Patent ID: 7511480

Claim:
A fluid administration device comprising a measuring assembly for measuring a position between spaced apart elements of said device, said measuring assembly comprising: at least one magneto-resistive sensor, said magneto-resistive sensor being fixedly connected to a casing of said device and being arranged opposite a sleeve of said device, said sleeve being rotationally and axially movable relative to said casing and being spaced apart from said casing, said sleeve serving both as a radially rotational dosing element for setting a dose amount to be administered and as an axial sliding element for administering a dose of fluid; a first permanent magnet fixedly arranged relative to said casing; and at least one second permanent magnet including a predetermined surface profile fixedly attached to said sleeve, said predetermined surface profile configured to enable detection by the at least one magneto-resistive sensor of (a) the set dose amount based upon radial rotation of the sleeve with respect to the casing and (b) the administration of the dose of fluid based upon axial movement of the sleeve with respect to the casing, wherein said magneto-resistive sensor is spaced apart from said surface profile.