Blood processing systems and methods which restrict in flow of whole blood to increase platelet yields

A device for separating a suspension of plasma and platelets from whole blood comprising

• a separation chamber operable for rotation about a rotational axis to create within the chamber a low-G wall and a high-G wall spaced radially further from the axis than the low-G wall,
• a whole blood inlet port to introduce whole blood into a whole blood entry region of the chamber during its rotation to initiate separation of red blood cells within the whole blood entry region toward the high-G wall and create a flow of plasma that moves within the whole blood entry region radially toward the low-G wall and into a plasma constituent collection region adjacent the whole blood entry region, the radial flow of plasma eluting platelets into suspension, the whole blood entry region including a first flow restricting dam on the high-G wall that restricts the flow of whole blood into the whole blood entry region to a reduced passage along the low-G wall, and
• a second flow restricting dam on the high-G wall to direct the radial flow of plasma and eluted platelets into the plasma constituent collection region to a plasma constituent outlet port adjacent the whole blood inlet port for transport from the chamber.

A method for separating a suspension of plasma and platelets from whole blood comprising the steps of

• rotating a separation chamber about a rotational axis to create within the chamber a low-G wall and a high-G wall spaced radially further from the axis than the low-G wall,
• introducing whole blood through a whole blood inlet port into a whole blood entry region of the chamber during its rotation through a reduced passage along the low-G wall to initiate separation of red blood cells within the first region toward the high-G wall and create a flow of plasma that moves within the whole blood entry region radially toward the low-G wall and into a plasma constituent collection region adjacent the whole blood collection region, the radial flow of plasma eluting platelets into suspension, and
• directing the radial flow of plasma and eluted platelets in the plasma constituent collection region through a reduced passage on the low-G wall to a plasma constituent outlet port adjacent to the whole blood inlet port for transport from the chamber.