Abstract:
Two relatively new approaches to model-based biosignal interpretation, qualitative
simulation and modelling by causal probabilistic networks, are compared to modelling
by differential equations. A major problem in applying a model to an individual patient
is the estimation of the parameters. The available observations are unlikely to allow
a proper estimation of the parameters, and even if they do, the task appears to have
exponential computational complexity if the model is non-linear. Causal probabilistic
networks have both differential equation models and qualitative simulation as special
cases, and they can provide both Bayesian and maximum-likelihood parameter estimates,
in most cases in much less than exponential time. In addition, they can calculate
the probabilities required for a decision-theoretical approach to medical decision
support. The practical applicability of causal probabilistic networks to real medical
problems is illustrated by a model of glucose metabolism which is used to adjust insulin
therapy in type I diabetic patients.
Keywords
Model-based Biosignal Interpretation - Parameter Estimation - Causal Probabilistic
Networks - Simulation - Physiological Systems