Research presented recently at the Association of Academic Physiatrists (AAP) Annual Meeting looks at the potential of using a brain-computer interface to help manipulate a prosthesis via one’s thoughts.
“In general, using a prosthesis is an unnatural act that requires training, extra effort and can have a certain amount of awkwardness to it,” explains the study’s lead investigator, Douglas P. Murphy, MD, from Hunter Holmes McGuire VA Medical Center.
Controlling a prosthesis with thoughts could be a big step toward helping to bring patients back to the same ease, comfort, and ability as with a natural leg, Murphy adds, in a media release from AAP.
In the study, Murphy—also an associate professor of PM&R at Virginia Commonwealth University—and his team worked with a patient whose leg has been amputated above the knee. Using surface scalp electrodes to transmit brainwave data to a computer software program, the patient was taught how to activate a knee-unlocking switch through mental imaging, the release explains.
“In our first attempt at using BCI with a lower extremity prosthesis, we wanted to test a simple system before moving on to more complicated ones to test the feasibility of the concept,” Murphy states. “Thus, we chose control of the simplest prosthetic knee, which is the manual locking knee. When locked, the knee is rigid and straight, and when unlocked the knee swings freely.”
“Someone with an above knee amputation would have to physically/manually unlock the knee to sit and could lock or unlock in standing or walking depending on his/her needs. We were interested to see if our participant could literally ‘think’ his way to unlocking his prosthetic.”
The participant learned to activate the knee-unlocking switch on his prosthesis that turned on a motor and unlocked his prosthetic knee. He then proceeded to walk up and down parallel bars while demonstrating his ability to unlock the knee to swing his leg and to sit down. Throughout the study, the participant was able to successfully unlock his knee anywhere from 50% to 100% of the time, and he noted (through a questionnaire) his reactions to using BCI with his prosthesis, the release adds.
“The ultimate goal of this research is to provide the individual with a prosthesis that more easily and more successfully meets his or her needs for movement and walking,” Murphy notes. “The system should be comfortable, easy to use, and serve useful purposes. The patient’s subjective experience should reflect these goals.”
“Our subject gave a very good example of how this system could help him. He likes to hike with his children. Sometimes he is carrying his daughter and coming down a hill. With BCI control he could adjust his prosthesis for descending the hill very easily. This is the type of daily life activity we believe can be improved with BCI.”
[Source(s): Association of Academic Physiatrists, Newswise]