Electronic System for a Drug Delivery Device

An electronic system for use with a drug delivery device for recording doses that are delivered from the drug delivery device, the electronic system comprising:

• an electrical power supply;
• a memory;
• a processor configured to control operation of the electronic system and coupled to the electrical power supply and to the memory;
• and
• a first light source, a second light source, a first optical sensor, and a second optical sensor that are in communication with the processor,
• wherein the first and second optical sensors are configured for detecting a movement of an encoder of the drug delivery device in an anti-phase arrangement, the movement being indicative of one or more of a dialed dose and a delivered dose from the drug delivery device,
• wherein the electronic system has a first low-power-consumption state and at least one further state having a higher power consumption compared with the first low-power-consumption state,
• wherein the processor is configured to (a) poll the first and second optical sensors in the first low-power-consumption state, (b) maintain the first low-power-consumption state when responses of the first and second optical sensors are identical to each other and identical to a preceding response, and (c) switch into the at least one further state when the responses of the first and second optical sensors are different from each other or are different from the preceding response.

A drug delivery device comprising:

• an electronic system comprising:
• an electrical power supply;
• a memory;
• a processor configured to control operation of the electronic system and coupled to the electrical power supply and to the memory;
• and
• a first light source, a second light source, a first optical sensor, and a second optical sensor that are in communication with the processor;
• and
• a dose setting and drive mechanism that is configured to perform a dose dialing operation for selecting a dose to be delivered by the drug delivery device, and a dose delivery operation for delivering the dose, the dose setting and drive mechanism comprising:
• an encoder rotatable in one or more of the dose delivery operation and the dose dialing operation, wherein the encoder comprises a ring of a plurality of light reflecting teeth spaced from each other, and
• wherein the electronic system is arranged such that depending on a rotational position of the encoder, light emitted by one of the first and second light sources is reflected by one of the teeth and detected by the respective first or second optical sensor, while light emitted by the other one of the first and second light sources is not reflected by any of the teeth.