Method and apparatus for the continuous fractionation of biological fluids

<u>Technical Field of the Invention</u>

The present invention generally relates to methods and apparatus for separating a fluid into its components, for example, a biological or sensitive fluid such as blood, and specifically to methods and apparatus that use centrifugal force to separate a fluid into its components by density so as to improve the component yield. One example is described in <patcit id="pcit0001" dnum="EP297216A"><text>EP297216</text></patcit>.

<u>Background Art</u>

With the advance of medical sciences, it has become possible to treat a patient's blood in closed-loop processes, returning the patient's own treated blood back to him in one medical treatment. An example of such processes include external treatment methods for diseases in which there is a pathological increase of lymphocytes, such as cutaneous T-cell lymphoma or other diseases affecting white blood cells. In such methods, the patient's blood is irradiated with ultraviolet light in the presence of a chemical or an antibody. Ultraviolet light affects the bonding between the lymphocytes and the chemical or antibody that inhibits the metabolic processes of the lymphocytes.

During one of these medical treatments, a centrifuge bowl, such as, for example, a Latham bowl, as shown in <patcit id="pcit0002" dnum="US4303193A"><text>U.S. Patent No. 4,303,193</text></patcit>, expressly incorporated by reference in its entirety herein, separates blood into red blood cells ("RBCs") and buffy coat. The Latham bowl is a blood component separator that has been used for some time in the medical apheresis market as well as in innovative medical therapies such as extracorporeal photopheresis (ECP). <patcit id="pcit0003" dnum="WO9736581A"><text>PCT Applications WO 97/36581</text></patcit> and <patcit id="pcit0004" dnum="WO9736634A"><text>WO 97/36634</text></patcit>, and <patcit id="pcit0005" dnum="US4321919A"><text>U.S. Patent Nos. 4,321,919</text></patcit>; <patcit id="pcit0006" dnum="US4398906A"><text>4,398,906</text></patcit>; <patcit id="pcit0007" dnum="US4428744A"><text>4,428,744</text></patcit>; and <patcit id="pcit0008" dnum="US4464166A"><text>4,464,166</text></patcit> provide descriptions of extracorporeal photopheresis.

The Latham bowl efficiency is often measured by the white blood cell ("WBC") "yield," which is typically about 50%. Yield is defined as the percentage of cells collected versus the number processed. When compared to other types of whole blood separators, this high yield enables the Latham bowl separator to collect much larger volumes of WBCs while processing much less whole blood from the donor patient. However, a major drawback to the Latham bowl separator is that the separation process must be repeatedly stopped to remove the packed RBCs and plasma once they fill the inside of the bowl, creating a "batch-type" process. Although the Latham bowl separator has a high volume yield, the constant filling and emptying of this bowl wastes time; thus, the process is considered less efficient with respect to time. Additionally, the Latham bowl requires a rotating seal, which is expensive and difficult to manufacture.

An additional drawback of centrifugal processing apparatus has been their high cost of manufacture due to strict tolerances, rotating seals, and extensive manufacturing processes.

<u>Disclosure of Invention</u>

The invention is defined by the appended claims. An object of the present invention is to provide methods and apparatus for separating a fluid, such as blood or other biological fluid, into its components. An additional object is to increase the efficiency of current fluid separation processes by decreasing the time necessary to separate out a desired amount of a fluid component from the fluid. Yet other objects of the present invention are to treat a patient more efficiently, to improve a photopheresis process, to improve a platelet removal process, or to create a more efficient manufacture of a centrifuge bowl. Still another object of the present invention may include improved or more elegant rotation of a centrifuge bowl. An additional object of the present invention is to separate and remove targeted cells by their specific gravity. Another object of the present invention is to eliminate the need to perform fluid separation processes in "batch" form. A still further object of the present invention is to increase the percent yield of a desired fluid component from a fluid being separated.

Additionally, the present invention solves the inadequacies of the prior art by being able to continuously separate fluid components without interrupting the process to empty a centrifuge bowl and remove a separated component. Thus, the present invention eliminates batch processing and other Latham bowl batch-type techniques.

In a particular embodiment of the present invention, a centrifuge bowl may be used in conjunction with a photopheresis process. In extracorporeal photopheresis, for example, there are three phases including 1) the collection of a buffy coat fraction (leukocyte-enriched), 2) irradiation of the collected buffy coat fraction, and 3) reinfusion of the treated white blood cells. Extracorporeal photopheresis may be utilized to treat numerous diseases including Graft-versus-Host disease, Rheumatoid Arthritis, Progressive Systematic Sclerosis, Juvenile Onset Diabetes, Inflammatory Bowel Disease and other diseases that are thought to be T-cell or white blood cell mediated, including cancer.

The apparatus, methods, and systems of the present invention may be used in conjunction with methods for ameliorating or preventing Graft-versus-Host disease in a subj ect undergoing ectoderm cell transplant, endoderm cell transplant, and/or mesenchymal cell transplant, comprising the step of treating the subject with extracorporeal photopheresis prior to undergoing the ectoderm cell transplant, endoderm cell transplant, and/or mesenchymal cell transplant.

Further, the apparatus, methods, and systems of the present invention may be used in conjunction with methods and systems for ameliorating or preventing organ transplant rejection in a subject undergoing an organ transplant comprising the step of treating the subject with extracorporeal photopheresis prior to undergoing the organ transplant. The organ transplant may be a syngeneic graft, an allograft, or a xenograft. The organ may be a liver, a kidney, a heart, a lung, a pancreas, pancreatic islets, or the skin. The organ may be human, artificial, clonal, or mammalian.

The apparatus, methods, and systems of the present invention may also be used in conjunction with methods for ameliorating or preventing tissue transplant rejection in a subject undergoing a tissue transplant. The tissue graft may be an autograft, a syngeneic graft, an allograft, or a xenograft. The tissue may be cartilage, bone, liver, small-bowel, neuronal, adrenal medullary tissue, fetal thymus tissue, or parathyroid tissue. The tissue may be human, artificial, clonal, or mammalian.

Additionally, the apparatus, methods, and systems of the present invention may be used in conjunction with methods for preventing the onset, delaying the onset, ameliorating the effects, or ameliorating the potential severity of an autoimmune disease in a subject predisposed to an autoimmune disease, such as: Alopecia Areata, Ankylosing Spondylitis, Antiphospholipid Syndrome, Autoimmune Addison's Disease, Autoimmune Hemolytic Anemia, Autoimmune Hepatitis, Behcet's Disease, Bullous Pemphigoid, Cardiomyopathy, Celiac Sprue-Dermatitis, Chronic Fatigue Immune Dysfunction Syndrome (CFIDS), Chronic Inflammatory Demyelinating Polyneuropathy, Churg-Strauss Syndrome, Cicatricial Pemphigoid, CREST Syndrome, Cold Agglutinin Disease, Crohn's Disease, Discoid Lupus, Essential Mixed Cryoglobulinemia, Fibromyalgia-Fibromyositis, Graves' Disease, Guillain-Barré Syndrome, Hashimoto's Thyroiditis, Idiopathic Pulmonary Fibrosis, Idiopathic Thrombocytopenia Purpura (ITP), IgA Nephropathy, Insulin Dependent Diabetes, Juvenile Arthritis, Lichen Planus, Ménière's Disease, Mixed Connective Tissue Disease, Multiple Sclerosis, Myasthenia Gravis, Pemphigus Vulgaris, Pernicious Anemia, Polyarteritis Nodosa, Polychondritis, Polyglandular Syndromes, Polymyalgia Rheumatica, Polymyositis and Dermatomyositis, Primary Agammaglobulinemia, Primary Biliary Cirrhosis, Psoriasis, Raynaud's Phenomenon, Reiter's Syndrome, Rheumatic Fever, Rheumatoid Arthritis, Sarcoidosis, Scleroderma, Sjögren's Syndrome, Stiff-Man Syndrome, Systematic Lupus Erythematosus, Takayasu Arteritis, Temporal Arteritis/Giant Cell Arteritis, Ulcerative Colitis, Uveitis, Vasculitis, Vitiligo, and Wegener's Granulomatosis.

The present invention may also be used to separate and collect platelets from a donor, or to separate and remove other types of specific cells from a donor, such as, for example, diseased or abnormal cells.

