Robot-aided rehabilitation for stroke patients could be just steps away thanks to the futuristic work of an Auckland-based biomechatronic lab.

The Department of Mechanical Engineering at Auckland University is working on a lightweight exoskeleton device that will help people with disabilities, particularly stroke patients or people with spinal cord injuries, relearn proper walking patterns.

"What we are trying to do here is make something that is not only easy to wear but that is low-cost and people can use in their everyday life," university medical robotics research group head Professor Shane Xie says.

One of the most common problems for people who have suffered stroke and are relearning to walk is compensating for the paralysed side of their body - often leading to a limp that is difficult to unteach.

The department's lab has been developing a biomechatronic leg that works to restrict movement, thereby training a patient's muscles into a correct walking pattern.

"We want it to be available for early use by stroke patients so they don't develop a bad gait," Professor Xie says.

Research fellow Andrew McDaid says since last Christmas the team has been working on the first prototype of the mechanical leg, which has been tested on healthy patients with success.

"The next stage is to get ethics approval for actual stroke patients, and to make it look more aesthetically pleasing," he says.

The team is in constant consultation with doctors and physios to check the requirements of the device.

"One of the main issues is making the devices not look robotic and look like something an elderly person is not going to be scared to put on," Dr McDaid says.

The aim is to have the device eventually worked into a compact backpack size, with the limb-brace small enough to fit inside a trouser leg.

Present treadmill-based rehabilitation for stroke patients involves three physiotherapists working on one person - one to support the upper body and two to manually move the patient's legs, Dr McDaid says.

"Stroke is a major issue in New Zealand and around the world," he says.

"There are heaps of massive costs with health care, especially with physios.

"It's not sustainable to have three physios working on one patient, so with a device like this the motivation is to take the rehabilitation out of the clinic and into someone's home."

Professor Xie says the device will also have the capacity to be used with computer games that are being developed by the lab.

"Sometimes people in rehabilitation get bored so we can make it more entertaining for them and we can also have real time displays in terms of how much progress they have made," he says.

"We can use the animation software to make it fun and make it more interactive for the patient."

The idea for the device was triggered four years ago while professor Xie was in Britain.

"Just to bring the patient from the wheelchair to set it up could take three hours, and you needed to have three people."

Large commercial devices are internationally rare because they cost about $200,000 each.

The team aims to make its lightweight exoskeleton device much more accessible.

"Potentially the hospitals could own quite a few, just like a wheelchair and crutches," Dr McDaid says.

It is hoped the mechanical leg will be ready to undergo clinical trials in the next six months.

- © Fairfax NZ News