Patent ID: 8801675

Claim:
A medical device comprising: a syringe barrel having a side wall with an inside surface defining a chamber for retaining fluid, an open proximal end, and a distal end including a distal wall having a passageway therethrough in fluid communication with the chamber, the open proximal end including a peripheral flange; and an elongate plunger rod disposed within the barrel, the plunger rod comprising a distal portion, a proximal portion, and a stopper disposed on a distal end of the distal portion, the stopper having a distal face and a proximal end, the proximal portion of the plunger rod slidably mounted for axial movement with respect to the distal portion so that the overall length of the plunger rod is adjustable to a plurality of selectively lockable lengths between a compressed locked length and a fully extended locked length, thereby permitting varying amounts of fluid to be expelled from the barrel corresponding to the plurality of locked lengths, based on movement of the overall length of the plunger rod within the barrel.