A group of scientists developing a thought-controlled computer cursor said on Monday that they are a step closer to offering a version of the device that people with paralysis can realistically use.
The team of US researchers say they have fine-tuned hardware and software to more accurately read brain activity, resulting in a device that works twice as fast as in previous trials, according to results published in the journal Nature Medicine.
Test subjects controlled the cursor via a number of electrodes implanted into their motor cortices - the section of the brain that controls physical movement. The motor cortices pick up signals from nearby neurons and transmit them to a computer that translates them into motion.
Improvements made to the cursor include filtering out electrical interference, which can weaken signals from neurons.
The brain-controlled cursor is a collaboration between Brown, Stanford, and Case Western Reserve universities, Massachusetts General Hospital and the US department of Veterans Affairs.
Precision problems
Perfecting brain-controlled devices is tricky because they currently function using the signals of only a few hundred neurons to estimate motor commands that take millions of neurons to issue, according to a July Stanford Report article about the development of thought-controlled cursors.
Tiny errors in this sample - ie, neurons that fire to fast or too slowly - can greatly reduce the speed and precision of thought-controlled commands, the article continues.
An interdisciplinary team led by Stanford electrical engineer Krishna Shenoy is tackling this problem by programming brain-controlled prostheses to instantaneously analyse and make dozens of corrective adjustments to these unreliable neuron samples, says the Stanford Report.
Changing lives
While brain-controlled devices may sound like indulgent inventions of science fiction, the goal of their development is to provide motor control to people with paralysis, for example those with amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease.
While many people with ALS can currently use eye or head movements to control a cursor and make commands, these technologies are fatiguing for people with ALS to use, and "neither provides the natural and intuitive control of readings taken directly from the brain", says the Stanford Report.
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