Telekommand was contacted by a manufacturer of touch foils to work with their sensors.
They were the first to produce this touch foil technology with huge polymer sheets that can be deployed over normal screens to make them touch sensitive. They used a capacitive sensing technology that measures tiny variations of the local electric fields around the sensor.
Their technology is so sensitive that it allows interacting with the touchscreen through double glazed windows.
The issue they were having was that the size of the sensor made it a perfect antenna to catch any electromagnetic disturbance in the environment. The noise sources ranged from lighting in the ceiling to noise from the monitor it was attached to. Their approach at the time consisted of decreasing the sensor gain to damp the environmental noise. This reduced the capability of identifying the tiny signals generated by the touch of the fingers, sometimes on a surface several inches away, and resulted in missing touches and sporadically generating ghost touches.
They had already made attempts of filtering by frequency, but had no luck with it due to the wide arrangement of sizes and construction of displays that gave very different touch signatures and noise environments.
Telekommand's approach was to characterize, identify and separate noise and touches at runtime, combining data from frequency and time domains using predictive control techniques, solving their problem.