The generator showed the potential to act as an adjunct to traditional batteries to extend the life of implanted devices. In the test, it produced one-third of the energy required to power a conventional cardiac pacemaker.

The device was designed by the Self-Energizing Implantable Medical Microsystem (SIMM) project, a partnership launched in late 2006. Members include Zarlink Semiconductor, InVivo Technology Ltd., Perpetuum Ltd., Finsbury Orthopaedics and Odstock Medical.

"The microgenerator taps an in-body energy supply--the heartbeat--to help enable more advanced, smaller implanted medical devices that will improve patient care and comfort," said Martin McHugh, business development manager with Zarlink's advanced packaging group and SIMM project coordinator, speaking in a prepared statement.

The consortium is currently discussing next steps for the project with medical device manufacturers, said Paul Roberts, an electrophysiologist at Southampton University Hospital in England who presented details on the effort at the event.

The SIMM generator is a catheter-mounted device placed on a conventional pacemaker or defibrillator lead. Placement of the generator is compatible with existing techniques for implanting cardiac devices.

"Previous attempts to harvest human energy have resulted in systems that require surgical techniques that pose an unacceptable risk to patients," said Roberts.

The device harvests energy by using differential pressure within the chambers of the heart to drive a linear generator. Next-generation generators are expected to fully power the pacemaker.

The project was funded by a grant about a million dollars from the U.K. Department of Trade and Industry and matching funds from the consortium members.