Patent Publication Number: US-7914477-B2

Title: Apparatus for the continuous separation of biological fluids into components and method of using same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of United States patent application Ser. No. 10/654,742, filed Sep. 3, 2003, now U.S. Pat. No. 7,211,037, which is a continuation-in-part of U.S. patent application Ser. No. 10/375,629, filed Feb. 27, 2003, now U.S. Pat. No. 7,186,230, which claims the benefit of U.S. Provisional Application Ser. No. 60/361,287, filed Mar. 4, 2002, both of which are hereby incorporated by reference in their entireties. 
    
    
     TECHNICAL FIELD OF THE INVENTION 
     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. 
     BACKGROUND ART 
     With the advance of medical sciences, it has become possible to treat a patient&#39;s blood in closed-loop processes, returning the patient&#39;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&#39;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 U.S. Pat. No. 4,303,193, 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). PCT Applications WO 97/36581 and WO 97/36634, and U.S. Pat. Nos. 4,321,919; 4,398,906; 4,428,744; and 4,464,166 provide descriptions of extracorporeal photopheresis, and are hereby expressly incorporated by reference in their entirety. 
     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. 
     DISCLOSURE OF THE INVENTION 
     The present invention provided an apparatus for separating components of a fluid 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 adapted for rotation about a center axis; said outer housing containing a core in said interior volume; the core having an outer wall, an upper core end, and a lower core end; said core connected with said outer housing for rotation therewith; and providing a separation volume between said core and said outer housing; said core end having a lumen connector and a lumen connector top surface; a first lumen for providing fluid communication from the housing outlet through the lumen connector and then radially outward through the core to the fluid separation volume; a second lumen providing fluid communications from the housing outlet extending axially along center axis to housing floor; a connection sleeve which forms with the lumen connector a chamber and provide fluid communications between the housing outlet and the separation volume. 
     In another embodiment of the present invention is provided a method for separating components of a fluid into a higher density component and a lower density component comprising: providing a centrifuge bowl have a first bowl channel, a second bowl channel, and a bowl chamber; 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 bowl chamber. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is described in detail with respect to the accompanying drawings, which illustrate an embodiment of the inventive apparatus, assemblies, systems, and methods. 
         FIG. 1  is a schematic representation of an embodiment of a disposable kit for use in photopheresis therapy embodying features of the present invention. 
         FIG. 2  is an elevated perspective view of an embodiment of a cassette for controlling fluid flow in the disposable photopheresis kit of  FIG. 1 . 
         FIG. 3  is an exploded view of the cassette of  FIG. 2 . 
         FIG. 4  is a top view of the cassette of  FIG. 2  with the cover removed and showing internal tubular circuitry. 
         FIG. 5  is a bottom view of a cover of cassette of  FIG. 2 . 
         FIG. 6  is an elevated perspective view of an embodiment of a filter assembly. 
         FIG. 7  is bottom perspective view of the filter assembly of  FIG. 6 . 
         FIG. 8  is an exploded view of the filter assembly of  FIG. 6 . 
         FIG. 9  is a rear perspective view of the filter assembly of  FIG. 6 . 
         FIG. 10  is schematic representation of the filter assembly of  FIG. 6  coupled to pressure sensors and a data processor. 
         FIG. 11  is a front view of an irradiation chamber. 
         FIG. 12  is a side longitudinal view of the irradiation chamber of  FIG. 11 . 
         FIG. 13  is a side transverse view of the irradiation chamber of  FIG. 11   
         FIG. 14  is a cut-away view of a section of the first plate and the second plate prior to being joined together to form the irradiation chamber of  FIG. 11 . 
         FIG. 15  is a cut-away dimensional end view of the irradiation chamber of  FIG. 11 . 
         FIG. 16  is a perspective view of the irradiation chamber of  FIG. 11  positioned within a UVA light assembly. 
         FIG. 17  is an elevated perspective view of an embodiment of a permanent tower system for use in conjunction with a disposable kit for facilitating a photopheresis therapy session. 
         FIG. 18  is a cross-sectional view of an embodiment of the photoactivation chamber, without a UVA light assembly, used in the tower system of  FIG. 17 . 
         FIG. 19  is a cross-sectional view of an embodiment of the centrifuge chamber used in the tower system of  FIG. 17 . 
         FIG. 20  is an electrical schematic of the leak detection circuit provided in the photoactivation chamber of  FIG. 18 . 
         FIG. 21  is an electrical schematic of the leak detection circuit provided in the centrifuge chamber of  FIG. 19 . 
         FIG. 22  is an elevated perspective view of an embodiment of the fluid flow control deck of the tower system of  FIG. 17 . 
         FIG. 23  is a perspective bottom view of the control deck of  FIG. 22 . 
         FIG. 24  is an exploded view of the control deck of  FIG. 22 . 
         FIG. 25  is a top perspective view of the control deck of  FIG. 22  with the cassette of  FIG. 2  loaded thereon. 
         FIG. 26  is a flowchart of an embodiment of a photopheresis treatment process. 
         FIG. 27  is a schematic of an embodiment of the fluid flow circuit used in performing the treatment process of  FIG. 26 . 
         FIG. 28  is top perspective view an embodiment of a peristaltic pump. 
         FIG. 29  is a cross sectional side view of the peristaltic pump of  FIG. 28 . 
         FIG. 30  is a top perspective view the rotor of the peristaltic pump of  FIG. 29 . 
         FIG. 31  is a bottom perspective view of the rotor of  FIG. 30 . 
         FIG. 32  is a top view of the peristaltic pump of  FIG. 28 . 
         FIG. 33  is a top view of the peristaltic pump of  FIG. 28  in a loading position and near the cassette of  FIG. 2 . 
         FIG. 34  is an electrical schematic of the infrared communication port circuit. 
         FIG. 35  illustrates an embodiment of a centrifuge bowl and a rotating frame. 
         FIG. 36  is a dimensional view of the bowl of  FIG. 35 . 
         FIG. 37  is an exploded view of the bowl of  FIG. 36 . 
         FIG. 38  shows a cross sectional view of the bowl of  FIG. 36  along the line XIX-XIX. 
         FIG. 39A  shows a cross sectional view of a connection sleeve in place with a lumen connector of the bowl of  FIG. 38  along the line XX. 
         FIG. 39B  shows another cross sectional view of a connection sleeve in place with a lumen connector of the bowl of  FIG. 38 . 
         FIG. 40  shows a cross sectional view of the top core of the bowl of  FIG. 37 . 
         FIG. 41  shows a dimensional view of the top core and upper plate of  FIG. 37 . 
         FIG. 42  shows a bottom view of the top core of  FIG. 41 . 
         FIG. 43A  shows a dimensional exploded view of the bottom core and a lower plate of the bowl of  FIG. 37 . 
         FIG. 43B  shows an dimensional cross section view of the bottom core and a lower plate of the bowl of  FIG. 43A  attached together. 
         FIG. 44  shows an exploded side view of the bottom core and a lower plate of  FIG. 43A . 
         FIG. 45  shows a dimensional view of another embodiment of a conduit assembly. 
         FIG. 46  shows a dimensional view of the connection sleeve of  FIG. 45 . 
         FIG. 47  shows a dimensional view of one end of conduit assembly of  FIG. 45 . 
         FIG. 48  shows a dimensional view of an anchor end of the present invention. 
         FIG. 49  shows a lateral cross-sectional view of an anchor end. 
         FIG. 50  shows a horizontal cross-sectional view of an anchor end taken along line XXI. 
         FIG. 51  illustrates a dimensional view of the rotating frame of  FIG. 35 . 
         FIG. 52  is an enlarged view of a holder for an external conduit. 
         FIG. 53  shows an alternative embodiment of the bowl with the cross-section taken similarly to that shown in  FIG. 38 . 
         FIG. 54  shows an alternative embodiment of the top core. 
         FIG. 55  shows an alternative embodiment of the connection sleeve. 
     
    
    
     MODES FOR CARRYING OUT THE INVENTION 
     Features of the present invention are embodied in the permanent blood driving equipment, the disposable photopheresis kit, the various devices which make up the disposable kit, and the corresponding treatment process. The following written description is outlined as follows: 
     I. Disposable Photopheresis Kit
         A. Cassette for Controlling Fluid Flow
           1. Filter Assembly   
           B. Irradiation Chamber   C. Centrifuge Bowl
           1. Drive Tube   
               

     II. Permanent Tower System
         A Photoactivation Chamber   B. Centrifuge Chamber   C. Fluid Flow Control Deck
           1. Cassette Clamping Mechanism   2. Self-Loading Peristaltic Pumps   
           D. Infra-Red Communication       

     III. Photopheresis Treatment Process 
     The above-outline is included to facilitate understanding of the features of the present invention. The outline is not limiting of the present invention and is not intended to categorize or limit any aspect of the invention. The inventions are described and illustrated in sufficient detail that those skilled in this art can readily make and use them. However, various alternatives, modifications, and improvements should become readily apparent without departing from the spirit and scope of the invention. Specifically, while the invention is described in the context of a disposable kit and permanent blood drive system for use in photopheresis therapy, certain aspects of the invention are not so limited and are applicable to kits and systems used for rendering other therapies, such as apheresis or any other extracorporeal blood treatment therapy. 
     I. Disposable Photopheresis Kit 
       FIG. 1  illustrates disposable photopheresis kit  1000  embodying features of the present invention. It is necessary that a new disposable sterile kit be used for each therapy session. In order to facilitate the circulation of fluids through photopheresis kit  1000 , and to treat blood fluids circulating therethrough, photopheresis kit  1000  is installed in permanent tower system  2000  ( FIG. 17 ). The installation of photopheresis kit  1000  into tower system  2000  is described in detail below. 
     Photopheresis kit  1000  comprises cassette  1100 , centrifuge bowl  10 , irradiation chamber  700 , hematocrit sensor  1125 , removable data card  1195 , treatment bag  50 , and plasma collection bag  51 . Photopheresis kit  1000  further comprises saline connector spike  1190  and anticoagulant connector spike  1191  for respectively connecting saline and anticoagulant fluid bags (not shown). Photopheresis kit  1000  has all the necessary tubing and connectors to fluidly connect all devices and to route the circulation of fluids during a photopheresis treatment session. All tubing is sterile medical grade flexible tubing. Triport connectors  1192  are provided at various positions for the introduction of fluids into the tubing if necessary. 
     Needle adapters  1193  and  1194  are provided for respectively connecting photopheresis kit  1000  to needles for drawing whole blood from a patient and returning blood fluids to the patient. Alternatively, photopheresis kit  1000  can be adapted to use a single needle to both draw whole blood from the patient and return blood fluids to the patient. However, a two needle kit is preferred because of the ability to simultaneously draw whole blood and return blood fluids to the patient. When a patient is hooked up to photopheresis kit  1000 , a closed loop system is formed. 
     Cassette  1100  acts both as a tube organizer and a fluid flow router. Irradiation chamber  700  is used to expose blood fluids to UV light. Centrifuge bowl  10  separates whole blood into its different components according to density. Treatment bag  50  is a 1000 mL three port bag. Straight bond port  52  is used to inject a photoactivatable or photosensitive compound into treatment bag  50 . Plasma collection bag  51  is 1000 mL two port bag. Both treatment bag  50  and plasma collection bag  51  have a hinged cap spike tube  53  which can be used for drainage if necessary. Photopheresis kit  1000  further comprises hydrophobic filters  1555  and  1556  which are adapted to connect to pressure transducers  1550  and  1551  to filter  1500  via vent tubes  1552  and  1553  for monitoring and controlling the pressures within tubes connecting the patient ( FIG. 10 ). Monitoring the pressure helps ensure that the kit is operating within safe pressure limits. The individual devices of photopheresis kit  1000 , and their functioning, are discussed below in detail. 
     A. Cassette for Controlling Fluid Flow 
       FIG. 2  shows a top perspective view of a disposable cassette  1100  for valving, pumping, and controlling the movement of blood fluids during a photopheresis treatment session. Cassette  1100  has housing  1101  that forms an internal space that acts as a casing for its various internal components and tubular circuitry. Housing  1101  is preferably made of hard plastic, but can be made of any suitably rigid material. Housing  1101  has side wall  1104  and top surface  1105 . Side wall  1104  of housing  1101  has tabs  1102  and  1103  extending therefrom. During a photopheresis treatment, cassette  1100  needs to be secured to deck  1200  of tower system  2000 , as is best illustrated in  FIG. 25 . Tabs  1102  and  1103  help position and secure cassette  1100  to deck  1200 . 
     Cassette  1100  has fluid inlet tubes  1106 ,  1107 ,  1108 ,  1109 ,  1110 ,  1111 , and  1112  for receiving fluids into cassette  1100 , fluid outlet tubes  1114 ,  1115 ,  1116 ,  1117 ,  1118 , and  1119  for expelling fluids from cassette  1100 , and fluid inlet/outlet tube  1113  that can be used for both introducing and expelling fluids into and out of cassette  1100 . These fluid input and output tubes fluidly couple cassette  1100  to a patient being treated, as well as the various devices of photopheresis kit  1000 , such as centrifuge bowl  10 , irradiation chamber  700 , treatment bag  50 , plasma collection bag  51 , and bags containing saline, anticoagulation fluid to form a closed-loop extracorporeal fluid circuit ( FIG. 27 ). 
     Pump tube loops  1120 ,  1121 ,  1122 ,  1123 , and  1124  protrude from side wall  1104  of housing  1101 . Pump tube loops  1120 ,  1121 ,  1122 ,  1123 , and  1124  are provided for facilitating the circulation of fluids throughout photopheresis kit  1000  during therapy. More specifically, when cassette  1100  is secured to deck  1200  for operation, each one of said pump tube loops  1120 ,  1121 ,  1122 ,  1123 , and  1124  are loaded into a corresponding peristaltic pump  1301 ,  1302 ,  1303 ,  1304 , and  1305  ( FIG. 4 ). Peristaltic pumps  1301 ,  1302 ,  1303 ,  1304 , and  1305  drive fluid through the respective pump tube loops  1120 ,  1121 ,  1122 ,  1123 , and  1124  in a predetermined direction, thereby driving fluid through photopheresis kit  1000  ( FIG. 1 ) as necessary. The operation and automatic loading and unloading of peristaltic pumps  1301 ,  1302 ,  1303 ,  1304 , and  1305  is discussed in detail below with respect to  FIGS. 28-33 . 
