  Biomedical systems are regulated by interacting mechanisms that operate
across multiple spatial and temporal scales and produce biosignals with linear
and non-linear information inside. In this sense entropy could provide a useful
measure about disorder in the system, lack of information in time-series and/or
irregularity of the signals. Essential tremor (ET) is the most common movement
disorder, being 20 times more common than Parkinson's disease, and 50-70% of
this disease cases are estimated to be genetic in origin. Archimedes spiral
drawing is one of the most used standard tests for clinical diagnosis. This
work, on selection of nonlinear biomarkers from drawings and handwriting, is
part of a wide-ranging cross study for the diagnosis of essential tremor in
BioDonostia Health Institute. Several entropy algorithms are used to generate
nonlinear feayures. The automatic analysis system consists of several Machine
Learning paradigms.
