After five years in a wheelchair, Hayden Allen (above) can now walk again thanks to a remarkable Kiwi invention.

The West Auckland motorbike racer is one of the first seven people in the world to use a "robotic exoskeleton" called Rex - a pair of robotic legs that strap around the outside of your legs and move them for you.

A small Albany company, Rex Bionics, has spent $10 million developing the product over the past seven years and believes it could potentially benefit five million wheelchair users in Europe and the United States.

The only snag is the price tag: US$150,000 ($208,000) in the US, and expected to be only slightly below that in New Zealand.

The company says this is not out of line with other medical devices. A bionic knee, for example, can set you back US$125,000 ($173,000).

Mr Allen, 23, was paralysed from the chest down in a motorbike accident five years ago.

He was introduced to Rex Bionics when he was working as a wheelchair salesman early this year and sold a chair to Rachel Peterson, 33, who has muscular dystrophy and plans to walk up the aisle in a Rex in December to marry Rex co-founder Richard Little.

Mr Allen now works at the company, standing in a Rex at his workbench for up to three hours at a time and feeling like a normal human being again.

"It will be a big benefit from a social aspect, being able to talk to someone at the same eye level," he said.

He can walk up five steps to his girlfriend's place with the Rex in 30 seconds, instead of inching himself up in a wheelchair, in an agonising process that used to take him 20 minutes.

And his health is better. "In a wheelchair you're prone to getting infections. Now I've had time on the Rex I don't seem to have had those complications any more."

Mr Little, 43, a Scottish-born former marine engineer who came to New Zealand 16 years ago, began work on Rex when fellow engineer Robert Irving, also 43, was diagnosed with multiple sclerosis seven years ago.

They spent four years creating the robotic legs in Mr Little's garage before seeking funding from Wellington venture capital firm No8 Ventures, whose founder Jenny Morel is also Rex's chief executive.

Ms Morel said Rex would be on sale in New Zealand by December.

* YouTube