Scientists working on the Smarthand European Research Project in Sweden have created one of the most sophisticated prototype artificial hands in the world. Not only does it replicate the movements of a real hand, but it also gives the user a sensation of touch, of feeling, when using an artificial hand.
Robin af Ekenstam lost his hand when an aggressive tumour was discovered on his right wrist – amputation was the only way to save his life and prevent the cancer spreading to the rest of his body. Normally he wears an electronic hook, but this is a crude device, only giving minimal manipulation and of course he can’t feel what the hook is doing at all.
But scientists in Lund are fitting Robin with their prototype robotic hand. It includes four electric motors and 40 pressure sensors – all designed to give Robin the sensation of touch.
Says Robin, “I am using muscles which I haven’t used for years. That is very hard. But if you are able to control a movement, it is great. It is a feeling that I have not had for a long time. And now I am also getting the sensation back from small motors, which put pressure on certain spots on my arm. When I grab something hard, then I can feel it in the fingertips, which is strange, as I don’t have them anymore. It’s amazing.”
Work continues at the Hand Surgery Department in the Malmö University Hospital. 30 years in the operating theatre has made Göran Lundborg an expert on how the brain controls hand movements.
He says, “We know that by placing pressure sensors on the fingers of the artificial hand, we can transpose that pressure signal to specific areas in the skin of the remaining hand. And if you find the right spots to stimulate, we know that also the correct areas of the brain cortex will be activated. In other words, if you put pressure on the index finger of the artificial hand, the index finger area of your brain will be activated.”
Scientists are still working on the sensory feedback system within the robotic hand. But this is only a step towards an even more visionary device. The cables and electric motors used here are far too bulky to be practical for daily use. What is needed – using nanotechnology – is a tiny processing unit, a power source, and a trans-skin communication method which can all be implanted into the user of the hand.
Fredrik Sebelius, the co-ordinator of the Smarthand Project says, “The neural interface of the future could be implanted inside the arm which could then be connected to the peripheral interface. The internal interface could then receive and measure signals coming directly from the brain, and at the same time send sensory signals to the brain. It would transmit the signals as radio waves to the external prosthesis which would then be controlled and register sensation.”
For Robin it’s a vision that would make a huge difference to his daily life. But already today, he is thrilled by the way he can control and feel the new robotic hand. This test shows that the dream could one day be reality.
For more information about the project see: