A method has been developed for parameter estimation using sensitivity analysis in a model for transport of substrates and ions between the blood stream and myocardial cells. Experimental data include indicator-dilution curves recorded from the coronary sinus of dogs and rabbits after bolus injections into the aorta. In addition, the intramyocardial density of deposition of radioactive microspheres was used to provide estimates of the heterogeneity of regional flows in the heart. The sensitivity analysis employed a calculation of the domains of dominance (regions of maximal impact defined with respect to the form of the indicator-dilution curves and the time after injection) for each parameter on the basis of their sensitivity functions.Parameter estimation in a new two-barrier convection-diffusion model of coronary circulation has been achieved with great efficiency. Computation time was reduced to several minutes on an Interdata minicomputer as compared with 45 minutes to several hours using conventional optimization techniques such as STEPT (a direct search routine) or Simplex. The new parameter estimation method based on selective sensitivity is recommended for the class of problems which involve parameters with a well expressed distribution over the range of the independent variable.
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