Scientists have developed a brain-computer interface that reads the brain's blood oxygen levels and enables communication by deciphering the thoughts of patients who are totally paralyzed and unable to talk.
In a trial of the system in four patients with complete locked-in syndrome — incapable of moving even their eyes to communicate — it helped them use their thought waves to respond yes or no to spoken questions.
People who are paralyzed except for up and down eye movements and blinking are classified as having locked-in syndrome. If all eye movements are lost, the condition is referred to as complete locked-in syndrome.