     Turning now to  FIG. 3 , cassette  1100  is shown with housing  1101  in an exploded state. For ease of illustration and description, the internal tubular circuitry within housing  1101  is not illustrated in  FIG. 3 . The internal tubular circuitry is illustrated in  FIG. 4  and will be discussed in relation thereto. Cassette  1100  has filter assembly  1500  positioned therein and in fluid connection with inlet tube  1106 , outlet tube  1114 , and one end of each of pump tube loops  1120  and  1121 . Filter assembly  1500  comprises vent chambers  1540  and  1542 . Filter assembly  1500 , and its functioning, is discussed in detail below with respect to  FIGS. 6-10 . 
     Housing  1101  comprises cover  1130  and base  1131 . Cover  1130  has top surface  1105 , a bottom surface  1160  ( FIG. 5 ), and side wall  1104 . Cover  1130  has openings  1132  and  1133  for allowing vent chambers  1540  and  1542  of filter assembly  1500  to extend therethrough. Side wall  1104  has a plurality of tube slots  1134  to allow the inlet tubes, outlet tubes, and pump loop tubes to pass into the internal space of housing  1101  for connection with the internal tubular circuitry located therein. Only a few tube slots  1134  are labeled in  FIG. 3  to avoid numerical crowding. Tabs  1102  and  1103  are positioned on side wall  1104  so as not to interfere with tube slots  1134 . Cover  1130  has occlusion bars  1162  and  1162 A extending from bottom surface  1160  ( FIG. 5 ). Occlusion bars  1162  and  1162 A are preferably molded into bottom surface  1160  of cover  1130  during its formation. 
     Base  1131  has a plurality of U-shaped tube-holders  1135  extending upward from top surface  1136 . U-shaped tube holders  1135  hold the inlet tubes, outlet tubes, pump loop tubes, filter assembly, and internal tubular circuitry in place. Only a few U-shaped holders  1135  are labeled in  FIG. 3  to avoid numerical crowding. Preferably, a U-shaped holder  1135  is provided on base  1131  at each location where an inlet tube, an outlet tube, or a pump loop tube passes through a tube slot  1134  on side wall  1104 . Male extrusions  1136  protrude from top surface  1136  of base  1131  for mating with corresponding female holes  1161  located on bottom surface  1160  of cover  1130  ( FIG. 5 ). Preferably, a male protrusion  1136  is located at or near each of the four corners of base  1130  and near filter  1500 . Male protrusions  1136  mate with the female holes  1161  to form a snap-fit and secure base  1131  to cover  1130 . 
     Base  1131  further comprises a hub  1140 . Hub  1140  is a five-way tube connector used to connect five tubes of the internal tubular circuitry. Preferably, three apertures  1137  are located near and surround three of the tubes leading into hub  1140 . Hub  1140  acts as a centralized junction which can be used, in conjunction with compression actuators  1240 - 1247  ( FIG. 22 ), to direct fluids through photopheresis kit  1000  and to and from the patient. In addition to hub  1140 , appropriate tube connectors, such as T-connectors  1141  and Y-connector  1142 , are used to obtain the desired flexible tubing pathways. 
     Five apertures  1137  are located on the floor of base  1130 . Each aperture  1137  is surrounded by an aperture wall  1138  having slots  1139  for passing portions of the internal tubular circuitry therethrough. An elongated aperture  1157  is also provided on the floor of base  1131 . Apertures  1137  are located on base  1131  to align with corresponding compression actuators  1243 - 1247  of deck  1200  ( FIG. 22 ). Aperture  1157  is located on base  1131  to align with compression actuators  1240 - 1242  of deck  1200  ( FIG. 22 ). Each aperture  1137  is sized so that a single compression actuator  1243 - 1247  can extend therethrough. Aperture  1157  is sized so that three compression actuators  1240 - 1242  can extend therethrough. Compression actuators  1240 - 1247  are used to close/occlude and open certain fluid passageways of the internal tubular circuitry in order to facilitate or prohibit fluid flow along a desired path. When it is desired to have a certain passageway open so that fluid can flow therethrough, the compression actuator  1240 - 1247  for that passageway is in a lowered position However, when it is desired to have a certain fluid passageway closed so that fluid can not flow therethrough, the appropriate compression actuator  1240 - 1247  is raised, extending the compression actuator  1240 - 1247  through aperture  1137  or  1157  and compressing a portion of the flexible tubular circuitry against bottom surface  1160  ( FIG. 5 ) of cover  1130 , thereby closing that passageway. Preferably, occlusion bars  1163  and  1173  ( FIG. 5 ) are positioned on bottom surface  1160  to align with the compression actuators  1240 - 1247  so that the portion of flexible tubing being occluded is compressed against occlusion bar  1163  or  1173 . Alternatively, the occlusion bar can be omitted or located on the compression actuators themselves. 
     It is preferable for cassette  1100  to have a unique identifier that can communicate with and relay information to permanent tower system  2000 . The unique identifier is provided to ensure that the disposable photopheresis kit is compatible with the blood drive equipment into which it is being loaded, and that the photopheresis kit is capable of running the desired treatment process. The unique identifier can also be used as a means to ensure that the disposable photopheresis kit is of a certain brand name or make. In the illustrated example, the unique identifier is embodied as data card  1195  ( FIG. 2 ) that is inserted into data card receiving port  2001  of permanent tower system  2000  ( FIG. 17 ). Data card  1195  has both read and write capabilities and can store data relating to the treatment therapy performed for future analysis. The unique identifier can also take on a variety of forms, including, for example, a microchip that interacts with the blood drive equipment when the kit is loaded, a bar code, or a serial number. 
     Cover  1130  has data card holder  1134  for holding data card  1195  ( FIG. 1 ). Data card holder  1134  comprises four elevated ridges in a segmented rectangular shape for receiving and holding data card  1195  to cassette  1100 . Data card holder  1134  holds data card  1195  in place via a snap-fit ( FIG. 2 ). 
     Referring now to  FIGS. 1 and 4 , the internal tubular circuitry of cassette  1100  will now be discussed. At least a portion of the internal tubular circuitry is preferably made of flexible plastic tubing that can be pinched shut by the exertion of pressure without compromising the hermetic integrity of the tube. Base  1131  of cassette  1100  is illustrated in  FIG. 4  so that the internal tubular circuitry can be viewed. Inlet tubes  1107  and  1108  and outlet tube  1115  are provided for coupling cassette  1100  to centrifuge bowl  10  ( FIG. 1 ). More specifically, outlet tube  1115  is provide for delivering whole blood from cassette  1100  to centrifuge bowl  10 , and inlet tubes  1107  and  1108  are respectively provide for returning a lower density blood components and higher density blood components to cassette  1100  for further routing through photopheresis kit  1000 . The lower density blood components can include, for example, plasma, leukocytes, platelets, buffy coat, or any combination thereof. The higher density components can include, for example, red blood cells. Outlet tube  1117  and inlet tube  1112  fluidly couple cassette  1100  to irradiation chamber  700 . More specifically, outlet tube  1117  is provided for delivering an untreated lower density blood component, for example buffy coat, to irradiation chamber  700  for exposure to photo energy, while inlet tube  1112  is provided for returning the treated lower density blood component to cassette  1100  for further routing. 
     Inlet tube  1111  and outlet tube  1116  couple treatment bag  50  to cassette  1100 . Outlet tube  1116  is provided to deliver an untreated low density blood component, for example buffy coat, to treatment bag  50 . Outlet tube  1116  has hematocrit (“HCT”) sensor  1125  operably connected thereto to monitor for the introduction of a high density blood component, such as red blood cells. HCT sensor  1125  is a photo sensor assembly and is operably coupled to a controller. HCT sensor  1125  sends a detection signal to the controller when red blood cells are detected in outlet tube  1116  and the controller will take the appropriate action. Inlet tube  1111  is provided to return the untreated low density blood component from treatment bag  50  to cassette  1100  for further routing. Inlet tubes  1109  and  1110  are respectively connected to a saline and anticoagulant storage bags (not shown) via spikes  1190  and  1191  and are provided for delivering saline and an anticoagulant fluid to cassette  1100  for further routing to the patient. 
     Inlet/Outlet tube  1113  and outlet tube  1118  couple plasma collection bag  50  to cassette  1100 . More specifically, outlet tube  1118  delivers a blood component, such as plasma, to plasma collection bag  51 . Inlet/Outlet tube  1113  can be used to either deliver red blood cells to plasma collection bag  51  from cassette  1100  or return the blood component(s) that build up in plasma collection bag  51  to cassette  1100  for further routing. Inlet tube  1106  and outlet tubes  1119  and  1114  are coupled to a patient. Specifically, outlet tube  1114  is provided to return treated blood, saline, untreated blood components, treated blood components, and other fluids back to the patient. Inlet tube  1106  is provided for delivering untreated whole blood (and a predetermined amount of an anticoagulant fluid) from the patient to cassette  1100  for routing and treatment within photopheresis kit  1000 . Outlet tube  1119  is specifically provided for delivering an anticoagulant fluid to inlet tube  1106 . It is preferable that all tubing is disposable medical grade sterile tubing. Flexible plastic tubing is the most preferred. 
     Cassette  1100  has five pump tube loops  1120 ,  1121 ,  1122 ,  1123 , and  1124  for driving blood fluids throughout cassette  1100  and photopheresis kit  1000 . More specifically, pump tube loop  1121  loads into whole blood pump  1301  and respectively drives whole blood in and out of cassette  1100  via inlet tube  1106  and outlet tube  1115 , passing through filter  1500  along the way. Pump loop tube  1120  loads into return pump  1302  and drives blood fluids through filter  1500  and back to the patient via outlet tube  1114 . Pump loop tube  1122  loads into red blood cell pump  1305  and draws red blood cells from centrifuge bowl  10  and drives them into cassette  1100  via inlet line  1108 . Pump loop tube  1123  loads into anticoagulant pump  1304  and drives an anticoagulant fluid into cassette  1100  via inlet tube  1124  and out of cassette  1100  to via outlet tube  1119 , which connects with inlet tube  1106 . Pump loop tube  1124  loads into recirculation pump  1303  and drives blood fluids, such as plasma, through treatment bag  50  and irradiation chamber  700  from cassette  1100 . 
     Each of peristaltic pumps  1301 - 1305  are activated when necessary to perform the photopheresis treatment therapy according to an embodiment of the method of the present invention which is described below in relation to  FIGS. 26-27 . Peristaltic pumps  1301 - 1305  can be operated one at a time or in any combination. The pumps  1301 - 1305  work in conjunction with compression actuators  1240 - 1247  to direct fluids through desired pathways of photopheresis kit  1000 . Apertures  1137  and  1157  are strategically located on base  1131  along the internal tubular circuitry to facilitate proper routing. Through the use of compression actuators  1240 - 1247 , the fluids can be directed along any pathway or combination thereof. 
     1. The Filter Assembly 
     Filter  1500 , which is located within cassette  1100  as described above, is illustrated in detail in  FIGS. 6-10 . Referring first to  FIGS. 6 and 7 , filter  1500  is illustrated fully assembled. Filter  1500  comprises a filter housing  1501 . Filter housing  1501  is preferably constructed of a transparent or translucent medical grade plastic. However, the invention is not so limited and filter housing  1501  can be constructed of any material that will not contaminate blood or other fluids that are flowing therethrough. 
     Filter housing  1501  has four fluid connection ports extruding therefrom, namely whole blood inlet port  1502 , whole blood outlet port  1503 , treated fluid inlet port  1504 , and treated fluid outlet port  1505 . Ports  1502 - 1505  are standard medical tubing connection ports that allow medical tubing to be fluidly connected thereto. Ports  1502 - 1505  respectively contain openings  1506 ,  1507 ,  1508  and  1509 . Openings  1506 ,  1507 ,  1508  and  1509  extend through ports  1502 ,  1503 ,  1504  and  1505 , forming fluid passageways into filter housing  1501  at the desired locations. 
     Ports  1502 ,  1503 ,  1504  and  1505  are also used to secure filter  1500  within cassette  1100 . In doing so, ports  1502 ,  1503 ,  1504  and  1505  can engage U-shaped fasteners  1135  of cassette  1100  ( FIG. 3 ). Filter housing  1501  also has a protrusion  1510  extending the bottom surface of housing floor  1518 . Protrusion  1510  fits into a guide hole of base  1131  of cassette  1100  ( FIG. 3 ). 
     Referring now to  FIG. 8 , filter  1500  is illustrated in an exploded state. Filter housing  1501  is a two-piece assembly comprising roof  1511  and base  1512 . Roof  1511  is connected to base  1512  by any means known in the art, such as ultrasonic welding, heat welding, applying an adhesive, or by designing roof  1511  and base  1512  so that a tight fit results between the two. While filter housing  1501  is illustrated as a two-piece assembly, filter housing  1501  can be either a single piece structure or a multi-piece assembly. 
     Base  1512  has chamber separation wall  1513  extending upward from a top surface of housing floor  1518  ( FIG. 7 ). When base  1512  and roof  1511  are assembled, top surface  1515  of chamber separation wall  1513  contacts the bottom surface of roof  1511 , forming two chambers within the filter housing, whole blood chamber  1516  and filter chamber  1517 . Fluid can not directly pass between whole blood chamber  1516  and filter chamber  1517 . 
     Whole blood chamber  1516  is a substantially L-shaped chamber having floor  1514 . Whole blood chamber  1516  has a whole blood inlet hole  1519  and a whole blood outlet hole (not illustrated) in floor  1514 . Whole blood inlet hole  1519  and the whole blood outlet hole are located at or near the ends of the substantially L-shaped whole blood chamber  1516 . Whole blood inlet hole  1519  forms a passageway with opening  1506  of inlet port  1502  so that a fluid can flow into whole blood chamber  1516 . Similarly, the whole blood outlet hole (not illustrated) forms a passageway with opening  1507  of outlet port  1503  so that fluid can flow out of whole blood chamber  1516 . 
