Drink coffee with the robotic arm

Paraplegics control mind robot arm

05/17/2012

US researchers have successfully tested the use of a robotic arm in paraplegics patients. The robot arm is using a novel „neural interface“ John Donoghue and Leigh Hochberg of Brown University (Rhode Island, USA) report in the magazine that John Smith's treatment is so precise that they can lift a bottle of coffee from the table and drink it without help from others „Nature“.

Since April last year, researchers have tested the functionality of the robotic arm on two patients with quadriplegia (paraplegia involving all limbs). With success, as now published results prove. Cathy Hutchinson, paralyzed from neck to neck, was able to direct the robotic arm so precisely over a neural interface that she could take the coffee off the table and feed it to her mouth. The 58-year-old is almost completely paralyzed and no longer able to speak since a stroke 15 years ago, according to the scientists. For the first time she is back „to raise something of their own volition“, Leigh Hochberg explained and added „We will never forget her smile.“

Neuronal interfaces as a connection between man and machine
„Paralyzes after spinal cord injuries, brain stem infarcts, amyotrophic lateral sclerosis and other disorders can separate the brain from the body, thereby eliminating the ability to perform volitional movements“, the researchers write, explaining the foundations of their research at the same time. By using neural interfaces, signals from the brain could be used to control artificial limbs, as suggested by the development of the now-tested robotic arm. „The challenge lies in decoding the neural signals and converting these signals into digital commands that the robotic device can follow to perform the precise intended motion“, explain the US scientists. The more complex the movement, the more difficult the decryption.

Electrode field in the brain receives the signals to control the robot arm
That even quadriplegic patients corresponding brain signals can pass on to a neuronal interface, was already known from previous studies in which two subjects moved the cursor on a computer screen with the help of their thoughts. However, the control of the robot arm was much more complex. The neuroscientists were all the more satisfied with the success. The fact that Cathy can grab even fixed objects and in four out of six attempts the bottle filled with coffee to her mouth and could drink with a straw from it clarifies, according to the researchers, which chances this technique offers for paraplegic patients. People with quadriplegia could do so „even years after injuries to the central nervous system, a multi-dimensional control of complex devices“ Using neuronal signals, the researchers explain in the article „Reaching and grasping people by means of quadriplegia with the help of a neuronically controlled robot arm“. The neuronal interface used is an aspirin-like tablet with almost 100 hair-fine electrodes, implanted in the motor cortex of the brains, which converts the neuron's impulses into commands to the robotic arm, Donoghue and Hochberg continue. (Fp)

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Image: Dieter Schütz