Patent ID: 8172813

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 chamber being pre-filled with a fluid; an elongate plunger rod disposed within the barrel and having proximal and distal ends, the plunger rod comprising a first plunger rod piece comprising a frame defining a cross-shaped hollow receptacle and a second plunger rod piece having a cross-shaped cross section that is complementary to the first plunger rod piece, the first plunger rod piece being slidably disposed about the second plunger rod piece thereby permitting the overall length of the plunger rod to be reversibly adjustable between a compressed length to an extended length; and a stopper having a proximal end and a distal end, the stopper attached to the distal end of the plunger rod, the medical device being operable to expel fluid upon extending the first and second plunger rod pieces of the plunger rod to the extended length and application of an axial force to the plunger rod in a distal direction.