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Publication numberCA2483931 A1
Publication typeApplication
Application numberCA 2483931
PCT numberPCT/US2003/012888
Publication date13 Nov 2003
Filing date24 Apr 2003
Priority date3 May 2002
Also published asCA2483931C, DE60314413D1, DE60314413T2, EP1509326A2, EP1509326B1, US7223346, US7470371, US7837884, US8187477, US8474630, US8950586, US20030205538, US20050186120, US20050196874, US20070034579, US20090101599, US20110065183, US20120230890, US20130294983, WO2003092894A2, WO2003092894A3
Publication numberCA 2483931, CA 2483931 A1, CA 2483931A1, CA-A1-2483931, CA2483931 A1, CA2483931A1, PCT/2003/12888, PCT/US/2003/012888, PCT/US/2003/12888, PCT/US/3/012888, PCT/US/3/12888, PCT/US2003/012888, PCT/US2003/12888, PCT/US2003012888, PCT/US200312888, PCT/US3/012888, PCT/US3/12888, PCT/US3012888, PCT/US312888
InventorsRandel Dorian, Richard Wood Storrs, Scott King
ApplicantHanuman Llc, Randel Dorian, Richard Wood Storrs, Scott King
Export CitationBiBTeX, EndNote, RefMan
External Links: CIPO, Espacenet
Method and apparatus for isolating platelets from blood
CA 2483931 A1
Abstract
A platelet collection device comprising a centrifugal spin-separator container with a cavity having a longitudinal inner surface. A float in the cavity has a base, a platelet collection surface above the base, an outer surface. The float density is below the density of erythrocytes and above the density of plasma. The platelet collection surface has a position on the float which places it below the level of platelets when the float is suspended in separated blood. During centrifugation, a layer of platelets or buffy coat collects closely adjacent the platelet collection surface. Platelets are then removed from the platelet collection surface. Movement of a float having a density greater than whole blood through the sedimenting erythrocytes releases entrapped platelets, increasing the platelet yield.
Description  available in
Claims(22)
1. A blood platelet separation device comprising a centrifugal spin-separator container having a cavity with a longitudinal inner surface;
a float positioned within the cavity, the float having a base and a platelet collection surface above the base, the float having an outer surface;
the float having a density less than the density of erythrocytes and greater than the density of plasma; and the platelet collection surface positioned on the float at a level which places it immediately below the level of platelets after centrifugation.
2. A blood platelet separation device of Claim 1 wherein the cavity has a cylindrical inner surface and the float has a cylindrical outer surface.
3. A platelet separation device of Claim 2 wherein the distance between the outer surface of the float and the inner surface of the tube is less than 0.5 mm.
4. A blood platelet collection device of Claim 1 comprising a flexible inner tube having an inner surface and a float positioned within the flexible inner tube;
the float having an outer surface in sealing engagement with the inner surface of the flexible tube in a neutral pressure condition, the sealing engagement preventing movement of fluid between the outer surface of the float and the inner surface of the flexible tube in a neutral pressure condition;
the outer surface of the float disengaging from contact with the inner surface of the flexible tube in an elevated pressure condition, thus enabling movement of fluid between the outer surface of the float and the inner surface of the flexible tube in the elevated pressure condition and movement of the float within the cylinder;

the float having a platelet receptor cavity with a platelet collection surface positioned immediately below the level of the platelet layer in separated blood after centrifugation; and the float having a channel communicating with the platelet receptor cavity for removing separated platelets after centrifugation.
5. A platelet collection device of Claim 4 wherein the float comprises a proximal segment having a distal surface and a distal segment having a proximal surface opposed to the distal surface, the distal surface and the proximal surfaces defining the platelet receptor cavity.
6. A platelet collection device of Claim 5 wherein the outer container includes a port for introducing blood into the inner tube at the beginning of a platelet separation process and for removing platelets from the inner tube at the end of the platelet separation process.
7. A platelet collection device of Claim 6 wherein the port includes a syringe coupling Luer locking device.
8. A platelet collection device of Claim 4 wherein the outer container has an inner surface for restraining expansion of the inner tube during centrifugation.
9. A blood platelet separation device of Claim 1 wherein the outer surface of the float is in sliding engagement with the inner surface of the cavity.
10. A blood platelet separation device of Claim 9 wherein the float comprises a unitary structure with a proximal segment having a distal surface and a distal segment having a proximal surface opposed to the distal surface, the distal surface and the proximal surfaces defining a platelet receptor cavity, the upper surface of the platelet receptor cavity defining the platelet collection surface.
11. A platelet collection device of Claim10 wherein the centrifugal spin-separator is a substantially rigid tube, and the float comprises a proximal segment having a distal surface, and a distal segment having a proximal surface opposed to the distal surface, the distal surface and the proximal surfaces defining the platelet receptor cavity.
12. A platelet collection device of Claim 1 wherein a top surface of the float constitutes the platelet collection surface, and the device includes a plunger positioned above the float and substantially axially concentric with the float and the cavity, the plunger having a cylindrical outer surface which is spaced from the inner surface of the cavity;
the bottom of the plunger defining a plasma expressing surface opposed to the platelet collection surface; and a fluid removal passageway extending through the plunger to the plasma expressing surface.
13. A platelet collection device of Claim 12 having at least one seal between the outer surface of the plunger and the inner surface of the cavity, the seal being positioned in sealing engagement with the outer and inner surfaces.
