Patent ID: 8221356

Claim:
A medication delivery device ( 100 ), comprising: A piston rod ( 154 ) for advancing a piston ( 152 ) for forcing drug out of a drug containing compartment ( 150 ) of a housing ( 151 , 160 ), a movable part ( 156 ) connected to the piston rod ( 154 ) and adapted to rotate relative to the housing ( 151 , 160 ) to move the piston rod ( 154 ) distally with sufficient force to expel the drug from the delivery device; at least two conductors comprising a first electrically conducting surface ( 200 ) and a second electrically conducting surface ( 202 )which are arranged such that an electrical characteristic is defined by the mutual position of the movable part ( 156 ) and the housing ( 151 , 160 ); and a detector for detecting a change of said electrical characteristic, wherein the movable part ( 156 ) comprising the first electrically conducting surface ( 200 ) and the housing ( 151 , 160 ) comprising the second electrically conducting surface ( 202 ) are stationary relative to each other during dose setting and in that the movable part ( 156 ) and the housing ( 151 , 160 ) are rotated relative to each other during dose ejection, such that the detector provides a signal indicative of the actual amount of the ejected dose.