Systems and methods for monitoring and controlling fluid balance during a biological fluid procedure

An extracorporeal photopheresis system, comprising:

• a separator configured to work in association with a disposable fluid circuit comprising a treatment container, the separator comprising a chamber configured to rotate about a rotational axis and convey whole blood from a blood source into an inlet region of the chamber for separation into a red blood cell component, a plasma component, and the target cell component;
• an irradiation device configured to treat the contents of the treatment container;
• and
• a microprocessor-based controller in communication with the separator, wherein the controller is configured to control the system to perform a procedure, the procedure including to draw anticoagulated whole blood into the disposable fluid circuit and the chamber at a whole blood flow rate, to separate the anticoagulated whole blood into the red blood cell component, the target cell component, and the plasma component, to direct the target cell component to the treatment container, to treat the treatment container comprising the target cell component to create a treated target cell component, and to return to the blood source the treated target cell component, a portion of the red blood cell component remaining in the fluid circuit, and/or a portion of the plasma component remaining in the fluid circuit,
• wherein the microprocessor-based controller is further configured to:
• estimate an end-of-procedure fluid balance, wherein the end-of-procedure fluid balance is estimated based on manual or automatic inputs comprising a patient body weight associated with the blood source and a total blood volume of the blood source,
• indicate the end-of-procedure fluid balance to an operator, and
• receive one or more changes that affect the end-of-procedure fluid balance after indicating the end-of-procedure fluid balance.