Valeri Polyakov's Blood Pressure Cuff

Origin
Valeri Vladimirovich Polyakov (1942 - ) is a former Russian cosmonaut and the holder of the longest single spaceflight in human history, staying aboard the Mir space station for more fourteen months. The loneliness that he had to endure while being in space was immense and he later confessed that he studied his medical texts and made sure that he was okay for being in space for so long. These feelings transferred into his blood pressure cuff as he would compulsively check his blood pressure as a relaxation method.

Effects
When held creates illusion of holder being the last person on earth, makes everyone else invisible to their eyes. Eventually the loneliness becomes too much and the user falls into a deep depression.

Trivia
Inspired the Twilight Zone episode "Where is Everybody?"