Brainwave reading implants have helped a paralyzed man who can't speak spell out 1,150 words. The researchers of the technology surgically implanted a high-density electrode on the surface of the man's brain, over the speech motor cortex. With the help of the brain implant, called a brain-computer interface, the brain waves sent by the paralyzed man can be translated into full sentences using a neuroprosthetic device.

　　The working theory is that after inserting a device on the brain, the brain waves can be caught by the neuroprosthetic device. The brain waves can be decoded by silently miming the 26 letters of the phonetic alphabet. A spelling interface then used language modeling to crunch the data in real time, working out possible words or errors.

　　Compared with using a pointer attached to a baseball cap to poke at letters on a screen, the researchers were able to decode more than 1,150 words, which represent over 85 percent of the content in commonly used English sentences.

　　The device decoded about 29 characters (around seven words) in a minute, with an error rate of six percent. The simulation of the vocabulary could be extended to more than 9,000 words, which is basically the number of words most people use in a year.