Patent ID: 7736336

Claim:
A device for use in paracentesis comprising: a) a cannula assembly comprising an inner cannula having an internal lumen and at least one lateral opening located proximal to its distal end, an outer cannula adapted to accommodate said inner cannula within, and cannula assembly housing, said inner cannula being movable relative to said outer cannula; b) a valve assembly comprising a valve housing, interior chamber, reinsertible valve positioned within said chamber, and a lateral access port, said valve assembly adapted to removably attach to said cannula assembly and to accommodate a portion of said cannula assembly when placed within; c) a catheter assembly comprising a flexible catheter having an internal lumen and at least one opening, said catheter assembly adapted to removably attach to said valve assembly and to accommodate the distal portion of said cannula assembly placed within; wherein said cannula assembly further comprises a locking mechanism controlled by a coupling of said cannula assembly to said valve assembly; and wherein said locking mechanism permits movement of the inner cannula relative to the outer cannula when the cannula assembly is engaged to said valve assembly, and which restricts the movement of said inner cannula relative to said outer cannula upon disengagement of the cannula assembly from said valve assembly.