Systems for separating high hematocrit red blood cell concentrations
First Claim
1. A blood separation system comprisinga membrane separation device comprising a gap between a microporous membrane and a surface facing the microporous membrane, one of the microporous membrane and the surface being rotatable relative to the other to cause separation of whole blood in the gap into plasma and concentrated red blood cells,an inlet pump element coupled to the membrane separation device to convey into the gap for separating whole blood from a blood donor selected from a population of blood donors, the whole blood of the selected blood donor having a known beginning hematocrit value that varies within the population of blood donors according to morphology of the selected blood donor,a drive element coupled to the membrane separation device to cause rotation of the rotatable one of the microporous membrane and the facing surface, andcontrol means including an input for receiving the known beginning hematocrit value of the selected blood donor, the control means being operative for commanding the inlet pump element and the drive element as a function of the known beginning hematocrit value to obtain concentrated red blood cells having an end hematocrit value that remains substantially constant for the population of blood donors despite variances in the known beginning hematocrit value according to morphology of the selected blood donor.
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Abstract
Blood separation systems and methods utilize a membrane separation device comprising a gap between a microporous membrane and a surface facing the microporous membrane, one of the microporous membrane and the surface being rotatable relative to the other to cause separation of whole blood in the gap into plasma and concentrated red blood cells. The systems and methods include an inlet pump element coupled to the membrane separation device to convey whole blood having a known beginning hematocrit value into the gap for separation. The systems and methods also include a drive element coupled to the membrane separation device to cause rotation of the rotatable one of the microporous membrane and the facing surface. The systems and methods command the inlet pump element and the drive element as a function of the known beginning hematocrit value. This command technique obtains concentrated red blood cells having a high end hematocrit value that remains substantially constant despite variances in the known beginning hematocrit value, and, in particular, when the known beginning hematocrit value is low.
141 Citations
25 Claims
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1. A blood separation system comprising
a membrane separation device comprising a gap between a microporous membrane and a surface facing the microporous membrane, one of the microporous membrane and the surface being rotatable relative to the other to cause separation of whole blood in the gap into plasma and concentrated red blood cells, an inlet pump element coupled to the membrane separation device to convey into the gap for separating whole blood from a blood donor selected from a population of blood donors, the whole blood of the selected blood donor having a known beginning hematocrit value that varies within the population of blood donors according to morphology of the selected blood donor, a drive element coupled to the membrane separation device to cause rotation of the rotatable one of the microporous membrane and the facing surface, and control means including an input for receiving the known beginning hematocrit value of the selected blood donor, the control means being operative for commanding the inlet pump element and the drive element as a function of the known beginning hematocrit value to obtain concentrated red blood cells having an end hematocrit value that remains substantially constant for the population of blood donors despite variances in the known beginning hematocrit value according to morphology of the selected blood donor.
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6. A blood separation system comprising
a membrane separation device comprising a gap between a microporous membrane and a surface facing the microporous membrane, one of the microporous membrane and the surface being rotatable relative to the other to cause separation of whole blood in the gap into plasma and concentrated red blood cells, an inlet pump element coupled to the membrane separation device to convey whole blood having a known beginning hematocrit value into the gap for separation, a drive element coupled to the membrane separation device to cause rotation of the rotatable one of the microporous membrane and the facing surface, and a control means coupled to the inlet pump element and the drive element including an input for receiving the known beginning hematocrit value, a processing element to generate an inlet pump command signal as a first function of the known beginning hematocrit value and a rotation command signal as a second function of the known beginning hematocrit value, and an output transmitting the inlet pump command signal to the inlet pump element and the rotation command signal to the drive element.
