Drive Mechanism for Drug Delivery Pumps with Integrated Status Indication

A drug pump comprising:

• a drug container including a plunger seal;
• a power and control system;
• a needle insertion mechanism;
• a fluid pathway connection;
• and
• a drive mechanism including:
• a drive housing defining an axis;
• a piston disposed for movement from at least a retracted first position to an extended second position along said axis, the piston adapted to impart movement to the plunger seal within the drug container;
• at least one biasing member disposed and adapted to cause movement of the piston from the retracted first position to the extended second position as the biasing member moves from an energized first position to a deenergized second position;
• a sleeve assembly disposed at least partially within the drive housing, at least a portion of the sleeve assembly being adapted to move along said axis with the piston;
• and
• an end-of-dose indicator, the end-of-dose indicator including a switch interconnect, the switch interconnect including a mechanical sensor adapted to selectively engage a portion of the sleeve assembly as a result of the movement of the piston from the retracted first position to the extended second position, the switch interconnect further being adapted to selectively engage the power and control system as a result of the engagement or disengagement of the sensor;
• wherein the power and control system initiates an end-of-dose indication as a result of the selective engagement of the switch interconnect.