https://qz.com/1229078/ai-gave-stephen-hawking-the-ability-to-communicate-despite-his-fears-of-the-tech/

For the last 10 years of his life, Stephen Hawking communicated only by tensing his cheek.

The famed physicist, known for his theories on black holes and for surviving ALS far longer than doctors’ estimates, wore a device on his glasses that monitored whether his cheek was flexed or not, and used the signal as a mouse-click to control his computer. When he first adopted this method, which one of his graduate students introduced in 2008, it was painfully slow and prone to error. It relied on a program called Word+ in which sentences had to be typed letter-by-letter, according to Wired.