1. A communication device for communicating with a computing element, the computing element executing a closed-loop algorithm for controlling a delivery rate of an infusion formulation by an infusion pump in response to a sensed biological state, the communication device comprising: an outer housing; a power source; a plurality of user-selectable operators attached to the housing, each of the plurality of user-selectable operators being selectable for initiating communication of signals to the computing element, the signals representing events affecting the sensed biological state; and a transmission device for transmitting the signals to the computing element; wherein the closed-loop algorithm processes the signals received by the computing element and adjusts the delivery rate of an infusion formulation in accordance with pre-programmed information relating to the events represented by the signals.