The invention faces the technical problem of further improving the safety and ensuring the quality of medicaments ejected from medical devices in an economic way without the need of additional space in the medical device. This technical problem is solved by an apparatus, comprising a lock out member configured to be implemented into a medical device, in particular a dispense interface, attachable to a second medical device, in particular a main body, wherein said lock out member is configured to prevent a second attachment of said medical device to said second medical device, wherein said lock out member has at least a first area with a first cross-sectional area, wherein said lock out member has at least a second area having a second cross-sectional area smaller than the first cross-sectional area, such that an electric resistance is defined between opposite ends of the lockout member and wherein said lock out member, at least in the second area, is made of a conductive material. The problem is further solved by a method comprising the steps of measuring the electric resistance of at least a second area of a lock out member, wherein said lock out member has at least a first area with a first cross-sectional area, wherein said second area has a second cross-sectional area smaller than the first cross-sectional area and wherein said lock out member, at least in the second area, is made of a conductive material and determining said electric resistance of at least said second area of said lock out member.La présente invention concerne le problème technique consistant à toujours plus améliorer la sécurité et garantir la qualité des médicaments éjectés des dispositifs médicaux de façon économique sans avoir besoin despace supplémentaire dans le dispositif médical. Ce problème technique est résolu par un appareil comprenant un élément de verrouillage conçu pour être mis en œuvre dans un dispositif médical, en particulier une interface de distributeur, pouvant être fixé à
