The invention relates to: A medication delivery device (1) for delivering a specific
dose comprising a medication
cartridge (11) having an outlet (111) and a
piston (112), and means (12) for holding said
cartridge, and a
piston rod (13) being operable to engage and displace said
piston, and electrically driven actuating means (15), and driving means (161, 162) for transferring movement from said actuating means to said
piston rod, and memory means (17) for storing data, and
processing means (18) for evaluating said data and for controlling said actuating means. The object of the present invention is to provide a medication
delivery system that combines a relatively high
dose accuracy with the use of relatively low quality
mechanical components and which enables compensation for built-in non-linearities. The problem is solved in that a first set of data (19) describing the actual movement (130) of said
piston rod (13) relative to said medication
cartridge (11) as a function of the movement (150) of said actuating means (15) is stored in said memory means (17), and the movement (130) of the
piston rod (13) governing the delivered
dose is controlled by the
processing means (18) on the basis of said first set of data (19). This has the
advantage of allowing compensation for mechanical inaccuracies and built-in non-linearities linearities. The invention may e.g. be used in injection or infusion devices for a person's self-treatment of a
disease such as diabetes.