Thought controlled robotic arm for paralyzed patients

The journal Nature reports on a science fiction style jump in technology, where an interface on the brain is used to connect to a robotic arm and provide real time thought control. It is a dramatic leap for the technology which has been tested with paralyzed patients and gives hope for Stars Wars style bionic technology, for wounded soldiers and paraplegics. The experiment was conducted on April 12th this year at Brown University in Providence, Rhode Island. The test subjects, a 58 year old woman (S3) and a 66 year old man (T2), had both been paralyzed by a stroke to the brain stem, which left them with no control of their limbs. Scientists used neural activity to interpret the person's thoughts and direct instructions to a computer controlled robotic arm. The experiment tested out two different devices. The first was manufactured by DLR Institute of Robotics and Mechatronics and the other by DEKA Research and Development Corp. The goal of the experiment was to be able to interpret thought commands to allow the patient to reach out across three dimensional space and grasp objects. Known as the Braingate2 pilot trial, it employed the experimental Braingate system, initially developed at Brown University. An interface the size of a small pill, containing a grid of 96 electrodes is implanted into the motor cortex in the brain. The motor cortex controls voluntary movement. The electrodes are close enough to the individual neurons to be able to record the neural activity accurately enough to process the instructions to a third party device outside the body. A computer is then used to translate the commands into language that the robotic arm can understand. The previous Braingate study had success with basic two dimensional control of robotic devices, such as controlling a mouse or clicking a cursor on a screen. The new study represents the first demonstration and the first peer-reviewed report of people with tetraplegia, to use brain controlled signals to control a robotic arm three dimensionally, although in 2009, the inventor and entrepreneur Raymond Kurzweil outlined a similar technology that he had tested, using a chip embedded in his arm. A documentary called the Transcendent Man, about the processes and many of his other inventions and life's work was released, and the concept of human's interfacing and incorporating technology directly into their brain's and bodies is certainly an interesting one that science fiction has been quite light on exploring. Lead author Dr. Leigh Hochberg, a neuroengineer and critical care neurologist who holds appointments at the Department of Veterans Affairs, Brown University, Massachusetts General Hospital and Harvard said : "Our goal in this research is to develop technology that will restore independence and mobility for people with paralysis or limb loss ... We have much more work to do, but the encouraging progress of this research is demonstrated not only in the reach-and-grasp data, but even more so in S3's smile when she served herself coffee of her own volition for the first time in almost 15 years." Dr. Hochberg, is the sponsor-investigator for the BrainGate2 pilot clinical trial. John Donoghue, the VA and Brown neuroscientist who pioneered BrainGate more than ten years ago said the new work demonstrates how far the field of brain-computer interfaces has come since it's inception. "This paper reports an important advance by rigorously demonstrating in more than one participant that precise three-dimensional neural control of robot arms is not only possible, but also repeatable ... We've moved significantly closer to returning everyday functions, like serving yourself a sip of coffee, usually performed effortlessly by the arm and hand, for people who are unable to move their own limbs. We are also encouraged to see useful control more than five years after implant of the BrainGate array in one of our participants. This work is a critical step toward realizing the long-term goal of creating a neurotechnology that will restore movement, control, and independence to people with paralysis or limb loss." Essentially, the robotic limb was able to be a substitute for the patients real arm. With more advanced battery power and light alloys, the concept of bionic limbs is simply a question of a few years away. In the Brown experiment, the target objects were relatively large, more than half the width of the robots hand, thus requiring the patient to exert a precise control of the device. In 158 trials held over four days, the woman (S3) was able to touch the target within an allotted time in 48.8 percent of the cases using the DLR robotic arm and hand, and 69.2 percent of the cases with the DEKA arm and hand, which has the wider grasp. In 45 trials using the DEKA arm, the man (T2) touched the target 95.6 percent of the time. Of the successful touches, S3 grasped the target 43.6 percent of the time with the DLR arm and 66.7 percent of the time with the DEKA arm. T2's grasp succeeded 62.2 percent of the time. "I just imagined moving my own arm and the [DEKA] arm moved where I wanted it to go." Patrick van der Smagt, head of bionics and assistive robotics at DLR, director of biomimetic robotics and machine learning labs at DLR and the Technische Universität München, and a co-senior author on the paper, discussed the development of the arm itself: "This is what we were hoping for with this arm. We wanted to create an arm that could be used intuitively by varying forms of control. The arm is already in use by numerous research labs around the world who use its unique interaction and safety capabilities. This is a compelling demonstration of the potential utility of the arm by a person with paralysis."