A method for connecting a mobile operator terminal to a device to be operated includes outputting a code using an output element associated with the device. The code is transmitted to the mobile operator terminal. At least one piece of information related to the device is determined by decoding the transmitted code using software installed on the mobile operator terminal. A connection from the mobile operator terminal to a control unit associated with the device is then established with the aid of the piece of information related to the device and a piece of information related to the mobile operator terminal is transmitted from the mobile operator terminal to the control unit associated with the device over the established connection. A mobile operator terminal, a device for medical diagnosis or therapy and a system including a mobile operator terminal and a device, are also provided.