Melbourne robotics give hi-tech helping hand for amputees

Significant advances in the field of robotics with biomedical applications are currently being made by scientists from the Australian state of Victoria. It is poised to produce the next generation of prosthetic limbs.

A group of researchers based in Melbourne, Australia, are leading the world in developing the bionic limbs of the future.

Their goal is a robotic prosthesis that will be able to perform as well as a natural human arm and hand, even allowing users to experience the sensation of touch.

Denny Oetomo, an associate professor in the University of Melbourne’s Department of Mechanical Engineering, explained the project had been undertaken in response to a need identified by orthopaedic surgeons at St Vincent’s Hospital, which treats many amputees who have suffered traumatic accidents or disease.

“For example, over the last 20 years or so, advances in treatment of bone and tissue cancer have meant much better survival rates,’’ he said.

“In the old days, these patients simply hoped to survive their cancer. But now we see many who have undergone amputations, or partial amputations, and are now cured and wishing to return to full functionality. They want to get back to work.’’

Current prosthetic arms allow some limited functionality, such as grasping, but a collaboration of researchers from six centres co-ordinated by the Aikenhead Centre for Medical Discovery (based in the St Vincent Hospital campus) aims to produce something far more advanced.

They are led by Professor Peter Choong, Director of Orthopaedics at St. Vincent’s Hospital, who says a key goal is an arm with a hand that does not simply grab objects, but also communicates with its owner.

“We’re trying to build up something that can also feel and perceive strength and pressure, feeding it back to the patient through an artificial means,’’ Prof Choong says.

“What we really want is for the machine to talk back to the brain, and that’s where a lot of the science is.”

Prof Oetomo, who heads up the University of Melbourne’s Melbourne Robotics Laboratory, says finding better ways for users and their prosthetic arms to communicate is one of the team’s greatest challenges.

Current-generation robotic prosthetics pick up electrical signals through the user’s skin using surface electrodes, which only allows for some basic commands.

“This works OK, but it is limited,’’ he says. “It is like trying to type using a two-key or four-key keyboard. There are simply not enough signals to transmit all the information we need.

“One way to get additional ‘bandwidth’ could be through a process called targeted reinnervation, where we re-route redundant nerves from other parts of the body.

“Or we can use a device such as an EEG hat, which can detect multiple signals from the brain.

“The ultimate prize, of course, would be a physical connection of wire to nerve, but how to do this is still not solved. Electrodes implanted in the body tend to deteriorate or get rejected.’’

Prof Oetomo’s team is also working to incorporate the latest advances in the field of robotics into their new limbs.

In conjunction with the ARC Centre of Excellence for Electromaterials Science at the University of Wollongong, they are experimenting with advanced soft materials that can take the place of metal motors inside a robotic arm.

These would result in a more lifelike, robust, and dextrous limb. And electromaterials that detect pressure could also provide the sensory feedback the team hope to incorporate into their artificial hands.

The collaborative group of researchers are part of a larger network pushing for the construction of a new Aikenhead Centre for Medical Discovery in Melbourne at an estimated cost of A$180 million, where they could expand their research.

The centre will be a research and education hub, concentrating on fields as diverse as organ and tissue regeneration, drug design, next-generation biomedical devices and prosthetics.

A group of private-sector partners, including Melbourne University, have agreed to raise A$60 million, and a further A$60 million has been pledged by the State Government of Victoria. The Australian Federal Government is being urged to follow suit.