14. A platelet collection device of Claim 11 wherein the top of the float includes a stop surface positioned above the plasma collection surface.
15. A platelet collection device of Claim 10 wherein the centrifugal spin-separator is a substantially rigid tube, and the float has a cylindrical outer surface, the float comprising a proximal segment having a distal surface, and a distal segment having a proximal surface opposed to the distal surface, the distal surface and the proximal surfaces defining the platelet receptor cavity.
16. A process for separating platelets from whole blood with a centrifugal spin-separator container having a cavity with a longitudinal inner surface, a proximal end and a distal end, including a float positioned within the cavity, the float having a base and a platelet collection surface above the base, the float having an outer surface, the distance between the outer surface of the float and the inner surface of the tube being less than 0.5 mm, the float having a density less than the density of erythrocytes and greater than the density of plasma, the platelet collection surface has a position on the float which places it immediately below the level of platelets when the float is suspended in fully separated blood, the process comprising the steps of a) introducing an amount of whole blood into the cavity, the amount of whole blood being sufficient to position the level of platelets following centrifugation at the position of the platelet collection surface, b) subjecting the centrifugal spin-separator container to centrifugation forces in the axial direction toward the distal end, whereby erythrocytes are caused to concentrate at the distal end, plasma to collect toward the proximal end, and platelets to collect closely adjacent the platelet collection surface, and c) removing platelets from the platelet collection surface.
17. A process of Claim 16 wherein the float has a density greater than whole blood, and under the centrifugal forces, the float moves toward the proximal end through the sedimenting erythrocytes, releasing entrapped platelets to allow them to collect closely adjacent the platelet collection surface, whereby the amount of platelets available for removal is increased.
18. A process of Claim 16 wherein the device includes a plunger positioned above the float and substantially axially concentric with the float and the cavity, the plunger having a cylindrical outer surface which is spaced from the inner surface of the cavity; the bottom of the plunger defining a plasma expressing surface opposed to the platelet collection surface;
and a fluid removal passageway extending through the plunger through the plasma expressing surface, wherein the process includes the steps of a) introducing an amount of whole blood into the cavity, the amount of whole blood being sufficient to position the level of platelets following centrifugation at the position of the platelet collection surface, b) subjecting the centrifugal spin-separator container to centrifugation forces in the axial direction toward the distal end, whereby blood cells are caused to concentrate at the distal end, plasma to collect toward the proximal end, and platelets to collect on the platelet collection surface, c) advancing the plunger in an axial direction against the top of the plasma until the plasma expressing surface is positioned near the platelet collection surface and spaced apart therefrom, d) extending a platelet extraction tube through the fluid removal passageway until the end thereof contacts the platelet layer; and e) removing a platelet concentrate through the platelet extraction tube.
19. A process of Claim 18 wherein the top of the float includes a stop surface positioned above the plasma collection surface and the plunger is advanced in an axial direction until the plasma expressing surface contacts the stop surface.
20. A process for separating platelets from whole blood with a flexible inner tube having an inner surface, a proximal end, and a distal end; a float positioned within the flexible inner tube; the float having an outer surface in sealing engagement with the inner surface of the flexible tube in a neutral pressure condition, the sealing engagement preventing movement of fluid between the outer surface of the float and the inner surface of the flexible tube in a neutral pressure condition; the float having a platelet receptor with a platelet collection surface immediately below the level of the platelets in separated blood after centrifugation;
the process comprising the steps of a) introducing an amount of whole blood into the inner tube under elevated pressure, the amount of whole blood being sufficient to position the level of platelets following centrifugation closely adjacent the level of the platelet support surface, b) subjecting the tube to centrifugation forces in the axial direction toward the distal end, causing the outer surface of the float to disengage from the inner surface of the flexible tube, enabling movement of fluid between the outer surface of the float and the inner surface of the flexible tube and movement of the float within the tube; can causing blood cells to concentrate at the distal end, plasma to collect at the proximal end, and platelets to collect at a level closely adjacent the platelet collection surface; and c) removing platelets from the platelet collection surface.
21. A process of Claim 20 wherein the inner tube is positioned in a rigid outer tube coaxial therewith, the outer tube having an inner surface for limiting expansion of the inner tube wall during centrifugation.
22. A process for separating platelets from whole blood by centrifugation in a container having a proximal end and a distal end, including a float positioned within the cavity, the float having a density less than the density of erythrocytes and greater than the density of whole blood, the process comprising the steps of a) introducing whole blood into the cavity, b) subjecting the container to centrifugation forces in the axial direction toward the distal end, whereby erythrocytes are caused to concentrate at the distal end, plasma to collect toward the proximal end, and platelets to collect in a platelet layer between the erythrocyte and the plasma collections, wherein during application of the centrifugal forces, the float moves through the sedimenting erythrocytes, the movement of the float releasing entrapped platelets, allowing them to collect in the platelet layer, and c) removing platelets from the platelet collection surface.
Classifications
International ClassificationG01N33/49, B01D21/00, A61K35/00, B01L99/00, B01L3/14, A61M1/02, B04B5/02, B01D21/26
Cooperative ClassificationB01D2221/10, A61M2202/0427, B01L3/50215, B01D21/262, B01D21/0012, B01L2200/026, A61K35/00, B01L2400/0633, G01N33/49, Y10T436/25375, A61M1/3693
European ClassificationB01L3/50215, B01D21/00F, B01D21/26, A61M1/36Z
Legal Events
DateCodeEventDescription
23 Apr 2008EEERExamination request