Cambridge

Cambridge Model

This model is taken from the work of Hovorka et al [1], with implementation based on [2].

Specifics and deviations

With the default parameters, this model has a very high insulin sensitivity and implies a very low basal rate.

In [1], the glucose absorption rate resulting from a meal was measured as a time signal

\[ U_G(t) = \dfrac{D_G\,A_G\,t\,e^{-t/t_{max,G}}}{t^2_{max,G}} \]

This approach is only suitable for a single meal. It is more elegant to formulate glucose absorption as a solution of an initial value problem, as done in [2]. For this purpose, the original model must be extended by two compartments.

Block diagram

The following scheme visualizes the state variables included in the model and the interactions between them:

Disclaimer

It must be expressly pointed out that this is only a mathematical model which can at most describe the real processes in the human body approximately and in parts. Therefore, although the simulation results qualitatively resemble clinical curves, they must be interpreted with caution and are not suitable for deriving individual treatment strategies from them (see disclaimer). We do not assume any responsibility for the correctness of the results or damages of any kind resulting from the use of the simulator (see license).

References

[1] Hovorka, R.; Canonico, V.; Chassin, L. J.; Haueter, U.; Massi-Benedetti, M.; Federici, M. O.; Pieber, T. R.; Schaller, H. C., Schaupp, L.; Vering, T.; Wilinska, M. E.: Nonlinear model predictive control of glucose concentration in subjects with type 1 diabetes. Journal of Phyiological Measurement, Volume 25, 2004.

[2] Andersen, S. H.: Software for in Silico Testing of an Artificial Pancreas. Master’s Thesis at Technical University of Denmark. 2014.

The arrangement of the block diagram was inspired by a template by Clara Furió Novejarque, Universitat Politècnica de València.

Leave a Comment