The invention relates to a method for testing at least one function of a medical functional device which is inserted in and connected and compressed with a medical treatment apparatus, and/or a function of this treatment apparatus, wherein between a hydraulic device or a pneumatic unit of the treatment apparatus and the functional device at least one fluid communication is established. It further relates to a detection device which is programmed and/or configured for executing the method according to the invention as well as a medical treatment apparatus which comprises at least one detection device and/or is in signal transmission or is connected for signal transmission with it, a digital storage medium, a computer program product as well as a computer program.