Patent ID: 8192386

Claim:
A system for controlling hematocrit during a blood processing procedure including: a first flow path for flowing whole blood from a patient; a separator communicating with the first flow path for separating at least red blood cells from plasma; a second flow path communicating with the separator for flowing the separated plasma from the separator; a third flow path communicating with the separator for flowing the separated red blood cells from the separator; a replacement red blood cell flow path communicating directly or indirectly with a patient configured to flow replacement red blood cells of a known hematocrit from a third party source thereof; a flow controller associated with the second and third flow paths to control fluid communication between the second and third flow paths and to control addition of separated plasma to the separated red blood cells; the resulting red blood cells and plasma having a resulting hematocrit; and the flow controller calculating the hematocrit in the third flow path or communicating with a hematocrit sensor operatively associated with the third flow path either upstream or downstream of the communication between the second and third flow paths, the flow controller controlling the amount of separated plasma added to the third flow path and thus controlling the resulting hematocrit based on the calculated hematocrit or the output of the hematocrit sensor.