Can you build a bionic body? The heart
Later this year a team of researchers will try out the first bionic eye implant in the UK hoping to help a blind patient see for the first time. It is one of the extraordinary medical breakthroughs in the field, which are extending life by years and providing near-natural movement for those who have lost limbs.
Over the coming weeks, BBC News will explore the field of bionics in a series of features. We start with a selection of the latest scientific developments. Here we look at the heart.
Heart transplant waiting lists are long and some patients die before a suitable organ becomes available. Plastic hearts buy people time - the longest a patient has survived on one is three years.
The whole heart is replaced by two chambers, with valves that let blood in and out. A pump housed in a backpack pushes the blood to the heart along tubes that enter the body below the rib cage. Air is rhythmically pumped into the artificial heart, forcing out blood round the body in much the same way that a beating heart would.
Matthew Green was the first UK patient to go home with a Total Artificial Heart after an operation at Papworth Hospital in Cambridgeshire at the end of 2011. It was fitted on the NHS at a cost of about £100,000 ($160,000; 120,000 euros). Consultant cardiothoracic surgeon, Steven Tsui, explains how it works in the video.
The Bionic Bodies series on the BBC News website will be looking at how bionics can transform people's lives. We will meet a woman deciding whether to have her hand cut off for a bionic replacement and analyse the potential to take the technology even further, enhancing the body to superhuman levels.