CA1317917C

CA1317917C - Centrifugation pheresis system

Info

Publication number: CA1317917C
Application number: CA000557694A
Authority: CA
Inventors: Richard I. Brown; Sidney Smith; David E. Cerny; John T. Foley
Original assignee: Baxter International Inc
Current assignee: Fenwal Inc
Priority date: 1987-01-30
Filing date: 1988-01-29
Publication date: 1993-05-18
Anticipated expiration: 2010-05-18
Also published as: US5316666A; JPH01502029A; DE3884871T2; EP0486480B1; EP0299054A4; EP0486480A2; EP0765687B1; EP0486480A3; DE3884871D1; DE3856327D1; DE3855891D1; DE3855891T2; EP0299054B1; US4834890A; EP0765687A1; EP0299054A1; DE3856327T2; WO1988005691A1; JP2556741B2

Abstract

Abstract of the Disclosure A system and method of separation of therapeutic components from blood. The system includes a dual member centrifuge and a disposable single use fluid transfer set. The set includes an elongated flexible separation chamber having an input port, a separated component output port and a residual fluid output port. The input port and the separated component output ports are located at opposite ends of the elongated separation chamber.
The centrifuge includes a receiving chamber with a selectively formed annular slot therein. The separation chamber is positioned in the annularly shaped slot and rotated at a predetermined rotational velocity. Fluids such as whole blood flows through the separation chamber and are separated into various therapeutic components such as platelet rich plasma and residual concentrated red blood cells. Platelet rich plasma can be drawn off as the separated therapeutic component. An alternate two part transfer set provides for highly efficient platelet pheresis. The platelet rich plasma is separated from the residual red blood cells in a first part. The platelet rich plasma flows into the second part and is separated into platelet poor plasma and platelets. The platelet poor plasma can be drawn off and returned to a donor or collected. The platelet concentrate can then be accumulated in a separate container.

Description

~ 317917 CENTRIFUGATION PHERESIS SYSTEM
Technical Field __ The invention pertains to the field of blo~d component separation and collection. More particularly, the invention pertains to the collection of platelets or plasma ~rom volunteer donors at temporary ~itest remote from medical facilities, with portable lightweight equipment capable ~f e~sy transport.
Background of the Invention The collection of blood from volunteer donors has become a very successful and very refined activity. The development of single needle, single use, disposable blood ~ollection sets has provided a safe, relatively inexpensive and donor comfortable medium ~or use in the blood collection process. Such ets have made possible large-scale collection of blood from volunteer donors at ~ites ~uch as church halls, schools or ofices which might be remote from medical facilities. The availability of volunteer donors is importan~ in that such donors tend to be relatively healthy~ In addi~ion, they provide a potentially much lar~er reservoir of donatable blood than is available from the available group of paid donors.
In recent years, processing of whole blood from a donor has come to routinely include separating the blood into therapeutic components. These components include red blood cells, platelets ~nd plasma. Various techniques and apparatus have been developed to facilitate the collection of whole blood and the subsequent separation of therapeutic components therefrom.
The collection of platelets or plasma ~rom Yolunteer donors, as opposed to the collection of ' ,., ., "~

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whole blood, has not been nearly as successful~ As a result, much of the plasma now collected comes from paid donors, as opposed to volunteer donors. It would be very desirable to be able to upgrade the collection of plasma 50 that it becomes a volunteer based activity to a much greater extent than it is currently.
Various methods are known for the collection of platel~ts or plasma. For example, a unit of blood can be drawn from a human donor in a conventional fashion and accumulated in a blood bag or other standard collection container~ This unit o~ blood can then be processed by a centrifuge to ~eparate the plasma from the o~her components of the blood unitO
The separated platelets and plasma can subsequently be removed from the blood bag. Although allowing all blood components ~o be harvested~ this process has the di~advantage that the donor must internally replace the complete unit of blood from which the plasma was extracted. The replacement process can take 6 to 12 weeks duriny which time ~he donor cannot again give blood. Further, this process yields only a small portion of available plasma/donor.
In a modification of the above system, plasmapheresis can be per~ormed by centrifugation at the ~ime of donation. The non-plasma portion of the blood i8 then returned to the donor immedia~ely.
While this process allows more frequent donation, often as fre~uently as once per week, the blood is physically separa~ed from the donor for centrifugation.
Such physical separation is undesirable because of the cost and complexity of systems ~nd procedures that have been developed to minimize the risk of error when several donors are being pro~essed simultaneously. In addition, physical separation of the blood from the d~nor could potentially raise concerns in the collection staff of exposure to infectous agents in the collected blo~d if fluid drips or leaks occur.
Separation systems in which the accumulated wfiole bIood is not physically separated from the donor are also ~nown. These can be either batch or continuous systems.
One continuous centrifuge based ~ystem is disclosed in Judson et al. United States Patent No.
3,655,123 entitled "Continuous Flow Blood Separator. n The system of the Judson et al. patent uses two needles, an outflow needle and ~n inflow needle. Whole blood is drawn from a donor via the outflow needle. The whole blood fills a buffer bag.
Blood from the buffer bag drains, under the force of gravity into a centrifuge. The system of the 3udson et al. patent uses the centrifuge to separate blood components. The plasma can be collected in a container. The red blood cells can be returned to the donor via the inflow needle.
Various systems are known ~hat utilize annular separation chambers for plasma pheresisa For example, United States Patent No~ 4,531, 932 to Luppin et al. entitled Cen~rifugal Plasmapheresis ~evice discloses a system which incorporates a centrifuge wi~h a rotating annular rotor. A
centrally located rotating seal couples stationary fluid flow lines to the rotating rotor~
Whole blood is drained from a donor, passed through the rotating seal and sub~ected to ~eparating rotational forces in the rotating rotor. Separated plasma is drawn off and concentrated whole blood cells are passed back through the rotating eal and returned to the donor.

