Surgeons have implanted an electrode microarray into the forearm of UK cybernetics professor Kevin Warwick. The centimetre-long device should allow two-way communication between a computer and neurons in the median nerve in Warwick鈥檚 arm.
鈥淚t is hoped that the project will result in considerable medical benefits for a large number of people, in particular assisting in movement for the spinally injured,鈥� says a statement from Warwick鈥檚 team at the University of Reading.
But experts in medical bioengineering dismiss the project as 鈥渁 gimmick鈥�. 鈥淚t鈥檚 good for the entertainment industry but it鈥檚 not going to contribute anything to neuroscience,鈥� says Nick Donaldson at University College London.
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Warwick is a controversial figure in cybernetics. He believes humans will become cyborgs 鈥� part-person, part-machine. And he has attracted criticism in the past for what some experts say are overly speculative pronouncements and media-friendly experiments.
In 1998, Warwick had a simple transmitter temporarily implanted in his arm. The transmitter was wirelessly linked to a computer, so when he walked around his department, doors opened and lights switched on.
Stimulating movement
The new implant consists of an electronic microarray with 100 tiny 鈥渟pikes鈥�, each as thin as a human hair. Wires linked to the implant have been tunnelled 15 centimetres up Warwick鈥檚 arm, where they poke through the skin. These wires are linked to a radio transmitter/receiver, which can communicate with a computer.
The median nerve contains sensory neurons and motor neurons. Some electrodes will pick up signals from and transmit signals to each type of neuron, and some from both, Warwick says.
In a series of tests over the next few weeks, Warwick will move individual fingers, for example, and the activity of motor neurons will be recorded. Sensory stimuli, such as a light touch or heat, will also be applied to various points on his hand.
鈥淲e鈥檙e then going to put signals into the nerves to see if we can get movement,鈥� Warwick told New 杏吧原创. 鈥淲e might be able to get my fingers to move 鈥� that鈥檇 be fantastic鈥�
Walking wounded
The type of array implanted in Warwick鈥檚 arm is being used in animals for basic neuroscience research, to investigate the concurrent activity of up to 100 neurons. But Donaldson is unconvinced that Warwick鈥檚 experiment will produce valuable results: 鈥淚 doubt that in a few weeks they鈥檒l do any useful neuroscience.鈥�
Warwick says he hopes such neural prostheses could be used to restore sensory and motor functions lost by spinal injury, other neurological lesions or limb amputation.
Electric stimulation has already been used to help patients with damaged spinal cords walk. 鈥淏ut the walking they do is very, very poor by normal standards,鈥� says Donaldson. 鈥淎nd my view is that no foreseeable technology is going to get paraplegics walking any better than has already been done.鈥�
The approach will probably be practically useful only for treating limited damage, involving monitoring and stimulating one or two neurons, he says.