Novo Nordisk A/S
ACCESSORY DEVICE FOR DRUG DELIVERY DEVICE

Abstract:

An add-on device adapted to be releasably mounted on a drug delivery device, the add-on device comprising an outer assembly with an add-on dose setting member adapted to be coupled to the outer housing of a pen housing, as well as an inner sensor assembly engaging the pen dose setting member and being in rotational engagement with the add-on dose setting member during dose setting. The invention addresses the issue of providing a stable inner platform for the sensor means, which in accordance with the invention is realized by actuating a clutch between the pen housing and the pen dose setting member during dose sensing, this preventing to a high degree that the inner sensor assembly rotates relative to the drug delivery housing during actuation of the drug expelling means.