APHERESIS APPARATUS AND METHOD

摘要

An apheresis apparatus and method is disclosed for increasing the purity and yield of platelets separated from donated whole blood in a centrifuge (11). The whole blood in the centrifuge (11) is diluted by recirculating fluid, such as plasma or saline, at a first flow rate, to mix with further withdrawn whole blood prior to entering the centrifuge. As plasma is collected (in plasma/air bag (18)), it is recirculated (via line 40) through the centrifuge (11) at a second flow rate to further improve the separation between the intermediate density components, i.e., platelets and white blood cells in the "buffy coat". The plasma is then recirculated through the centrifuge at a third flow rate and platelets are displaced out of the centrifuge while the plasma is recirculating through the centrifuge at the third flow rate.