A unit quaternion based SOM for anatomical joint constraint modelling

The accurate simulation of anatomical joint models is becoming increasingly important for both realistic animation and diagnostic medical applications. Recent models have exploited unit quaternions to eliminate singularities when modelling orientations between limbs at a joint. This has led to the development of unit quaternion based joint constraint validation and correction methods. This paper builds on previous work which suggested that Self Organizing Maps (SOMs) were capable of modelling regular spherical constraints on the orientation of the limb. Here we consider the extensions to this approach in the form of a SOM with weights in unit quaternion space and appropriate distance and update methods.