When using non-contact finger tracking, fingers can be classified
as to which hand they belong to by analysing the phase
relation of physiological tremor. In this paper, we show how
3D capacitive sensors can pick up muscle tremor in fingers
above a device. We develop a signal processing pipeline
based on nonlinear phase synchronisation that can reliably
group fingers to hands and experimentally validate our technique.
This allows significant new gestural capabilities for
3D finger sensing without additional hardware