Methods and devices for processing blood
First Claim
1. A method of processing blood, comprising the steps of:
- determining the total blood volume of a subject undergoing a blood processing procedure;
removing blood from said subject at a removal flow rate thereby generating removed blood, wherein said removal flow rate is adjusted during operation of the blood processing procedure based on said total blood volume;
processing said removed blood, thereby generating processed blood including at least one return component; and
returning at least a portion of said return component to said subject at a return flow rate, wherein said return flow rate is adjusted during operation of the blood processing procedure based on said total blood volume of said subject.
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Abstract
Methods, devices and device components are presented for blood processing. Particularly, methods, devices and device components are presented for separating blood into blood components and collecting one or more separated blood components, which reduce the incidence of blood vessel infiltration and enhance donor comfort. In one aspect, the invention provides blood processing methods having a return flow rate which decreases systematically during a return time. In another aspect, the invention provides blood processing methods having a removal flow rate, return flow rate or both which are derived from a subject'"'"'s total blood volume. In another aspect, the present invention provides blood processing methods wherein the fraction by volume of removed blood corresponding to collected components is selected to optimize blood processing efficiency and enhance the purities of collected blood components.
107 Citations
66 Claims
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1. A method of processing blood, comprising the steps of:
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determining the total blood volume of a subject undergoing a blood processing procedure; removing blood from said subject at a removal flow rate thereby generating removed blood, wherein said removal flow rate is adjusted during operation of the blood processing procedure based on said total blood volume; processing said removed blood, thereby generating processed blood including at least one return component; and returning at least a portion of said return component to said subject at a return flow rate, wherein said return flow rate is adjusted during operation of the blood processing procedure based on said total blood volume of said subject. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64)
wherein the fraction by volume of said removed blood comprising said collected component is selected to prevent contamination of said collect component with red blood cells.
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50. The method of claim 49 further comprising the step of sequentially repeating said draw and return cycles for a selected blood processing time.
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51. The method of claim 49 further comprising the step of adding an anticoagulant agent to said removed blood.
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52. The method of claim 49 wherein said blood separation system comprises a density centrifuge operationally connected to a centrifugal elutriation system.
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53. The method of claim 49 wherein said removed blood has a first hematocrit, Hrem, and said recirculated component has a second hematocrit, Hrecir, and wherein the weighted average of the hematocrit of said removed blood and the hematocrit of said recirculated component is less than or equal
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54. The method of claim 49 wherein the weighted average of the hematocrit of said removed blood and the hematocrit of said recirculated component is less than 70%.
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55. The method of claim 49 wherein said removed blood and said recirculated component are conducted through said blood processing system at a first rate, R1, during said return cycle and wherein said removed blood and said recirculated component are conducted through said blood processing system at a second rate, R2, during said draw cycle, wherein said removed blood has a first hematocrit, Hrem, and said recirculated component has a second hematocrit, Hrecir, wherein tdraw is the duration of the draw cycle and tret is the duration of the return cycle, wherein the fraction by volume of said removed blood comprising said collected component, Fcmax, is provided by the equation:
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56. The method of claim 55 wherein b is a value selected from the range of about 0.46 to about 0.85.
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57. The method of claim 55 wherein D is a value selected from the range of about 0.60 to about 0.73.
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58. The method of claim 55 wherein Cr is a value selected from the range of about 0.4 to about 0.6.
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59. The method of claim 49 wherein said collect component is platelets.
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60. The method of claim 49 wherein said collect component is plasma.
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61. The method of claim 49 wherein said collect component is white blood cells.
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62. The method of claim 49 wherein said collect component is white blood cells and platelets.
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63. The method of claim 49 wherein said removed blood is removed through an access needle and said return component is returned through said access needle.
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64. The method of claim 49 wherein said removed blood and said recirculated component are conducted through said blood processing system at a first rate, R1, during said return cycle and wherein said removed blood and said recirculated component are conducted through said blood processing system at a second rate, R2, during said draw cycle, wherein said removed blood has a first hematocrit, Hrem, and said recirculated component has a second hematocrit, Hrecir, wherein tdraw is the duration of the draw cycle and tret is the duration of the return cycle, wherein Vsvn is the volume of removed blood required to fill a fixed volume return reservoir and Vsvnr is the volume of the recirculated component recirculated each draw and return cycle, wherein the fraction by volume of said removed blood comprising said collected component, Fcmax, is provided by the equation:
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65. A method of processing blood, comprising the steps of:
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determining the total blood volume of a subject undergoing a blood processing procedure; removing blood from said subject at a selected removal flow rate thereby generating removed blood, wherein said selected removal flow rate is adjusted during operation of the blood processing procedure based on said total blood volume; processing said removed blood, thereby generating processed blood including at least one return component; and returning at least a portion of said return component to said subject at a return flow rate.
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66. A method of processing blood, comprising the steps of:
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determining the total blood volume of a subject undergoing a blood processing procedure; removing blood from said subject, thereby generating removed blood; processing said removed blood, thereby generating processed blood including at least one return component; and returning at least a portion of said return component to said subject at a selected return flow rate, wherein said selected return flow rate is adjusted during operation of the blood processing procedure based on said total blood volume of said subject.
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Specification