consultant electro-physiologist at Southampton University Hospital in the U.K., described the experiment as being a “proof-of-concept;” more research is needed, but the results are quite encouraging.

 

 “Harvesting surplus energy might be a major transition in implantable pacemakers and defibrillators because engineers will have more energy to work with,” Roberts said in a statement.

 

The study, co-authored by Giles Stanley and John Mark Morgan, could be the start of a turning point in pacemaker design, which Roberts said has reached something of a standstill. Adding new features to artificial heart monitoring devices is problematic because this requires more power, resulting in larger devices that are less comfortable and less aesthetically acceptable to patients.

 

A prototype generator of the type tested in this study — referred to as a “self-energizing implantable medical microsystem” or SIMM — was developed by a consortium of companies in the U.K. using government funds. The consortium is now testing different materials to determine the best method of manufacturing the SIMM.

“With different materials, we’re seeing even greater energy harvesting,” Roberts said. “While at the moment we see about 20 percent harvesting, we’re anticipating that will be significantly more in the next iteration of the device.”

 

While patients are waiting to see what happens with artificial pacemaker development, they should be careful to ensure proper operation of their currently implanted devices. One danger that patients might be not be aware of is headphones used with portable music devices like Apple’s (News - Alert) iPod.

 

Associated Press on Sunday reported that a study (led by William Maisel, a cardiologist at Beth Israel Deaconess Medical Center in Boston) found headphones can interfere with heart devices when in close proximity.

 

The reason for the danger is that headphones contain magnets, a problem even if the headphones are not plugged into a portable player or if the layer is turned off. iPods and other music players themselves do not interfere with heart devices, the study found.

 

To determine if headphones posed a danger, AP said, Maisel and a team of other doctors tested eight different models (earbuds and over-the-ear) with 60 heart device patients. When the headphones came within an inch from an implanted device, some type of interference was detected almost a quarter of the time — “in four of the 27 pacemaker patients and 10 of the 33 with defibrillators.” In one case a pacemaker reset itself.

 

Maisel said patients shouldn’t overreact to this new information, but instead should just take sensible precautions by not letting earbuds/headphones rest on one’s chest when not in use. Likewise, it’s a good idea to avoid letting someone wearing headphones rest his/her head on the patient’s chest.