Moving basal engine for a fluid delivery device

A fluid delivery device comprising:

• a fluid reservoir configured to contain medicament, the fluid reservoir being sealed proximate a proximal end with a sliding seal piston;
• a delivery path configured to fluidly couple the fluid reservoir and a patient wearing the fluid delivery device;
• a hydraulic fluid passage having a proximal end and a distal end, the distal end of the hydraulic fluid passage being coupled to the proximal end of the fluid reservoir;
• a basal actuator including a basal element slidingly coupled to an inside surface of a hydraulic fluid reservoir containing a hydraulic fluid, the hydraulic fluid reservoir being fluidly coupled to the proximal end of the hydraulic fluid passage, the basal actuator configured to force a sliding seal element in a distal direction to force the hydraulic fluid to flow out of the hydraulic fluid reservoir through hydraulic fluid passage moving the sliding seal piston at a controlled basal rate;
• and
• a bolus actuator directly coupled to a proximal end of the basal actuator, configured to directly or indirectly move the sliding seal piston a discrete bolus amount at a time.