The present invention relates to a medical apparatus (200) comprising at least one hard unit (201) having fluid lines (202) conducting a medical fluid, in particular blood, through the hard unit (201)； at least one converter (205, 207, 209, 211, 213), said converter (205, 207, 209, 211, 213) being arranged for measuring a property of the medical fluid while the latter is present in one of the fluid lines (202), and at least part of the converter (205, 207, 209, 211, 213) being applied to the hard unit (201) by means of additive techniques, preferably by a printing process.
