For those of you who went to the discussion group yesterday, you might remember my mentioning of a news article about a woman who received a prosthetic arm that she could move with her thoughts. Well, here it is:
Mitchell, who lives in Ellicott City, is the fourth person — and first woman — to receive a “bionic” arm, which allows her to control parts of the device by her thoughts alone. The device, designed by physicians and engineers at the Rehabilitation Institute of Chicago, works by detecting the movements of a chest muscle that has been rewired to the stumps of nerves that once went to her now-missing limb.
You can read more about it in this article from the Washington Post. It even has some of the technical details geeks like us always love:
The bionic arm makes use of several features of the human body that would be impossible to create from scratch. Luckily, a person still has them even after suffering an injury as grievous as the loss of an arm at the shoulder.
One feature is the “motor cortex” of the brain, where cells that control voluntary muscles reside. The millions of nerve cells that “drive” the arm and hand remain after amputation. When an amputee pretends to move his missing hand, those cells fire and send impulses down the spinal cord and out to nerves that terminate at the stump.
Those nerves are huge electrical conduits filled with tens of thousands of fibers carrying a wide assortment of information. Some are motor nerves telling muscles to move. Some are sensory nerves, carrying impulses back from the hand to the brain, where the information will be interpreted as touch, temperature, pressure and pain.
Anyway, this technology isn’t news to computer science and engineering researchers, but its application in medicine is just beginning. According to this article, the US will soon be offering robotic arms to soldiers who have lost limbs. Maybe those cyborgs that we see in science fiction movies won’t just be in science fiction anymore. For now, though, there is still a lot of room for improvement.
In the future, electrodes in the hand will send touch signals up the arm to the chest skin, which will send them on to the brain, where they will be perceived as sensation.
Update: here is an article that mentions that the University of Utah is going to be working on developing a “wireless bionic arm.”
Today, the University of Utah announced a $10 million contract, as part of the overall project, to develop a “peripheral nerve interface.” The implanted device would relay nerve impulses wirelessly from what’s left of a limb to a computer worn on the person’s belt. From there, the signals would be routed to a bionic arm and back to the remainder of the amputated arm, where they would then flow naturally back to the brain.