Posts tagged prosthetic limbs
Articles and news from the latest research reports.
Cyborg Possibilities – The Arms and Legs
The most recent advancements in bionic arms seem to be included in the BeBionic prosthetic arms. This arm can detect signals in the nerves that exist in whatever amount of the arm remains and then uses those signals to drive the prosthetic’s functions. Essentially, operation ought to work much like the user’s original arm did: The person thinks about moving their arm in a certain way and the arm responds.
Despite looking cooler, the BeBionic hand is still a ways away from a human hand. Yet, the improvements are impressive. Grip strength has improved from about 17 pounds to about 31. It can hold about 100 pounds of weight, up from about 70. It also comes in a range of designs. The hand isn’t exorbitantly expensive, but at $25,000 to $35,000 it isn’t exactly cheap either. At that price range, concerns that future human enhancement technology will be a possibility only for the well to do seem likely.
Prosthetics through time
(Source: BBC)
Monkey manoeuvres reveal how the brain spurs actions
19 July 2012 by Nicola Guttridge
Whether a tree branch or a computer mouse is the target, reaching for objects is fundamental primate behaviour. Neurons in the brain prepare for such movements, and this neural activity can now be deciphered, allowing researchers to predict what movements will occur. This discovery could help us develop prosthetic limbs that can be controlled by thought alone.
What happens next? (Image: Gallo Images/Rex Features)
To find out what goes on in the brain when we reach for things, biomedical engineers Daniel Moran and Thomas Pearce at Washington University in St Louis, Missouri, trained two rhesus macaques to participate in a series of exercises. When the monkeys reached for items, electrodes measured the activity of neurons in their dorsal premotor cortex, a region of the brain that is involved in the perception of movement.
The monkeys were trained to reach for a virtual object on a screen to receive a reward. In some tasks the monkeys had to reach directly for an object, in others they had to reach around an obstacle to get to the target.
Impulsive grab
Moran and Pearce managed to identify the neural activity corresponding with several aspects of the planned movement, such as angle of reach, hand position and the final target location.
The findings could one day allow the design of prosthetic limbs that can be controlled with thought alone, which is “one of the reasons we did the study”, says Moran.
"The two subjects actually used different strategies to perform the task, and we were able to see this in their neural activity," Moran says. One monkey waited to receive all the information before reaching, but the other reached immediately, even though there was a good chance that an obstacle might appear and the reaching action would need to be rethought.
"If the decoding strategy is a robust finding, then this has wider consequences concerning mind-reading – particularly if we can get equivalent results for more complex strategic differences at higher cognitive levels," says Richard Cooper, a cognitive researcher at Birkbeck, University of London. "However, this is all very speculative."
Source: NewScientist