Moreover, the apparatus, methods, and systems of the present invention may be used in conjunction with methods and systems for inducing apoptosis of cells. Apoptosis is a programmed cell death which results in the apoptic cells disintegrating and being phagocytosed while not becoming disrupted. Apoptosis has been proposed as a mechanism to treat autoimmune diseases by re-infusing the apoptic cells back into the host body, as described in <patcit id="pcit0009" dnum="US5945291A"><text>U.S. Patent No. 5,945, 291</text></patcit> and <patcit id="pcit0010" dnum="US6204058B"><text>U.S. Patent No. 6,204,058</text></patcit>.

Additional objects and advantages of the invention will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.

In one aspect, the invention is an apparatus for separating components of a fluid, the apparatus comprising: an outer housing with an upper housing end and a lower housing end, wherein said outer housing increases in diameter from said upper housing end to said lower housing end, said lower housing end having a housing floor and said housing upper end having a housing outlet, said outer housing having an interior volume and adapted for rotation about a center axis; a core connected with said outer housing for rotation therewith; said core having an outer wall having an upper core end and a lower core end, said lower core end having a core floor and said upper core end having a core outlet; said core occupying a coaxial volume of said interior volume of said outer housing and forming a separation volume between said core and said outer housing; a lower plate having a top surface, said lower plate positioned within said separation volume, beneath said core floor and above said housing floor; a lumen positioned inside said core, said lumen extending axially through said core; a first bowl channel within said lumen to said top surface of said lower plate for inflowing said fluid; a second bowl channel from within said separation volume beneath said lower plate for removing a first separated fluid component; and a third bowl channel from said separation volume above said lower plate for removing a

It is preferable that said outer wall of said core increases in diameter from said upper core end to said lower core end. Additionally, said second bowl channel and said third bowl channel can be positioned within said lumen so as to form a multi-axial lumen.

The apparatus of the present invention further comprises a connection sleeve that is adapted to be secured to said apparatus near said housing outlet for rotation therewith. The connection sleeve is adapted to fluidly connect each of the first, second, and third bowl channels to a corresponding conduit channel of an external conduit. The connection sleeve can be adapted to be secured to said lumen or to said core. Preferably, the connection sleeve will also comprise a sleeve flange, and said housing outlet will be adapted to retain said sleeve flange.

Said lumen has an upper lumen end and a lower lumen end, and increases in diameter from said upper lumen end to said lower lumen end. The core comprises a neck fitted around said lumen. Additionally, the core floor can comprise a floor flange that extends into said separation volume. This floor flange is adapted to guide the flow of said second separated fluid component upward into said separation volume while allowing said first separated fluid component to flow to said housing floor.

It is also preferable that the lower plate be circular and that said lumen and said floor of said core be a single structure. The apparatus is also designed so as to be closed to undesired contagions. Alternatively, the apparatus can be adapted to allow rotation of said core, said lower plate, and said outer housing about said lumen.

Said outer housing comprises a locking mechanism adapted to secure said outer housing to means for rotating said outer housing about said axis. The locking mechanism comprises protrusions and/or key slots that engage the outer housing to the means for rotating. It is further preferred that said means for rotating comprises a bracket that is adapted to engage and rotate an external conduit that is fluidly connected to said first bowl channel, said second bowl channel, and said third bowl channel. As such, the rotation means can be adapted to rotate said outer housing and said external conduit using 1-omega/2-omega spin technology, as is discussed in <patcit id="pcit0011" dnum="US3986442A"><text>U.S. Patent No. 3,986,442</text></patcit>. Thus, a rotatable seal is not required.

The elimination of the rotating fluid seal from the centrifuge bowl reduces cost and cell damage, enables longer cell processing times, and increases the survival and storage time for platelets and packed RBCs. Additionally, the elimination of the rotating seal and replacement with a completely sealed system reduces the likelihood of contamination or a hazardous biological spill. Further, the rotating seal has typically been a weak point in the machinery in terms of performance lifetime, complexity and fragility of its parts, and the necessity for a continuous and comparable degree of lubrication. During on-line blood separation, as applied to the collection of blood cells, rotating seals become critical in terms of platelet injury, red cell hemolysis, and obstruction of channels by aggregates and impaired lubrication of the rotating seals.

The apparatus can be economically fabricated from plastic by known molding techniques while maintaining tight tolerances. This results in the apparatus being manufactured inexpensively.

In yet another embodiment, the apparatus further comprises: means to remove said fluid from a source, said means to remove said fluid fluidly connected to said first bowl channel; means to remove said first separated fluid component via said second bowl channel; means to remove said second separated fluid component via said third bowl channel; and means to treat said second separated fluid component subsequent to being removed via said third bowl channel. In this embodiment, it is preferable that the apparatus also have a means to reinfuse treated second separated fluid component and said first separated fluid component back into said source, wherein said apparatus is a closed-loop apparatus when connected to said source.

Preferably, the source is a patient and the fluid is blood. In such a case, both the reinfusion means and the means to remove said fluid from said source will comprise a needle or a catheter. When the fluid is blood, the apparatus should further comprise an anticoagulant source fluidly connected between said means to remove said fluid from said source and said first bowl channel. Moreover, the means to remove said first separated fluid component via said second bowl channle can be a pump that provides substantially stable flow, as disclosed, for example, in <patcit id="pcit0012" dnum="US389463A" dnum-type="L"><text>U.S. Patent Application No.09/389,463</text></patcit>. It is preferred that said treatment means comprise a chamber and a source of ultraviolet radiation.

Also described is an improved connection sleeve for fluidly connecting an external conduit having a first conduit channel to a centrifuge bowl having a first bowl channel. The connection sleeve comprises: a body having an upper sleeve end and a lower sleeve end, said lower sleeve end adapted to be secured to said centrifuge bowl; a stub having a first stub channel extending therethrough, wherein said first stub channel is adapted to form a first passageway from said first conduit channel to said first bowl channel; a wall surrounding said stub near said upper sleeve end; and a trench between said wall and said stub, said trench adapted to receive and hold said external conduit. This improved connection sleeve is more durable than prior art connection sleeves and can better withstand cyclical rotational forces without failing.

The connection sleeve can comprise a sleeve flange positioned on said lower sleeve end, wherein said sleeve flange is adapted to engage said centrifuge bowl. Also preferably, the trench will be tapered and the body will increase in diameter from said upper sleeve end to said lower sleeve end. In this embodiment, it is further preferable that the wall be raised above said stub. In order to accommodate the inflow of said fluid and the outflow of said first and second separated fluid components, it is preferable that said stub further comprise second and third stub channels extending therethrough, said second and third stub channels adapted to form second and third passageways from second and third conduit channels to second and third bowl channels. The connection sleeve can be overmolded to said external conduit.

In yet another aspect, the invention is a method for separating components of a fluid into higher and lower density components, using an apparatus as in claim 1 the method comprising: providing a centrifuge bowl comprising a first bowl channel, a second bowl channel, and a third bowl channel; flowing said fluid from a source into said centrifuge bowl through said first bowl channel; rotating said centrifuge bowl about an axis; removing said higher density component from said bowl via said second bowl channel; and removing said lower density component from said bowl via said third bowl channel concurrently with said removing of said higher density component.

Said higher density component can be removed via said second bowl channel by applying negative pressure to said second bowl channel with a pump. This pump should be adapted so as to provide substantially stable flow of said higher density component. Alternatively, said higher density component can be removed via said second bowl channel by applying positive pressure to said centrifuge bowl, forcing said higher density component out of the centrifuge bowl.

The inventive method can be performed using a biological fluid as the fluid, preferably blood. When blood is used, said higher density component comprises red blood cells and said lower density component can comprise a buffy coat. Thus, the inventive method can be used to collect platelets. The red blood cells can then be continuously reinfused into a source. Continuous reinfusal into a patient is not covered by the claimed method.

In another embodiment, the inventive method will comprise the further steps of: treating said lower density component; and reinfusing said treated lower density component into said source to treat, ameliorate, prevent, or delay the onset of diseases. The treatment can be continuous. Because the method can be performed continuously without the need to batch process said fluid, patient treatment time can be greatly reduced, and treatment can be completed in less than 70 minutes. The higher density component can be continuously reinfused into a source.

