Novo Nordisk A/S
An Injection Device With Needle Cleaning

Abstract:

The invention relates to a medical injection device having a needle cannula for multiple use and which needle cannula is cleaned between subsequent injections. The needle cannula is preferably cleaned at the distal tip in a cleaning assembly having a hollow cleaning chamber with a variable volume. The distal tip of the needle cannula is maintained inside the cleaning chamber between subsequent injections. The cleaning chamber is defined by an inner surface, a distal seal and a proximal seal. In order to increase the volume of the cleaning chamber during filling of the cleaning chamber one of the seals is formed as a movable plunger which is movable in one direction to expand the volume of the cleaning chamber. To release the movable plunger from the inner surface of the hollow cleaning chamber in order to commence the filling of the cleaning chamber, the movable plunger and the inner wall surface of the hollow cleaning chamber are rotatable in relation to each other during filling of the cleaning chamber.