US Patent 7094222 Syringe device for simultaneous infusion and withdrawal

A syringe device includes a first chamber defined by a cylindrical barrel, a plunger head within the barrel and a hollow needle sealed to an administering end of the barrel but open to an environment outside of the first chamber. A second chamber is defined by the barrel, the plunger head and a seal that seals around a plunger shaft leading to the plunger head and that seals an actuation end of the barrel. A receiving container having a second hollow needle attached and sealed at one end is also attached and sealed to the syringe, to thereby define a receiving chamber in fluid communication with the second chamber of the syringe and, via the second needle, with an environment outside of the receiving chamber. Depressing the plunger will infuse a substance through the first needle while simultaneously withdrawing a substance through the second needle. Reverse action is possible.