Microsoft Research paper: http://research.microsoft.com/en-us/projects/typehoverswipe/
GravitySpace is a new approach to tracking people and objects indoors. Unlike traditional solutions based on cameras, GravitySpace reconstructs scene data from a pressure-sensing floor. While the floor is limited to sensing objects in direct contact with the ground, GravitySpace reconstructs contents above the ground by first identifying objects based on their texture and then applying inverse kinematics.
GravitySpace is a research project by Alan Bränzel, Daniel Hoffmann, Marius Knaust, Patrick Lühne, René Meusel, and Stephan Richter supervised by Christian Holz, Dominik Schmidt, and Patrick Baudisch at the Human Computer Interaction Lab at Hasso Plattner Institute.