A new pacemaker which synchronises heart rate with breathing could "revolutionise" the lives of people with heart failure, scientists say.
The device, which is being developed at the Universities of Bath and Bristol, is targeted at more than 750,000 patients who live with heart failure in the UK.
More than 40,000 patients in England had a pacemaker fitted during 2012 to 2013.
Currently, the pulses from pacemakers are set at a constant rate when fitted - which does not replicate the natural beating of the human heart.
The normal, healthy variation in heart rate during breathing is lost in cardiovascular disease and is an indicator for sleep apnoea, cardiac arrhythmia, hypertension, heart failure and sudden cardiac death.
The new pacemaker uses synthetic neural technology to restore this natural variation of heart rate with lung inflation - modulating its pulses to matching breathing rates.
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Researchers say the device works by saving the heart energy, improving its pumping efficiency and improving blood flow to the heart muscle itself.
Pre-clinical trials suggest the device gives a 25% increase in the pumping ability, which is expected to extend the lives of patients with heart failure.
The project, which is being awarded funding by the British Heart Foundation, aims to miniaturise the device to the size of a postage stamp.
Dr Alain Nogaret, senior lecturer in physics at the University of Bath, said the team aim to develop an implant that can be used within humans within five years.
"Our work to develop a new type of pacemaker will significantly improve the lives of patients suffering with heart failure, both in the UK and internationally," Dr Nogaret said.
"Using state of the art nanotechnology, the new pacemaker will respond to patients' breathing rate to increase the pumping efficiency of the diseased heart.
"This is a unique therapy for heart failure which will complement existing therapies for cardiac arrhythmias and cardiac resynchronisation which are addressed by existing pacemakers."
Dr Nogaret said the pacemaker delivered treatment "not currently addressed by mainstream cardiac rhythm management devices."
The research team has patented the technology and is working with NHS consultants at the Bristol Heart Institute, the University of California at San Diego and the University of Auckland.
Professor Jeremy Pearson, associate medical director at the British Heart Foundation, said: "This study is a novel and exciting first step towards a new generation of smarter pacemakers. More and more people are living with heart failure so our funding in this area is crucial.
"The work from this innovative research team could have a real impact on heart failure patients' lives in the future."
It is hoped the technology can also be applied to other areas of brain research, including prosthetics and potentially to stimulate the rebuilding of nerves following a stroke.
The findings of the research have been published in the Journal of Neuroscience Methods.