Bloorview Hospital in Toronto is Canada's largest children's rehabilitation hospital. It cares for many children with multiple disabilities, some of whom are in a totally locked-in state, unable to make their wishes known. In an effort to help them, a team has constructed a device which is able to tell the preference of a person who has been given two different choices. It's mind reading on a very limited scale and appears to be 80% accurate.When a region of the brain is active, both the oxygen and the hemoglobin in its blood increase.