Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
  • B04B—CENTRIFUGES
  • B04B5/00—Other centrifuges
  • B04B5/04—Radial chamber apparatus for separating predominantly liquid mixtures, e.g. butyrometers
  • B04B5/0407—Radial chamber apparatus for separating predominantly liquid mixtures, e.g. butyrometers for liquids contained in receptacles
  • B04B5/0428—Radial chamber apparatus for separating predominantly liquid mixtures, e.g. butyrometers for liquids contained in receptacles with flexible receptacles

Definitions

• This invention is in the field of blood processing and more particularly relates to the separation of blood, including whole blood, into two or more components.
• a flexible, disposable blood processing bag is mounted in a contoured pro cessing chamber consisting of a pair of support shoes within the centrifuge rotor.
• the contoured chamber is designed to support the blood bag in a position whereby separated blood components traverse a short distance in the process of separation.
• a flexible diaphragm or displacer bag is also positioned in the blood processing chamber of the rotor in a complementary relationship to the flexible disposable blood bag.
• the flexible diaphragm can be moved to apply pressure to the disposable blood bag in response to the introduction or expulsion, respectively, of a displacement fluid while the centrifuge rotor is either rotating or stationary. Additionally, displacer fluid can be expelled by pumping blood into the flexible, disposable blood processing bag.
• the support shoes are held in a closed position by a support shoe holder having two side walls with curved lips which extend around the side edges of the shoes and are intended to maintain the shoes in a fixed side-by-side relationship with one another.
• the invention comprises an apparatus and process for separating blood into components thereof in a centrifuge.
• a pair of processing bags one containing whole blood to be processed .and one containing displacer fluid are disposed in contacting relationship within the contours of a pair of support shoes.
• the support shoes are placed in the centrifuge rotor in an upright position adjacent the cylindrical outer wall of the rotor.
• a pressure plate is placed against the inner wall of the support shoe nearest the center of rotation of the rotor. The mass of this pressure plate is critical. It must be specifically chosen to at least equalize the inner pressure generated by the processing bags.
• the mass of the pressure plate is correctly chosen to at least equalize the inner pressure of the blood bag at, say, a rotor speed of one revolution per minute (r.p.m.), it will at least equalize at all rotor speeds.
• a pressure plate slightly greater in mass than that required to exactly equalize the pressure of the blood bag is used. This will guarantee closure of the shoes with practical variations in software mounting, etc.
• the mass of the pressure plate is greatly in excess of that required to balance or equalize the inner pressure generated by the blood bag under the influence of centrifugal force, then it is possi ble that the shoes, which are usually made of moderately rigid plastics, such as, foamed poly urethane, will collapse under the excess pressure exerted by the weight.
• FIG. 1 is a plan view of a centrifuge in accordance with the invention.
• FIG. 2 is a partially cut-away side elevational view of the centrifuge rotor of FIG. 1.
• FIG. 1 and 2 there is shown a blood processing bag 150 and a flexible displacement pouch 154, which are held in a complementary relationship in a contoured processing chamber formed between a pair of support shoes 152 and 156.
• Support shoes 152 and 156 can be formed from polymers such as foamed polyurethane. In some eases, it will be preferred to have transparent support shoes, in which case they can be formed from transparent polymers, such as polymethyl methacrylate. Many other materials could be used in forming these support shoes, of course.
• Displacer fluid pouch 154 is mounted on shoe 156 by inserting pegs (not shown) through registration holes in the peripheral seal of pouch 154.
• Pro cessing bag 150 is similarly mounted on pegs on shoe 156.
• Shoes 156 and 152 are then closed together so that the pegs extend into matching holes in the edge of shoe 152.
• shoes 156 and 152 form an enclosed contoured processing chamber containing blood processing bag 150 and fluid displacer pouch 154, which are positioned so that their contacting planar panels assume a complementary relationship.
• Bag 150 is supported by contoured shoe 152 so that bag 150 has an inner surface having a slightly greater slope at its upper portion than at its lower portion. This increased slope provides more efficient emptying during operation.
• Displacer pouch 154 is contoured into a complementary shape by support shoe 156.
• Tubing 158 connects bag 150 to receiver container 61.
• pouch 154 serves as a displacement chamber having a fluid-actuated dia phragm.
• displacer fluid is introduced into pouch 154, via conduit 134, it expands to force blood or blood components out of processing bag 150.
• an equal volume of displacer fluid is forced from the flexible displacement pouch 154.
• Pressure plate 90 is mounted adjacent shoe 152 on brackets (not shown) .
• Pressure plate 90 has sufficient mass to exert an outward force (as shown by the arrow 12 in Fig. 2) which equalizes or is slightly greater than the force exerted inwardly (as shown by arrow 10 in Fig. 2) by the fluid in bag 150 when both are rotating at the same speed.
• the mass of the plate 90 once correctly established for a given rotational velocity will balance the pressure from the bag at all velocities. This may be deduced from the following analysis:
• the force F P exerted by the plate against the shoe is equal to the mass of the plate M times the acceleration ( ⁇ 2 r M ) where r m is the radius of the plate from the center of rotation or:
• Equation V the value of is independent of the rotational velocity of the centrifuge rotor. Also, given the values of ⁇ , r b , ⁇ m and A, the mass of the plate M can be readily calculated.
• Centrifuge motor 102 (Fig. 1) is activated to cause centrifuge rotor 94 to rotate at a speed sufficient to separate withdrawn whole blood contained in pro cessing bag 150 into a plasma-rich component and a plasma-poor component.
• a typical rotor speed for example, might be about 4800 r.p.m.
• plasma-poor component which in this case consists primarily of red blood cells, white blood cells and platelets, moves towards the radially outer face of disposable blood processing bag 150.
• Plasma-rich component is expressed through conduit 158 of the flexible blood processing bag 150 and is transported to receiver container 61 as rotor 94 continues spinning and further separation occurs.

Landscapes

• Centrifugal Separators (AREA)
• External Artificial Organs (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=22574725

Family Applications (1)

Country Status (7)

Cited By (5)

Families Citing this family (31)

Citations (4)

Family Cites Families (3)

• 1980
  • 1980-06-16 US US06/159,932 patent/US4304357A/en not_active Expired - Lifetime
• 1981
  • 1981-06-15 ES ES503053A patent/ES8303122A1/es not_active Expired
  • 1981-06-16 IT IT8167830A patent/IT8167830A0/it unknown
  • 1981-06-16 EP EP19810901957 patent/EP0053182A4/en not_active Ceased
  • 1981-06-16 JP JP56502381A patent/JPS6363030B2/ja not_active Expired
  • 1981-06-16 WO PCT/US1981/000811 patent/WO1981003626A1/en not_active Ceased
• 1982
  • 1982-02-15 DK DK64682A patent/DK64682A/da not_active Application Discontinuation

Patent Citations (4)

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