Patent ID: 8857674

Claim:
A disposable pump cartridge for use in a system including a pump drive mechanism, whereby the pump drive mechanism includes a reciprocating drive shaft that operates with a first movement and a second rearward movement, said disposable pump cartridge comprising: at least one barrel having an inlet valve and outlet valve associated therewith at a from end of said barrel; a retention mechanism positioned in said barrel that defines an operational portion and non-operational portion of said barrel, wherein said retention mechanism has a first axial distance from said front end of said barrel defining said non-operational portion; a piston movable within said barrel from a non-operational position to a first operational position and a second operational position, said piston including a piston coupling mechanism having a first coupler adapted for moving the piston from its non-operational position, and a second coupler adapted to preclude the piston from returning to said nonoperational position during operation; wherein said retention mechanism releasably maintains the piston in the non-operational position; a reciprocating shaft coupling mechanism that engages said first coupler of said piston coupling mechanism during said first movement, wherein said piston coupling mechanism has a from wall and said reciprocating shaft coupling mechanism has a second axial distance from said front wall that is greater than or equal to said first axial distance during said first movement; wherein said piston moves to a second operational position during said second movement of said reciprocating shaft; and said reciprocating shaft coupling mechanism engages said second coupler of said piston shaft coupling mechanism during subsequent movement of said reciprocating drive shaft thereby precluding movement of said piston within said non-operational portion of said barrel.