1925: the Isolator helmet by Hugo Gernsback

FLASHBACK to 1925:

The Isolator is a bizarre helmet invented in 1925 that encourages focus and concentration by rendering the wearer deaf, piping them full of oxygen, and limiting their vision to a tiny horizontal slit. The Isolator was invented by Hugo Gernsback, editor of Science and Invention magazine, member of “The American Physical Society,” and one of the pioneers of science fiction.

Winston Churchill has something grander.