Systems and methods for mid-processing calculation of blood composition

1. A blood separation method comprising:

processing blood in a device to separate a blood component from the blood;

conveying fluid containing said blood component from the device by an outlet line;

optically measuring the blood component in the outlet line;

calculating a blood component pre-count, based at least in part on the optical measurement of the blood component in the outlet line;

ceasing said calculating; and

processing additional blood in the device after ceasing said calculating wherein said blood component is platelets.

2. The method of claim 1 , further comprising reducing the amount of plasma in the device, while retaining substantially all of the platelets in the device, prior to said conveying fluid containing said blood component from the device by the outlet line.

3. The method of claim 1 , wherein said conveying fluid containing said blood component from the device by the outlet line comprises circulating a fluid containing platelets from the device through the outlet line and then back into the device, and wherein said optically measuring includes optically measuring the platelets in the outlet line while simultaneously circulating the fluid containing platelets from the device through the outlet line and then back into the device.

4. A blood separation method comprising:

processing blood in a device to separate platelets from the blood;

circulating a fluid containing platelets from the device through an outlet line and then back into the device while simultaneously optically measuring the platelets in the outlet line;

calculating a current platelet yield, a platelet pre-count, the volume of blood to process to collect a target amount of platelets, and/or the processing time required to collect a target amount of platelets, based at least in part on the optical measurement of the platelets in the outlet line;

ceasing said calculating; and

processing additional blood in the device after ceasing said calculating, wherein said circulating the fluid containing platelets from the device through the outlet line and then back into the device is repeated until the fluid containing platelets is substantially uniform.

5. A blood separation method comprising:

processing blood in a device to separate platelets from the blood;

conveying fluid containing platelets from the device by an outlet line;

optically measuring the platelets in the outlet line;

calculating a current platelet yield, a platelet pre-count, the volume of blood to process to collect a target amount of platelets, and/or the processing time required to collect a target amount of platelets, based at least in part on the optical measurement of the platelets in the outlet line;

ceasing said calculating; and

processing additional blood in the device after ceasing said calculating, wherein

said processing blood in a device includes spinning the device to separate platelets from the blood, and

said calculating a current platelet yield includes comparing the calculated platelet yield to a target and, if the calculated platelet yield exceeds the target, spinning the device at a greater speed to reduce the amount of platelets in the outlet line or, if the calculated platelet yield falls below the target, spinning the device at a slower speed to increase the amount of platelets in the outlet line.

6. The method of claim 1 , further comprising conveying separated platelets and an amount of platelet storage fluid to a platelet collection container, wherein said amount of platelet storage fluid is based, at least in part, on the optical measurement of the platelets in the outlet line.

7. A blood separation method comprising:

processing blood in a device having a first outlet line and a second outlet line to separate platelets from the blood;

conveying fluid containing platelets from the device by an outlet line;

optically measuring the platelets in the outlet line;

calculating a current platelet yield, a platelet pre-count, the volume of blood to process to collect a target amount of platelets, and/or the processing time required to collect a target amount of platelets, based at least in part on the optical measurement of the platelets in the outlet line;

ceasing said calculating; and

processing additional blood in the device after ceasing said calculating, wherein

said processing blood in a device comprises

spinning the device at a separation speed sufficient to separate the blood in the device into a red blood cell layer, a plasma layer, and a layer containing platelets;

conveying a flow of the separated plasma from the device through one of the outlet lines and conveying a flow of the separated red blood cells from the device through the other outlet line, while retaining substantially all of the layer containing platelets in the device;

spinning the device in alternating directions at a relatively low mixing speed to mix the separated plasma, the separated red blood cells, and the layer containing platelets remaining in the device; and

spinning the device at a harvest speed that is less than the separation speed to separate the mixed plasma, red blood cells, and layer containing platelets into a layer of red blood cells and a layer containing plasma and platelets;

said conveying fluid containing platelets from the device by the outlet line comprises circulating the layer containing plasma and platelets from the device through the first outlet line and then back into the device to reduce the number of red blood cells and leukocytes in the layer containing plasma and platelets; and

said optically measuring the platelets in the outlet line comprises optically measuring the platelets in the first outlet line while simultaneously circulating the layer containing plasma and platelets from the device through the first outlet line and then back into the device.

8. The method of claim 7 , wherein said circulating the layer containing plasma and platelets from the device through the first outlet line and then back into the device is repeated until the layer containing plasma and platelets is substantially uniform.

9. The method of claim 7 , wherein said calculating a current blood component yield includes comparing the calculated blood component yield to a target and, if the calculated blood component yield exceeds the target, spinning the device at a greater speed to reduce the amount of platelets in the first outlet line or, if the calculated blood component yield falls below the target, spinning the device at a slower speed to increase the amount of platelets in the first outlet line.

10. The method of claim 7 , further comprising conveying separated platelets and an amount of platelet storage fluid to a platelet collection container, wherein said amount of platelet storage fluid is based, at least in part, on the optical measurement of the platelets in the first outlet line.