infusion systems and methods for infusing one or more drugs or other agents into the body of a human or animal subject . the system is programmed to take remedial action upon sensing of a fault or error in connection with the infusion . in some embodiments , an agent may be infused through redundant flowpaths and , if a fault occurs in one flowpath , the system may respond by increasing flowrate through other non - faulting flowpath . in some embodiments , the fault may be a physiological reaction or symptom in the subject and the system may respond by adjusting or stopping flowrate or one or more agents or changing the ratio of simultaneously infused agents .