On the structural identifiability of biological compartmental systems in a general input output configuration

The problem of the structural identifiability of biological compartmental systems, that is, the a priori evaluation of the possibility of estimating all their unknown parameters by an input-output tracer experiment, is studied. The analysis is developed in a linear system theory context. Theorems relating the controllability and observability of compartmental systems to their structure are proved, and they are employed for the solution of the problem of structural identifiability. The importance of the presented theory in tracer experiments for parameter estimation in biological compartmental systems is illustrated, and two examples are given. © 1976.