  Bimanual gestures are of the utmost importance for the study of motor
coordination in humans and in everyday activities. A reliable detection of
bimanual gestures in unconstrained environments is fundamental for their
clinical study and to assess common activities of daily living. This paper
investigates techniques for a reliable, unconstrained detection and
classification of bimanual gestures. It assumes the availability of inertial
data originating from the two hands/arms, builds upon a previously developed
technique for gesture modelling based on Gaussian Mixture Modelling (GMM) and
Gaussian Mixture Regression (GMR), and compares different modelling and
classification techniques, which are based on a number of assumptions inspired
by literature about how bimanual gestures are represented and modelled in the
brain. Experiments show results related to 5 everyday bimanual activities,
which have been selected on the basis of three main parameters: (not)
constraining the two hands by a physical tool, (not) requiring a specific
sequence of single-hand gestures, being recursive (or not). In the best
performing combination of modeling approach and classification technique, five
out of five activities are recognized up to an accuracy of 97%, a precision of
82% and a level of recall of 100%.
