Technology Review: Wheelchair Makes the Most of Brain Control: "But EEG has limited accuracy and can only detect a few different commands. Maintaining these mental exercises when trying to maneuver a wheelchair around a cluttered environment can also be very tiring, says, Jos�del Mill�n, director of noninvasive brain-machine interfaces at the Federal Institute of Technology, who led the project. 'People cannot sustain that level of mental control for long periods of time,' he says. The concentration required also creates noisier signals that can be more difficult for a computer to interpret.
Shared control addresses this problem because patients don't need to continuously instruct the wheelchair to move forward; they need to think the command only once, and the software takes care of the rest. 'The wheelchair can take on the low-level details, so it's more natural,' says Mill�n."