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'

"Our next step is to fabricate a complete self-powered pacemaker and examine it with animal tests, " wrote Dr. Karami in an email.

WSJ: Harnessing Energy From the Body to Power Devices

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

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