From the United Kingdom comes a news story about a new type of pacemaker currently in clinical trials. It is not by any means a product you can buy commercially. But the Self-Energizing Implantable Medical Microsystem (SIMM) in development by a conglomerate of companies and investors has a very appealing attribute.
It would run entirely on energy harvested from within the body. That's right, no battery.
Since the battery takes up the lion's share of real estate in any implantable cardiac device, getting rid of a battery could make the devices radically smaller. But manufacturers might decide to keep the pacemakers roughly the same size and just fill up that space now taken up by the battery with greater memory and more circuits so that pacemakers could get smarter than ever.
Many manufacturers would like to offer more monitoring functions, diagnostic reports, memory for stored ECGs, and sensors but just lack the space in today's streamlined pacemakers. By getting rid of the battery, devices might just gain more advanced functionality.
Pacemakers run on electrical energy and the SIMM system would be the same, except this voltage would come from the differential between the heart's upper chambers and lower chambers. The biggest hurdle to developers so far is the fact that cardiac energy is typically low-frequency, and it is easier to get energy from high-frequency sources.
So far, prototypes have been able to get about one-third of the energy they need from the body's natural heart function. Studies to date confirm that this SIMM device does not stress the heart or drain energy from it. However, the device is still in development and more studies are needed.