The method can be used to treat white blood cell and T-cell mediated diseases selected from the group consisting of cancer, T-cell lymphoma, Graft-versus-Host disease, Rheumatoid Arthritis, Progressive Systematic Sclerosis, Juvenile Onset Diabetes, Inflamatory Bowel Disease, Alopecia Areata, Ankylosing Spondylitis, Antiphospholipid Syndrome, Autoimmune Addison's Disease, Autoimmune Hemolytic Anemia, Autoimmune Hepatitis, Behcet's Disease, Bullous Pemphigoid, Cardiomyopathy, Celiac Sprue-Dermatitis, Chronic Fatigue Immune Dysfunction Syndrome, Chronic Inflammatory Demyelinating Polyneuropathy, Churg-Strauss Syndrome, Cicatricial Pemplugoid, CREST Syndrome, Cold Agglutinin Disease, Crohn's Disease, Discoid Lupus, Essential Mixed Cryoglobulinemia, Fibromyalgia-Fibromyositis, Graves' Disease, Guillain-Barré Syndrome, Hashimoto's Thyroiditis, Idiopathic Puhnonary Fibrosis, Idiopathic Thrombocytopenia Purpura, IgA Nephropathy, Insulin Dependent Diabetes, Juvenile Arthritis, Lichen Planus, Ménière's Disease, Mixed Connective Tissue Disease, Multiple Sclerosis, Myasthenia Gravis, Pemphigus Vulgaris, Pernicious Anemia, Polyarteritis Nodosa, Polychondritis, Polyglandular Syndromes, Polymyalgia Rheumatica, Polymyositis and Dermatomyositis, Primary Aganunaglobulinemia, Primary Biliary Cirrhosis, Psoriasis, Raynaud's Phenomenon, Reiter's Syndrome, Rheumatic Fever, Rheumatoid Arthritis, Sarcoidosis, Scleroderma, Sjögren's Syndrome, Stiff-Man Syndrome, Systematic Lupus Erythematosus, Takayasu Arteritis, Temporal Arteritis/Giant Cell Arteritis, Ulcerative Colitis, Uveitis, Vasculitis, Vitiligo, and Wegener's Granulomatosis.

Additionally, the inventive method can be used to ameliorate or prevent organ or tissue transplant rejection. Preferably, said treatment step will comprise irradiating said lower density component. Moreover, the inventive method can be performed to induce anpptosis within said lower density component.

Also described is a conduit assembly for fluidly connecting a source of fluid to a centrifuge bowl, the conduit assembly comprising: an external conduit of approximately constant diameter having a first conduit end and a second conduit end; a connection sleeve secured to said first conduit end, said connection sleeve adapted to fluidly connect to said centrifuge bowl; an anchor sleeve secured to said second conduit end; a first bearing ring surrounding said external conduit and positioned between said connection sleeve and said anchor sleeve, said first bearing ring adapted to engage a means for rotating said centrifuge bowl; and a first assembly channel extending through said conduit assembly. The conduit assembly of the present invention is inexpensive and easy to manufacture, allows easy optimization, and has improved durability.

Preferably, the connection sleeve and the anchor sleeve will be overmolded to said external conduit. The anchor sleeve can have a first anchor end and a second anchor end wherein the first anchor end is secured to said external conduit. The anchor sleeve can increase in diameter from said first anchor end to said second anchor end. It is further preferable that the connection sleeve have an upper sleeve end and a lower sleeve end, wherein said upper sleeve end of said connection sleeve is secured to said external conduit, and said connection sleeve increased in diameter from said upper sleeve end to said lower sleeve end.

In this embodiment, the connection sleeve will preferably have a wall surrounding a stub near said upper sleeve end. The connection sleeve will further have a trench between said wall and said stub, wherein said trench is adapted to receive and secure said external conduit. Preferably, the trench is tapered and the wall is raised above said stub. Also, the connection sleeve will further comprise a sleeve flange.

Because the conduit assembly can be used to inflow a fluid and outflow two separated fluid components, the conduit assembly will preferably also comprise a second assembly channel and a third assembly channel. In order to reduce wear of the conduit assembly, the conduit assembly can further comprise a second bearing ring surrounding said conduit and positioned between said first bearing ring and said anchor sleeve. This second bearing ring will be adapted to engage a means for rotating said centrifuge bowl. The first and second bearing rings should be 7.5 to 9.5 inches apart, wherein the first bearing ring is 5.0 to 5.5 inches from the lower end of said connection sleeve.

It is understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed. The accompanying drawings illustrate several embodiments of the invention and together with the description serve to explain the principles of the invention.

<u>Brief Description of the Drawings</u>

<ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">Figure 1</figref> is a front elevational view of an embodiment a centrifuge bowl, a connection sleeve, and a portion of an external conduit according to the present invention.</li><li><figref idref="f0002">Figure 2</figref> is a front elevational view of the apparatus of <figref idref="f0001">FIG. 1</figref> partially in section.</li><li><figref idref="f0003">Figure 3</figref> is a cross-sectional view of the apparatus of <figref idref="f0001">FIG. 1</figref> along line III-III.</li><li><figref idref="f0004">Figure 4</figref> is a front elevational view of the centrifuge bowl and connection sleeve of <figref idref="f0001">FIG. 1</figref>, wherein the connection sleeve and outer housing are exploded.</li><li><figref idref="f0005">Figure 5</figref> is an exploded view of the centrifuge bowl of <figref idref="f0001">FIG. 1</figref>.</li><li><figref idref="f0006">Figure 6</figref> is a schematic of one embodiment of the apparatus of the present invention, a closed-loop system for ameliorating, preventing, treating, or delaying the onset of diseases.</li><li><figref idref="f0007">Figure 7</figref> is a front-elevational view of an embodiment of a connection sleeve according to the present invention.</li><li><figref idref="f0008">Figure 8</figref> is a cross-sectional view of the connection sleeve of <figref idref="f0007">FIG. 7</figref> along line XIII-XIII.</li><li><figref idref="f0009">Figure 9</figref> is a top view of the connection sleeve of <figref idref="f0007">FIG. 7</figref>.</li><li><figref idref="f0010">Figure 10</figref> is a bottom view of the connection sleeve of <figref idref="f0007">FIG. 7</figref>.</li><li><figref idref="f0011">Figure 11</figref> is a top elevational view the connection sleeve of <figref idref="f0007">FIG. 7</figref> having a portion of an external conduit fluidly secured to said connection sleeve.</li><li><figref idref="f0012">Figure 12</figref> is a schematic of an embodiment of the apparatus of <figref idref="f0001">FIG. 1</figref> positioned in a 1-omega 2-omega rotational device.</li><li><figref idref="f0013">Figure 13</figref> is a perspective view of a bracket and rotational base of the rotational device of <figref idref="f0012">FIG. 12</figref> with a portion of the centrifuge bowl of <figref idref="f0001">FIG. 1</figref> positioned therein.</li><li><figref idref="f0014">Figure 14</figref> is a perspective view an embodiment of a conduit assembly according to the present invention.</li><li><figref idref="f0015">Figure 15</figref> is an elevated view of the conduit assembly of <figref idref="f0014">FIG. 14</figref> from a different perspective.</li><li><figref idref="f0016">Figure 16</figref> is a cross sectional view of the connection sleeve of the conduit assembly of <figref idref="f0015">FIG. 15</figref> along line XVII-XVII.</li><li><figref idref="f0017">Figure 17</figref> is a cross sectional view of the anchor sleeve of the conduit assembly of <figref idref="f0014">FIG. 14</figref> along line XVIII-XVIII.</li><li><figref idref="f0018">Figure 18</figref> is a perspective view of a second embodiment of a centrifuge bowl according to the present invention.</li><li><figref idref="f0019">Figure 19</figref> is a perspective view of the apparatus of the centrifuge bowl of <figref idref="f0018">FIG. 18</figref> partially in section.</li></ul>

<u>Modes for Carrying Out the Invention</u>

Reference will now be made in detail to the present preferred or exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings.

