Analysis of information sources in references of the Wikipedia article "Ergonomic keyboard" in English language version.
The aspect of the hand that they worked from is the curvature traced around the periphery of the fingers that can be observed when you look at the back of your hand with your fingers together. The thought was that if they built the surface of the keyboard in the form of two concave bowls – one for each hand – the result would fit the hand much better than the traditional more-or-less flat traditional keyboard surface.
This keyboard works by having each of your ten fingers choosing the character you want by selecting from a radial menu. You can push down, or move north, south, east or west, and get a different character for each.
