A microprocessor controlled medical apparatus for an extracorporeal blood treatment, comprising at least a software component driving a user interface connected to a screen and a storage unit in which a set of rules is stored that defines the relationship between settings of mutually dependent parameters (60; 61; 62) based on which the medical apparatus is operated, wherein the medical apparatus further comprises means for manual selection and amendment of the settings of said mutually dependent parameters (60; 61; 62) by an operator, means configured for setting and implementing said mutually dependent parameters (60; 61; 62) with the following method for setting the mutually dependent parameters (60; 61,62) of the medical apparatus for extracorporeal blood treatment, the method comprising: - displaying on the screen settings of a set of said at least two mutually dependent parameters (60; 61, 62); - displaying on the screen a range of possible setting values for at least one of said mutually dependent parameters (60; 61; 62); - adjusting a setting of one of said mutually dependent parameters (60; 61; 62) upon manual selection by an operator; - automatically determining and displaying the value of at least one setting of another one of said mutually dependent parameters (60; 61; 62), which is a dependent parameter among the mutually dependent parameters, depending on the setting of said one of said mutually dependent parameters (60; 61; 62) that is adjusted by the operator, whereby the determination of the setting of said dependent parameter (60; 61; 62) is at least based on the defined relationships between settings of said mutually dependent parameters (60; 61; 62); - implementing the set of settings of said mutually dependent parameters (60; 61; 62) that is amended by actuating a batch setting acceptance operation; and - operating the processes of the medical apparatus based on the set of amended settings of said mutually dependent parameters (60; 61; 62), characterized in that upon a passing of a therapy time as a first parameter of said mutually dependent parameters (60; 61; 62) at least one of variable range limiters (96, 82, 83) within an overall range of possible values of at least one second parameter (60; 62) of said mutually dependent parameters (60; 61; 62) is automatically set so as to change within the overall range of possible values as at least a function of said therapy time and/or an adjustment of parameter settings again; and said at least one of variable range limiters (96; 82; 83) is mutable. - displaying on the screen settings of a set of said at least two mutually dependent parameters (60; 61, 62); - displaying on the screen a range of possible setting values for at least one of said mutually dependent parameters (60; 61; 62); - adjusting a setting of one of said mutually dependent parameters (60; 61; 62) upon manual selection by an operator; - automatically determining and displaying the value of at least one setting of another one of said mutually dependent parameters (60; 61; 62), which is a dependent parameter among the mutually dependent parameters, depending on the setting of said one of said mutually dependent parameters (60; 61; 62) that is adjusted by the operator, whereby the determination of the setting of said dependent parameter (60; 61; 62) is at least based on the defined relationships between settings of said mutually dependent parameters (60; 61; 62); - implementing the set of settings of said mutually dependent parameters (60; 61; 62) that is amended by actuating a batch setting acceptance operation; and - operating the processes of the medical apparatus based on the set of amended settings of said mutually dependent parameters (60; 61; 62),