Contiguous independently-controllable conveyor system zones are controlled by zone control modules executing a program element associated with each module. Integrated circuitry formed according to the method, and other methods, is also disclosed. Additionally, the method comprises outlining the bolus in each fluoroscopic image to generate a plurality of silhouettes of the bolus. This behavior is achieved, in part, through the use of a physical or logical clock to establish the temporal order of topological change events.