April 25, 2012
Swiss Robot Gives Paraplegic Man Mobility Via Mind-Control
Mobility is something most of us take for granted, and when we lose that ability through paralysis we lose a huge part of our independence. Now, a team of Swiss scientists are making strides in giving paraplegics back at least some of their mobility through the use of a new mind-controlled robot.
The robot is controlled by the brainwaves of a paraplegic wearing an electrode-fitted cap. The person wearing the cap, Mark-Andre Duc, demonstrated the device from a hospital in the Swiss town of Sion.
Duc, who lost the use of his legs and fingers in a fall and is now considered partially quadriplegic, used his thoughts to send a mental command to a computer in his room, which transmitted the thoughts to another computer that moved a small robot 60 miles away in the city of Lausanne.
The robot and the technology behind it is the brainchild of Jose Millan, a specialist in brain-machine interfacing at Switzerland´s Federal Polytechnic School in Lausanne. Milan and his colleagues said they have successfully demonstrated how a partially paralyzed person can control a robot by thought alone, a step that they hope will one day allow immobile people to interact with their surroundings through so-called “avatars.”
This technique is not new by any means. Similar experiments have taken place in the United States and Germany. But the main difference between those studies and the new Swiss experiment is the fact they were not able to produce similar results without the use of invasive brain implants.
In the Swiss experiment, Duc´s thoughts produced electrical signals in his brain when he imagined lifting his paralyzed fingers. Those signals were decoded almost instantly by a laptop computer at the hospital. The signals were then transmitted to the robot in Lausanne, which responded to Duc´s thoughts.
Controlling the robot was not that difficult on a good day. “But when I´m in pain it becomes more difficult,” he told The Associated Press (AP) via a video link screen on another laptop attached to the robot.
The researchers noted that while the results show promise, there are some problems that need to be resolved if the technology is to go mainstream. Background noise caused by pain or even a wandering mind are major challenges in the research of brain-computer interfaces, added Millan.
While the human brain is readily capable of performing several tasks at once, a paraplegic would have to focus the entire time that they are directing the device. “Sooner or later your attention will drop and this will degrade the signal,” Millan told AP's Frank Jordans.
To get around this problem, Millan and colleagues programmed the decoding computer to work in a similar fashion to how the brain´s subconscious works. In effect, once the computer receives a command to start walking, it continues to execute the command until it receives another to stop walking, or if the robot encounters an obstacle.
The robot technology is an advance on previous experiments that allowed patients to control an electric wheelchair with their mind. The scientists noted that by using a robot complete with camera and screen, users will be able to extend their virtual presence to places that are inaccessible by wheelchair.
Besides giving mobility to paraplegics, neuroprosthetics could be used to help patients recover lost senses, the researchers said.
In essence, that is what Stephanie Lacour, Assistant Professor, Institute of Microengineering at EPFL, Switzerland is currently working on. She and colleagues are developing “electric skin” for amputees -- a glove fitted with tiny sensors that sends information directly to the user´s nervous system.
Lacour told the AFP news agency that one day, researchers hope to create mechanized prosthetics that are as mobile and sensitive as a natural hand.
And other Swiss researchers are currently engaged in technologies to enable paraplegics the ability to walk again by using electrodes implanted in their spinal cords.
“The goal is that after a year of training with a robotic aide, the patient will be able to walk without a robot. The electrodes would stay implanted for life,” said Professor Gregoire Courtine, who is currently setting up clinical trials and hopes to run experiments at Zurich´s university hospital within a year.
Millan´s research appeared to mark an advance in the field, said Rajesh Rao, an associate professor at the University of Washington, Seattle, who has tested similar systems with able-bodied participants.
“Especially if the system can be used by the paraplegic person outside the laboratory,” he told USA Today in an email.
Millan said that although their device has already been tested in the home setting, it is not as easy to use as some commercially available gadgets that employ brain signals, including simple toys like Mattel´s MindFlex headset.
However, he said, “this will come in a matter of years.”