A new pacemaker which harvests energy from within the body is being developed.
Researchers from Imperial College London's Control and Power Research Group claim that the heart device powers itself by taking energy from the body's "inexhaustible" supply of energy.
The advantage of such a device would be that the need for invasive procedures to change batteries would be greatly reduced.
Speaking on BBC Radio 4's Frontiers programme, Dr Paul Mitcheson said: "It's a very… residual amount of energy that you require in the background all the time which, of course, would drain a battery but, with the activity of a human being walking around, then… you've got this steady supply of energy."
He added that the innovative device would be able to overcome the problem of power loss if the heart where to stop beating by incorporating an electrical storage element, such as a rechargeable battery or capacitor.
This follows news from the US that a new 'brain pacemaker' could help treat Parkinson's disease.