A method for operating a system, comprising - a medical device , having at least one of a sensor device for sensing medical data and a medication delivery device for delivering medication, - a portable electronic consumer device , - an intermediate device provided with a first communication protocol for data communication with the portable electronic consumer device and a second communication protocol for data communication with the medical device , and - a control module provided in the intermediate device , the method comprising, in the control module , - receiving control data from the portable electronic consumer device by a receiving functionality provided in the control module , the control data being configured for controlling operation of the medical device , wherein the control data are configured to control at least one critical operation function of the medical device selected from the group of critical operation functions: sensing medical data by the sensor device, calibrating the sensor device, re-calibrating the sensor device, and delivering medication by the medication delivery device, characterised in that - determining whether the control data can be confirmed by a confirmation functionality provided in the control module , and - if the control data are confirmed, transmitting the control data to the medical device by a transmission functionality provided in the control module ; wherein the determining further comprises confirming the control data in response to receiving, in the control module , confirmation from a confirmation algorithm running in the intermediate device , wherein the confirmation is provided if it is determined by the confirmation algorithm that the control data are within control data limits provided in a memory device of the intermediate device , wherein the confirming further comprises determining if at least some of the control data received in the intermediate device are not within the data limits and amending such control data to be within the data limits, and wherein data different from the control data is transmitted by the intermediate device in pass through-data communication, such pass-through data communication being free of at least the confirmation process. - a medical device , having at least one of a sensor device for sensing medical data and a medication delivery device for delivering medication, - a portable electronic consumer device , - an intermediate device provided with a first communication protocol for data communication with the portable electronic consumer device and a second communication protocol for data communication with the medical device , and - a control module provided in the intermediate device , - receiving control data from the portable electronic consumer device by a receiving functionality provided in the control module , the control data being configured for controlling operation of the medical device , - determining whether the control data can be confirmed by a confirmation functionality provided in the control module , and - if the control data are confirmed, transmitting the control data to the medical device by a transmission functionality provided in the control module ; <EOS>