Abstract: A fluid processing system includes a fluid processing device and a fluid flow circuit. The device includes a pump configured to convey a priming fluid through the circuit. The pressure in a conduit of the circuit is measured while the pump is operated at a particular rate. When the magnitude of the pressure is less than the magnitude of a predetermined pressure at the end of a time interval, the pump is operated at an increased rate. When the magnitude of the pressure is greater than the magnitude of the predetermined pressure at the end of the time interval, the pump is instead operated at a decreased rate. The magnitude of the pressure in the conduit is again compared to the magnitude of the predetermined pressure after the pump has operated at the increased or decreased rate for the time interval to determine how to next adjust the operational rate.

Abstract: Systems and methods are provided for dynamic calibration and correction of the stroke volume of a pump. During a fluid processing procedure, the change in volume of a fluid in a container associated with a volume measurement system is calculated for a plurality of time periods. The standard deviation of the plurality of changes in volume is calculated, with it being determined that the volume measurement system is operating correctly when the standard deviation is below a target threshold. Upon determining that the volume measurement system is operating correctly, the stroke volume of the pump is calculated and a target change in volume of the fluid in the container is compared to an actual change in volume. When there is a difference between the two changes in volume, a correction factor is calculated, with the operation of the pump being adjusted based at least in part on the correction factor.

Abstract: A fluid processing system includes a fluid processing device and a fluid flow circuit. The device includes a pump configured to convey a priming fluid through the circuit. The pressure in a conduit of the circuit is measured while the pump is operated at a particular rate. When the magnitude of the pressure is less than the magnitude of a predetermined pressure at the end of a time interval, the pump is operated at an increased rate. When the magnitude of the pressure is greater than the magnitude of the predetermined pressure at the end of the time interval, the pump is instead operated at a decreased rate. The magnitude of the pressure in the conduit is again compared to the magnitude of the predetermined pressure after the pump has operated at the increased or decreased rate for the time interval to determine how to next adjust the operational rate.

Abstract: A method and device are provided for centrifugally separating plasma from whole blood in which whole blood is introduced into a flow circuit having a blood access device connected to a first tubing for drawing whole blood from a blood source and for flowing whole blood to a centrifugal separation chamber; a volume of saline is added to the whole blood as it flows through the first tubing to dilute the whole blood; the volume of saline added to the whole blood is tracked; the whole blood having the volume of saline added thereto is separated in the centrifugal separation chamber so that an interface is created between the plasma and added saline and the cellular components of the whole blood; the separated plasma and added saline is flowed from the centrifugal separation chamber to a collection container; and a volume for the plasma and added saline in the collection container is determined.