Methods and devices for processing blood

• US 7,824,355 B2
• Filed: 08/07/2008
• Issued: 11/02/2010
• Est. Priority Date: 10/08/2003
• Status: Active Grant

• Current Assignee: Terumo BCT, Inc. (Terumo Corporation)
• Original Assignee: Caridianbct Biotechnologies LLC (Baxter International Inc.)
• Inventors: Langley, Robert W., Van Waeg, Geert, Bainbridge, Marlene Adele, Felt, Thomas J.
• Primary Examiner(s): Deak; Leslie R.
• Assistant Examiner(s): MARCETICH, ADAM M
• Application Number:
  US12/187,988
• Publication Number:
  US 20090043237A1
• Time in Patent Office: 817 Days
• Field of Search: 604/4.01, 604/5.01, 604/6.16, 604/27, 604/118, 604/119, 422/44
• US Class Current: 604/4.01
• CPC Class Codes: A61M 1/304 Treatment chamber used as reservoir, e.g. centrifuge bowl or filter with movable membrane
• CPC Class Codes: A61M 1/3603 in the same direction
• CPC Class Codes: A61M 1/3639 Blood pressure control, pressure transducers specially adapted therefor
• CPC Class Codes: A61M 1/3656 Monitoring patency or flow at connection sites; Detecting disconnections
• CPC Class Codes: A61M 1/3693 using separation based on different densities of components, e.g. centrifuging
• CPC Class Codes: A61M 1/3696 with means for adding or withdrawing liquid substances during the centrifugation, e.g. continuous centrifugation

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.

Claims

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 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.

2. 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, 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.

3. 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.

4. The method of claim 3 wherein said return and removal flow rates are linearly correlated to said total blood volume of said subject.

5. The method of claim 4 wherein said return and removal flow rates increase with increasing total blood volume of said subject.

6. The method of claim 3 wherein said removal flow rate is provided by the expression:

Z_rem=(M_rem)×

(V_B)≦

Q_{rem max},

wherein Z_rem is the removal flow rate, M_rem is a removal flow rate slope, V_B is the total blood volume of said subject and Q_{rem max} is a maximum removal flow rate.

7. The method of claim 6 wherein M_rem is a value selected from the range of about 0.0066 min⁻

1 and about 0.05 min<sup>−

1</sup> and Q_{rem max} is a value selected from the range of about 100 ml min<sup>−

1</sup> to about 160 ml min<sup>−

1</sup>.

8. The method of claim 7 wherein Q_{rem max} is about 142 ml min⁻

1.

9. The method of claim 6 wherein M_rem is provided by the expression:

M_rem=(C_qr)×

(A_rem)

wherein C_qr is a selectably adjustable processing rate parameter, A_rem is a constant having a value selected from the range of about 0.01 min<sup>−

1</sup> to about 0.05 min<sup>−

1</sup> wherein the value of C_qr is selected to avoid the occurrence of infiltration of an access blood vessel of said subject.

10. The method of claim 3 wherein said return flow rate is provided by the expression:

Z_ret=(M_ret)×

(V_B)≦

Q_{ret max}

wherein Z_ret is the return flow rate, M_ret is a return flow rate slope, V_B is the total blood volume of said subject, and Q_{ret max} is a maximum return flow rate.

11. The method of claim 10 wherein M_ret is a value selected from the range of about 0.025 min⁻

1 and about 0.200 min<sup>−

1</sup> and Q_{ret max} is a value selected from the range of about 200 ml min<sup>−

1</sup> and about 400 ml min.<sup>−

1</sup>.

12. The method of claim 11 wherein Q_{ret max} is about 302 ml min.⁻

1.

13. The method of claim 10 wherein M_ret is provided by the expressions:

M_ret=(C_qr)×

(A_ret),

wherein C_qr is a selectably adjustable parameter, A_ret is a constant having a value selected from the range of about 0.05 min<sup>−

1</sup> to about 0.20 min<sup>−

1</sup>, and wherein the value of C_qr is selected to avoid discomfort of said subject.

14. The method of claim 3 wherein said subject is a human male and said total blood volume is determined using the expression:

V_B=604+(3.669×

10<sup>−

4</sup>)(L³)+(32.187)(W),

wherein L is the length of the subject in units of centimeters, W is the weight of the subject in units of kilograms and V_B is total blood volume in units of milliliters.

15. The method of claim 3 wherein said subject is a human female and said total blood volume is determined using the expression:

V_B=183+(3.561×

10<sup>−

4</sup>)(L³)+(33.069)(W),

wherein L is the length of the subject in units of centimeters, W is the weight of the subject in units of kilograms and V_B is total blood volume in units of milliliters.

16. The method of claim 3 wherein said removed blood is removed through an access needle and said return component is returned through said access needle.

17. The method of claim 3 wherein said removed blood is removed through a first access needle and said return component is returned through a second access needle.

18. The method of claim 3 wherein said blood is removed during a draw cycle and said portion of said return component is returned during a return cycle.

19. The method of claim 18 further comprising the step of sequentially repeating said draw and return cycles for a selected blood processing time.

20. The method of claim 3 wherein said processing step comprises the steps of:

separating said removed blood into a plurality of separated blood components including at least one collect component and said return component; and

collecting a collect component.

21. The method of claim 20 wherein said separating step comprises conducting said removed blood through a density centrifuge system.

22. The method of claim 20 wherein said separating step comprises conducting said removed blood through a centrifugal elutriation system.

23. The method of claim 20 wherein said collect component is plasma.

24. The method of claim 20 wherein said collect component is red blood cells.

25. The method of claim 20 wherein said collect component is white blood cells.

26. The method of claim 20 wherein said collect component is platelets.

27. The method of claim 3, further comprising the step of:

sequentially repeating said steps of removing blood and of returning blood for a selected blood processing time, whereby the removal flow rate is increased each draw cycle by a selected flow adjustment increment.