This "blinking in Morse code" is not a new idea: in the late 70s/early 80s, the University of Edinburgh built a computer that could translate muscle spasms of sleeping lucid dreamers, who had been taught morse code and who had been told to "slap your thigh in Morse code" when lucid. I saw the BBC documentary on the whole research and prima facie, it worked.. and one of the subjects was able to communicate directly to the computer whilst fast asleep.