As part of DARPA’s project to create viable full arm prosthesis, researchers at Johns Hopkins University’s Applied Physics Laboratory have hacked the controller of the Guitar Hero video game to accept residual nerve signals from electrodes attached to amputee limbs. The new system provides a positively more exhilarating twist on testing new electrodes and signal processing algorithms.
From IEEE Spectrum:
Inspired by Wii-hab, Armiger [Robert Armiger, APL engineer] and colleague Jacob Vogelstein borrowed a colleague’s copy of Guitar Hero and attacked the controller with a soldering iron. They rewired the standard guitar-shaped controller to take instructions from the VIE.
Next they substituted muscle contractions for button presses. In particular, they had to rejigger the inputs. Two-handed gamers normally play by using one hand to press colored “fret” buttons to correspond to the correct notes while using the other hand to push a “strum” button in time with the note. Onscreen, these same five colored buttons scroll down the display in time with the notes the players are supposed to hit. To correctly play a note, the player must press the right color fret button and the strum button with the opposite hand.
But Vogelstein and Armiger wanted to use the game to train an amputee. So first they needed to make the game’s controls one-handed. They did that by wiring the two controls together so that an input from a muscle contraction would be read by the VIE as a simultaneous “fret” and “strum.”