The special procedure is grouped in three subsequent stages (see Fig. 18.104.22.168). In the first stage (5A), a simple evaluation is carried out using parameter values chosen a priori: before the evaluation is carried out. The procedure is very similar to the “Standard procedure” (Stage 3). The main difference is that in a special procedure there should be more than one measurement.
In the second stage (5B), procedures are applied for varying the two main factors related to the inhaled material: the AMAD and absorption Type, and also the time of intake, if not known, using the measurement data (a posteriori).
In the third stage (5C), an advanced evaluation is carried out. It applies to cases where there are comprehensive data available. The fundamental approach of this stage is that the model parameter values are adjusted systematically, in a specific order, until the goodness of fit is acceptable (i.e. the fits obtained to all the data are not rejected by the specified criteria).