The Increment sub-tab is mainly used for visualization purposes. For each fitable parameter the current value is shown next to an increment value and an increment slider. When the arrow buttons are selected, the parameter value is incremented or decremented accordingly. The slider allows to increment/decrement a parameter smoothly. The minimal and maximal values for the slider as well as the initial increment are obtained from the values on the Restrictions tab.
After every parameter change the curve display is updated, so that the user can observe its effect on the global uptake (model curve) and on the uptake in the different compartments (C1(t), C2(t)).
For instance, as shown below, it can be nicely demonstrated that a change in K1 simply scales the model curve, but does not change the curve shape: Set the curve display to relative scaling by selecting the % in the upper right and then change K1. Nothing changes in the % display, provided that the blood volume fraction is set to 0. Any modification of the other parameters changes the curve shapes notably.