The adaptive identification and simulation of the hepatobiliary transport and storage of intravenously injected indocyanine green.

The mathematical model of hepatobiliary transport of indocyanine green in man was extended by modeling the dye injection and its mixing in blood plasma, too. The time constant of mixing and five coefficients characterizing the dye transport among blood plasma, liver cells, bile and intestine were estimated by methods based on adaptive systems of identification. The resulting plasma disappearance curve of indodyanine green has three distinct phases with successively decreasing rate of clearance. The estimated values of five inconstant rate coefficients do not differ substantially from those for constant coefficients. The findings support the validity of previous calculations estimating liver uptake, storage and excretory function, bile storage function and dye transport from bile into intestine. The usefulness of system approach in this field is stressed.