In my newsletter commentary of a couple of weeks ago “And now, a good-news story”, I listed the four finalists for this year’s RAEng MacRobert Award. The result was duly announced on June 9, with Livingston based Touch Bionics triumphant with its i-LIMB artificial hand. And while there may be more advanced prosthetic hands currently under development in laboratories around the world, the i-LIMB is here and now and is already helping some 200 amputees – many of them soldiers injured in recent conflicts.
The i-LIMB features an intuitive control system that uses a traditional two-input myoelectric signal (the electrical signal generated when muscles contract) to open and close the hand’s life-like fingers. Myoelectric controls respond to the electrical signals generated by the muscles in the surviving part of the patient’s limb, and these are sensed by electrodes on the surface of the skin. However, unlike basic myoelectric prosthetic hands, the i-LIMB’s control system is able to operate five articulating digits independently, providing the patient with unprecedented levels of manual dexterity from a prosthetic device.
But, ingenious as this development is, it is still dependent upon local stimuli from residual tissues. The future of prosthetic control, it seems, will centre on the brain itself. Currently a number of research projects around the world are looking into using brain controlled interaction with computers to improve the lives of people with disabilities, and this research is now leading to the development of commercially available products.
There have been recent reports of experiments with monkeys that are able to control robotic limbs through their own thought processes. Tiny electrodes implanted into the monkeys’ primary motor cortex sense the electrical impulses that control movement. These are analysed by a computer and converted into signals capable of controlling the robotic limb. The brain controls movement by planning where to go, rather than by directing individual muscles to make the limb get there. This has great potential for patients disabled after spinal cord injuries or amputations.
And the technology is not the sole preserve of medical science. Earlier this year, Emotiv Systems, a company with operations in the US and Australia, opened its API and provided a range of tools to enable developers to integrate neurotechnology into a wide range of applications. It is hoped the initiative will spur the adoption of brain-computer interface technology in video gaming, enabling consumers to experience an entirely new form of human-machine interaction.
What might once have been thought of as science fiction – the brain-machine interface - now seems to be very much science fact.
Les Hunt
Editor