Dose detection and drug identification for a medication delivery device

A drug delivery device comprising:

• a sensed component comprising one or more sensed elements arranged in a ring;
• a sensor assembly comprising one or more coils or antennas, each of the one or more coils or antennas arranged about the axis of rotation, wherein the sensed component and the sensor assembly are arranged to rotate relative to each other during ejection of medicament from the drug delivery device such that an output signal is produced in the sensor assembly when a increment of dose is ejected;
• and
• a processing circuitry configured to:
• receive the output signal,
• increment a counter in response to receipt of the output signal, and
• determine information corresponding to a number of units of dose ejected during the dose delivery.

A drug delivery device comprising:

• a first rotatable component, and a second rotatable component configured to rotate relative to the first rotatable component during ejection of medicament from the drug delivery device;
• a sensed component comprising one or more sensed elements arranged in a ring;
• a sensor assembly comprising one or more coils or antennas, each of the one or more coils or antennas arranged about the axis of rotation, wherein the sensed component and the sensor assembly are arranged to rotate relative to each other during ejection of medicament from the drug delivery device such that an output signal is produced in the sensor assembly when a increment of dose is ejected,
• wherein one of the sensed component and the sensor assembly is supported on, or is integral with, the first rotatable component of the drug delivery device, and the other of the sensed component and the sensor assembly is supported on, or is integral with, the second rotatable component of the drug delivery device;
• and
• a processing circuitry configured to:
• receive the output signal,
• increment a counter in response to receipt of the output signal, and
• determine information corresponding to a number of units of dose ejected during the dose delivery.