AN ALGORITHM FOR IDENTIFIABLE PARAMETERS AND PARAMETER BOUNDS FOR A CLASS OF CASCADED MAMMILLARY MODELS

A complex structural identifiability problem for a class of unidirecti onally interconnected n-compartment linear mammillary models with mult iple inputs is discussed. This class is particularly useful in the stu dy of drug/metabolite kinetics and other interconversion kinetic proce sses. An explicit algorithm is developed for this model class that pro vides identifiable parameter combinations, parameter bounds, steady-st ate pool sizes, and production rates, with input forcing and output me asurements in central compartments. A six-compartment model of the com bined dynamics of the prohormone thyroxine (T-4) and hormone triiodoth yronine (T-3) illustrates how physiological parameter values or their smallest ranges, such as tissue T-4 to T-3 conversion rates and separa te T-4 and T-3 production rates, can be determined from stimulus-respo nse measurements in plasma alone.