| abstract |
The invention relates to an auto-injector (1) with a housing, a product container, a torsion spring (15), a drive element (13) and a push element (14), wherein the torsion spring (15) will The pouring of liquid from the product container puts the drive element (13) into rotation, and the rotating drive element (13) causes the propulsion element (14) and the piston in the product container to move Propel movement. The auto-injector further comprises a rotation sensor (22) and a processor unit, wherein the rotation sensor is adapted to continuously detect at least two rotational positions of the drive element (13) for each revolution of the drive element (13) alternately and continuously during pouring, And the processor unit is adapted to determine the axial piston position of the piston in the product container from the detected rotational position. |