The present invention relates to a blood treatment device having at least one touch screen for inputting data by the user of the blood treatment device and having at least one memory for storing a prescription, wherein the blood treatment device has at least one processor which is connected both to the touch screen and to the memory and which is configured to determine a prescription based on a progression drawn on the touch screen by the user, wherein the processor is furthermore configured only to determine this prescription based on the progression drawn by the user and without using values of the prescription stored in the memory in advance.
