Centrifuge

Patent metadata

Field	Value
Publication number	US-11167292-B2
Application number	US-202016833743-A
Country	US
Kind code	B2
Filing date	Mar 30, 2020
Priority date	Nov 19, 2010
Publication date	Nov 9, 2021
Grant date	Nov 9, 2021

Abstract

Centrifuges are useful to, among other things, remove red blood cells from whole blood and retain platelets and other factors in a reduced volume of plasma. Platelet rich plasma (PRP) and or platelet poor plasma (PPP) can be obtained rapidly and is ready for immediate injection into the host. Embodiments may include valves, operated manually or automatically, to open ports that discharge the excess red blood cells and the excess plasma into separate receivers while retaining the platelets and other factors in the centrifuge chamber. High speeds used allow simple and small embodiments to be used at the patient's side during surgical procedures. The embodiments can also be used for the separation of liquids or slurries in other fields such as, for example, the separation of pigments or lubricants.

First claim

What is claimed is:

1. A method of isolating and concentrating a fraction of a biologic liquid mixture, the method comprising the steps of:
a. providing a centrifuge comprising:
i. a chamber comprising a barrel having a longitudinal axis, a first end, a second end, and a sidewall extending between said second end and said first end, wherein said first end has a diameter smaller than the diameter of said second end, wherein at least a portion of said sidewall is transparent, and wherein the sidewall extends in a taper from the second end to the first end,
iii. a first port provided in said chamber at a first radial distance from said longitudinal axis, and in fluid communication with a first valve by a first passage,
iv. a second port provided in said chamber at a second radial distance from said longitudinal axis and in fluid communication with a second valve by a second passage, with said second radial distance being less than said first radial distance,
v. a motor to rotate said chamber about the longitudinal axis;

b. introducing a sample of a biologic liquid mixture into the chamber, wherein the sample comprises constituents having at least two different specific gravities;
c. rotating said chamber about said longitudinal axis, and separating said sample by specific gravity into a first fraction and a second fraction;
d. selectively opening said first valve to eject at least a portion of said first fraction from said chamber through said first port, thereby leaving a residual of said sample in said chamber; and
e. selectively opening said second valve after the opening of said first valve, to eject at least a portion of said residual of said sample from said chamber through said second port.

2. The method of claim 1 , further comprising the step of:
f. collecting at least a portion of said sample remaining within said chamber.

3. The method of claim 1 , further comprising between step d and step e, the step of monitoring an interface between said first fraction and said second fraction through said sidewall.

4. The method of claim 1 , further comprising between step d and step e, the step of detecting an interface occurring between separated constituents of said sample by at least one automatic detector.

5. The method of claim 1 , further comprising between step d and step e, the step of closing said first valve.

6. The method of claim 3 , further comprising between step d and step e, the step of closing said first valve.

7. The method of claim 4 , further comprising between step d and step e, the step of closing said first valve.

8. The method of claim 1 , wherein said sidewall extends in a uniform taper from said second end to said first end.

9. The method of claim 1 , wherein said chamber further comprises an annular wedge located within said barrel and projecting from second end toward the first end, said annular wedge having a wall located adjacent said sidewall of said barrel to define therebetween a circumferential channel.

10. The method of claim 1 , wherein said biologic liquid mixture is blood and said separation of said fractions results in one or more of: at least a 6.3 platelet concentration factor; at least 87% platelet recovery; and at least 92% of red blood cells removed from said biologic liquid mixture.

11. The method of claim 9 , wherein the first passage is in fluid communication with the circumferential channel.

12. The method of claim 11 , wherein the circumferential channel comprises a restriction configured to at least partially restrict fluid flow into the circumferential channel over some portion of the circumferential channel.

13. The method of claim 12 , wherein the restriction is configured to restrict fluid flow into the circumferential channel in a direction from a surface of the wedge that is nearest the first end towards the first passage.

14. The method of claim 12 , wherein the restriction is configured to restrict fluid flow into the circumferential channel over from about 20 to 180 degrees of the circumference of the circumferential channel.

15. The method of claim 14 , wherein the restriction is configured to restrict fluid flow into the circumferential channel in a direction from a surface of the wedge that is nearest the first end towards the first passage.

16. The method of claim 12 , wherein the restriction extends from the wall of the wedge toward the sidewall of the barrel.

17. The method of claim 15 , wherein the restriction extends from the wall of the wedge toward the sidewall of the barrel.

18. The method of claim 12 wherein the restriction is configured to provide a variable reduction in the width of the circumferential channel.

19. The method of claim 15 , wherein the greatest restriction into the circumferential channel is at the portion of the circumferential channel nearest the first port.

20. The method of claim 15 , wherein the fluid flow in a direction circumferentially around the circumferential channel is unrestricted over at least a portion of the height of the wall of the annular wedge.

Assignees

• Dsm Ip Assets Bv

Inventors

• Nash John E
• Fisher William T
• Evans Douglas G

Classifications

• A61M1/3696

  with means for adding or withdrawing liquid substances during the centrifugation, e.g. continuous centrifugation · CPC title

• B04B2005/0485

  with a displaceable piston in the centrifuge chamber · CPC title

• B04B7/08

  Rotary bowls (centrifugal casting machines B22D) · CPC title

• A61M1/3693

  using separation based on different densities of components, e.g. centrifuging · CPC title

• B01D21/34

  Controlling the feed distribution; Controlling the liquid level {; Control of process parameters} · CPC title