A 
surgical instrument (e.g., endocutter, grasper, cutter, staplers, clip applier, access device, 
drug / 
gene therapy delivery device, and 
energy device using 
ultrasound, RF, 
laser, etc.) may benefit from having a plurality of hydraulically actuated subsystems (e.g., severing, stapling, articulation, locking / unlocking, lockout enabling / disabling, grasping, etc.) supplied with hydraulic power from a trigger actuated 
rotary pump (e.g., 
lobe pump, rotary 
gear pump, internal rotating 
gear pump, flexible vane rotor pump, 
rotary vane pump). Thereby, an available amount of 
mechanical advantage available at a firing trigger may be optimally distributed to various end 
effector components, perhaps sequenced by an electroactive 
polymer or piezoelelectrically actuated function switch block.