Abstract: An implantable medical device includes a telemetry unit wirelessly receiving data signals and control commands; a control unit connected to the telemetry unit; and a comparator unit which compares data signals received via the telemetry unit with data signals generated in or detected by the implantable medical device. Each of the data signals represents specific features, e.g., patient characteristics. The comparator unit generates a release signal if data signals received via the telemetry unit represent one or more features that are similar, according to a specified similarity measure, to one or more features represented by data signals generated in or detected by the implantable medical device. The control unit executes control commands received via the telemetry unit, or receives control commands via the telemetry unit, in response to such a release signal (or, in the absence of the release signal, does not execute or receive control commands).