( post-doctoral student Nicholas Hatsopou...)Brain-computer link lets paralyzed patients convert thoughts into actions

At the time, Donohue assigned Hatsopoulos -- now an assistant professor of organismal biology and anatomy at the University of Chicago -- the task of creating algorithms to translate the chatter between neurons in the motor cortex into a language the computer could understand and use to control other devices. Hatsopoulos and other students in the Donoghue lab were slowly able to match neuronal signal patterns with specific arm movements. In 2002, he, Donohue and colleagues at Brown showed that monkeys could learn to control the cursor without moving a muscle.

Meanwhile, in order to move into human trials, Donohue, Hatsopoulos, Gerhard Friehs and Mijail Serruya, all then at Brown, formed Cyberkinetics, which was incorporated in 2001. In 2002, they merged with Bionics, makers of the sensor, raised $5 million, and applied to the FDA for approval to conduct a pilot clinical trial. The trial began in 2004. So far, four patients have enrolled.

For each trial patient, training sessions begin soon after the sensor is inserted. The volunteer is asked to imagine moving one hand as if he were controlling the computer mouse. The researchers study the data and build filters to convert patterns of neural spikes into two- dimensional commands.

"Training patients to move things with their minds is different with each patient," said Maryam Saleh, who worked with the first two patients as a Cyberkinetics technician and is now a doctoral student in Hatsopoulos's Chicago lab.

The current BrainGate System is still in its infancy and is far from perfect. It is bulky and cumbersome. The quality of the signal can vary from patient to patient and from day to day. A great deal of work remains to be done to extend the longevity and reliability of the sensor. Patient two never developed as muc
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Source:University of Chicago Medical Center