In a specific embodiment, the present invention relates to methods and apparatus that separate fluid components, such as, for example, the components of a biological fluid by density or weight. Biological fluids encompass fluids that comprise, exist in, or are used in, or delivered to living organisms. Indeed, biological fluids may comprise bodily fluids and their components, such as blood cells, plasma, and other fluids that comprise biological components, including living organisms such as bacteria, cells, or other cellular components. Biological fluids may also comprise whole blood or specific whole blood components, including red blood cells, platelets, white blood cells, and precursor cells. In particular, it may be desirable to remove blood from a patient for treatment, such as for example, extracorporeal treatment. It is to be understood, however, that the present invention is adaptable to use with various centrifugal processing apparatus, and the specific example given herein is merely for illustrative purposes. Other uses for the separation techniques and apparatus may include other medical processes such as dialysis, chemotherapy, platelet separation and removal, and separation and removal of other specific cells. Additionally, the present invention may be used to separate other types of fluids that include a wide variety of non-medical uses, such as, for example, oil and fluid component separation. All components used in the present invention should not adversely affect biological fluids or render them unsuitable for their intended uses, such as those described herein and may be made of any suitable material compatible with uses described herein including, but not limited to plastics, such as polycarbonate, methyl methacrylate, styrene-acrylonitrile, acrylic, styrene, acrylonitrile or any other plastic.

To achieve the objects in accordance with the purpose of the invention, as embodied and broadly described herein, <figref idref="f0001">Figure 1</figref> depicts a specific embodiment of the invention. The embodiment of the present invention depicted in <figref idref="f0001">Figure 1</figref> comprises a centrifuge bowl <b>10</b> in fluid connection with connection sleeve <b>500.</b> Lower sleeve end <b>832</b> (<figref idref="f0007">FIG. 7</figref>) of connection sleeve <b>500</b> is secured to bowl <b>10.</b> Upper sleeve end <b>831</b> of connection sleeve <b>500</b> is secured to external conduit <b>20,</b> thus fluidly connecting external conduit <b>20</b> to bowl <b>10.</b> This fluid connection enables fluid <b>800</b> to be supplied through external conduit <b>20</b> to bowl <b>10.</b> Similarly, this fluid connection also enables separated fluid components <b>810, 820</b> to be removed from bowl <b>10</b> through external conduit <b>20.</b> Bowl <b>10</b> is adapted to be rotated around its center axis <b>11.</b>

Bowl <b>10</b> comprises outer housing <b>100</b> and core <b>200.</b> As illustrated, outer housing <b>100</b> is constructed of clear plastic so that core <b>200</b> is visible therethrough. Outer housing <b>100</b> comprises housing floor <b>180</b> which in turn comprises protrusions <b>150</b> for locking bowl <b>10</b> into rotational device <b>900</b> (<figref idref="f0012">FIG. 12</figref>). Bowl <b>10</b> is preferably simplified in construction and is easy to manufacture by molding or other known manufacturing processes, such that it may be disposable or used for a limited number of treatments, and is most preferably capable of containing about 125 ml of fluid, such fluid possibly being pressurized. In alternative embodiments, the volume capacity of the bowl may vary depending upon the health of the patient and his or her allowable extracorporeal volume. The volume capacity of the bowl may also vary depending upon the use of the bowl or the particular treatment for which the bowl is utilized. Additionally, to avoid contamination of biological fluids, or exposure of persons involved in the processing operation to the fluids, the transfer operations are preferably carried out within a sealed flow system, possibly pressurized, preferably formed of flexible plastic or similar material which can be disposed of after each use.

Referring to <figref idref="f0002">FIG. 2</figref>, outer housing <b>100</b> is substantially conical-shaped with an upper housing end <b>110</b> and a lower housing end <b>190.</b> Outer housing <b>100</b> may be made of plastic (such as those plastics listed previously), or any other suitable material. Upper housing end <b>110</b> preferably has a neck <b>115.</b> Neck <b>115</b> forms housing outlet <b>700</b> (<figref idref="f0004">FIG. 4</figref>) which is sized to secure and hold sleeve flange <b>790</b> of connection sleeve <b>500.</b> However connection sleeve <b>500</b> can be secured to bowl <b>10</b> by any suitable means, including for example, a lip, groove, or tight fit and adhesive with a component of bowl <b>10.</b> Lower housing end <b>190</b> has a housing floor <b>180</b> of greater diameter than upper end <b>110.</b> Housing floor <b>180</b> may have an indentation <b>185</b> that is used to collect denser fluid <b>810.</b> The diameter of outer housing <b>100</b> increases from upper housing end <b>110</b> to lower housing end <b>190.</b>

Outer housing <b>100</b> is adapted to rotatably connect to a rotational device <b>900</b> (<figref idref="f0012">FIG. 12</figref>), such as for example, a rotor drive system or a rotating bracket <b>910.</b> The rotatable connection may, for example, be a bearing that allows free rotation of bowl <b>10.</b> Outer housing <b>100</b> has a locking mechanism. The locking mechanism may be one or more protrusions <b>150</b> designed to interact with corresponding indentations in a centrifuge container or any other suitable interconnect or locking mechanism or equivalent known in the art. The locking mechanism may also comprise a key slot <b>160</b> (<figref idref="f0018">FIG. 18</figref>).

Referring to <figref idref="f0004">FIG. 4</figref>, outer housing <b>100</b> has an interior volume <b>710</b> in which core <b>200</b> will fit when bowl <b>10</b> is assembled. In assembling bowl <b>10,</b> connection sleeve <b>500</b> is first mounted to lumen <b>400.</b> Upon outer housing <b>100</b> being connected, connection sleeve <b>500</b> extends through housing outlet <b>700</b> until sleeve flange <b>790</b> engages outer housing <b>100</b> near upper housing end <b>110.</b> When fully assembled, core <b>200</b> is fully within interior volume <b>710</b> of outer housing <b>100</b>,occupying a coaxial volume of interior volume <b>710</b> about axis <b>11.</b>

Referring back to <figref idref="f0002">FIG. 2</figref>, bowl <b>10</b> comprises core <b>200</b> positioned inside of outer housing <b>100</b> as described above. Core <b>200</b> has an outer wall <b>210</b> that is a stacked-conical shape that follows the general shape of outer housing <b>100.</b> In an alternative embodiment, outer wall <b>210</b> may be a truncated cone-shape that is substantially smooth. The interior of core <b>200</b> is hollow, but may be solid if so desired. Interior wall <b>210</b> of core <b>200</b> provides a hollow cylindrical section for lumen <b>400</b> to pass through. Core <b>200</b> also comprises upper and lower core ends <b>205</b> and <b>295,</b> respectively. Lower core end <b>295</b> has a core floor <b>290.</b> The diameter of core <b>200</b> preferably increases from upper core end <b>205</b> to lower core end <b>295.</b> Upper core end <b>205</b> of core <b>200</b> has a neck <b>215</b> fitted around the outside diameter of multi-axial lumen <b>400.</b>

Referring to <figref idref="f0005">FIG. 5</figref>, neck <b>215</b> of core <b>200</b> forms core outlet <b>720</b> near upper core end <b>205.</b> Core outlet <b>720</b> is sized so that lumen <b>400</b> can extend therethrough when assembled. In one embodiment of bowl <b>10,</b> core floor <b>290</b> and lumen <b>400</b> are molded so as to be a single structure and having a plurality of fins <b>250</b> that provide support for lumen <b>400.</b> Alternatively, bowl <b>10</b> can be constructed so that core floor <b>290</b> and lumen <b>400</b> are separate pieces. In such an embodiment, core floor <b>290</b> will have an opening through which lumen <b>400</b> will extend therethrough. This alternative embodiment makes it possible for bowl <b>10</b> to be adapted so that core <b>200,</b> outer housing <b>100,</b> and lower plate <b>300</b> can rotate about a stationary lumen <b>400.</b>

Referring back to <figref idref="f0002">FIG. 2</figref>, core <b>200</b> is positioned inside outer housing <b>100,</b> occupying a coaxial volume of interior volume <b>710</b> of bowl <b>10</b> and forming separation volume <b>220</b> between outer wall <b>210</b> of core <b>200</b> and outer housing <b>100.</b> Separation volume <b>220</b> is that space of interior volume <b>710</b> that is between core <b>200</b> and outer housing <b>100.</b>

