It sounds like a simple video game, but this innovative new system could one day restore physical control to the lives of paralyzed people.
Neurosurgeons from Stanford and Brown University implanted microelectrodes into the brain of a paralyzed research participant, connecting it to a computer to allow the transmission of electrical signals. The test subject, thanks to the microelectrodes, was able to pilot a virtual drone through a video game-like obstacle course using only his thoughts. The achievement, as detailed in a press release dated January 20 study published in the journal Natural medicinehas important implications for allowing paralyzed people to enjoy activities that were previously inaccessible to them, and perhaps one day regain their independence of movement.
“We have developed a high-performance, finger-based brain-computer interface system enabling continuous control of three independent (virtual) finger groups, of which the thumb can be controlled in two dimensions, giving a total of four degrees of freedom,” said the researcher. the researchers wrote in the study. Although scientists have used brain-computer technology for more than a decade to help paralyzed people, it has always faced challenges in replicating complex movements, such as those of the fingers, a study suggests. Nature statement.
The study participant is a 69-year-old right-handed man who suffered a spinal cord injury that gave him quadriplegia, an extreme form of paralysis that affects most of the body. As detailed in the new paper, microelectrodes were implanted in his left precentral gyrus, the part of the brain that controls hand movement. The neurosurgeons asked the participant to observe the movements of a virtual hand, then used artificial intelligence to identify the electrical brain activity associated with particular finger movements.
This association then allowed the AI system to predict the desired finger movements, even if the participant cannot move their own fingers. The brain-computer interface thus allows him to control the movements of a virtual hand using his thoughts. The virtual hand was divided into three segments, which he could move vertically and horizontally, sometimes simultaneously: the thumb, the index and middle fingers, the ring finger and the little finger.
“This is a greater degree of functionality than anything previously based on finger movements,” said Matthew Willsey of Stanford University, who led the study and is also an assistant professor at the University of Michigan (UM), Ann Arbor, in a press release. statement. With practice, the participant was able to use this brain-computer interface to control the movement and speed of a virtual drone in a simulated obstacle course, much like how non-paralyzed people use game controllers to play video games.
The interface “takes signals created in the motor cortex (in the brain) that simply occur when the participant tries to move their fingers and uses an artificial neural network to interpret what the intentions are to control the virtual fingers in the simulation” , added Willsey. . “Then we send a signal to control a virtual quadcopter (drone).”
“The quadcopter simulation was not an arbitrary choice” because “the research participants were passionate about flying,” said Donald T. Avansino of Stanford University, who also participated in the study. “While meeting participants’ desire for flight, the platform also showcased multi-finger control.”
Microelectrodes located in the participant’s brain are physically connected to a computer. Less invasive approaches, including electroencephalography (EEG, a painless technique that measures the brain’s electrical activity without the need for surgery), have already allowed paralyzed patients to play video games. However, researchers suggest that fine motor control is best achieved by working more closely with neurons, according to the UM release. In fact, they noted in the study that their brain-computer interface allowed the participant to control the drone six times more precisely than a similar previous study which used EEG.
While the ability to play a video game allows paralyzed patients to socialize and participate in leisure activities, precise and dexterous control has even greater potential.
“By being able to move multiple virtual fingers with brain control, you can have multifactorial control schemes for all kinds of things,” explained Jaimie M. Henderson of Stanford University, who also participated in the study. “This could mean anything from using CAD software to composing music.” In other words, such technology could enable patients to pursue broader activities and even careers that were previously impossible for them.
While Star WarsCharacters use “the force” to control objects from a distance, scientists exploit technological advances to help paralyzed patients regain control of their lives.