     Filter chamber  1517  has floor  1520 . Floor  1520  has elevated ridge  1521  extending upward therefrom. Elevated ridge  1521  is rectangular and forms a perimeter. While elevated ridge  1521  is rectangular in the illustrated embodiment, elevated ridge  1521  can be any shape so long as it forms an enclosed perimeter. The height of elevated ridge  1521  is less than the height of chamber separation wall  1513 . As such, when roof  1511  and base  1512  are assembled, space exists between the top of elevated ridge  1521  and the bottom surface of roof  1511 . Elevated ridge  1521  and chamber separation wall  1513  form a trench  1524  there between. 
     In order to facilitate fluid flow through filter chamber  1517 , floor  1520  of filter chamber  1517  has treated fluid inlet hole  1522  and treated fluid outlet hole  1523 . Treated fluid inlet hole  1522  is located exterior of the perimeter formed by elevated ridge  1521  and forms a passageway with opening  1508  of inlet port  1504  so that a fluid can flow into filter chamber  1517  from outside filter housing  1501 . Treated fluid outlet hole  1523  is located interior of the perimeter formed by elevated ridge  1521  and forms a passageway with opening  1509  of outlet port  1505  so that a fluid can flow out of filter chamber  1517 . 
     Filter  1500  further comprises filter element  1530 . Filter element  1530  comprises frame  1531  having filter media  1532  positioned therein. Frame  1531  has a neck  1534  that forms a filter inlet hole  1533 . Filter element  1530  is positioned in filter chamber  1517  so that frame  1531  fits into trench  1524  and neck  1534  surrounds treated blood inlet hole  1522 . Filter inlet hole  1533  is aligned with treated fluid inlet hole  1522  so that incoming fluid can freely flow through holes  1522  and  1533  into filter chamber  1517 . Frame  1531  of filter element  1530  forms a hermetic fit with elevated ridge  1521 . All fluid that enters filter chamber  1517  through holes  1522  and  1533  must pass through filter media  1532  in order to exit filter chamber  1517  via treated fluid outlet hole  1523 . Filter media  1532  preferably has a pore size of approximately 200 microns. Filter media  1532  can be formed of woven mesh, such as woven polyester. 
     Filter chamber  1517  further comprises filter vent chamber  1540  within roof  1511 . Filter vent chamber  1540  has gas vent  1541  in the form of a hole ( FIG. 9 ). Because gas vent  1541  opens into filter vent chamber  1540  which in turn opens into filter chamber  1517 , gases that build-up within filter chamber  1517  can escape through gas vent  1541 . Similarly, whole blood chamber  1516  comprises blood vent chamber  1542  within roof  1511 . Blood vent chamber  1541  has gas vent  1543  in the form of a hole. Because gas vent  1543  opens into blood vent chamber  1542  which in turn opens into whole blood chamber  1517 , gases that build-up in whole blood chamber  1516  can escape via gas vent  1543 . 
       FIG. 10  is a top view of filter  1500  having pressure sensors  1550  and  1551  connected to gas vents  1541  and  1543 . Pressure sensors  1550  and  1551  are preferably pressure transducers. Pressure sensor  1550  is connected to gas vent  1541  via vent tubing  1552 . Vent tubing  1552  fits into gas vent  1541  so as to form a tight fit and seal. Because gas vent  1541  opens into filter vent chamber  1540  which in turn opens into filter chamber  1517 , the pressure in vent tubing  1552  is the same as in filter chamber  1517 . By measuring the pressure in vent tubing  1552 , pressure sensor  1550  also measures the pressure within filter chamber  1517 . Similarly, pressure sensor  1551  is connected to gas vent  1543  via vent tubing  1553 . Vent tubing  1553  fits into gas vent  1543  so as to form a tight fit and seal and pressure sensor  1551  measures the pressure within whole blood chamber  1516 . Filter vent chamber  1540  and blood vent chamber  1542  extend through openings  1132  and  1133  of cassette  1100  when filter  1500  is positioned therein ( FIG. 2 ). This allows the pressure within chambers  1516  and  1517  to be monitored while still protecting filter chamber  1500  and the fluid connections thereto. 
     Pressure sensors  1550  and  1551  are coupled to controller  1554 , which is a properly programmed processor. Controller  1554  can be a main processor used to drive the entire system or can be a separate processor coupled to a main processor. Pressure sensors  1550  and  1551  produce electrical output signals representative of the pressure readings within chambers  1517  and  1516  respectively. Controller  1554  receives on a frequent or continuous basis data representing the pressure within chambers  1516  and  1517 . Controller  1554  is programmed with values representing desired pressures within chambers  1516  and  1517 . Controller  1554  continuously analyzes the pressure data it receives from pressure sensors  1550  and  1551  to determine whether the pressure readings are within a predetermined range from the desired pressure for chambers  1517  and  1516 . Controller  1554  is also coupled to whole blood pump  1301  and return pump  1302 . In response to the pressure data received from pressure sensors  1551  and  1550 , controller  1554  is programmed to control the speed of whole blood pump  1301  and return pump  1302 , thereby adjusting the flow rates through the pumps  1301  and  1301 . Adjusting these flow rates in turn adjust the pressure within whole blood chambers  1516  and filter chamber  1517  respectively. It is in this way that the pressure within the lines drawing and returning blood to and from the patient is maintained at acceptable levels. 
     The functioning of filter  1500  during a photopheresis therapy session will now be discussed in relation to  FIGS. 1 ,  6 , and  10 . While the functioning of filter  1500  will be described in detail with respect to drawing whole blood from a patient and returning a component of said whole blood back into the patient after it is treated, the invention is not so limited. Filter  1500  can be used in connection with almost any fluid, including red blood cells, white blood cells, buffy coat, plasma, or a combination thereof. 
     Whole blood pump  1601  draws whole blood from a patient who is connected to photopheresis kit  1000  via a needle connected to port  1193 . The rotational speed of whole blood pump is set so that the pressure of the line drawing the whole blood from the patient is at an acceptable level. Upon being drawn from the patient, the whole blood passes into cassette  1100  via inlet tube  1106 . Inlet tube  1106  is fluidly connected to inlet port  1502  of filter  1500 . The whole blood passes through opening  1506  of inlet port  1502  and into L-shaped whole blood chamber  1516 . The whole blood enters chamber  1516  through inlet hole  1519  which is located on floor  1514 . As more whole blood enters chamber  1516 , the whole blood spills along floor  1514  until it reaches the whole blood outlet hole (not illustrated) at the other end of L-shaped whole blood chamber  1516 . As discussed above, the whole blood outlet whole forms a passageway with opening  1507  of outlet port  1503 . The whole blood that is within chamber  1516  flows across floor  1514 , through the whole blood outlet hole, into outlet port  1503 , and out of filter  1500  through opening  1507 . 
     As the whole blood passes through whole blood chamber  1516 , gases that are trapped in the whole blood escape. These gases collect in blood vent chamber  1542  and then escape via gas vent  1543 . Pressure sensor  1551  continuously monitors the pressure within blood chamber  1516  through vent tube  1553  and transmits corresponding pressure data to controller  1554 . Controller  1554  analyzes the received pressure data and if necessary adjusts the speed of whole blood pump  1301 , thereby adjusting the flow rate and pressure within chamber  1516  and inlet tube  1106 . Controller  1554  adjust the pump speed to ensure that the pressure is within the desired pressure range. 
     The whole blood then exits filter  1500  through outlet port  1503  and passes out of cassette  1100  via outlet tube  1115 . The whole blood is then separated into components and/or treated as described in detail below. Before being returned to the patient, this treated fluid (i.e. treated blood or blood components) must be filtered. Untreated fluids such as red blood cells also must be filtered and will subjected to the below filtering process. The treated fluid is fed into filter chamber  1517  through opening  1508  of inlet port  1504 . Inlet port  1504  is fluidly connected to pump loop tube  1120 . The treated fluid enters filter chamber  1517  through inlet hole  1522  and passes through filter inlet hole  1533  of filter element  1530 . The treated fluid fills filter chamber  1517  until it spills over frame  1531  of filter element  1530 , which is secured to elevated ridge  1521 . The treated fluid passes through filter media  1532 . Filter media  1532  removes contaminants and other undesired materials from the treated fluid while at the same facilitating the release of trapped gases from the treated fluid. The treated fluid that passes through filter media  1532  gathers on floor  1520  of filter chamber  1517  within the perimeter formed by elevated ridge  1521 . This treated fluid then passes into treated fluid outlet hole  1523  and out of filter  1500  through opening  1506  of outlet port  1502 . The treated fluid is then returned to the patient via outlet tube  1114 , which is fluidly connected to outlet port  1502 . The treated fluid is driven through filter chamber  1517  and outlet tube  1114  by return pump  1302 . 
     Gases that are trapped in the treated fluid escape and collect in filter vent chamber  1540  as the treated fluid flows through filter chamber  1517 . These gases then escape filter  1500  via gas vent  1541 . Pressure sensor  1550  continuously monitors the pressure within filter chamber  1517  through vent tube  1552  and transmits corresponding pressure data to controller  1554 . Controller  1554  analyzes the received pressure data and compares it to the desired pressure value and range. If necessary, controller  1554  adjusts the speed of return pump  1302 , thereby adjusting the flow rate and pressure within chamber  1517  and outlet tube  1114 . 
     B. Irradiation Chamber 
       FIGS. 11-16  illustrate irradiation chamber  700  of photopheresis kit  1000  in detail. Referring first to  FIG. 11 , irradiation chamber  700  is formed by joining two plates, a front and a back plate having a thickness of preferably about 0.06 in. to about 0.2 in., which are preferably comprised of a material ideally transparent to the wavelength of electromagnetic radiation. In the case of ultraviolet A radiation, polycarbonate has been found most preferred although other materials such as acrylic may be employed. Similarly, many known methods of bonding may be employed and need not be expanded on here. 
     The first plate  702  has a first surface  712  and a second surface  714 . In a preferred embodiment the first plate  702  has a first port  705  on a first surface  712 , in fluid communications with the second surface  714 . The second surface  714  of the first plate  702  has a raised boundary  726 A defining an enclosure. The boundary  726 A preferably extends substantially perpendicular from the second surface  714  (i.e. about 80-100 degrees). Extending from the second surface  714  (preferably substantially perpendicularly) are raised partitions  720 A. The boundary  726 A surrounds the partitions  720 A. One end of each partition  720 A extends and contacts the boundary  726 A. 
     The second plate  701  has a first surface  711  and a second surface  713 . In a preferred embodiment the second plate  701  preferably has a second port  730  on a first surface  711 , in fluid communications with the second surface  713 . The second surface  713  of the back plate  701  has a raised boundary  726 B defining an enclosure. The boundary  726 B preferably extends substantially perpendicular from the second surface  713  (i.e. about 80-100 degrees). Extending from the second surface  713  (preferably substantially perpendicular) are raised partitions ( 720 B). The boundary  726 B surrounds the partitions  720 B. One end of each partition  720 A extends and contacts one side of boundary ( 726 B). 
     The joining of the second surfaces of the first and second plates results in a fluid tight junction between boundaries  726 A and  726 B thereby forming boundary  726 . Partitions  720 A and  720 B are also joined forming a fluid tight junction thereby forming partition  720 . The boundary  726  forms an irradiation chamber  700  and together with the partitions  720  provides a pathway  710  having channels  715  for conducting fluid. The pathway maybe serpentine, zig-zag, or dove-tailed. Currently preferred is a serpentine pathway. 
     With reference to  FIGS. 11 and 12 , irradiation chamber  700  comprises a serpentine pathway  710  for conducting patient fluid, such as buffy coat or white blood cells, from inlet port  705  to outlet port  730 , i.e., the serpentine pathway  710  is in fluid communication with inlet port  705  of front plate  702  and outlet port  730  of back plate  701 . Patient fluid is supplied from cassette  1100  to inlet port  705  via outlet tube  1117 . After photoactivation and passing through serpentine pathway  710 , the treated patient fluid is returned to cassette  1100  via inlet tube  1112  ( FIGS. 1 and 4 ). The patient fluid is driven by recirculation pump  1303 . Self-shielding effects of the cells is reduced while the cells are photoactivated by irradiation impinging upon both sides of irradiation chamber  700 . 
       FIG. 11  shows pin  740  and recess  735  which align the two plates of irradiation chamber prior to being joined together in a sealing arrangement by RF welding, heat impulse welding, solvent welding or adhesive bonding. Joining of the plates by adhesive bonding and RF welding is more preferred. Joining of the front and back plates by RF welding is most preferred as the design of the raised partitions  720  and perimeter  725  minimizes flashing and allows for even application of RF energy. Locations of pin  740  and recess  735  may be inside serpentine pathway  710  or outside of serpentine pathway  710 .  FIG. 2  also shows a view of an irradiation chamber with axis L. Rotation of chamber  700  180 degree about axis L gives the original configuration of the irradiation chamber. The irradiation chamber of the present invention has C 2  symmetry about axis L. 
     Referring to  FIGS. 11 ,  13 , and  16 , the leukocyte enriched blood, plasma, and priming solution are delivered through inlet port  705  of front plate  702  of irradiation chamber  700  into channel  715 . The channel  715  in the irradiation chamber  700  is relatively “thin” (e.g. on the order of approximately 0.04″ as distance between two plates) in order to present large surface area of leukocyte rich blood to irradiation and reduce the self-shielding effects encountered with lower surface area/volume ratios. The cross section shape of channel  715  is substantially rectangular (e.g. rectangular, rhomboidal or trapezoidal) which has as its long side the distance between partition  720  and the distance between the plates as its short side. The shape of the cross section is designed for optimal irradiation of cells passing through channel  715 . While a serpentine pathway  710  is preferred in order to avoid or minimize stagnant areas of flow, other arrangements are contemplated. 
     The irradiation chamber  700  allows efficient activation of photoactivatable agents by irradiation from a light array assembly, such as the PHOTOSETTE®&#39;s two banks of UVA lamps ( 758 ) for activation ( FIG. 16 ). The irradiation plate and UVA light assembly ( 759 ) are designed to be used in a setting where edge  706  is oriented downward and edge  707  points upward. In this orientation, fluids entering input port  705  can exit from outlet port  730  with the aid of gravity. In the most preferred embodiment, irradiation of both sides of the irradiation chamber takes place concurrently while still permitting facile removal of the chamber. UVA light assembly  759  is located within UV chamber  750  of permanent tower system  2000  ( FIGS. 17 and 18 ). 