Bowl <b>10</b> further comprises lower plate <b>300</b> having top surface <b>730.</b> Lower plate <b>300</b> is positioned within separation volume <b>220</b> beneath core floor <b>290</b> and above housing floor <b>180.</b> Lower plate <b>300</b> is circular and curves upward radially from its center (illustrated in <figref idref="f0003">FIG. 3</figref>). Alternatively, lower plate <b>300</b> can be flat. When positioned between core floor <b>290</b> and housing floor <b>180</b> as stated above, space still exists both between lower plate <b>300</b> and core floor <b>290</b> and between lower plate <b>300</b> and housing floor <b>180.</b> These spaces allow fluid <b>800</b> to flow along top surface <b>730</b> of lower plate <b>300</b> and further allows a first separated fluid component <b>810</b> to flow under lower plate <b>300</b> atop housing floor <b>180.</b> Top surface <b>730</b> of lower plate <b>300</b> may also have protrusions, indentations, or other guides that extend from the center of lower plate <b>300</b> radially outward to the edge of plate <b>300</b> to direct fluid <b>800</b> outward. Lower plate <b>300</b> may be made of plastic or any other suitable material. Lower plate <b>300</b> has opening <b>302</b> (<figref idref="f0005">FIG. 5</figref>) near its center through which that portion of lumen <b>400</b> that forms second bowl channel <b>410</b> extends. Opening <b>302</b> can be sized to form a tight fit with this portion of lumen <b>400</b> which will hold lower plate <b>300</b> suspended above housing floor <b>180.</b>

Multi-axial lumen <b>400</b> is located inside core <b>200.</b> Lumen <b>400</b> has an upper lumen end <b>480</b> and a lower lumen end <b>490</b> wherein the diameter of lumen <b>400</b> increases from upper lumen end <b>480</b> to lower lumen end <b>490.</b> In the illustrated embodiment lumen <b>400</b> comprises first bowl channel <b>420,</b> second bowl channel <b>410,</b> and third bowl channel <b>740.</b> First bowl channel <b>420</b> provides a passageway through lumen <b>400</b> to top surface <b>730</b> of lower plate <b>300</b> for the inflow of fluid <b>800.</b> Second bowl channel <b>410</b> is located inside first bowl channel <b>420</b> and is completely enclosed therein. Second bowl channel <b>410</b> forms a passageway through lumen <b>400</b> from below lower plate <b>300</b> for the removal of a first separated fluid component <b>810</b> that gathers in indentation <b>185</b> of housing floor <b>180.</b> Third bowl channel <b>740</b> forms a passage way through lumen <b>400</b> from separation volume <b>220</b> above lower plate <b>300</b> for the removal of second separated fluid component <b>820.</b> Preferably, third bowl channel <b>740</b> forms a passageway from that portion of separation volume <b>220</b> that is at or near upper housing end <b>110.</b> As illustrated, third bowl channel <b>740</b> is L-shaped. In alternative embodiments, first, second, and third bowl channels <b>820, 810, 740</b> can be placed at different positions on bowl <b>10.</b> The bowl channels <b>820, 810, 740</b> may be arranged so as not to be all within lumen <b>400,</b> so long as the necessary passageways are formed. For example, alternate configurations such as a single lumen partitioned into equal sections forming multiple lumens and/or fluid passageways will suffice. In another embodiment, there may be a non-coaxial bundle of lumens that are truncated in the appropriate sections of the centrifuge bowl. For example, the lumen carrying fluid <b>800</b> may be truncated below the bottom of the core <b>200</b> and above lower plate <b>300.</b> Each bowl channel <b>820, 810, 740</b> may be made of any type of flexible or rigid tubing (such as medical tubing) or other such device providing a sealed passageway, possibly for pressurized or unpressurized fluid flow, and which preferably can be disposable and sterilizable, i.e., of simple and efficient manufacture.

Referring to <figref idref="f0005">FIG. 5</figref>, bowl <b>10</b> is adapted so that outer housing <b>100,</b> core <b>200,</b> lower plate <b>300,</b> and lumen <b>400</b> are in connection and rotate together. Housing floor <b>180</b> of outer housing <b>100</b> (not illustrated in <figref idref="f0005">FIG. 5</figref>) comprises double ridges <b>181</b> on its top surface. Each double ridge <b>181</b> comprises two substantially parallel raised protrusions. Lower plate <b>300</b> has single ridges <b>301</b> on both its top surface <b>730</b> and bottom surface (not illustrated on bottom surface). Each single ridge <b>301</b> comprises a single raised linear protrusion. When assembled, each single ridge <b>301</b> on the bottom surface of lower plate <b>300</b> rests between and engages the two substantially parallel raised protrusions of a corresponding double ridge <b>181</b> on housing floor <b>180.</b> Similarly, each single ridge <b>301</b> on top surface <b>730</b> of lower plate <b>300</b> will engage a corresponding double ridge <b>301</b> on the bottom surface of core floor <b>290</b> of core <b>200.</b> Thus, when outer housing <b>100</b> is rotated, core <b>200,</b> lower plate <b>300,</b> and lumen <b>400</b> will rotate therewith.

Referring again to <figref idref="f0002">FIG. 2</figref>, connection sleeve <b>500</b> is secured to bowl <b>10</b> by means of sleeve flange <b>790.</b> Connection sleeve <b>500</b> is also secured to external conduit <b>20</b> and is adapted to fluidly connect conduit channels <b>780, 760, 770</b> of external conduit <b>20</b> to bowl channels <b>420, 410, 740</b> of lumen <b>400</b> respectively. When assembled, connection sleeve <b>500</b> is mounted to lumen <b>400.</b> Specifically, connection sleeve <b>500</b> is adapted to be mounted to lumen connector <b>481</b> (<figref idref="f0004">FIGS. 4</figref> and <figref idref="f0005">5</figref>).

Referring now to <figref idref="f0007">FIGS. 7</figref> and <figref idref="f0010">10</figref>, connection sleeve <b>500</b> comprises body <b>830</b> having an upper sleeve end <b>831</b> and lower sleeve end <b>832.</b> Lower sleeve end <b>832</b> has sleeve flange <b>790</b> which is sized to engage upper housing end <b>110</b> when body <b>830</b> of connection sleeve <b>500</b> is slidably inserted through housing outlet <b>700.</b> Lower sleeve end <b>832</b> also comprises lumen mounting recess <b>851.</b> Lumen mounting recess <b>851</b> is sized so that lumen connector <b>481</b> (<figref idref="f0004">FIG. 4</figref>) will fit tightly therein. Lumen mounting recess <b>851</b> is triangularly shaped but can take on any shape, so long as it corresponds in shape to that of lumen connector <b>481.</b> However it is preferred that lumen mounting recess <b>851</b> not be circular. A circular shape would allow connection sleeve <b>500</b> to rotate about lumen <b>400,</b> causing unwanted friction and possibly producing contaminants.

Referring to <figref idref="f0007">FIGS. 7</figref> and <figref idref="f0008">8</figref>, upper sleeve end <b>831</b> is adapted to be secured to external conduit <b>20.</b> Upper sleeve end <b>831</b> comprises wall <b>835</b> surrounding stub <b>836.</b> Upper sleeve end <b>831</b> further comprises trench <b>837</b> positioned between wall <b>835</b> and stub <b>836.</b> Trench <b>837</b> is preferably tapered. External conduit <b>20</b> is secured to connection sleeve <b>500</b> (as illustrated in <figref idref="f0011">FIG. 11</figref>) by sliding a raised outer wall portion of external conduit <b>20</b> into trench <b>837.</b> Body <b>831</b> is sized and shaped so that when sleeve flange <b>790</b> engages outer housing <b>100,</b> body <b>831</b> fits tight in housing outlet <b>700,</b> protruding therefrom. This tight fit helps ensure that contagions do not enter bowl <b>10.</b>

