“Jedi” helmets from the 1980s, used in conjunction with MRI scanners to investigate the brain without having to crack open the cranium. The word “Jedi” was used to ensure that children put it on without too much fuss. From this article: http://www.iflscience.com/technology/ten-weird-and-terrifying-medical-instruments-past#LOSWREVeoTqpZIbC.99Report