The Wii Vitality Sensor, Nintendo's strangest announcement of its E3 lineup, seems even stranger when you know that it has its roots in a nearly-identical Nintendo 64 device.
Produced by Seta and released in 1998 alongside Tetris 64, the "Bio Sensor" did exactly what the Wii Vitality Sensor does - reads a player's pulse as they play a game. It did it by clipping onto their earlobes, rather than their index fingers. In this particular title, you could have the game of Tetris either speed up or slow down as your heart rate increased. The former game mode would allow you to relax when things got too tense, and the latter would force you to control your reactions if you didn't want the game to get uncontrollably difficult.