Patent ID: 6802982
Filing Date: 2004-10-12
Classification: A61M,B01D,B04B

Abstract:
A blood processing system comprisinga centrifugal separation device rotatable about a rotational axis, an inlet path operable to convey whole blood from a donor into the separation device for separation into red blood cells and a plasma constituent, an outlet path operable to remove plasma constituent from the separation device at least in part while whole blood is conveyed into the separation device and red blood cells are removed from the separation device, the outlet path including a branch that recirculates at an established rate at least a portion of the plasma constituent for mixing with whole blood conveyed into the separation device, an outlet path operable to remove red blood cells from the separation device at least in part while whole blood is conveyed into the separation device and plasma constituent is removed from the separation device, and a controller including a stage operable, at least in part while whole blood is conveyed into the separation device and plasma constituent and red blood cells are removed from the separation device, to generate a control command controlling the established rate of recirculation based, at least in part, upon a factor representing hematocrit of red blood cells separated in the separation device derived based upon sensed operating conditions and physical dimensions of the separation device and without use of a physical sensor to sense actual hematocrit of red blood cells.