Dr Amin Karami told a meeting of the American Heart Association that pacemaker batteries needed to be replaced approximately every seven years.

BBC: Heartbeat 'could power pacemaker'

ATLANTA, Georgia (CNN) -- A pacemaker device could help up to half of all heart failure patients live a more active life, researchers told the American College of Cardiology Tuesday.

CNN: Pacemakers found to help heart failure patients

Their team showed that the device could generate 18 times the amount of energy needed to power a pacemaker using a normal heart beat, according to Dr. Karami.

WSJ: Harnessing Energy From the Body to Power Devices

Several manufacturers expect their pacemaker devices to win marketing approval for heart failure patients by the end of the year.

CNN: Pacemakers found to help heart failure patients

The new pacemaker uses three wires, or leads, which are threaded into both sides of the heart to help it pump more efficiently.

CNN: Pacemakers found to help heart failure patients

This is similar system to that used by some heart pacemaker systems, but these only report back technical information about the condition of the implant, rather than gather extensive data about the condition of the patient.

BBC: Telephone heart sensor under test

Amin Karami, an aerospace engineering research fellow, presented data at the American Heart Association annual conference in November showing an experimental energy harvester can convert the energy from the beating of a heart into enough usable electrical energy to, in theory, operate a pacemaker.

WSJ: Harnessing Energy From the Body to Power Devices

In one of those incidents, heart surgeon Charles Sciolaro says he had a patient who requested a pacemaker made by St.

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