Controlled delivery drive mechanisms for drug delivery pumps

A controlled delivery drive mechanism, comprising:

• a drug container having a barrel and a plunger seal;
• a drive housing within which at least initially partially resides a piston having an interface surface and a drive rack;
• a power spring coupled, directly or indirectly, to a drive pinion which interfaces with the drive rack of the piston to convert rotational movement of the power spring and the drive pinion to axial translation of the drive rack, wherein the piston is configured to contact and axially translate the plunger seal within the barrel, and wherein a regulating mechanism meters the drive pinion such that the piston is axially translated within the barrel at a controlled rate;
• and
• a status reader configured to read or recognize one or more corresponding status triggers, wherein, during operation of the drive mechanism, interaction between the status reader and the status triggers transmits a signal to a power and control system to provide feedback to a user.