A brain activity-controlled robotic exoskeleton suit, which demonstrates the very latest advances in neuroscience and neuroengineering, will make its debut at the FIFA 2014 World Cup in Brazil. It is planned that the exoskeleton suit will be worn by a paraplegic patient, who will take the first kick of the World Cup during the opening ceremony at the Arena Corinthians in São Paulo on June 12th, before Brazil takes on Croatia in the first match of the tournament.
The exoskeleton suit has been developed as part of the Walk Again Project, a nonprofit international collaboration of scientist and specialists, under the scientific command of Brazilian neuroscientist Miguel Nicolelis, Duke University Center for Neuroengineering, NC. The goal of the project is to develop and implement a brain-machine interface technology that enables paralyzed individuals, or those with restricted mobility, to regain mobility of their limbs, as well as sensory abilities, using a mind-controlled external mechanism.
How the exoskeleton works
The brain-machine interface technology used in the exoskeleton was developed through Nicolelis' pioneering research into new assistive technologies for restoring motor control and tactile sensitivity in patients suffering severe paralysis.
The research helped to create a technology to read electrical signals produced in the brain, then convert these signals to a motor control that could be used by the machine, before sending information back to the brain. Early research demonstrated that directly linking the brains of monkeys to an artificial device allowed them to control the movement of a variety of robots, making them capable of enacting voluntary motor movements, simply by thinking about the arm movement they wanted to produce. While research published in Nature this year furthered the project, highlighting an innovative neuroprosthetic that integrates state-of-the-art microelectrode cubes to wirelessly record the activity of over 1,000 of interconnected neurons across multiple cortical areas in a primate.
A non-invasive neuroprostheic device, worn by the patient, is used to take electrophysiological measurements of the electrical signals from thousands of neurons in the regions of the brain responsible for voluntary movement. When the operator thinks of an action e.g. 'I want to walk', the electrical signals associated with this action are recorded and decoded by a computer worn in a backpack, and used to control the hydrolytic drivers of the exoskeleton suit that generate movement.
In order to make the act of walking as close to reality as possible, a tactile feedback technology, developed by a group of researchers led by Gordon Cheng, the Technical University of Munich, Germany, provides the operator with the ability to recognize the body’s spatial location. Feedback on movement is provided by pressure, temperature and speed sensors located in printed circuit boards applied to the patient’s feet. When contact with the ground is made, signals are sent to a vibrating device worn in the forearm of the operator’s shirt, stimulating their skin. The user’s brain then interprets this stimulus as coming from their foot, allowing them to co-ordinate movement of the exoskeleton suit.
Dr Miguel Nicolelis told the BBC: "What happens when you practice for a long time is that the brain starts associating the movements of the legs with the vibration in the arm. So the patient starts developing the sensation that he has legs and that he is walking."
Eight patients from the Association for Assistance to Disabled Children began the first clinical tests in January 2014, with a clinical team led by Brazilian physician Lumy Sawaki of the University of Kentucky, USA. Patients began the trials using a computer-generated virtual simulator and progressed to training with the exoskeleton suit. It has now been reported that by May 20th, all patients had walked an average of 120 steps using the exoskeleton, while further tests leading up to the World Cup demonstration, are expected to occur in an environment similar to the atmosphere of the opening ceremony.
It is hoped that this revolutionary technology will one day be accessible to all, enabling anyone with paralysis to regain movement and sensation.