Glucose sensor signals and medication delivery control signals are monitored and these signals are modified for compatibility and safety purposes. In one application, output control signals from a controller directed to a delivery device are modified as a function of an actual amount of insulin delivered to the user. The safety layer method allows for an increased level of safety in an integrated delivery management (“IDM”) system and permits the development of separate hardware and software upgrades for components of the IDM system while assuring that compatibility between components will continue and safety is increased.