     The irradiation chamber&#39;s fluid pathway loops to form two or more channels in which the leukocyte-enriched blood is circulated during photoactivation by UVA light. Preferably, irradiation chamber  700  has between 4 to 12 channels. More preferably, the irradiation chamber has 6 to 8 channels. Most preferably, the irradiation chamber has 8 channels. 
       FIG. 14  shows cut-away views of the irradiation chamber. The channels  715  of serpentine pathway  710  are formed by the joining of raised partition  720  and perimeter  726  of the plates. 
     The irradiation chamber of the present invention can be made from a biocompatible material and can be sterilized by known methods such as heating, radiation exposure or treatment with ethylene oxide (ETO). 
     The method of irradiating cells using irradiation chamber  700  during extracorporeal treatment of cells with electromagnetic radiation (UVA) to be used in the treatment of a patient (such as to induce apoptosis in the cells and administer the cells into the patient) will now be discussed. Preferably the cells treated will be white cells. 
     In one embodiment of this method, a photoactivatable or photosensitive compound is first administered to at least a portion of the blood of a recipient prior to the extracorporeal treatment of the cells. The photoactivatable or photosensitive compound may be administered in vivo (e.g., orally or intravenously). The photosensitive compound, when administered in vivo may be administered orally, but also may be administered intravenously and/or by other conventional administration routes. The oral dosage of the photosensitive compound may be in the range of about 0.3 to about 0.7 mg/kg., more specifically, about 0.6 mg/kg. 
     When administered orally, the photosensitive compound may be administered at least about one hour prior to the photopheresis treatment and no more than about three hours prior to the photopheresis treatment. If administered intravenously, the times would be shorter. Alternatively, the photosensitive compound may be administered prior to or contemporaneously with exposure to ultraviolet light. The photosensitive compound may be administered to whole blood or a fraction thereof provided that the target blood cells or blood components receive the photosensitive compound. A portion of the blood could first be processed using known methods to substantially remove the erythrocytes and the photoactive compound may then be administered to the resulting enriched leukocyte fraction. In one embodiment, the blood cells comprise white blood cells, specifically, T-cells. 
     The photoactivatable or photosensitive compound may, in the case of some psoralens, be capable of binding to nucleic acids upon activation by exposure to electromagnetic radiation of a prescribed spectrum, e.g., ultraviolet light. 
     Photoactive compounds may include, but are not limited to, compounds known as psoralens (or furocoumarins) as well as psoralen derivatives such as those described in, for example, U.S. Pat. No. 4,321,919 and U.S. Pat. No. 5,399,719. The photoactivatable or photosensitive compounds that may be used in accordance with the present invention include, but are not limited to, psoralen and psoralen derivatives; 8-methoxypsoralen; 4,5′8-trimethylpsoralen; 5-methoxypsoralen; 4-methylpsoralen; 4,4-dimethylpsoralen; 4-5′-dimethylpsoralen; 4′-aminomethyl-4,5′,8-trimethylpsoralen; 4′-hydroxymethyl-4,5′,8-trimethylpsoralen; 4′,8-methoxypsoralen; and a 4′-(omega-amino-2-oxa) alkyl-4,5′,8-trimethylpsoralen, including but not limited to 4′-(4-amino-2-oxa)butyl-4,5′,8-trimethylpsoralen. In one embodiment, the photosensitive compound that may be used comprises the psoralen derivative, amotosalen (S-59) (Cerus, Corp., Concord, Calif.). See, e.g., U.S. Pat. Nos. 6,552,286; 6,469,052; and 6,420,570. In another embodiment, the photosensitive compound that may be used in accordance with the invention comprises 8-methoxypsoralen. 
     Methoxsalen is a naturally occurring photoactive substance found in the seed of the Ammi majus (umbelliferae plant). It belongs to a class of compounds known as psoralens or furocoumarins. The chemical name is 9-methoxy-7H-furo[3,2-g][1]-benzopyran-7-one. The formulation of the drug is a sterile liquid at a concentration of 20 mcg/mL in a 10 mL vial. See http://www.therakos.com/TherakosUS/pdf/uvadexpi.pdf. Toxicology studies of extracorporeal photopheresis and different dosages of UVADEX® and ultraviolet light in beagle dogs is located in the investigator&#39;s brochure. 
     Next, the portion of the subject&#39;s blood, recipient&#39;s blood, or the donor&#39;s blood to which the photoactive compound has been administered is treated by subjecting the portion of the blood to photopheresis using ultraviolet light. The photopheresis treatment may be carried out using long wavelength ultraviolet light (UVA) at a wavelength within the range of 320 to 400 nm. Such a range is not limiting, however, but is merely provided as an example. The exposure to ultraviolet light during the photopheresis treatment may have a duration of sufficient length to deliver, for example, about 1-2 J/cm 2  to the blood. 
     The photopheresis step is carried out in vitro by installing irradiation chamber  700  into photoactivation chamber  750  of permanent tower system  2000  ( FIGS. 17 and 18 ). In one embodiment, when the photopheresis step is carried out in vitro, at least a fraction of the treated blood is returned to the subject, recipient, or donor. The treated blood or the treated enriched leukocyte fraction (as the case may be) may then be administered back to the subject, recipient, or donor. 
     The photopheresis process consists of 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. This process will be discussed below in greater detail. Generally, whole blood is centrifuged and separated in centrifuge bowl  10 . A total of approximately 240 ml of buffy coat and 300 ml of plasma are separated and saved for UVA irradiation. 
     The collected plasma and buffy coat are mixed with heparinized normal saline and UVADEX®. (water soluble 8-methoxypsoralin). This mixture flows in a 1.4 mm thick layer through the irradiation chamber of the present invention. The irradiation chamber  700 , is inserted in photoactivation chamber  750  of tower system  2000  between two banks of UVA lamps of the PHOTOSETTE® ( FIG. 15 ). PHOTOSETTE® UVA lamps irradiate both sides of this UVA-transparent irradiation chamber  700 , permitting exposure to ultraviolet A light, yielding an average exposure per lymphocyte of 1-2 J/cm 2 . Following the photoactivation period, the cells are removed from the irradiation chamber  700 . 
     In a preferred embodiment of the present invention the cells are removed by the action of gravity and any cells remaining in the chamber are displaced from the chamber with additional fluid selected from the group consisting of saline, plasma, and combinations thereof. For patients who are small such as children (e.g. under 30 kg) or patients whose vascular system is easily overloaded with fluids the amount of additional fluid used to was the irradiation chamber will preferably be not more than 2× the volume of the chamber, preferably not more than 1× the volume of the chamber, more preferably not more than 0.5× the volume of the chamber 0.25× the volume of the chamber. The treated cells volume is reinfused to the patient. 
     For a description of similar photopheresis systems and methods, see U.S. patent application Ser. No. 09/480,893, which is expressly incorporated herein by reference. Also useful herein are the methods and systems described in U.S. Pat. Nos. 5,951,509; 5,985,914; 5,984,887, 4,464,166; 4,428,744; 4,398,906; 4,321,919; PCT Publication Nos. WO 97/36634; and WO 97/36581, all of which are entirely expressly incorporated herein by reference. 
     The effective amount of light energy that is delivered to the biological fluids may be determined using the methods and systems described in U.S. Pat. No. 6,219,584, which is entirely expressly incorporated herein by reference. Indeed, the application of ECP to the various diseases described herein may require an adjustment of the amount of light energy to optimize the treatment process. 
     Furthermore, the photosensitizing agent used in the ECP process may be removed prior to returning the treated biological fluid to the patient. For example, Methoxsalen (UVADEX®) is utilized in the ECP process. Methoxsalen belong to a group of compounds known as psoralens. The exposure to methoxsalen or other psoralens may cause undesirable effects on the subject, recipient, or donor such as phototoxicity or other toxic effects associated with psoralen and their decomposition products. Therefore, the psoralen, psoralen derivatives, or psoralen decomposition products that may remain in the biological fluid may be removed after UV exposure. A process for the removal of psoralen biological fluids is described in U.S. Pat. No. 6,228,995, which is entirely expressly incorporated herein by reference. 
     C. Centrifuge Bowl 
     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. Where parts of the present invention are indicated to be attached together and form a fluid tight seal any appropriate conventional means of joining the parts may be used including but not limited to, adhesives, ultrasonic welding or RF welding. 
     The present invention has several advantages over centrifuges what use conventional Latham bowl. The Latham bowl in the UVAR® XTS™ system has one inlet port that allows whole blood to come into the bowl and one outlet port that allows plasma and buffy coat to come out. Having only two ports limits the volume of buffy coat that can be collected per cycle. Each cycle involves filling the bowl with whole blood; 2) spinning the bowl to separate whole blood into plasma, buffy coat, and red blood cells; 3) collecting buffy coat for treatment, 4) bringing the bowl to rest; and 5) returning collected plasma and red blood cells. This buffy coat collection method may be characterized as being “batch-like” as the volume of buffy coat required for irradiation treatment can only be collected after several cycles of buffy coat collection. The limited volume of collected buffy coat per cycle results from the accumulated red blood cells remained inside the bowl. Thus the accumulated red blood cells that can only be emptied at the end of a buffy coat collection cycle is an inherent limitation of the Latham Bowl. 
     The bowl of the instant invention has three separate fluid conduits that can be used as an inlet port and two outlet ports. The additional fluid conduits allows for 1) reduce patient treatment time by having continuous spinning during the entire buffy coat collection process without having to stop spinning the bowl for removal of accumulated red blood cells; 2) treat small blood volume patients; by having collected red blood cells returned to patients continuously, these patients may be more amenable to medical treatments requiring the use of the buffy coat or fractions thereof such as extracorporeal photopheresis; 3) better separation of different components of fractions of cells within the buffy coat due to the increased spinning or rotation time and 4) the ability to separate high density red blood cells fractions from whole blood. This centrifuge bowl also provides the opportunity for reduced treatment time for any medical procedure requiring buffy coat fractions to be collected from patients that are substantially free of red blood cells, such as extra corporeal photopheresis. 
     To achieve the objects in accordance with the purpose of the present invention, as embodied and broadly described herein,  FIGS. 35 and 36  depict specific embodiments of the present invention. The embodiment depicted in  FIG. 35  comprises a centrifuge bowl  10 A, conduit assembly  860 A, frame  910 A and stationary restraint  918 A. The centrifuge bowl  10 A is in fluid communications with external conduit  20 A of conduit assembly  860 A. Lower sleeve end  832 A ( FIG. 46 ) of connection sleeve  500 A is secured to bowl  10 A. Upper sleeve end  831 A of connection sleeve  500 A is secured to external conduit  20 A, connecting the external conduit  20 A to bowl  10 A and providing fluid communications from external conduit  20 A to bowl  10 A. The fluid communications enables fluid  800  to be supplied through external conduit  20 A to the bowl  10 A. Similarly this fluid communications also enables separated fluid components  810  and  820  to be removed from bowl  10 A through external conduit  20 A. Bowl  10 A and frame  910 A are adapted to be rotated around center axis  11 A. 
     Referring to  FIG. 36 , bowl  10 A comprises outer housing  100 A, connection sleeve  500 A, top core  200 A, bottom core  201 A, and housing floor  180 A. Outer housing  100 A may be constructed of any suitable biocompatible material as previously described for the purpose of the illustration in  FIG. 36  the outer housing  100 A is constructed of clear plastic so that cores  200 A and  201 A are visible there through. Outer housing  100 A is attached to a housing floor  180 A, which in turn comprises protrusions  150 A for locking bowl  10 A into a rotational device such as rotational device  900 A. Bowl  10 A 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. 
     As is illustrated in  FIGS. 36 and 37 , the outer housing  100 A is substantially conical having an upper housing end  110 A, an outer housing wall  120 A and a lower housing end  190 A. Outer housing  100 A may be made of plastic (such as those plastics listed previously), or any other suitable material. Upper housing end  110 A has an outer surface  110 B, inner surface  110 C and housing outlet  700 A providing a passage between said surfaces. Preferably the upper housing will also have a neck  115 A formed about the housing outlet  700 A. The housing outlet  700 A and neck  115 A are sized to allow body  830 A of the connection sleeve  500 A to pass through while retaining sleeve flange  790 A, which extends from the body  830 A of connection sleeve  500 A. In one embodiment of the present invention an o-ring  791 A may be inserted between the sleeve flange  790 A and inner surface  110 C of the housing end  110 A to ensure a fluid tight seal is provided. In an alternative embodiment of the present invention illustrated in  FIG. 53 , a second sleeve flange  790 B extends from the body  830 A of connection sleeve  500 B distal to the sleeve flange  790 A. Both sleeve flange  790 A and  790 B being adapted to fit within neck  115 A and retain o-ring  791 A therebetween. A fluid tight seal is provided in this embodiment by the o-ring contacting body  830 A and inner surface  110 C of the housing end  110 A adjacent to the neck  115 A. However, connection sleeve  500 A can be secured to bowl  10 A by any suitable means, including for example, a lip, groove, or tight fit and adhesive with a component of bowl  10 A. The outer housing wall joins the upper housing end  110 A and lower housing end  190 A. Lower housing end  190 A is attached to a housing floor  180 A of greater diameter than upper end  110 A. Housing floor  180 A is adapted to mate with the lower housing end  190 A and provide a fluid tight seal therewith. Any conventional means may be used to secure the lower housing end  190 A to the housing floor  180 A, including but not limited to, adhesives, ultrasonic welding or RF welding. Housing floor  180 A may have an indentation  185 A that is used to collect denser fluid  810 . The diameter of outer housing  100 A increases from upper housing end  110 A to lower housing end  190 A. 
     Outer housing  100 A is adapted to rotatably connect to a rotational device  900  ( FIG. 35 ), such as for example, a rotor drive system or a rotating bracket  910 . The rotatable connection may, for example, be a bearing that allows free rotation of bowl  10 A. Outer housing  100 A preferably has a locking mechanism. The locking mechanism may be one or more protrusions  150 A 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  160  ( FIG. 51 ). 