Referring to <figref idref="f0007">FIGS. 7</figref> and <figref idref="f0009 f0010 f0011">9-11</figref>, stub <b>836</b> comprises first stub channel <b>840,</b> second stub channel <b>841,</b> and third stub <b>channel 842.</b> First, second, and third stub channels <b>840, 841, 842</b> extend through stub <b>836,</b> each forming a passageway through connection sleeve <b>500.</b> When fluidly connect to external conduit <b>20</b> and bowl <b>10,</b> first stub channel <b>840</b> fluidly connects first conduit channel <b>780</b> with first bowl channel <b>420</b> for inflowing fluid <b>800</b> from external conduit <b>20</b> into bowl <b>10</b> for separation. Similarly, second stub channel <b>841</b> fluidly connects second conduit channel <b>760</b> to second bowl channel <b>410</b> for removing first separated fluid component <b>810</b> from bowl <b>10</b> into external conduit <b>20.</b> Finally, third stub channel <b>842</b> fluidly connects third conduit channel <b>770</b> to third bowl channel <b>740</b> for removing second separated fluid component <b>820</b> from bowl <b>10</b> into external conduit <b>20.</b>

Connection sleeve <b>500</b> connects bowl <b>10</b> to external conduit <b>20</b> without use of a rotatable seal, which would otherwise normally be located between bowl <b>10</b> and connection sleeve <b>500.</b> The seal-less connection between bowl <b>10</b> and connection sleeve <b>500</b> may occur as explained above or alternatively through use of, for example, an O-ring, a groove, or lip, grommet-type connection, welding, or a tight fit with or without adhesive in either bowl <b>10</b> or connection sleeve <b>500.</b>

In order for bowl <b>10</b> to be used to separate fluid <b>800</b> into its higher and lower density components <b>810, 820</b> it is necessary that bowl <b>10</b> be rotated in a device capable of spinning bowl <b>10</b> at an adequate rotational velocity. However, this spinning must be achieved while still maintaining both the structural integrity of bowl <b>10</b> and all of the fluid connections between bowl <b>10,</b> connection sleeve <b>500,</b> and external conduit <b>20.</b> For the present invention, rotation of bowl <b>10</b> without the use of a rotating seal is achieved through the use of 1-omeg 2-omega spin technology. The importance of 1-omega/2-omega spin technology is well known in the art, as seen for example, in <patcit id="pcit0013" dnum="US3986442A"><text>U.S. Patent No. 3,986,442</text></patcit>. Rotational devices utilizing 1-omega 2-omega spin technology allow bowl <b>10</b> and external conduit <b>20</b> to rotate without the use of a rotatable seal and eliminate any tangling of external conduit <b>20.</b>

Referring to <figref idref="f0012">FIGS. 12</figref> and <figref idref="f0013">13</figref>, a rotational device <b>900</b> capable of utilizing 1-omega 2-omega spin technology is illustrated with bowl <b>10</b> positioned therein. Bowl <b>10</b> is rotatably connected to rotational device <b>900,</b> which includes a rotating bracket <b>910</b> and an outer frame <b>914,</b> both of which are, for example, made of aluminum or some other lightweight, sturdy metal. Rotating bracket <b>910</b> is rotatably connected to bowl <b>10</b> and has holders <b>915</b> (generically illustarted in <figref idref="f0012">FIG. 12</figref>) that restrain external conduit <b>20</b> in a specific configuration that resembles a "truncated reverse-S shape." Although external conduit <b>20</b> must maintain a particular configuration, it is still capable of loose rotation within holders <b>915.</b> Thus, external conduit <b>20</b> is, for example, fed into holders <b>915.</b> Holders <b>915</b> may have a wear plate designed to reduce friction and heat generated by friction between external conduit <b>20</b> and holder <b>915.</b> Bracket <b>910</b> also has an opening through bottom ledge <b>916</b> that is designed to rotatably connect bowl <b>10</b> to bracket <b>910</b> to allow free rotation of bowl <b>10.</b> This particular configuration allows external conduit <b>20</b> to act as a flexible shaft that transmits torque to bowl <b>10</b> and provides 2-omega spin. Rotating bracket <b>910</b> rotates while holding external conduit <b>20,</b> providing 1-omega revolution, and is preferably driven by a motor <b>912</b> or some other energy source known in the art. Motor <b>912</b> has a drive shaft <b>913</b> that rotates. Drive shaft <b>913</b> is connected to and transmits torque to bracket shaft <b>911</b> through the use of a belt, chain, or other connection (not illustrated). Bracket shaft <b>911</b> in turn transmits rotational energy to bracket <b>910</b> and thus to bowl <b>10.</b> External conduit <b>20</b> may be lightly restrained by restraint <b>918</b> located on outer frame <b>914.</b>

Because the rotation and revolution of bracket <b>910</b> are in the same direction, this transposition of the bracket <b>910</b> results in summation of the rates of rotation and revolution. Consequently, the bracket rotates at half the speed of the bowl (1ω) around central axis <b>11,</b> hence the term "1-omega." The bowl <b>10</b> rotates at twice the speed (2ω) of the bracket, hence the term "2-omega."

Alternatively, other rotational systems may be used such as that described in <patcit id="pcit0014" dnum="US3986442A"><text>U.S. Patent No. 3,986,442</text></patcit>. This rotational system includes a drive system for the rotation of bowl <b>10.</b> In this assembly, bowl <b>10</b> would be connected to a rotor assembly that is rotatably mounted on a rotor drive assembly that is rotatably mounted to a stationary base.

Bowl <b>10</b> and the rotational device <b>900</b> may be used in conjunction with a larger system, such as the closed-loop continuous flow system <b>630</b> depicted in <figref idref="f0006">Figure 6</figref>. A source <b>600,</b> such as a patient for example, is connected to system <b>630</b> by a needle or catheter <b>605.</b> System <b>630</b> can be any suitable system that can be used to treat, ameliorate, prevent, or delay the onset of T-cell or white blood cell mediated diseases, such as a photopheresis-type unit. System <b>630</b> comprises anticoagulant source <b>615,</b> centrifuge bowl <b>10</b> within rotational apparatus <b>900</b> (not illustrated), buffy coat treatment assembly <b>609,</b> a plasma storage chamber (not illustrated), saline source <b>613,</b> and drip chamber/filter <b>614.</b> All of these elements are fluidly connected using sterile tubing so that a liquid, such as blood, can flow therethrough. System <b>630</b> can be adapted to be a closed-loop system by connecting return needle or catheter <b>606</b> to source <b>600</b> to reinfuse separated RBCs and treated buffy coat back into the source/patient <b>600.</b>

System <b>630</b> has a plurality of pumps <b>617</b> strategically located to ensure proper pressures and continuous flow throughout system <b>630.</b> In one embodiment of the present invention, an uninterrupted continuous flow pump is used, such as the pump described in <patcit id="pcit0015" dnum="US389463A" dnum-type="L"><text>U.S. Patent Application No. 09/389,463</text></patcit>. System <b>630</b> further comprises a plurality of flow regulation valves <b>618</b> located throughout system <b>630</b> to appropriately facilitate and control the flow of fluid through the fluid connections of system <b>630.</b>

In utilizing system <b>630</b> to treat a patient for one of the aforementioned diseases or conditions, the treatment procedure begins when centrifuge bowl <b>10,</b> possibly part of a disposable kit, is placed inside a photopheresis-type unit, or another suitable system, and is locked into rotational device <b>900</b> (<figref idref="f0012">FIG. 12</figref>) via protrusions <b>150</b> and/or key slots <b>160</b> by a twisting motion. Once bowl <b>10</b> is properly locked into place and fluidly connected to system <b>630,</b> blood is drawn from patient <b>600</b> and into a sterile tubing set using needle <b>605.</b> Anticoagulant is then added to the inflowing blood from anticoagulant source <b>615</b> in a proportion known in the art to prevent coagulation, such as, for example, disclosed in <patcit id="pcit0016" dnum="US480893A" dnum-type="L"><text>U.S. Patent Application Serial No. 09/480,893</text></patcit>, herein expressly incorporated by reference. The incoming whole blood, with a percentage of anticoagulant) then enters bowl <b>10.</b>

