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Thu 11 Nov, 2004 01:51 pm
From New Scientist : Full story here
http://www.newscientist.com/news/news.jsp?id=ns99996645
Moving brain implant seeks out signals
19:00 10 November 04
Exclusive from New Scientist Print Edition.
A device that automatically moves electrodes through the brain to seek out the strongest signals is taking the idea of neural implants to a new level. Scary as this sounds, its developers at the California Institute of Technology in Pasadena say devices like this will be essential if brain implants are ever going to work.
Implants could one day help people who are paralysed or unable to communicate because of spinal injury or conditions such as amyotrophic lateral sclerosis (Lou Gehrig?s disease). Electrodes implanted in the brain could, in principle, pick up neural signals and convey them to a prosthetic arm or a computer cursor.
But there is a problem. Implanted electrodes are usually unable to sense consistent neuronal signals for more than a few months, according to Igor Fineman, a neurosurgeon at the Huntington Hospital, also in Pasadena.
This loss of sensitivity has a number of causes: the electrodes may shift following a slight knock or because of small changes in blood pressure; tissue building up on the electrodes may mask the signal; or the neurons emitting the signals can die.
To get around these problems, Joel Burdick and Richard Andersen at Caltech have developed a device in which the electrodes sense where the strongest signal is coming from, and move towards it. Their prototype, which is mounted on the skull, uses piezoelectric motors to move four electrodes independently of each other in 1-micrometre increments.
Tuning in
It has successfully been used to decode motor signals in rats and intention signals in monkeys. When surgeons implant electrodes in the brain they normally have to ?tune? individual electrodes by positioning them to pick up signals from a single brain cell...........
Tomorrow high school students will refer to the '80's, 90's and '00's to the time when the best scientists tackled the brain with hammers and screwdrivers.
Neurologically we live in exciting times.
Indeed we do!!!! Fascinating times.
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