     Referring to  FIG. 37 , outer housing  100 A and the base  180 A define an interior volume  710 A in which cores  200 A and  201 A will fit when bowl  10 A is assembled. When fully assembled, cores  200 A and  201 A are fully within interior volume  710 A of outer housing  100 A, occupying a coaxial volume of interior volume  710 A about axis  11 A. 
     Referring to  FIGS. 38 ,  40  and  44 , the top core  200 A and bottom core  201 A are substantially conical and respectively have upper core ends  205 A,  206 A; outer core walls  210 A,  211 A; and lower core ends  295 A,  296 A. The cores  200 A,  201 A occupy coaxial volumes of interior volume  710 A of bowl  10 A and forming separation volume  220 A between upper end  205 A and outer wall  210 A of top core  200 A and outer wall  211 A and lower core end  296 A of bottom core  201 A and outer housing  100 A. Separation volume  220 A is that space of interior volume  710 A that is between cores  200 A and  201 A and outer housing  100 A. 
     As depicted in  FIGS. 40 and 41  top core  200 A comprises upper core end  205 A and a lower core end  295 A that are joined by outer core wall  210 A. The outer core wall  210 A having an outer surface  210 B and inner wall surface  210 C and a lower edge  210 D. The diameter of top core  200 A preferably increases from upper core end  205 A to lower core end  295 A. Upper core end  205 A also comprises an outer surface  205 B and an inner surface  205 C. Centrally located about center axis and extending perpendicularly from the upper surface  205 B is lumen connector  481 A. Lumen connector  481 A has a top surface  482 A and a wall surface  482 B. Top surface  482 A has two passages  303 B and  325 D that provide fluid communications through the upper core end  205 A with second bowl channel  410 A and first bowl channel  420 A respectively. Second bowl channel  410 A is a conduit that has a conduit wall  325 A that extends perpendicularly from the inner surface  481 C of lumen connector  481 A. 
     As shown on  FIGS. 39B ,  39 A and  40 , second bowl channel  410  has fluid communication with conduit channel  760 A through conduit  321 A having a first end  321 B and a second end  321 C that is adapted to fit into passage  325 D of lumen connector  481 A. In operation conduit channel  760 A of external conduit  20 A has fluid communication with bowl channel  410 A. First bowl channel  420 A is a second conduit that has a channel wall  401 A that extends substantially perpendicularly from inner surface  481 C of the lumen connector  481 A. As shown in  FIGS. 39A ,  39 B and  40 , first bowl channel  420 A has fluid communication with conduit channel  780 A of external conduit  20 A through hollow cylinder  322 A having a first end  322 B and a second end  322 C adapted to fit opening  303 B top surface  482 A. As is illustrated in one embodiment of the present invention, second bowl channel  410 A is disposed within first bowl channel  420 A. In an alternative embodiment of the present invention illustrated in  FIG. 53 , conduit wall  325 A may be composed of upper part  325 F and lower part  325 G and be fused with channel walls  401 A and  402 A. 
     Top surface  482 A also has indentation  483 A which provides fluid communications with chamber  740 A. When assembled, chamber  740 A is defined by lumen mounting recess  851 A less the volumes occupied by hollow cylinders  321 A and  322 A in the connection junction of connection sleeve  500 A and lumen connector  481 A. Chamber  740 A has fluid communication with conduit channel  770 A and with separation volume  220 A near neck  115 A through indentation  483 A. Thus indentation  483 A forms a passageway for the removal of second separated fluid component  820  through bowl chamber  740 A. Optionally present on the outer surface  205 B are a plurality of spacers  207 A which extend from the outer surface and contact the inner surface  110 C of the upper housing end  110 A to ensure fluid communications between the separation volume  220 A and the passageway formed by the indentations  483 A. 
     In an alternative embodiment illustrated in  FIGS. 53 ,  54  and  55 , conduits  321 A and  322 A may be affixed to openings  325 D and  303 B in the top surface  482 A of the lumen connector  481 A. Additionally, indentations  483 A may form a plurality channels in the lumen connector  481 A and be adapted to form chamber  740 B when connected to connection sleeve  500 A or  500 B. Chamber  740 B is adapted to have one or more surfaces  742 A that can mate with the male end  853 A of the connection sleeve  500 A (male end  853 A surrounds end  861  of external conduit  20 A). To facilitate the correct orientation of the connection sleeve  500 A to the lumen connector  481 A the shape of the male end  853 A and chamber  740 B may be nonsymmetrical or as is illustrated in  FIGS. 53 ,  54  and  55  a guide  855 A may be provided which extends from the top surface of the lumen connector  481 A and is adapted to fit within opening  857 A of the sleeve flange  790 A. 
     Referring back to  FIG. 40 , the lower core end  295 A comprises an upper plate  299 A having a top surface  298 A, a bottom surface  297 A, and an edge  299 B that attaches and makes direct contact with lower edge  210 D of the outer core wall  210 A. The edge  299 B of the upper plate  299 A is adapted to be joined with lower edge  210 D of outer core wall  210 A and form a fluid tight seal therewith. Extending perpendicularly from the top surface  298 A of upper plate  299 A is a channel wall  402 A, having an upper end  402 B and a lower end  402 C and surrounds opening  303 A which is substantially in the center of upper plate  299 A. A number of fins  403 A, attached to the outside surface of channel wall  402 A and top surface  298 A, supports lumen wall  402 A. The channel wall  402 A is adapted to mate with channel wall  401 A forming a fluid tight seal and providing lumen  400 A. First bowl channel  420 A is in fluid communications with conduit channel  780 A of external conduit  20 A through conduit  322 A. Opening  303 A provides fluid communications from lumen  400 A to separation volume  220 A as will be further discussed. First bowl channel  420 A also surrounds second bowl channel  410 A. 
     Referring to  FIGS. 43A ,  43 B and  44 , bottom core  201 A comprises an upper core end  206 A, a outer core wall  211 A and a lower core end  296 A. The outer core wall  211 A having an outer surface  211 B, an inner wall  211 C and lower edge  211 D. The diameter of bottom core  201 A preferably increases from upper core end  206 A to lower core end  296 A. Bottom core  201 A also has a top surface  309 A and a bottom surface  309 B. Top surface  309 A has an indentation  186 A (preferably generally circular) substantial in the center of the surface  309 A of the upper core end  206 A. The indentation  186 A has an upper surface  186 B and an inner surface  186 C. The upper surface  186 B of the indentation  186 A has therein an opening  324 D which extends through to the inner surface  186 C. In an alternative embodiment of the present invention illustrated in  FIG. 53 , the upper surface  186 B, may also have a recess a  186 D adapted to receive an o-ring and form a fluid type seal around the lower end of  325 B of conduit wall  325 A. Extending perpendicularly from inner surface  186 C around said opening  324 D is conduit wall  324 A having a distal end  324 B. On the top surface  309 A extending from the indentation  186 A to the outer surface  211 B of the outer core wall  211 A are one or more channels  305 A. The top surface  309 A may be horizontal or slope upward or downward from indentation  186 A. If top surface  309 A slopes upward or downward from indentation  186 A to core end  206 A, one skilled in the art would be able to adjust the shapes of upper plate  299 A and upper core end  295 A accordingly. Channels  305 A may have an even depth through out the length of the channel  305 A. However, channel  305 A may slope downward or upward radially from the center. One skilled in the art would see that if top surface  309 A slopes upward or downward and channel  305 A has a constant depth, then channel  305 A slopes upward or downward accordingly. 
     Referring to  FIG. 38 , the bottom surface  297 A of upper plate  299 A is in direct contact with the top surface area  309 A of bottom core  201 A when completely assembled. This contact forms a fluid tight seal between the two surface areas forming an opening  305 B from the indentation  186 A to channel  305 A. A second opening  305 C from channel  305 A is formed in the outer surface  211 B of outer core wall  211 A. The opening  305 B provides fluid communications from indentation  186 A through channel  305 A and opening  305 C to separation volume  220 A ( FIGS. 38 and 40 ). Thus fluid  800  flows through conduit channel  780 A and subsequently passes through first bowl channel  420 A. From first bowl channel  420 A, fluid  800  then goes to through channel  305 A to the separation volume  220 A. 
     Referring to  FIGS. 43A and 44 , the lower core end  296 A has a lower plate  300 A, which has a top surface  300 B, a bottom surface  300 C and outer edge  300 D. Extending from the bottom surface  300 C of the lower plate  300  are one or more protrusions  301 A. The outer edge  300 D is adapted to be attached to the lower edge  211 D of the outer core wall  211 A and provide a fluid tight seal therewith. Positioned above housing floor  180 A, lower plate  300 A is circular and curves upward radially from its center (illustrated in  FIG. 44 ). Alternatively, lower plate  300 A can be flat. As shown in  FIG. 38  when positioned above housing floor  180 A, a volume  220 C exists between lower plate  300 A and housing floor  180 A. This volume  220 C is in fluid communication with separation volume  220 A. Lower plate  300 A may be made of plastic or any other suitable material. Additionally, extending substantially perpendicularly from the lower surface  300 C of lower plate  300 A is a conduit  320 A. Conduit  320 A has a first end  320 B that extends into the space  220 C between lower plate  300 A and housing floor  180 A and a second end  320 C that extends above the top surface  300 B of lower plate  300 A. The diameter of conduit  320 A is adapted to have a tight fit with conduit wall end  324 B. The volume inside conduit walls  324 A and  325 A comprises a lumen  400 B. The volume defined by lower plate  300 A, inner surface  211 C, and ceiling  253 A of bottom core  201 A, excluding second bowl channel  410 A, may comprise of air or a solid material (See  FIGS. 43B and 44 ). 
     In an alternative embodiment of the present invention as illustrated in  FIG. 53 , support walls  405 A and  407 A may be optionally present. Support wall  405 A extends perpendicularly from bottom surface  309 B. Support wall  407 A extends perpendicularly from the top surface  300 B of lower plate  300 A and connects with support wall  405 A when the bottom core  201 A is assembled. Conduit wall  324 A may be connected to conduit  320 A to form a fluid tight seal and conduits  324 A,  320 A may be fused respectively with supports walls  405 A and  407 A. Additionally present extending from the bottom surface  300 C of lower plate  300 A are one or more orientation spacers  409 A that mate within indentation  185 A. 
     As will be readily apparent to one of ordinary skill in the art, the bowl  10 A will need to be balanced about center axis  11 A. Accordingly, weights may be added as part of the device as is appropriate to facilitate the balancing of the bowl  10 A such as weight  408 A illustrated in  FIG. 53 . 
     Referring to  FIG. 38 , bowl  10 A is adapted so that outer housing  10 A, cores  200 A and  201 A, lower plate  300 A and upper plate  299 A, housing floor  180 A, external conduits  20 A and connection sleeve  500 A, and lumens  400 A and  400 B are in connection and rotate together. Housing floor  180 A of outer housing  100 A comprises recesses  181 A on its top surface and these recesses are shaped to fit protrusion  301 A of lower plate  300 A. As shown, lower plate  300 A has round protrusion  301 A on its bottom surface  300 C to restrict movement of lower plate  300 A with respect to housing floor  180 A. When assembled, each single protrusion  301 A on the bottom surface of lower plate  300 A forms a tight fit with recess  181 A on housing floor  180 A. Thus, when outer housing  100 A is rotated, external conduit  20 A and connection sleeve  500 A, top core  200 A, upper plate  299 A, bottom core  201 A, lower plate  300 A, housing floor  180 A, and lumens  400 A and  400 B will rotate therewith. 
     As illustrated in  FIG. 38  lumen  400 A allows whole blood  800  to come into bowl  10 A via a first bowl channel  420 A. First bowl channel  420 A provides a passageway for inflow of fluid  800  through lumen  400 A to indention  186 A and then to the separation volume  220 A through channel  305 A. Lumen  400 A is located inside top core  200 A. Lumen  400 A has a height from upper lumen end  480 A and lower lumen end  402 C. Lumen  400 A is formed by the connection of channel wall  401 A extending from the inner surface  481 C of lumen connector  481 A and channel wall  402 A extending from the top surface  298 A of upper plate  299 A. Channel wall  401 A is supported by a plurality of fins  251 A which are attached to the inner wall surface  210 C of the outer core wall  210 A and inner surface  205 C of the upper core end  205 A, and channel wall  402 A is supported by a plurality of fins  403 A ( FIG. 40 ). It can readily be seen that height of lumen  400 A can be adjusted by changing the sizes and shapes of core  200 A, channel wall  401 A, channel wall  402 A, conduit wall  325 A, and the height of conduit wall  324 A. 
     As illustrated in  FIG. 38 , lumen  400 A, from upper lumen end  480 A to lower lumen end  402 C, encloses an inner lumen  400 B. Lower lumen end  402 C has an opening  303 A which is in fluid communication with separation volume  220 A through a number of channel  305 A. In the illustrated embodiment lumen  400 A comprises first bowl channel  420 A. Second bowl channel  410 A is located inside first bowl channel  420 A of the top core  200 A and is enclosed therein from lumen end  480 A and to lumen  402 C. Furthermore, second bowl channel  410 A forms a passageway through lumen  400 B from below lower plate  300 A for the removal of a first separated fluid component  810  that gathers in indentation  185 A of housing floor  180 A. Second bowl channel  410 A extends from housing floor  180 A of outer housing  100 A through lumen  400 B and to conduit channel  760 A of external conduit  20 A. 
