The invention provides for a a medical system (100, 200, 300) comprising a control unit (102) and a medical appliance (104). The medical appliance is a body-worn medical appliance with a subcutaneous portion (110). The medical appliance is powered by a first battery (120). The medical appliance comprises a first wireless communication module (116). The monitoring system comprises a sensor (110) for measuring an analyte concentration (124). The subcutaneous portion comprises at least a portion of an analyte sensor. The control unit comprises a second wireless communication module (152) and a second memory (136). The second memory comprises an application partition (138) and a persistent partition (140). The application partition contains a medical application (142) and application data (144). The persistent partition contains archived data (146). The archived data comprises a copy of at least a portion of the application data. Execution of the controller instructions cause the second processor to control the monitoring system via wireless communication channel. The medical application is configured for modifying the application data in the application partition and storing the portion of the application data comprised in the archived data in the persistent partition. The medical data entry comprises the analyte concentration, wherein execution of the medical appliance instructions cause the first processor to: record the analyte concentration using the monitoring system, generate a medical data entry at least partially using the analyte concentration, and transfer the medical data entry to the control unit using the wireless communication channel, wherein the application data comprises the medical data entry. The second memory further contains an operating system. wherein the operating system is operable for de-installing the medical application. The de-installation deletes the application data and preserves the archived data on the persistent partition.
