Abstract: In a patient controlled analgesia (PCA) system, physiological data is processed and alarms are provided by the controller of the physiological module sensing the data according to a first rule. The physiological data is also processed by a second, separate controller according to a second rule independent from the first controller. According to the second rule, the physiological data may be filtered, processed with physiological data and non-physiological data obtained from another source, such as a remote server, and the PCA delivery device controlled to prevent delivery of medication accordingly. The provided system of multiple processors and rules enables normal alarming by physiological sensor modules while the pausing or prevention of the PCA delivery is controlled by a separate controller. Through this means, not only are false pauses and alarms for PCA delivery reduced, but the normal alarms of the monitors are permitted to function normally.