SYSTEM IDENTIFICATION OF PHOTOSENSITISER UPTAKE KINETICS IN PHOTODYNAMIC THERAPY

This study presents the contributions of system identification techniques to the experimental modelling of photosensitiser uptake kinetics in photodynamic therapy. The experimental framework is limited to one cancer cell line (HT29-A4), one photosensitiser (Chlorin e6), one photosensitiser dose (5μg · ml–1), four albumin rates in a monolayer culture and eight measurements between 1h and 24h. Issues associated with this experimental modelling study are the deficiency of measurement points, low signal-to-noise ratios and 'poor' excitation signals (step signals). This paper deals with model structure selection, parameter estimation and parameter uncertainty description by probabilistic confidence regions. Moreover, an explicit relationship between the static gain of the estimated model and the albumin rate of the culture medium has been established.