INDISTINGUISHABILITY FOR A CLASS OF NONLINEAR COMPARTMENTAL-MODELS

Indistinguishability, as applied to nonlinear compartmental models, is analyzed by means of the local state isomorphism theorem. The method of analysis involves the determination of all local, diffeomorphic tra nsformations connecting the state variables of two models. This is the n applied to two two-compartment models, in the first instance with li near eliminations, and then with the addition of eliminations with Mic haelis-Menten kinetics. In the nonlinear example, the state transforma tion turns out to be linear or possibly affine. It is found that the n onlinear analysis could be eased by splitting the state isomorphism eq uations into those of the initial linear models together with extra eq uations due to the nonlinearities.