Abstract: An add-on device adapted to be releasably attached to a drug delivery device, the drug delivery device comprising an indicator adapted to display a dose amount during dose setting, and to display the remaining dose amount to be expelled during drug expelling. The add-on device comprises an electronically controlled display adapted to display a set dose amount, a sensor assembly adapted to detect movement of the dose setting member when the add-on device is attached to a drug delivery device, a camera device adapted to capture an image of the indicator, and processor means adapted to (i) control the display dynamically to show the set dose amount based on input from the sensor assembly, and (ii) determine an expelled dose amount based on input from the camera device.

Abstract: An electronically controlled add-on device with a switch arrangement comprises a powered switch which is open during most of its lifetime, i.e. during both storage and operational use. More specifically, in one embodiment the add-on device comprises a secondary switch so that there are an open and a closed switch. The logics of the electronic circuitry control the circuitry so that the closed switch will be un-powered and the open switch will be powered. When the switch is mechanically changed, both switches are changed by the controller so that the closed switch will be un-powered and the open switch will be powered.

Abstract: An add-on device configured to be releasably attached to a drug delivery device comprising a housing with a reference marker and a scale drum with a zero identifier and an initial marker. The add-on device comprises a memory and a camera adapted to capture an image of the housing reference marker and the initial marker when the scale drum is in a (near) initial position. The add-on device is adapted to perform a reference offset value determination, comprising: capture an image, perform an image analysis to determine if the captured image comprises the zero identifier, if so, determine a reference offset value based on the distance between the housing reference marker and the initial marker, the reference off-set value representing the initial rotational position, and if no reference offset value is stored in the memory or if the determined reference offset value corresponds to a smaller set dose amount than a currently stored value, store in the memory the determined reference offset value.

Abstract: An electronically controlled add-on device with a switch arrangement comprises a powered switch which is open during most of its lifetime, i.e. during both storage and operational use. More specifically, in one embodiment the add-on device comprises a secondary switch so that there are an open and a closed switch. The logics of the electronic circuitry control the circuitry so that the closed switch will be un-powered and the open switch will be powered. When the switch is mechanically changed, both switches are changed by the controller so that the closed switch will be un-powered and the open switch will be powered.

Abstract: A rotary sensor assembly comprises an indicator member adapted to rotate and having first and second axial positions, input means adapted to be actuated by movement of the indicator member, and a processor adapted to receive input from the input means. The indicator member comprises a plurality of actuator structures, and the input means comprises one or more switches adapted to be actuated by an actuator structure. Zero or more switches is/are actuated when the indicator member is moved from the first to the second axial position, this corresponding to a first switch pattern, and zero or more switches is/are actuated when the indicator member is moved from the second to the second axial position, this corresponding to a second switch pattern. Based on input from one or more switches corresponding to the first and second switch patterns, the processor is adapted to determine rotational movement of the indicator member.