Systems and methods for on line collecting and resuspending cellular-rich blood products like platelet concentrate

• US 5,427,695 A
• Filed: 07/26/1993
• Issued: 06/27/1995
• Est. Priority Date: 07/26/1993
• Status: Expired due to Term

• Current Assignee: Fenwal Incorporated (Fresenius SE & Co. KGaA)
• Original Assignee: Baxter International Inc.
• Inventors: Brown, Richard I.
• Primary Examiner(s): KIM, SUN U
• Application Number:
  US08/097,293
• Time in Patent Office: 701 Days
• Field of Search: 210/97, 210/109, 210/134, 210/143, 210/145, 210/147, 210/195.1, 210/198.1, 210/205, 210/208, 210/252, 210/257.1, 210/325, 210/359, 210/360.1, 210/364, 210/365 , 210/388, 210/512.1, 210/805, 210/767, 210/780, 210/782, 210/787, 210/789, 210/806, 604/4, 604/5, 604/6, 604/410, 494/7, 494/37
• US Class Current: 210/805
• CPC Class Codes: A61M 1/30 Single needle dialysis ; Reciprocating systems, alternately withdrawing blood from and returning it to the patient, e.g. single-lumen-needle dialysis or single needle systems for hemofiltration or pheresis
• CPC Class Codes: A61M 1/302 having a reservoir for withdrawn untreated blood
• CPC Class Codes: A61M 1/303 having a reservoir for treated blood to be returned
• 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
• CPC Class Codes: A61M 2202/0071 product to be retained or harvested, e.g. by pheresis
• CPC Class Codes: A61M 2202/0427 Platelets; Thrombocytes
• CPC Class Codes: B01D 21/262 by using a centrifuge
• CPC Class Codes: B01D 21/302 Active control mechanisms with external energy, e.g. with solenoid valve
• CPC Class Codes: B01D 2221/08 Mobile separation devices
• CPC Class Codes: B01D 2221/10 Separation devices for use in medical, pharmaceutical or laboratory applications, e.g. separating amalgam from dental treatment residues
• CPC Class Codes: B04B 2005/045 having annular separation channels
• CPC Class Codes: B04B 5/0442 with means for adding or withdrawing liquid substances during the centrifugation, e.g. continuous centrifugation

Abstract

Systems and methods resuspend cellular-rich concentrates of blood by rocking the separation chamber to create variable agitation forces within the separation chamber. The systems and methods also add resuspension fluids to aid the resuspension.

Claims

1. A method for collecting a resuspended platelet-rich concentrate comprising the steps of

(a) rotating a separation chamber about an axis to create centrifugal forces within the chamber, while:

(i) continuously conveying a suspension of platelets into the separation chamber for separation in response to the centrifugal forces into a platelet-rich concentrate and a platelet-poor component,

(ii) continuously conveying the platelet-poor component from the separation chamber, leaving the platelet-rich concentrate behind in the separation chamber, and

(iii) continuously collecting a predetermined portion of the platelet-poor component in a reservoir,

(b) terminating rotation of the separation chamber and the conveyance of platelet suspension into the separation chamber when a desired yield of platelet-rich concentrate occupies the chamber,

(c) removing about one-half of the fluid volume occupying the chamber by conveying platelet-poor component from the separation chamber to the reservoir,

(d) rocking the separation chamber, with about one-half of its fluid volume removed, to create intensified variable agitation forces within the separation chamber,

(e) returning platelet-poor component from the reservoir to the chamber, while rocking the separation chamber, in a volume sufficient to essentially replace the fluid volume removed in step (c), to thereby at least partially resuspend platelet-rich concentrate within the separation chamber in response to the agitation forces,

(f) conveying a partial volume of platelet-rich concentrate, resuspended in returned platelet-poor component, from the separation chamber to a collection container, leaving a remaining volume of platelet-rich concentrate occupying the separation chamber, and

repeating steps (c) to (f) in succession until substantially all of the platelet-rich concentrate is resuspended with returned platelet-poor component and is conveyed to the collection container.

2. A method for collecting a resuspended platelet-rich concentrate comprising the steps of

(a) rotating a separation chamber about an axis to create centrifugal forces within the chamber, while:

(i) continuously conveying a suspension of platelets into the separation chamber for separation in response to the centrifugal forces into a platelet-rich concentrate and a platelet-poor component,

(ii) continuously conveying the platelet-poor component from the separation chamber, leaving the platelet-rich concentrate behind in the separation chamber, and

(iii) continuously collecting a predetermined portion of the platelet-poor component in a reservoir,

(b) terminating rotation of the separation chamber and the conveyance of platelet suspension into the separation chamber when a desired yield of platelet-rich concentrate comprising about 4.0×

10¹¹ platelets occupies the separation chamber,

(c) removing about one-half of the fluid volume occupying the chamber by conveying platelet-poor component from the separation chamber to the reservoir,

(d) rocking the separation chamber, with about one-half of its fluid volume removed, to create intensified variable agitation forces within the separation chamber,

(e) returning platelet-poor component from the reservoir to the chamber, while rocking the separation chamber, in a volume sufficient to essentially replace the fluid volume removed in step (c), to thereby at least partially resuspend platelet-rich concentrate within the separation chamber in response to the agitation forces,

(f) conveying a partial volume of platelet-rich concentrate, resuspended in returned platelet-poor component, from the separation chamber to a collection container, leaving a remaining volume of platelet-rich concentrate occupying the separation chamber, and

repeating steps (c) to (f) in succession until substantially all of the platelet-rich concentrate is resuspended with about 200 ml of returned platelet-poor component and conveyed to the collection container.