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13. A blood separation system comprising
a membrane separation device comprising a gap between a microporous membrane and a surface facing the microporous membrane, one of the microporous membrane and the surface being rotatable relative to the other to cause separation of whole blood in the gap into plasma and concentrated red blood cells, an inlet pump element coupled to the membrane separation device to convey whole blood having a known beginning hematocrit value into the gap for separation subject to a transmembrane pressure, a sensor for sensing the transmembrane pressure, a drive element coupled to the membrane separation device to cause rotation of the rotatable one of the microporous membrane and the facing surface, an outlet pump element coupled to the membrane separation device to convey concentrated red blood cells from the membrane separation device, and a control element coupled to the inlet pump element, the drive element, the outlet pump element, and the sensor including an input for receiving the known beginning hematocrit value, a processing element to generate an inlet pump command signal as a first function of the known beginning hematocrit value received by the input, a rotation command signal as a second function of the known beginning hematocrit value received by the input, and an outlet pump command signal as a third function of transmembrane pressure sensed by the sensor, an output transmitting the inlet pump command signal to the inlet pump element, the rotation command signal to the drive element, and the outlet pump command signal to the outlet pump element, and a red blood cell container having a characteristic beneficial to storage of red blood cells for at least twenty-four hours, the red blood cell container communicating with the outlet pump element to receive concentrated red blood cells conveyed from the separation device, the concentrated red blood cells having as a result of the first, second, and third functions an end hematocrit value that remains substantially constant despite variances in the known beginning hematocrit value received by the input.
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16. A blood separation system comprising
a membrane separation device comprising a gap between a microporous membrane and a surface facing the microporous membrane, one of the microporous membrane and the surface being rotatable relative to the other to cause separation of whole blood in the gap into plasma and concentrated red blood cells, a first pump operable at a variable command pumping rate, RATE1, to convey anticoagulated whole blood into the gap, the anticoagulated whole blood having a hematocrit HCTWB when entering the gap, a driver coupled to the membrane separation device to rotate the rotatable one of the membrane and surface at a variable command rate of rotation, ROTOR, to separate whole blood in the gap into plasma, which is passes from the gap through the membrane subject to a transmembrane pressure, and red blood cells, which remain in the gap, a sensor for sensing the transmembrane pressure, TMPSENSED, a second pump operable at a variable command pumping rate, RATE2, to convey red blood cells from the gap at a hematocrit HCTRBC, a controller coupled to the first pump, the second pump, the driver, and the sensor including an element for inputting HCTWB, and a processing element to operate the first pump, the second pump, and the driver to maintain HCTRBC at a desired value comprising an element that derives ROTOR according to a first function of HCTWB that increases ROTOR as HCTWB decreases, an element that derives RATE1 according to a second function of HCTWB that increases RATE1 as HCTWB increases, an element that derives a control value for transmembrane pressure, TMPset, according to a third function of HCTWB ; - ROTOR; and
RATE1, andan element that commands the driver to rotate the membrane at ROTOR while commanding the first pump to operate at RATE1 while commanding the second pump to operate at RATE2 to maintain TMPSENSED ≈
TMPset. - View Dependent Claims (17, 20, 21, 22, 23, 24, 25)
- ROTOR; and
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18. A blood separation system comprising
a membrane separation device comprising a gap between a microporous membrane and a surface facing the microporous membrane, one of the microporous membrane and the surface being rotatable relative to the other to cause separation of whole blood in the gap into plasma and concentrated red blood cells, a first pump operable at a variable command pumping rate, RATE1, to convey anticoagulated whole blood into the gap, the anticoagulated whole blood having a hematocrit HCTWB when entering the gap, a driver coupled to the membrane separation device to rotate the rotatable one of the membrane and the surface at a variable command rate of rotation, ROTOR, to separate whole blood in the gap into plasma, which is passes from the gap through the membrane subject to a transmembrane pressure, and red blood cells, which remain in the gap, a sensor for sensing the transmembrane pressure, TMPSENSED, a second pump operable at a variable command pumping rate, RATE2, to convey red blood cells from the gap at a hematocrit HCTRBC, a controller coupled to the first pump, the second pump, the driver and the sensor including an element for inputting HCTWB, and a processing element to operate the first pump, the second pump, and the driver to maintain HCTRBC at a desired value according to processing steps comprising deriving ROTOR according to a first function of HCTWB that increases ROTOR as HCTWB decreases, deriving RATE1 according to a second function of HCTWB that increases RATE1 as HCTWB increases, deriving a control value for transmembrane pressure, TMPset, according to a third function of HCTWB ; - ROTOR; and
RATE1, andcommanding the driver to rotate the membrane at ROTOR while commanding the first pump to operate at RATE1 while commanding the second pump to operate at RATE2 to maintain TMPSENSED ≈
TMPset. - View Dependent Claims (19)
- ROTOR; and
Specification