Boffins refine mind-to-prosthetic link
Cogito ergo moveo
Scientists in the US have developed a technique that could massively improve the control amputees have over their prosthetic limbs.
The technique, known as targeted muscle reinnervation (TMR) allows a motorised prosthesis to respond directly to the brain's signals.
The research has been led by Dr Todd Kuiken, a physiatrist at the Rehabilitation Institute of Chicago and professor at Northwestern University. He explains: "The idea is that when you lose your arm, you lose the motors, the muscles, and the structural elements of the bones. But the control information should still be there in the residual nerves."
So Kuiken took the residual nerves that used to be associated with a patient's arms, and connected them up to the chest muscles. Some of the patients said when researchers touched their chests, they could feel a sensation in the limbs they no longer had, a phenomenon similar to the ghost limbs some amputees experience.
Crudely speaking, when the patient thinks about moving the missing limb, the nerves (now reconnected to the chest muscle) are stimulated. This causes the chest muscle to contract, which sends an electrical impulse to the prosthesis.
So far the team reports patients are able to "instruct" their new limb to make four fairly crude movements: open and close hand, and bend and straighten elbow. But new research, published in the Journal of Neurophysiology, has shown that the technique has the potential to do far more.
The researchers placed 79 to 128 electrodes on the chest muscles of a group of five patients. Using an EMG (electromyogram), they tried to identify the distinct signals associated with 16 arm and hand movements, right down to manipulation of missing fingers and thumbs. The team reports an accurate recognition rate of 95 per cent.
The work also demonstrated that the neural pathways associated with a limb remain intact for nine to 15 months after the event that leads to an amputation, the team says.
The researchers are now working with US servicemen who have lost limbs in the line of duty. ®
They HAVE been trying it for a long time, but the neurons just don't like it and tend to shrink away from artificial attachments. Also, it's hard to attach them and keep them from being yanked out, and a bit of a complicated wiring job when each one of thousands of neurons is just a few microns across and mother nature forgot to colour code them so you don't know what each one does. Also, need a chip that can individually either detect chemical neurotransmitters, cos that what you get in neuronal synapses, or one that can detect the NA+/K+ ion charge differences caused by the wave of depolarisation in each stimulated neuonal axon. Tough one that. Also, could be frustrating when your battery goes flat during periods of intensive arm movement.
Eventually: mind-reading limbs
When mind-reading limbs finally reach the market, you can be certain that there will be incidents of unintended breast-fondling.
"Oh sorry. I was just imagining doing that. But I didn't actually intend to do it. I think my new arms require some firmware updates."
@ Anonymous Coward
Thats a good summary of the process of taking a shit, however, Lets say, some poor bugger with his prosthetic sphincter (highly unlikely, i know, but for arguments sake) is out in public and he steps in dogshit, or even dodges the dogshit whatever, and he thinks to himself, "shit, i almost stepped in ..." but by then, the magic word has been thought of, and he's shat himself not once, but twice.......
Wouldn't that shit ya...