Systems and methods for converting an apheresis fluid processing circuit to single or double needle mode

A system for performing an apheresis procedure comprising:

• a) a reusable, fluid processing device, said device comprising valves for opening and closing flow paths of a disposable fluid circuit, one or more pumps for moving blood through flow paths of the disposable fluid circuit, a controller, and a user interface;
• b) the disposable fluid circuit, wherein the disposable fluid circuit is mountable onto said device, said circuit comprising a separation chamber, a draw line including a fluid source access device wherein said draw line is in flow communication with said chamber, and a return line including a fluid source access device wherein said return line is in flow communication with said chamber, wherein the return line comprises a filter;
• and
• c) wherein said controller is configured to (i) provide and display instructions on the user interface for converting said disposable fluid circuit from a double needle configuration to a single needle configuration and (ii) provide and display instructions on the user interface for converting said disposable fluid circuit from a single needle configuration to a double needle configuration, (iii) recirculate blood through the separation chamber during conversion of the disposable fluid circuit from the double needle configuration to the single needle configuration and from the single needle configuration to the double needle configuration, (iv) perform one or more checks to verify that the apheresis procedure may continue in a converted configuration, and (v) clear stagnant unanticoagulated blood from the return line or the draw line after placing the disposable fluid circuit in the converted configuration and initiate flow of the unanticoagulated blood through the filter in the return line.