     Referring  FIG. 38  (shown without conduit  321 C), inner lumen  400 B allows red blood cells  810  to exit bowl  10 A via a second bowl channel  410 A that provides fluid communication from the housing floor above indentation  185 A to opening  324 E. Inner lumen  400 B has an upper conduit end  325 C and a lower conduit end  324 B and comprises two conduit walls  324 A and  325 A which are connected in a fluid tight manner and form second bowl channel  410 A that has a smaller diameter than and is separate and distinct from first bowl channel  420 A. Conduit wall  325 A is supported by a fin  251 A that extends through channel wall  401 A and attaches to conduit wall  325 A. Unlike lumen  400 A which has one end near indentation  186 A, lumen  400 B extends beyond indentation  186 A and through bottom plate  300 A. The first conduit wall  325 A has an upper end  325 C which has an opening  325 D on the top surface  482 A of lumen connector  481 A and a lower end  325 B having an opening  325 E adapted to fit tightly with upper end  324 C of conduit wall  324 A. Upper end  324 C of conduit wall  324 A is higher than indentation  186 A and has an opening  324 D. Conduit wall  324 A also has end lower end  324 B and is supported by a plurality of fins  252 A. Lower end  324 B having opening  325 E is adapted to connect to conduit  320 A having opening  302 A located near the center of lower plate  300 A. The connection of openings  325 E and  302 A provide fluid communication between lumen  400 B and the space  220 C between lower plate  300 A and housing floor  180 A. The space  220 C between lower plate  300 A and housing floor  180 A in turn has fluid communication with separation volume  220 A. 
     Conduit  320 A provides a tight fit with lower end  324 B, providing support for second bowl channel  410 A. Each bowl channel  420 A and  410 A 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. 
     1. Drive Tube 
     As illustrated in  FIGS. 39A and 39B , conduit assembly  860 A is attached to bowl  10 A via connection sleeve  500 A which is attached onto the first end  861 A of external conduit  20 A having a first conduit channel  780 A, a second conduit channel  760 A, and a third conduit channel  770 A. Each conduit channel has fluid communication with a first bowl channel  420 A, a second bowl channel  410 A, and a bowl chamber  740 A. The three conduit channels are equally spaced 120° apart and equal in diameter in external conduit  20 A (See  FIG. 50 ). When fluidly connect to external conduit  20 A and bowl  10 A, conduit channel  780 A is fluidly connected with first bowl channel  420 A for inflowing fluid  800  from external conduit  20 A into bowl  10 A for separation. Similarly, second conduit channel  760 A fluidly connects to second bowl channel  410 A for removing first separated fluid component  810  from bowl  10 A into external conduit  20 A. Finally, third conduit channel  770 A connects to bowl chamber  740 A for removing second separated fluid component  820  from bowl  10 A. 
     As is illustrated in  FIG. 45 , external conduit  20 A has a connection sleeve  500 A on the first end  861 A and an anchor sleeve  870 A on the second end  862 A of external conduit  20 A. Optionally present between the connection sleeve  500 A and the anchor sleeve  870 A on external conduit  20 A are a first shoulder  882  and a second shoulder  884  which extend perpendicularly from the external conduit  20 A and are of a larger diameter. Between the connection sleeve  500 A and anchor sleeve  870 A (or if present the first and second shoulder  882 ,  884 ) are a first and second bearing rings  871 A and  872 A. External conduit  20 A, anchor sleeve  870 A, and connection sleeve may be prepared from the same or different biocompatible materials of suitable strength and flexibility for use in this type of tubing in a centrifuge (one such preferred material is HYTREL®). The connection sleeve  500 A and the anchor sleeve  870 A may be attached through any suitable means such as adhesives, welding etc., however, for ease of manufacture it is preferred that the connection sleeve  500 A and the anchor sleeve  870 A be overmolded to the external conduit  20 A. 
     Referring to  FIGS. 45 ,  48  and  49  anchor sleeve  870 A comprises a body  877 B having a first anchor end  873 A and second anchor end  874 A. Anchor sleeve  870 A is attached to second conduit end  862 A of external conduit  20 A (preferably by overmolding) and increases in diameter from first collar  873 A to the collar  874 A. Spaced distally from second end  874 A is a collar  886 A, which extends perpendicularly from body  877 B and of a larger diameter than the body  877 B of the anchor sleeve  870 A. A plurality of ribs  877 A having a first rib end  877 B between the collar  886 A and second anchor end  873 A and a second rib end  877 C extending beyond the first anchor end  873 A are attached to the body  877 B. The second rib ends  877 C are joined together by a ring  880 A, which is also attached to external conduit  20 A. The ribs  877 A run parallel to the external conduit  20 A and are preferably placed over the region where conduit channels  760 A,  770 A, and  780 A, are closest to the surface of the external conduit  20 A ( FIG. 50 ). The regions where the conduit channels  760 A,  770 A and  780 A are closest to the outside diameter of external conduit  20 A unless reinforced tend to fail during high speed rotation. Having ribs parallel with the conduit channels beyond the anchor sleeve end  873 A provides reinforcement to this region and prevents conduit failure at high speed rotation. In one aspect, the ribs prevent the buckling of the external conduit  20 A in this region and act as structural elements to transfer the torsional stress to the anchor sleeve  870 A. 
     Connection sleeve  500 A comprises body  830 A having an upper sleeve end  831 A and lower sleeve end  832 A ( FIGS. 46 and 47 ). Lower sleeve end  832 A has sleeve flange  790 A and a plurality of protrusions  843 A, which are sized to engage indentations  484 A on the wall surface  482 A of lumen connector  481 A. When the bowl  10 A is assembled, a fluid tight seal may be provided by placing o-ring  791 A around body  830 A and compressing the o-ring  791 A between flange  790 A and housing  100 A. Upper sleeve end  831 A is adapted to be secured to external conduit  20 A. Referring to  FIGS. 46 ,  39 A and  39 B, connection sleeve  500 A is secured to bowl  10 A by means of sleeve flange  790 A and is adapted to fluidly connect conduit channels  780 A,  760 A,  770 A of external conduit  20 A to bowl channels  420 A and  410 A, and chamber  740 A of bowl  10 A. When assembled, connection sleeve  500 A is mounted to lumen connector  481 A ( FIGS. 39A and 39B ). 
     Connection sleeve  500 A preferably increases in diameter from upper sleeve end  831 A to lower sleeve end  832 A and is overmolded to first conduit end  861 A of external conduit  20 A. Connection sleeve  500 A connects bowl  10 A to external conduit  20 A without use of a rotatable seal, which would otherwise normally be located between bowl  10 A and connection sleeve  500 A. The seal-less connection between bowl  10 A and connection sleeve  500 A 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  10 A or connection sleeve  500 A. 
     As illustrated in  FIGS. 46 and 39B , sleeve flange  790 A has a bottom surface  847 A that contacts with top surface  482 A of lumen connector  481 A forming a tight seal. However, lumen connector  481 A has a plurality of indentation  483 A that provides for fluid communication between separation chamber  220 A and bowl chamber  740 A, which, in turn has fluid communication with conduit channel  770 A. Bowl chamber  740 A is defined by lumen mounting recess  851 A and top surface  482 A of lumen connector  481 A, excluding the space occupied by hollow cylinders  321 A and  322 A. A plurality of protrusions  843 A on the bottom surface  847 A of sleeve flange  790 A engages and slides into indentations  484 A on the wall surface  482 B of lumen connector  481 A, thus providing a tight fit. 
     Connection sleeve  500 A helps to secure external conduit  20 A to bowl  10 A, thus fluidly connecting external conduit  20 A to bowl  10 A. This fluid connection enables fluid  800  to be supplied through external conduit  20 A to bowl  10 A. Similarly, this fluid connection also enables separated fluid components b,  820  to be removed from bowl  10 A through external conduit  20 A. 
     External conduit  20 A has an approximately constant diameter which helps to reduce the rigidity. An excessively rigid external conduit  20 A will heat up and fail more quickly. Additionally, a constant diameter conduit is cheap/easy to manufacture, allows easy experimentation with connection sleeve  500 A and anchor sleeve  870 A sizes, and allows bearing rings  871 A,  872 A to be easily slid thereon. Preferably the movement of bearings  871 A and  872 A will be constrained by first and second shoulders  882 A and  884 A. External conduit  20 A 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. 
     II. Permanent Tower System 
       FIG. 17  illustrates tower system  2000 . Tower system  2000  is the permanent (i.e., non-disposable) piece of hardware that receives the various devices of photopheresis kit  1000 , such as, cassette  1100 , irradiation chamber  700 , and centrifuge bowl  10  ( FIG. 1 ). Tower system  2000  performs the valving, pumping, and overall control and drive of fluid flow through disposable photopheresis kit  1000 . Tower system  2000  performs all of the necessary control function automatically through the use of a properly programmed controller, for example a processor or IC circuit, coupled to all of the necessary components. While a new disposable kit must be discarded after each photopheresis therapy session, tower system  2000  is used over and over again. Tower system  2000  can be modified to perform a number of extracorporeal blood circuit treatments, for example apheresis, by properly programming the controller or by changing some of its components. 
     Tower system  2000  has a housing having an upper portion  2100  and a base portion  2200 . Base portion  2200  has a top  2201  and a bottom  2202 . Wheels  2203  are provided at or near the bottom  2202  of base portion  2200  so that tower system  2000  is mobile and can easily be moved from room to room in a hospital setting. Preferably, the front wheels  2203  are pivotable about a vertical axis to allow ease in steering and maneuvering tower system  2000 . Top  2201  of base portion  2200  has a top surface  2204  having control deck  1200 , best illustrated in  FIG. 22 , built therein (see  FIG. 22 ). In  FIG. 17 , cassette  1100  is loaded onto control deck  1200 . Base portion  2200  also has hooks (not illustrated), or other connectors, to hang plasma collection bag  51  and treatment bag  50  therefrom. Such hooks can be located anywhere on tower system  2000  so long as their positioning does not interfere with the functioning of the system during therapy. Base portion  2200  has photoactivation chamber  750  ( FIG. 18 ) located behind door  751 . Additional hooks (not illustrated) are provided on tower system  2000  for hanging saline and anticoagulant bags. Preferably, these hooks are located on upper portion  2100 . 
     Photoactivation chamber  750  ( FIG. 18 ) is provided in base portion  2200  of tower system  2000  between top  2201  and bottom  2202  behind door  751 . Door  751  is hingedly connected to base portion  2200  and is provided for access to photoactivation chamber  750  and to allow the operator to close photoactivation chamber  750  so that UV light does not escape into the surrounding during treatment. Recess  752  is provided to allow tubes  1112 ,  1117  ( FIG. 1 ) to pass into photoactivation chamber  750  when irradiation chamber  700  is loaded and when door  751  is closed. The photoactivation chamber is discussed in detail below with respect to  FIGS. 16 and 18 . 
     Upper portion  2100  is located atop base portion  2200 . Centrifuge chamber  2101  ( FIG. 19 ) is located in upper portion  2100  behind centrifuge chamber door  2102 . Centrifuge chamber door  2102  has a window  2103  so an operator can see in centrifuge chamber  2101  and monitor for any problems. Window  2103  is constructed with glass thick enough to withstand any forces that may be exerted on it from an accident during centrifugation which can rotate the centrifuge bowl at speeds greater than 4800 RPMs. Preferably, window  2103  is constructed of shatter-proof glass. Door  2102  is hingedly connected to upper portion  2100  and has an automatic locking mechanism that is activated by the system controller during system operation. Centrifuge chamber  2101  is discussed below in more detail with respect to  FIG. 19 . 
     Preferably, deck  1200  is located on top surface  2204  of base portion  2200  at or near the front of system tower  2000  while upper portion  2100  is extending upward from base portion  2200  near the rear of tower system  2000 . This allows the operator easy access to control deck  1200  while simultaneously affording the operator access to centrifuge chamber  2101 . By designing tower system  2000  to have the centrifuge chamber  2101  in the upper portion  2100  and having the photoactivation chamber  750  and deck  1200  in base portion  2200 , an upright configuration is achieved. As such, system tower  2000  has a reduced footprint size and takes up a reduced amount of valuable hospital floor space. The height of system tower  2000  remains below sixty inches so that one view is not obstructed when transporting the machine around the hospital form the rear. Additionally, having deck  1200  in a fairly horizontal position will provide the operator with a place to set devices of photopheresis kit  1000  during the loading of other devices, facilitating easy loading. Tower system  2000  is robust enough to withstand forces and vibrations brought on by the centrifugation process. 
     A monitor  2104  is provided on centrifuge chamber door  2102  above window  2103 . Monitor  2104  has a display area  2105  for visually displaying data to an operator, such as, for example, user interfaces for data entry, loading instructions, graphics, warnings, alerts, therapy data, or therapy progress. Monitor  2104  is coupled to and controlled by the system controller. A data card receiving port  2001  is provided on a side of monitor  2104 . Data card receiving port  2001  is provided to slidably receive data card  1195  which is supplied with each disposable photopheresis kit  1000  ( FIG. 1 ). As mentioned above, data card  1195  can be pre-programmed to store serve a variety of data to supply to the system controller of tower system  2000 . For example, data card  1195  can be programmed to relay information so that the system controller can ensure: (1) that the disposable photopheresis kit is compatible with the blood drive equipment into which it is being loaded; (2) that the photopheresis kit is capable of running the desired treatment process; (3) that the disposable photopheresis kit is of a certain brand name or make. Data card receiving port  2001  has the necessary hardware and circuitry to both read data from, and write data to, data card  1195 . Preferably, data card receiving port  2201  will record treatment therapy data to data card  1195 . Such information can include for example, collection times, collection volumes, treatment times, volumetric flow rates, any alarms, malfunctions, disturbances in the process, or any other desired data. While data card receiving port  2001  is provided on monitor  2104 , it can be located anywhere on tower system  2000  so long as it is coupled to the system controller or other appropriate control means. 
     A. Photoactivation Chamber for Receiving Irradiation Chamber 
     Referring now to  FIGS. 16 and 18 , photoactivation chamber  750  is illustrated in cross section. Photoactivation chamber  750  is formed by housing  756 . Housing  756  fits within base portion  2200  of tower system  2000  behind door  751  ( FIG. 17 ). Photoactivation chamber  750  has a plurality of electrical connection ports  753  provided on back wall  754 . Electrical connection ports  753  are electrically coupled to a source of electrical energy. Photoactivation chamber  750  is designed to receive UVA light assembly  759  ( FIG. 16 ). When fully loaded into photoactivation chamber  750 , electrical contacts (not illustrated) located on contact wall  755  of UVA light assembly  759  form an electrical connection with electrical connection ports  753 . This electrical connection allows electrical energy to be supplied to UVA lamps  758  so that they can be activated. Preferably, three electrical connection ports are provided for each set of UVA lamps  758 . More preferably, UVA light assembly  759  has two sets of UVA lamps  758  forming a space which irradiation chamber  700  can be inserted. The supply of electrical energy to UVA lamps  758  is controlled by the properly programmed system controller using a switch. UVA lamps  758  are activated and deactivated as necessary by the controller during the photopheresis therapy session. 