Referring to <figref idref="f0002">Figure 2</figref>, this incoming whole blood <b>800</b> enters rotating centrifuge bowl <b>10</b> by passing into first conduit channel <b>780</b> of external conduit <b>20,</b> through first stub channel <b>840</b> (<figref idref="f0009">FIG. 9</figref>) of connection sleeve <b>500,</b> and into first bowl channel <b>420</b> of bowl <b>10.</b> Whole blood <b>800</b> flows downward through first bowl channel <b>420</b> until it reaches top surface <b>730</b> of lower plate <b>300</b> in separation volume <b>220.</b> As bowl <b>10</b> is rotated about axis <b>11,</b> centrifugal forces separate the whole blood <b>800</b> into a first separated fluid component <b>810</b> and second separated fluid component <b>820.</b> Separated fluid components <b>810, 820</b> are separated into different fractions in accordance with the component densities. The higher density fluid component <b>810</b> comprises red blood cells ("RBCs") while the lower density component <b>820</b> comprises buffy coat (WBCs, platelets, and plasma). As bowl <b>10</b> continues to be rotated, the fluids/components flow outwardly along top surface <b>730</b> of lower plate <b>300</b> until reaching the edge of lower plate <b>300.</b> At this point, the higher density component, which in the present embodiment is RBCs <b>810,</b> falls to the bottom of bowl <b>10</b> and onto housing floor <b>180</b> of outer housing <b>100.</b> As the RBCs <b>810</b> flow downward, due to their heavier weight, they flow in an opposite direction of the buffy coat <b>810,</b> which may flow, for example, upwards. As RBCs <b>810</b> aggregate in the bottom of bowl <b>10,</b> some RBCs <b>810</b> will eventually be pushed into and gather in indentation <b>185</b> in the center of housing floor <b>180</b> in that part of separation volume <b>220</b> below lower plate <b>300.</b> Once gathered in indentation <b>185</b> below lower plate <b>300,</b> the RBCs <b>810</b> are removed from bowl <b>10</b> by the RBCs <b>810</b> flowing upward through second bowl channel <b>410,</b> through second stub channel <b>841</b> of connection sleeve <b>500,</b> and into second conduit channel <b>760</b> of external conduit <b>760.</b>

Meanwhile, the less dense blood component, buffy coat <b>820,</b> begins to aggregate and rise through separation volume <b>220</b> because it is less dense. As more whole blood <b>800</b> enters bowl <b>10,</b> the buffy coat <b>820</b> rises in bowl <b>10,</b> forcing buffy coat <b>820</b> towards the top of separation volume <b>220.</b> The buffy coat <b>820</b> enters third bowl channel <b>740,</b> flowing upward out of bowl <b>10</b> via third bowl channel <b>740,</b> through third stub channel <b>842</b> (<figref idref="f0009">FIG. 9</figref>) of connection sleeve <b>500,</b> and into third conduit channel <b>770</b> of external conduit <b>20.</b>

In an alternative embodiment, RBCs <b>810</b> may be removed from bowl <b>10</b> via a pumping means. In another alternative embodiment, buffy coat <b>820</b> may be prevented from exiting bowl <b>10</b> by any means known in the art, thus, for example, increasing the overall pressure in the bowl, forcing the RBCs <b>810</b> out of the bowl.

Bowl <b>10,</b> via external conduit <b>20,</b> may be continuously emptied of its contents (RBCs <b>810</b> and buffy coat <b>820</b>) to prevent a pause in a treatment cycle, or a "batch-type" process. Because bowl <b>10</b> provides a more continuous separation system, the effective separation of the components should increase with respect to time. Again, the apparatus and methods of the present invention may also, for example, be used to remove platelets from blood in much the same way, with the exception that the platelets may be removed instead of buffy coat. In this particular alternative application, a surge-type technique may be used. In this technique, plasma may be flushed into the bowl to float platelets to the top of the separation volume for their removal. Additionally, the centrifuge apparatus and associated systems and methods may be automated by sensors, controllers, and other means of automation known in the art.

RBCs <b>810</b> and buffy coat <b>820</b> are preferably pumped or pushed out of bowl <b>10</b> and then continue to be used in a photopheresis treatment system, such as system <b>630.</b>

Referring back to <figref idref="f0006">FIG. 6</figref>, external conduit <b>20</b> (not illustrated) is properly connected to system <b>630</b> so that the RBC's <b>810</b> flow into sterile tubing <b>607</b> and buffy coat <b>820</b> flows into sterile tubing <b>608</b> after leaving bowl <b>10.</b> Once in tubing <b>608,</b> buffy coat <b>820</b> flows into buffy coat treatment assembly <b>609</b> (generically illustrated) where it is properly processed for reinfusion back into source 600 for treatment or amelioration of the aforementioned conditions or diseases. Buffy coat treatment assembly <b>609</b> will comprise the equipment necessary to process the buffy coat <b>820</b> as necessary for proper patient treatment, such as a chamber for holding buffy coat <b>810</b> and a source of ultra-violet radiation adapted to expose the buffy coat <b>820</b> to UV radiation. The exact equipment and design of buffy coat treatment assembly <b>609</b> will depend on the exact treatment requirements of the patient as known to those skilled in the art. After being processed in treatment assembly <b>609,</b> the buffy coat exits treatment assembly <b>609</b> for reinfusion into source/patient <b>600.</b>

Upon leaving bowl <b>10,</b> the RBCs <b>810</b> flow into tubing <b>607</b> to be directly reinfused into source/patient <b>600.</b> Before reinfusing RBC's <b>810</b> and/or buffy coat <b>820</b> into patient <b>600</b> via needle or catheter <b>606,</b> these fluids are flowed through drip chamber/filter <b>614.</b> Saline can also be added to the fluids from saline source <b>613.</b> When needle/catheter <b>606</b> is connected to patient <b>600,</b> a closed-loop system is formed that can be used to continuously treat patient <b>600</b> without the need to batch-process blood <b>800.</b> While needles/catheters <b>605</b> and <b>606</b> are illustrated as single lumen nedles/catheters, it is possible to use a double lumen catheter in system <b>630</b> so that the same needle/catheter can be used to both remove and reinfuse fluids from the patient.

It has been discovered that increasing the time that buffy coat <b>810</b> is subjected to rotational motion in centrifuge bowl <b>10</b> yields a "cleaner cut" of buffy coat <b>820.</b> A "cleaner cut" means that the hermatocrit count (HCT%) is decreased. HCT% is the amount of red blood cells present per volume of buffy coat. The amount of time that buffy coat <b>820</b> is subjected to rotational motion in centrifuge bowl <b>10</b> can be maximized in the following manner. First, whole blood <b>800</b> is fed into first bowl channel <b>420</b> as centrifuge bowl <b>10</b> is rotating. As discussed above, whole blood <b>800</b> is separated into buffy coat <b>820</b> and RBC's <b>810</b> as it moves outwardly atop lower plate <b>300.</b> Second bowl channel <b>410</b> and third bowl channel <b>740</b> are closed at this time. The inflow of whole blood <b>800</b> is continued until the separation volume <b>220</b> is filled with a combination of buffy coat <b>820</b> near the top and RBC's <b>810</b> near the bottom of centrifuge bowl <b>10.</b> By removing RBC's <b>810</b> from centrifuge bowl <b>10</b> via second bowl channel <b>410</b> only, additional volume is created for the inflow of whole blood <b>800</b> and the unremoved buffy coat <b>820</b> is subjected to rotational forces for an extended period of time. As centrifuge bowl <b>10</b> continues to rotate, some of the RBC's <b>810</b> that may be trapped in buffy coat <b>820</b> get pulled to the bottom of centrifuge bowl <b>10</b> and away from third bowl channel <b>740</b> and buffy coat <b>820.</b> Thus, when third bowl channel <b>740</b> is opened, the buffy coat <b>820</b> that is removed has a lower HCT%. By controlling the inflow rate of whole blood <b>800</b> and the outflow rates of buffy coat <b>820</b> and RBC's <b>810,</b> a steady state can be reached that yields a buffy coat <b>820</b> with an approximately constant HCT%.

