The power of the mind has been harnessed by US researchers who have enabled a paralysed woman to pick up and drink from a flask of coffee using a robotic arm directed only by her thoughts.
It was the first time the 58-year-old woman, paralysed after a stroke, had picked anything up of her own volition in 15 years.
''The smile on her face when she did this was something that I and our whole research team will never forget,'' Brown University neuroengineer Leigh Hochberg said.
A decade in the making, the breakthrough is a significant advance in the race to restore movement to those who have lost control of their muscles.
It establishes a machine can be programmed to interpret brain signals as arm and hand motion.
But more exciting for neurologists was that the experiment showed the motor cortex area of the brain, which controls movement, was still able to function despite not being used in years.
Scientists wondered if neurons died or stop generating meaningful signals after years of disuse.
Bryce Vissel of Sydney's Garvan Institute of Medical Research said: ''We know that when there is injury, parts of the brain are reorganised. But this has shown that even though the injury occurred some years earlier, there is still capacity to drive movement.''
The woman had been paralysed since 1996, while a 66-year-old man who also took part had a stroke in 2006. As well as picking up the flask, researchers tested their ability to pick up foam balls placed in front of them.
Dr Vissel said that the results, outlined this week in the journal Nature, were a big deal.
''People have been working on this for a while and we are now in the future … we have reached a level of success that is quite astounding,'' he said.
The technology works by implanting a silicon-coated chip the size of a tablet into the motor cortex, at the top of the brain. The chip's 100 electrodes pick up the signals generated by brain cells, which are then read and interpreted by a computer. The movement messages are then sent to the robotic arm.
The patient is ''plugged in'' but researchers are trying to create a wireless model. However, the team behind the ''BrainGate'' project - including brain scientists, engineers, mathematicians and computer scientists from Brown University and Harvard Medical School - says it will be years before the device is widely available, wireless or otherwise.