Syringe, adaptor, and check valve combination for parenteral infuser

Claim 1

For use in a parenteral infuser comprising a cradle adapted to receive an annular or disc-shaped element fitting into the cradle and a switch adapted to disable the parenteral infuser unless such an element is fitted into the cradle, a combination comprising: a. a syringe having a chamber adapted to hold an infusible liquid and including 1. a vial having a tubular wall with a closed end and an open end, having a longitudinal axis, and enclosing the chamber except at one end opposite the closed end of the vial, 2. a plunger arranged within the vial, in liquid-tight relation to the tubular wall of the vial, for relative movement of the plunger and the vial along the axis of the vial, the plunger having an axial hole and closing the chamber liquid-tightly at the end opposite the closed end of the vial except at the axial hole, 3. a tubular needle extending axially through the open end of the vial, and liquid-tightly through the axial hole of the plunger, and 4. a flange mounted around the tubular needle in fixed, spaced relation to the plunger, the flange being too small to fit into the cradle, b. a first set of male and female tubular connectors adapted to be releasably connected to each other, the first set of tubular connectors including a first connector axially attached to the flange of the syringe so as to communicate with the tubular needle and a second connector; c. an adaptor having an upper portion including an outer rim adapted to fit into the cradle and an inner rim adapted to fit over the flange of the syringe and a lower tubular portion axially spaced from the upper portion; d. a check valve having a fluid inlet, a fluid outlet, and means for allowing fluid to flow only from the inlet to the outlet, said valve adapted to fit in the tubular portion of the adaptor and fluidly connected to the first connector at the fluid inlet by the second connector of the first set of tubular connectors so as to allow the infusible liquid to flow from the chamber, through the tubular needle, and through the check valve, but not oppositely, when the adaptor is fitted over the flange of the syringe and into the cradle and the first and second connectors of the first set of tubular connectors are connected to each other; and e. a second set of tubular connectors adapted to be releasably connected to each other, the second set of tubular connectors including a first connector attached to the fluid outlet of the check valve and axially extended from the tubular portion of the adaptor and a second connector adapted to connect a tube leading toward a site for parenteral infusion of a patient.