In more than 30 years of work, Niels Birbaumer and his colleagues from the university of Tübingen have shown that people can control the so called "slow cortical potentials" (SCP), a wave-type with among the lowest frequencies (0.1-0.5 Hz) that can be detected by an EEG (see picture). The thought-translation-device (TTD), which uses SCP-waves, is in use with patients with late-stage ALS (more) and is very successful in providing basic communication capabilities.

In the standard form (more), users receive visual feedback about their thought-activity from a computer screen with two choices on bottom and on top (see picture). Selection takes around four seconds (more). TTDs with auditory or even tactile feedback are also available. After a long training period (more), users switch to a language support program (see picture) that gives ALS-patients back a certain communication capability (more). The TTD-system is highly valued by the patients who use it and even provides internet access to one user up to now.