Jan, who is paralyzed from the neck down, can use the robotic arm to eat chocolate.
A woman who is paralyzed from the neck down is displaying what one neurobiologist called “completely unexpected” skill at manipulating a robotic arm using nothing more than her thoughts. The patient, a 52 year old woman named Jan, doesn’t have the use of her limbs because of a degenerative spinal disease. She controls the arm using a program that translates her brain activity into fluid movements – she can simply think about her goals instead of each individual motion, exactly like someone who would normally pick up a cup or ball. She sends her input to the device through a grid of electrodes implanted in to her brain near the motor cortex. She now has small connectors on her head, to which the device is attached. Before implanting Jan with the device, doctors took scans of her brain imagining an arm performing various tasks. Now that the device is implanted, the program looks for the previously recorded patterns to control the arm.
In the beginning, the arm was programmed to ignore small mistakes in Jan’s movement, but by the third month she was able to do the trials effectively without help, and her performance is better than anyone else before her. Andrew Schwartz, a doctor who worked with Jan, said “At the end of a good day, when she was making these beautiful movements, she was ecstatic.” Jan can now use the arm to manipulate objects on a surface, as well as to eat and drink.
The technology isn’t perfect, but improvements are on the horizon. As it stands, a thin layer of scar tissue builds up around the tips of the electrodes and degrades the signal. New, thinner wires may solve that problem and prevent the scar buildup by keeping the reaction that makes scar tissue from triggering. The researchers also hope to build senses into the arm, so that the patient can feel texture and temperature in objects. Scientists are currently working on a wireless version of the system so that patients don’t have to be plugged into a machine physically.
Source: The Guardian
Published: Dec 20, 2012 03:00 pm