Evaluating movement patterns of rats-the measurement theoretical point of view

Behavior (movement patterns) of animals has been used for a long time in medical sciences as an indicator of the "system state" i.e. of the influence of a particular treatment upon the animal's condition. Until recently the evaluation of such behavior was done visually, by the experimenter, without any possibility of on objective measurement procedure. The introduction of the passive marker based motion analysis in controlled laboratory conditions led to the reproducible generation of observables, that can be relatively easily quantified and processed. The selection of an adequate model and the appropriate signal processing constitutes the major problem. The models must describe the rat behavior in two levels. The quantitative (low level) model is used to describe the physical movement. In the paper we present the measurement setup, the low-level model and the conclusions regarding movement patterns drawn from several long-term measurements. The qualitative (high level) model can be established with the involvement of medical experts.