     Vent hole  757  is provided in the top of housing  756  near back wall  754  of photoactivation chamber  750 . Vent hole  757  connects to vent duct  760  which leads out of the back of tower system  2000 . When heat generated by UVA lamps  758  builds up in photoactivation chamber  750  during a treatment therapy, this heat escapes photoactivation chamber  750  via vent hole  757  and vent duct  760 . The heat exits tower system  2000  through tower housing hole  761  located in the rear of tower system  2000 , away from the patient and the operator. 
     Photoactivation chamber  750  further comprises tract  762  for receiving irradiation chamber  700  and holding irradiation in an upright position between UVA lamps  758 . Tract  762  is at or near the bottom of photoactivation chamber  750 . Preferably, a leak detector circuit  763  is provided below tract  762  to detect any fluid leaks irradiation chamber  700  during, before, or after operation. Leak detector circuit  762  has two electrodes patterned in a U shape located on an adhesive backed flex circuit. The electrodes are designed to allow for application of a short circuit to test for discontinuities. One end of each electrode goes to an integrated circuit while the other end of each electrode is tied to a solid-state switch. The solid-state switch can be used to check for continuity of the electrodes. By closing the switch the electrodes are shorted to one another. The integrated circuit then detects the short. Closing the switch causes a situation equivalent to the electrodes getting wet (i.e., a leak). IN If the electrodes are damaged in any way, the continuity check will fail. This is a positive indication that the electrodes are not damaged. This test can be performed each time at system start-up or periodically during normal operation to ensure that leak detection circuit  762  is working properly. Leak detection circuit  762  helps ensure that leaks do not go unnoticed during an entire therapy session because the leak detection circuit is damaged. An electrical schematic of leak detector circuit  762  is provided in  FIG. 20 . 
     B. Centrifuge Chamber 
       FIG. 19  illustrates centrifuge chamber  2101  in cross section with the housing of tower system  2000  removed. Rotational device  900  (also in cross-section) capable of utilizing 1-omega 2-omega spin technology is positioned within centrifuge chamber  2101 . Rotational device  900  includes a rotating bracket  910  and a bowl holding plate  919  for rotatably securing centrifuge bowl  10  ( FIG. 1 ). Housing  2107  of centrifuge chamber  2101  is preferably made of aluminum or some other lightweight, sturdy metal. Alternatively, other rotational systems may be used within tower system  2000  such as that described in U.S. Pat. No. 3,986,442, which is expressly incorporated herein by reference in its entirety. 
     Leak detection circuit  2106  is provided on back wall  2108  of housing  2107 . Leak detection circuit  2106  is provided to detect any leaks within centrifuge bowl  10  or the connecting tubes during processing. Leak detection circuit  2106  is identical to leak detector circuit  762  described above. An electrical schematic of leak detection circuit  2106  is provided in  FIG. 21 . 
     C. Fluid Flow Control Deck 
       FIG. 22  illustrates control deck  1200  of tower system  2000  ( FIG. 17 ) without a cassette  1100  loaded thereon. Control deck  1200  performs the valving and pumping so as to drive and control fluid flow throughout photopheresis kit  1000 . Preferably, deck  1200  is a separate plate  1202  that is secured to base portion  2200  of tower system  2000  via screws or other securing means, such as, for example, bolts, nuts, or clamps. Plate  1202  can be made of steel, aluminum, or other durable metal or material. 
     Deck  1200  has five peristaltic pumps, whole blood pump  1301 , return pump  1302 , recirculation pump  1303 , anticoagulant pump  1304 , and red blood cell pump  1305  extending through plate  1202 . Pumps  1301 - 1305  are arranged on plate  1202  so that when cassette  1100  is loaded onto deck  1200  for operation, pump loop tubes  1120 - 1124  extend over and around pumps  1301 - 1305  ( FIG. 25 ). 
     Air bubble sensor assembly  1204  and HCT sensor assembly  1205  are provided on plate  1202 . Air bubble sensor assembly  1204  has three trenches  1206  for receiving tubes  1114 ,  1106 , and  1119  ( FIG. 25 ). Air bubble sensor assembly  1204  uses ultrasonic energy to monitor tubes  1114 ,  1106 , and  1119  for differences in density that would indicate the presence of air in the liquid fluids normally passing therethrough. Tubes  1114 ,  1106 , and  1119  are monitored because these lines go to the patient. Air bubble sensor assembly  1204  is operably coupled and transmits data to the system controller for analysis. If an air bubble is detected, the system controller will shut down operation and prohibit fluid flow into the patient by occluding tubes  1114 ,  1106 , and  1109  by moving compression actuators  1240 - 1242  to a raised position, thereby compressing tubes  1114 ,  1106 , and  1119  against cassette  1100  as discussed above and/or shutting down the appropriate pump. HCT sensor assembly  1205  has trench  1207  for receiving HCT component  1125  of tube  1116 . HCT sensor assembly  1205  monitors tube  1116  for the presence of red blood cells by using a photoelectric sensor. HCT sensor assembly  1205  is also operably coupled to and transmits data to the system controller. Upon HCT sensor assembly  1205  detecting the presence of red blood cells in tube  1116 , the system controller will take the appropriate action, such as stopping the appropriate pump or activating one of compression actuators  1243 - 1247 , to stop fluid flow through tube  1116 . 
     Deck  1200  also has five compression actuators  1243 - 1247  and three compression actuators  1240 - 1242  strategically positioned on plate  1202  so that when cassette  1100  is loaded onto deck  1200  for operation, each of compression actuators  1240 - 1247  are aligned with corresponding apertures  1137  and  1157 . Compression actuators  1240 - 1247  can be moved between a lowered position and a raised position. As illustrated in  FIG. 22 , compression actuators  1243 - 1247  are in the lowered position and compression actuators  1240 - 1242  are in the raised position. When in a raised position, and when cassette  1100  is loaded onto deck  1200  as illustrated in  FIG. 25 , compression actuators  1240 - 1247  will extend through the corresponding apertures  1137  or  1157  and compress the portion of flexible tubing that is aligned with that aperture, thereby pinching the flexible tube shut so that fluid can not pass. When in the lowered position, compression actuators  1240 - 1247  do not extend through apertures  1137  and  1157  and thus do compress the flexible tubing. 
     Compression actuators  1243 - 1247  are spring retracted so that their default position is to move to the lowered position unless activated. Compression actuators  1243 - 1247  are independently controlled and can be raised r lowered independent of one another. Compression actuators  1240 - 1242  on the other hand are coupled together. As such, when one compression actuator  1240 - 1242  is lowered or raised, the other two compression actuators  1240 - 1242  are also lowered in raised accordingly. Additionally, compression actuators  1240 - 1242  are spring loaded so that their default position is to move to the raised position. Thus, if the system loses power during a therapy session, compression actuators  1240 - 1242  will automatically move to the raised position, occluding tubes  1114 ,  1106 , and  1119  and preventing fluids from entering or leaving the patient. 
     Referring now to  FIGS. 23 and 24 , deck  1200  further includes system controller  1210 , cylinder assembly  1211 , manifold assemblies  1213 , pump cable  1215 , pump motor cable  1216 , and timing belt assembly  1217 . System controller  1210  is a properly programmed integrated circuit that is operably coupled to the necessary components of the system to perform all of the functions, interactions, decisions, and reaction discussed above and necessary to perform a photopheresis therapy according to the present invention. Cylinder assembly  1211  couples each of compression actuators  1240 - 1247  to a pneumatic cylinder. Air ports  1212  are provided on the various elements of deck  1200  as necessary to connect air lines to the devices and the appropriate one of manifolds  1213 . As such, air can be provided to the devices as necessary to actuate the necessary component, such as compression valves  1240 - 1247 . All of these functions and timing are controlled by system controller  1210 . Timing belt assembly  1217  is used to coordinate the rotation of rotating clamps  1203 . Finally, plate  1202  includes a plurality of holes  1215 ,  1219 ,  1220 ,  1221 , and  1218  so that the various components of deck  1200  can be properly loaded into and so that deck  1200  can be secured to tower system  2000 . Specifically, pumps  1301 - 1305  fit into holes  1314 , HCT sensor assembly  1205  fits into hole  1220 , air bubble detector assembly  1204  fits into hole  1219 , compression actuators  1240 - 1247  extend through holes  1218 , and bolts extend through holes  1221  to secure deck  1200  to tower assembly  2000 . 
     1. Cassette Clamping Mechanism 
     Referring now to  FIGS. 22 and 25 , the method by which cassette  1100  is loaded and secured to deck  1200  will now be discussed. In order for system  2000  to perform a photopheresis therapy, cassette  1100  must be properly loaded onto deck  1200 . Because of the compression actuator valving system incorporated in the present invention, it is imperative that cassette  1100  be properly secured to deck  1200  and not shift or become dislodged when compression actuators  1240 - 1247  occlude portions of the flexible tubing by compressing the flexible tubing against cover  1130  of cassette  1100  ( FIG. 3 ). However, this requirement competes with the desired goals of ease in loading cassette  1100  onto deck  1200  and reducing operator errors. All of these goals are achieved by the below described cassette clamping mechanism. 
     In order to facilitate clamping of cassette  1100  to deck  1200 , deck  1200  is provided with two catches  1208  and two rotating clamps  1203  and  1223 . Catches  1208  have a slot  1228  near the middle of the top plate. Catches  1208  are secured to plate  1202  at predetermined positions so that the spacing between them is substantially the same as the spacing between tabs  1102  and  1103  on cassette  1100  ( FIG. 2 ). Rotating clamps  1203  and  1223  are illustrated in a closed position. However, rotating clamps  1203  and  1223  can be rotated to an open position (not illustrated) manually or through the automatic actuation of a pneumatic cylinder. Rotating clamps  1203  and  1223  are spring loaded by torque springs so as to automatically return to the closed position when additional torque is not being applied. Rotating clamps  1203  and  1223  are linked together by timing belt assembly  1217  ( FIG. 24 ). 
     Referring now to  FIG. 23 , timing belt assembly  1217  comprises timing belt  1226 , torque spring housings  1224 , and tension assembly  1225 . Timing belt assembly  1217  coordinates the rotation of rotational clamps  1203  and  1223  so that if one is rotated, the other also rotates in the same direction and the same amount. In other words, rotational clamps  1203  and  1223  are coupled. Tension assembly  1217  ensures that timing belt  1226  is under sufficient tension to engage and rotate the rotational clamp  1203  or  1223  that is being coordinated. Torque spring housings  1224  provide casings for the torque springs that torque rotational clamps  1203  and  1223  to the closed position. 
     Referring back to  FIGS. 22 and 25 , when loading cassette  1100  onto deck  1200 , cassette  1100  is placed at an angle to deck  1200  and tabs  1102  and  1103  ( FIG. 2 ) are aligned with catches  1208 . Cassette  1100  is moved so that tabs  1102  and  1103  slidably insert into catches  1208 . Rotational clamps  1203  and  1223  are in the closed position at this time. The rear of the cassette  1100  (i.e. the side opposite the tabs  1102  and  1103 ) contacts rotational clamps  1203  and  1223  as tabs  1102  and  1103  are being inserted in catches  1108 . As force is applied downward on cassette  1100 , rotational clamps  1103  and  1123  will be rotated to the open position, allowing the rear of cassette  1100  to move downward to a position below ledges  1231  of rotational clamps  1203  and  1223 . Once cassette  1100  is in this position, the rotational clamps  1203  and  1223  spring back from the force applied by the torque springs and rotate back to the closed position, locking cassette  1100  in place. When in the locked position, cassette  1100  can resist upward and lateral forces. 
     To remove cassette  1110  after the therapy session is complete, rotational clamps  1203  and  1223  are rotated to the open position either manually or automatically. Automatic rotation is facilitated by an air cylinder that is coupled to an air line and system controller  1210 . Once rotational clamps  1203  and  1223  are in the open position, cassette  1100  is removed by simple lifting and sliding tabs  1102  and  1103  out of catches  1208 . 
     2. Self-Loading Peristaltic Pumps 
     Referring to  FIG. 24 , peristaltic pumps  1301 - 1305  are provided on deck  1200  and are used to drive fluids through photopheresis kit  1000  ( FIG. 1 ) along desired pathways. The activation, deactivation, timing, speed, coordination, and all other functions of peristaltic pumps  1301 - 1305  are controlled by system controller  1210 . Peristaltic pumps  1301 - 1305  are identical in structure. However, the placement of each peristaltic pump  1301 - 1305  on deck  1200  dictates the function of each peristaltic pump  1301 - 1305  with respect to which fluid is being driven and along which pathway. This is because the placement of peristaltic pumps  1301 - 1305  dictates which pump loop  1220 - 1224  will be loaded therein. 
     Referring now to  FIGS. 28 and 29 , whole blood pump  1301  is illustrated in detail. The structure and functioning of whole blood pump will be described with the understanding that peristaltic pumps  1302 - 1305  are identical. Whole blood pump  1301  has motor  1310 , position sensor  1311 , pneumatic cylinder  1312 , pneumatic actuator  1313 , rotor  1314  (best illustrated in  FIG. 30 ), and housing  1315 . 
     Rotor  1314  is rotatably mounted within housing  1315  and is in operable connection with drive shaft  1316  of motor  1310 . Specifically, rotor  1314  is mounted within curved wall  1317  of housing  1315  so as to be rotatable by motor  1310  about axis A-A. When rotor  1314  is mounted in housing  1315 , a space  1318  exists between rotor  1314  and curved wall  1317 . This space  1318  is the tube pumping region of whole blood pump  1301  into which pump loop tube  1121  ( FIG. 33 ) fits when loaded for pumping. Position sensor  1316  is coupled to drive shaft  1316  of motor  1310  so that the rotational position of rotor  1314  can be monitored by monitoring drive shaft  1316 . Position sensor  1311  is operably connected and transmits data to system controller  1210  ( FIG. 24 ). By analyzing this data, system controller  1210 , which is also coupled to motor  1310 , can activate motor  1310  to place rotor  1314  in any desired rotational position. 