The elimination of batch processing and the improved yields achieved by the current invention, have reduced the treatment time necessary to properly treat patients. For an average sized adult, 90-100 milliliters of buffy coat/white blood cells must be captured in order to conduct a full photophoresis treatment. In order to collect this amount of buffy coat/white blood cells, the present invention needs to process around 1.5 liters of whole blood. The required amount of buffy coat/white blood cells can be removed from the 1.5 liters of whole blood in about 30-45 minutes using the present invention, collecting around 60% or more of the total amount of the buffy coat/white blood cells that are subjected to the separation process. The captured buffy coat/white blood cells have an HCT of 2% or less. In comparison, one existing apparatus, the UVAR XTS, takes around 90 minutes to process 1.5 liters of whole blood to obtain the sufficient amount of buffy coat/white blood cells. The UVAR XTS only collects around 50% of the total amount of the buffy coat/white blood cells that are subjected to the separation process. The HCT of the buffy coat/white blood cells collected by the UVAR XTS is around, but not substantially below, 2%. Another existing apparatus, the Cobe Spectra^™ by Gambro, must process 10 liters of whole blood in order to collect the sufficient amount of buffy coat/white blood cells. This typically takes around 150 minutes, collecting only 10-15% of the total amount of the buffy coat/white blood cells that are subjected to the separation process, and having an HCT of about 2%. Thus, it has been discovered that while existing apparatus and systems require anywhere from 152 to 225 minutes to separate, process, treat, and reinfuse the requisite amount of white blood cells or buffy coat, the present invention can perform the same functions in less than 70 minutes. These times do not include the patient preparation or prime time. The times indicate only the total time that the patient is connected to the system <b>630.</b>

Referring back to <figref idref="f0012">FIG. 12</figref>, bowl <b>10</b> must be secured within rotational device <b>900</b> and allowed to rotate therein while remaining fluidly connected to system <b>630</b> (<figref idref="f0006">FIG. 6</figref>). As mentioned earlier, the use of a rotatable seal is undesirable. However, the cyclical rotation of bowl <b>10</b> and external conduit <b>20</b> can cause the fluid connection to fail in a variety of ways, including structural failure. In order to more effectively and efficiently fluidly connect bowl <b>10</b> to system <b>630,</b> conduit assembly <b>860</b> (<figref idref="f0014">FIG. 14</figref>) is utilized.

Referring to <figref idref="f0014">FIG. 14</figref>, conduit assembly <b>860</b> is illustrated. Conduit assembly <b>860</b> comprises external conduit <b>20,</b> connection sleeve <b>500,</b> anchor sleeve <b>870,</b> and first and second bearing rings <b>871, 872.</b> Connection sleeve <b>100</b> is adapted to be secured to bowl <b>10</b> when bowl <b>10</b> is in rotational device <b>900.</b> Anchor sleeve <b>870</b> is connected in a stationary position to restraint <b>918</b> of rotational device <b>900</b> (<figref idref="f0012">FIG. 12</figref>) and fluidly connects external conduit <b>20</b> to the rest of system <b>630.</b> Conduit assembly <b>860</b> further comprises first, second, and third assembly channels <b>990, 991,</b> and <b>992</b> that extend through conduit assembly <b>860</b> and through which fluids can flow.

External conduit <b>20</b> has an approximately constant diameter. Constructing external conduit <b>20</b> to have a constant diameter helps reduce the problem of the external conduit being too rigid. An excessively rigid external conduit will heat up and fail more quickly. Additionally, a constant diameter conduit is cheap/easy to manufacture, allows easy experimentation with connection sleeve <b>500</b> and anchor sleeve <b>870</b> sizes, and allows bearing rings <b>871, 872</b> to be easily slid thereon. External conduit <b>20</b> may be made of any type of flexible tubing (such as medical tubing) or other such device providing a sealed passageway for the flow of fluids, which may be pressurized, into or out of a reservoir of any sort, and which preferably can be disposable and sterilizable.

First and second bearing rings <b>871, 872</b> surround external conduit <b>20</b> and allow free rotation of external conduit <b>20</b> therein. When conduit assembly <b>860</b> is connected to bowl <b>10</b> and positioned in rotational device <b>900,</b> external conduit <b>20</b> is supported by bracket <b>910</b> through the use of holders <b>915</b> which are generically illustrated in <figref idref="f0012">FIG. 12</figref>. Referring to <figref idref="f0013">FIG. 13</figref>, holders <b>15</b> can be roller assemblies adapted to engage ring bearings <b>871</b> and <b>872</b> so as to allow rotation of external conduit <b>20</b> therein. The positioning of ring bearings <b>871</b> and <b>872</b> on external conduit 20 is critical to the cyclical duration of the external conduit <b>20.</b> For a centrifuge bowl having a height of 5 inches and a width of 5 inches, an external conduit having a length of approximately 21 inches is used. For this embodiment, it has been found that having first bearing ring <b>871</b> and second bearing <b>872</b> between 7.5 to 9.5 inches apart will increase the survival time of external conduit <b>20.</b> Preferably first bearing ring <b>871</b> and second bearing <b>872</b> will be approximately 8.5 inches apart. It is also preferable that first bearing ring <b>871</b> be between 5.0 to 5.5 inches away from first end <b>832</b> of connection sleeve <b>500</b> (<figref idref="f0016">FIG. 16</figref>). These distances are exemplary only. Optimal distance/spacing measurements are dependent on the length of the external conduit, the size of the centrifuge bowl, and the spacing between and number of holder <b>15</b> used.

Referring to <figref idref="f0016">FIG. 16</figref>, connection sleeve <b>500</b> has upper sleeve end <b>831</b> and lower sleeve end <b>832.</b> Lower sleeve end <b>832</b> comprises sleeve flange <b>790</b> which can be used to secure connection sleeve <b>500</b> to centrifuge bowl <b>10,</b> as described above. Lower sleeve end <b>832</b> also comprises lumen mounting recess <b>851</b> (<figref idref="f0015">FIG. 15</figref>). Lumen mounting recess <b>851</b> is adapted and sized to mount to a lumen <b>400</b> of a centrifuge bowl <b>10</b> as described above. Connection sleeve <b>500</b> preferably increases in diameter from upper sleeve end <b>831</b> to lower sleeve end <b>832</b> and is overmolded to first conduit end <b>861</b> of external conduit <b>20.</b> The remaining characteristics of connection sleeve <b>500</b> of conduit assembly <b>860</b> are described above.

Referring to <figref idref="f0017">FIG. 17</figref>, anchor sleeve <b>870</b> has first anchor end <b>873</b> and second anchor end <b>874.</b> Anchor sleeve <b>870</b> is overmolded to second conduit end <b>862</b> of external conduit <b>20</b> and increases in diameter from first anchor end <b>873</b> to second anchor end <b>874.</b>

<figref idref="f0018">FIGS. 18</figref> and <figref idref="f0019">19</figref> illustrate a second embodiment of bowl <b>10.</b> In order to avoid redundancy, only those important aspects of the second embodiment that differ from the first embodiment will be discussed. Referring to <figref idref="f0018">FIG. 18</figref>, the locking mechanism for securing the second embodiment of bowl <b>10</b> to rotational device <b>900</b> comprises both protrusions <b>150</b> and key slots <b>160.</b>

Referring now to <figref idref="f0019">FIG. 19</figref>, core floor <b>290</b> of core <b>200</b> extends past outer wall <b>210</b> into separation volume <b>220</b> and provides, for example, a curved floor flange <b>280.</b> When using this second embodiment to separate blood into its components, the curve of floor flange <b>280</b> may helps to move the buffy coat upward, possibly acting as a barrier to the buffy coat, thereby preventing the buffy coat from being dragged by the RBCs.

Additonally, lower plate <b>300</b> may comprise hollow cylinder <b>320.</b> In another embodiment, hollow cylinder <b>320</b> may be more than one cylinder stacked on top of each other having various diameters and heights. Hollow cylinder <b>320</b> has an outer diameter substantially less than lower plate <b>300</b> and is adapted to surround lumen <b>400</b> by tight fit and holds lower plate <b>300</b> suspended above housing floor <b>180.</b> Second channel <b>410</b> extends from housing floor <b>180</b> of outer housing <b>100</b> through hollow cylinder <b>320</b> to connection sleeve <b>500.</b> Hollow cylinder <b>320</b> provides a tight fit around inner lumen <b>410,</b> providing support for lumen <b>400</b> at its lower end.

Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and the practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, the scope of the invention being indicated by the following claims. It will further be apparent to those skilled in the art that this apparatus need not be limited to just the separation of whole blood. Other fluids requiring particle separation may also be treated by the methods, systems, and apparatus described herein. It will also be evident that the upward orientation of certain apparatus components could be altered to permit orientation of lumens and the connection sleeve in a downward direction.