A single needle extracorporeal blood circuit for connection to a blood treatment device includes an arterial portion having an arterial reservoir, an end for connection to the needle, an end for connection to the blood treatment device, and a first valve for flow communicating the needle with the arterial...http://www.google.ca/patents/US5318511?utm_source=gb-gplus-sharePatent US5318511 - Method and apparatus for controlling the circulation of blood in a single needle circuit
