Can you build a bionic body? The leg

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 leg.

Lighter hi-tech materials and technological advancements now mean that bionic legs are closely replicating natural movement.

One of the most sophisticated is the Genium, launched in the UK at the end of last year.

Seven sensors, including a gyroscope and an accelerometer - the same technologies used in a Wii remote control - detect the leg in a three-dimensional space. An on-board computer operates hydraulic valves which control the leg's movement. The leg can respond differently to walking backwards, climbing stairs and various walking speeds.

The cost of the leg, depending on patient need, is around £50,000 ($80,000; 60,000 euros). This includes all fitting, warranty and future servicing costs.

Geoffrey Harding, from Ottobock, the company behind the invention 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.