     Housing  1315  also includes a housing flange  1319 . Housing flange  1319  is used to secure whole blood pump  1310  to plate  1202  of deck  1200  ( FIG. 22 ). More specifically, a bolt is extended through bolt holes  1320  of housing flange  1319  to threadily engage holes within plate  1202 . Housing flange  1319  also includes a hole (not shown) to allow pneumatic actuator  1313  to extend therethrough. This hole is sized so that pneumatic actuator  1313  can move between a raised and lowered position without considerable resistance. Pneumatic actuator  1313  is activated and deactivated by pneumatic cylinder  1312  in a piston-like manner through the use of air. Pneumatic cylinder  1312  comprises air inlet hole  1321  for connecting an air supply line. When air is supplied to pneumatic cylinder  1312 , pneumatic actuator extends upward through housing flange  1319  to a raised position. When air ceases to be supplied to pneumatic cylinder  1312 , pneumatic actuator retracts back into pneumatic cylinder  1312 , returning to the lowered position. System controller  1210  ( FIG. 22 ) controls the supply of air to air inlet hole  1321 . 
     Curved wall  1317  of housing  1315  contains two slots  1322  (only one visible). Slots  1322  are located on substantially opposing sides of curved wall  1317 . Slots  1322  are provided for allowing pump loop tube  1121  ( FIG. 33 ) to pass into tube pumping region  1318 . More specifically, pump inlet portion  1150  and outlet portions  1151  ( FIG. 33 ) of pump loop tube  1121  pass through slots  1322 . 
     Turning now to  FIGS. 30 and 31 , rotor  1314  is illustrated as removed from housing  1315  so that its components are more clearly visible. Rotor  1314  has a top surface  1323 , angled guide  1324 , rotor flange  1325 , two guide rollers  1326 , two drive rollers  1327 , and rotor floor  1328 . Guide rollers  1326  and drive rollers  1327  are rotatably secured about cores  1330  between rotor floor  1328  and a bottom surface  1329  of rotor flange  1325 . As is best illustrated in  FIG. 29 , cores  1330  fit into holes  1331  of rotor floor  1328  and recesses  1332  in bottom surface  1329 . Guide rollers  1326  and drive rollers  1327  fit around cores  1330  and can rotate thereabout. Preferably, two guide rollers  1326  and two drive rollers  1327  are provided. More preferably, guide rollers  1326  and drive rollers  1327  are provided on rotor  1314  so as to be in an alternating pattern. 
     Referring to  FIGS. 29 and 31 , drive rollers  1327  are provided to compress the portion of pump loop tube  1121  that is loaded into tube pumping region  1318  against the inside of curved wall  1317  as rotor  1314  rotates about axis A-A, thereby deforming the tube and forcing fluids to flow through the tube. Changing the rotational speed of rotor  1314  will correspondingly change the rate of fluid flow through the tube. Guide rollers  1326  are provided to keep the portion of pump loop tube  1121  that is loaded into tube pumping region  1318  properly aligned during pumping. Additionally, guide rollers  1326  help to properly load pump tube loop  1121  into tube pumping region  1318 . While guide rollers  1326  are illustrated as having a uniform cross-section, it is preferred that the top plate of the guide rollers be tapered so as to come to a sharper edge near its outer diameter. Tapering the top plate results in a guide roller with a non-symmetric cross-sectional profile. The tapered embodiment helps ensure proper loading of the tubing into the tube pumping region. 
     Rotor  1314  further includes cavity  1328  extending through its center. Cavity  1328  is designed to connect rotor  1314  to drive shaft  1316  of motor  1310 . 
     Referring now to  FIGS. 30 and 32 , rotor flange has opening  1333 . Opening  1333  is defined by a leading edge  1334  and a trailing edge  1335 . The terms leading and trailing are used assuming that rotating rotor  1314  in the clockwise direction is the forward direction while rotating rotor  1314  in a counterclockwise direction is the rearward direction. However, the invention is not so limited and can be modified for counterclockwise pumps. Leading edge  1334  is beveled downward into opening  1333 . Trailing edge  1335  extends upward from the top surface of rotor flange  1325  higher than the leading edge  1334 . Leading edge is provide for trailing edge for capturing and feeding pump loop tube  1121  into tube pumping region  1318  upon rotor  1314  being rotated in the forward direction. 
     Rotor  1314  also has angled guide  1324  extending upward, at an inverted angle, from rotor flange  1325 . Angled guide  1324  is provided for displacing pump loop tube  1121  toward rotor flange  1325  upon rotor  1314  being rotated in the forward direction. Preferably, angled guide  1324  has elevated ridge  1336  running along top surface  1323  for manual engagement by an operator if necessary. More preferably, angled guide  1314  is located forward of leading edge  1334 . 
     Referring now to  FIGS. 28 and 33 , whole blood pump  1301  can automatically load and unload pump lop tube  1121  into and out of tube pumping region  1318 . Using position sensor  1311 , rotor  1314  is rotated to a loading position where angled guide  1324  will face cassette  1100  when cassette  1100  is loaded onto deck  1200  ( FIG. 25 ). More specifically, rotor  1314  is preset in a position so that angled guide  1324  is located between inlet portion  1150  and outlet portion  1151  of pump loop  1121  when cassette  1100  is secured to the deck, as is illustrated in  FIG. 13 . When cassette  1100  is secured to deck  1200 , pump lop tube  1121  extends over and around rotor  1314 . Pneumatic actuator  1313  is in the lowered position at this time. 
     Once cassette  1100  is properly secured and the system is ready, rotor  1314  is rotated in the clockwise direction (i.e., the forward direction). As rotor  1314  rotates, pump tube loop  1121  is contacted by angled guide  1324  and displaces against the top surface of rotor flange  1325 . The portions of pump loop tube  1121  that are displaced against rotor flange  1325  are then contacted by trailing edge  1325  and fed downward into tube pumping region  1318  through opening  1333 . A guide roller  1326  is provided directly after opening  1333  to further properly position the tubing within tube pumping chamber for pumping by drive rollers  1327 . When loaded, inlet portion  1150  and outlet portion  1151  of pump loop tube  1121  pass through slots  1322  of curved wall  1317 . One and a half revolutions are needed to fully load the tubing. 
     To automatically unload pump tube loop  1121  from whole blood pump  1301  after the therapy is complete, rotor  1314  is rotated to a position where opening  1333  is aligned with the slot  1322  through which outlet portion  1151  passes. Once aligned, pneumatic actuator  1313  is activated and extended to the raised position, contacting and lifting outlet portion  1151  to a height above trailing edge  1335 . Rotor  1314  is then rotated in the counterclockwise direction, causing trailing edge to  1335  to contact and remove pump loop tube  1121  from tube pumping region  1318  via opening  1333 . 
     D. Infra-Red Communication 
     Referring to  FIG. 34 , tower system  2000  ( FIG. 17 ) preferably further includes a wireless infrared (“IR”) communication interface (not shown). The wireless IR interface consists of three primary elements, system controller  1210 , IRDA protocol integrated circuit,  1381 , and IRDA transceiver port  1382 . The IR communication interface is capable of both transmitting and receiving data via IR signals from a remote computer or other device having IR capabilities. In sending data, system controller  1210  sends serial communication data to the IRDA protocol chip  1381  to buff the data. IRDA protocol chip  1381  adds additional data and other communication information to the transmit string and then sends it to IRDA transceiver  1382 . Transceiver  1382  converts the electrical transmit data into encoded light pulses and transmits them to a remote device via a photo transmitter. 
     In receiving data, IR data pulses are received by a photo detector located on the transceiver chip  1382 . The transceiver chip  1382  converts the optical light pulses to electrical data and sends the data stream to IRDA protocol chip  1381  where the electrical signal is stripped of control and additional IRDA protocol content. The remaining data is then sent to the system controller  1210  where the data stream is parsed per the communication protocol. 
     By incorporating an IR communication interface on tower system  2000  real time data relating to a therapy session can be transmitted to a remote device for recording, analysis, or further transmission. Data can be sent via IR signals to tower system  2000  to control the therapy or allow protocols to be changed in a blinded state. Additionally, IR signals do not interfere with other hospital equipment, like other wireless transmission methods, such as radio frequency. 
     III. Photopheresis Treatment Process 
     Referring together to  FIG. 26 , a flow chart illustrating an embodiment of the invention which includes photactivation of buffy coat, and  FIG. 27 , a schematic representation of apparatus which can be employed in such an embodiment, the process starts  1400  with a patient  600  connected by means of a needle adapter  1193  carrying a needle, for drawing blood, and needle adapter  1194  carrying another needle, for returning treated blood and other fragments. Saline bag  55  is connected by connector  1190  and anticoagulant bag  54  is connected by connector  1191 . Actuators  1240 ,  1241 , and  1242  are opened, anticoagulant pump  1304  is turned on, and saline actuator  1246  is opened so that the entire disposable tubing set is primed  1401  with saline  55  and anticoagulant  54 . The centrifuge  10  is turned on  1402 , and blood-anticoagulant mixture is pumped  1403  to the centrifuge bowl  10 , with the A/C pump  1304  and WB pump  1301  controlled at a 1:10 speed ratio. 
     When the collected volume reaches 150 ml  1404 , the return pump  1302  is set  1405  at the collection pump  1301  speed until red cells are detected  1406  at an HCT sensor (not shown) in the centrifuge chamber  1201  ( FIG. 19 ). Packed red cells and buffy coat have at this point accumulated in the spinning centrifuge bowl and are pumped out slowly at a rate, controlled by the processor, which maintains the red cell line at the sensor interface level. 
     The red cell pump  1305  is then set  1407  at 35% of the inlet pump speed while controlling  1408  the rate to maintain the cell line at the interface level until the collection cycle volume is reached  1409 , at which point the red cell pump  1305  is turned off  1410  and the fluid path to the treatment bag  50  via the HCT sensor  1125  is opened by lowering actuator  1244 , and stops when the HCT sensor  1125  detects  1411  red cells. “Collection cycle volume” is defined as the whole blood processed target divided by the number of collection cycles, for example a white blood process target of 1500 ml may require 6 cycles, and so 1500/6 is a volume of 250 ml. With whole blood continuing at  1410  to be delivered from the patient to the bowl and the red cell pump off, red cells will accumulate and will push out the buffy coat from inside the bowl  10 . The red cells are used to push out the buffy coat and will be detected by the effluent hematocrit (HCT) sensor, indicating that the buffy coat has been collected. 
     If another cycle is needed  1412 , the centrifuge  10  effluent path is returned  1413  to the plasma bag  51  and the red cell pump  1305  rate is increased  1413  to the inlet pump  1301  pump rate until red cells are detected  1414 , which is the beginning of the second cycle. If another cycle  1412  is not needed, the centrifuge  10  is turned off  1415  and inlet pump  1301  and anticoagulant pump  1304  are set at KVO rate, 10 ml/hr in this embodiment. The effluent path is directed  1416  to the plasma bag  51 , the red cell pump  1305  rate is set  1417  at 75 ml/min, the recirculation pump  1303  and photoactivation lamps are turned on  1418  for sufficient period to treat the buffy coat, calculated by the controller depending on the volume and type of disease being treated. 
     When the bowl  10  is empty  1419 , the red cell pump  1305  is turned off  1420  and the plasma bag  51  is emptied  1421  by opening actuator  1247  and continuing return pump  1302 . The return pump  1302  is turned off  1422  when the plasma bag  51  is empty and when photoactivation is complete  1423 , the treated cells are returned  1424  to the patient from the plate  700  by means of the return pump  1302 . Saline is used to rinse the system and the rinse is returned to the patient, completing the process  1425 . 
     The anticoagulant, blood from patient, and fluid back to patient are all monitored by air detectors  1204  and  1202 , and the fluid back to the patient goes through drip chamber and filter  1500 . The pumps,  1304 ,  1301 ,  1302 ,  1303 , and  1305 , the actuators  1240 ,  1241 ,  1242 ,  1243 ,  1244 ,  1245 ,  1246 , and  1247 , and the spinning of the bowl  10  are all controlled by the programmed processor in the tower. 
     The process and related apparatus have significant advantages over prior processes and apparatus in that the invention allow buffy coat to be in the bowl longer since red cells are being drawn off while collecting buffy coat in the bowl while centrifuging, keeping more buffy coat in the bowl until the desired amount of buffy coat cells are collected prior to withdrawing the collected buffy cells. Platelets, leukocytes, and other buffy coat fractions can also be separated, or red cells can be collected rather than returning them with plasma to the patient as the illustrated process does. 
     It has been found that increasing the time that buffy coat  810  is subjected to rotational motion in centrifuge bowl  10  yields a “cleaner cut” of buffy coat  820 . A “cleaner cut” means that the hematocrit count (HCT %) is decreased. HCT % is the amount of red blood ceils present per volume of buffy coat. The amount of time that buffy coat  820  is subjected to rotational motion in centrifuge bowl  10  can be maximized in the following manner. First, whole blood  800  is fed into first bowl channel  420  as centrifuge bowl  10  is rotating. As discussed above, whole blood  800  is separated into buffy coat  820  and RBC&#39;s  810  as it moves outwardly atop lower plate  300 . Second bowl channel  410  and third bowl channel  740  are closed at this time. The inflow of whole blood  800  is continued until the separation volume  220  is filled with a combination of buffy coat  820  near the top and RBC&#39;s  810  near the bottom of centrifuge bowl  10 . By removing RBC&#39;s  810  from centrifuge bowl  10  via second bowl channel  410  only, additional volume is created for the inflow of whole blood  800  and the unremoved buffy coat  820  is subjected to rotational forces for an extended period of time. As centrifuge bowl  10  continues to rotate, some of the RBC&#39;s  810  that may be trapped in buffy coat  820  get pulled to the bottom of centrifuge bowl  10  and away from third bowl channel  740  and buffy coat  820 . Thus, when third bowl channel  740  is opened, the buffy coat  820  that is removed has a lower HCT %. By controlling the inflow rate of whole blood  800  and the outflow rates of buffy coat  820  and RBC&#39;s  810 , a steady state can be reached that yields a buffy coat  820  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 photopheres is 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.