Using Thoughts Alone, Paralyzed Man Flys Virtual Drone With Remarkable Accuracy

It sounds like a simple video game, but the innovative new system could one day restore physical control to the lives of people with paralysis.

Stanford and Brown University neurosurgeons implanted microelectrodes in the brain of a paralyzed research participant, connecting it to a computer to trigger the transmission of electrical signals. The test subject, through the microelectrodes, was able to pilot a virtual drone through a video game-like obstacle course using only his thoughts. The success, as detailed in a January 20 to study published in the newspaper Natural Medicineit has important implications to allow people with paralysis to enjoy activities previously inaccessible to them, and perhaps one day resume autonomous movement.

“We have developed a finger-based brain-computer interface system, which allows the continuous control of three independent (virtual) finger groups of which the thumb can be controlled in two dimensions, yielding a total of four degrees of freedom,” the researchers wrote in the study. Although scientists have used brain computing technology for more than a decade to help people with paralysis, it has historically faced challenges in replicating complex movements, such as those of fingers, according to a Nature statement

The participant in the study is a 69-year-old straight man who suffered a spinal cord injury that gave him tetraplegia, an extreme form of paralysis that affects most of the body. As detailed in the new document, the microelectrodes were implanted in his left precentral gyrus, the part of the brain that controls the movement of the hands. The neurosurgeons asked the participant to watch the movements of a virtual hand, and then used artificial intelligence to identify the electrical activity of the brain associated with particular finger movements.

This association allowed the AI ​​system to predict the desired finger movements, even if the participant cannot move their fingers. The brain-computer interface then allowed him to control the movements of a virtual hand with his thoughts. The virtual hand was divided into three segments, which could move vertically and horizontally, sometimes simultaneously: the thumb, index and middle, and ring and little finger.

“This is a higher 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, said in a UM. declaration. 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, similar to the way people without paralysis use game controllers to play the video games.

The interface “takes the signals created in the motor cortex (in the brain) that are only found when the participant tries to move his fingers and uses an artificial neural network to interpret what the intentions are to control the fingers virtual in the simulation,” Willsey added. . “Then we send a signal to control a virtual quadcopter (drone).”

“The quadcopter simulation was not an arbitrary choice,” as the “research participant had a passion for flight,” said Donald T. Avansino of Stanford University, who also participated in the study. “While also fulfilling the participant’s desire for flight, the platform also showed multi-finger control.”

Microelectrodes in the participants’ brains are physically wired 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 previously allowed patients with paralysis to play video games. However, the researchers suggest that fine motor control is best achieved by working closer to the neurons, according to the UM statement. 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 patients with paralysis to socialize and engage in leisure activities, precise dexterity control has even greater potential.

“By being able to move multiple virtual fingers with brain control, you can have multi-factor control schemes for all kinds of things,” explains Jaimie M. Henderson of Stanford University, who also participated in the study. “This could mean anything from running CAD software to composing music.” In other words, such technology could allow patients to pursue broader activities and even careers that were previously impossible for them.

While Star WarsCharacters use “the force” to control objects at a distance, scientists exploit technological advances to help patients with paralysis regain control of their lives.