Medication delivery device with sensing system

A medication delivery device comprising:

• a first member and a second member rotatable relative to the first member about an axis of rotation in proportion to an amount of a dose set by operation of the medication delivery device;
• a third member and a fourth member rotatable relative to the third member about the axis of rotation in proportion to an amount of a dose delivered by operation of the medication delivery device;
• a first wiper coupled to said first member and projecting in a first radial direction;
• a second wiper coupled to said third member and projecting in a second radial direction;
• an electrically operable first sensing band coupled to said second member;
• an electrically operable second sensing band coupled to said fourth member, each of the first and second sensing bands arranged in a curved shape and radially disposed relative to and in a contacting relationship with the first and second wipers, respectively, wherein, during relative rotation between said first and second members and relative rotation between said third and fourth members, each of said first and second sensing bands is operable to generate outputs associated with relative angular positions of the corresponding first and second wipers along an operational angular length of the respective first and second sensing bands that is indicative of relative rotational positions of said first and second members and said third and fourth members;
• and
• a controller electrically coupled with each of said first and second sensing bands to determine, based on the outputs generated by said first and second sensing bands, the amount of the dose set and the amount of the dose delivered by operation of the medication delivery device.