Patent ID: 8287499

Claim:
A syringe, comprising: a clear syringe barrel having a first bottom end having a throughhole, a second end, and defining a barrel cavity therebetween; a clear plunger slidably disposed within the syringe cavity, the plunger rod comprising a first end having a first orifice, a second end having a second orifice, and defining a plunger cavity therebetween; a gasket positioned on the first end of the plunger, extending into the barrel cavity, and contacting an interior surface of the barrel cavity, the gasket comprising an orifice fluidly connected to the barrel cavity and the plunger cavity; and a return-flow prevention mechanism positioned at the second end of the plunger thereby allowing fluid flowing into the plunger from the first end of the plunger to flow in an outward direction from the inside of the plunger, the return-flow prevention mechanism being constructed to permit fluid to flow past the mechanism and out of the plunger in response to fluid pressure acting on the mechanism from within the plunger.