CHICAGO - RESEARCHERS have developed a tiny generator which can harvest the excess energy of a beating heart and help power a pacemaker or defibrillator, said a study released on Monday.

'What this might mean is that in the next era of pacemakers, you'd get devices that lasted significantly longer and we could add more functions to help monitor the heart,' said lead author Paul Roberts of Southampton University Hospital in Britain.

'It's possible they could be efficient enough to allow complete and indefinite powering of pacemakers.'

Adding new functions to pacemakers is currently limited by battery technology, Dr Roberts said.

The only way to increase power to the implanted devices is to increase the size and weight of the battery, which makes them more uncomfortable and less cosmetically acceptable to patients.

Dr Roberts and his colleagues developed an experimental microgenerator which captured enough surplus heart energy to provide 17 per cent of the power needed to run a pacemaker.

The microgenerator is able to capture energy from the pressure of each heartbeat and translate it into electricity for the pacemaker's battery.

The researchers are now working on improving the materials used in the generator in order to improve the energy harvesting.

The research was presented at the American Heart Association's annual meeting. -- AFP