7 9 ~ 7 Related types of systems which incorp~rate rotatable, disposable annular ~epar~ti~n chambers coupled via rotary seals to stationary tubing members are disclosed in United States Patents No. 4,387,848;
4,094,461, 4,007,871; and 4,010,B94.
~ne consideration in the processing of whole biood is the requirement that the processing take place under ~terile conditions. A second consideration is the requirement that processing take place so as to maximize storage life. Unless the processing takes place within a single ~ealed system, the permitted storage duration and usable lifetime of the blood components is ~ubstantially ~hortened.
Components processed within a ~ealed system can be stored for four to six weeks or ionger before user On the other hand, whole blood or components thereof must be used within 24 hours if the system seal is broken .
To promote the desired ends of sterile processin~ within a single sealed system, a family of dual member centrifuges can be used to effect cell separation. One example of this type of ~entriuge is disclosed in United States Patent No. RE ~9,738 to Adams entitled "Apparatus ~or Pzoviding Energy Communication Between a Moving and a Stationary Terminal. n As is now well known, due to the characteristics o~ ~uch dual member centrifuges, i~
is possible to rota~e a cont~iner containing a ~luid, such as a unit of donated blood ~nd to withdraw a separated fluid component, such a~ plasma, into a stationary container, outside of the cen~rifuge without using rotating seals. Such container ~y~tems can be formed as closed, sterile ~ransfer sets.
~ 35 ., , 13~ 7917 The Adams patent discloses a centr~ifuge having an outer rotatable member and an inner rotatable member. The inner member is positioned within and rotatably supported by the outer member.
The outer member rotates at one rotational velocity, usually called one omega, and the inner rotatable member rotates at twice the rotational velocity o the outer housing or two omega. There is thus a one omega difference in rotational ~peed of the two members. For purposes of this document, the term ~dual member centrifuge" shall refer to centrifuges of the Adams type.
The dual member centrifuge of the Adams patent is particularly advantageo~s in that, as noted above no seals are needed between the container of fluid being rotated and the non-moving component collection containers. The system of the Adams patent, provides a way to process blood into components in a 5ingle, sealed, sterile system wherein whole bl~od from a donor can be infused into the centrifuge while the two member~ of the centrifuge are being rotated.
; An alternate to the apparatus of ~he Adams ~ patent is illustrated in United States Pa~ent No.
-; 25 4,056,224 to Lolachi entitled "Flow System for Centrifugal Liquid Processing Apparatus.~ The system of the Lolachi patent includes a dual member centrifuge of the Adams type. Tbe outer member of the Lolachi centrifuge is rotated by a ~ingle electric motor which is coupled to the in~err.al rotatable housing by ~el~s and sha~ts.
United States Patent No. 4,108,353 ~o Brown entitled ~Centrifugal Apparatus With Oppositely Positioned Rotational Support Means" di~closes a 35 centrifuge struc'cure o~ the Adams type which inclu~es ; 1317~ 7 two separate electrical motors. One electric motor is coupled by a belt to the outer member and rotates the outer member at a desired nominal rotational velocity.
The second motor is carried within the rotating exterior member and rotates the inner member at the desired higher velocity, twice that of the exterior member.
United States Patent No. 4,109,855 to Brown et al.
entitled "Drive 5ystem For Centrifugal Processing Apparatus" discloses yet another drive system. The system of the Brown et al. patent has an outer shaft, affixed to the outer member for rotating the outer member at a selected velocity. An inner shaft, coaxial with the outer shaft, is coupled to the inner m~mber.
The inner shaft rotates the inner member at twice the rotational velocity as the outer member. A similar system is disclosed in ~nited States Patent No.
4,109,854 to Brown entitled "Centrifugal Apparatus With Outer Enclosure".
Centri~uges of the type disclosed in the above identified Brown et al. and Brown patents can be utilized in combination with a sealed fluid flow transfer set of the type disclosed in United States Patent No. 4,379,452 to DeVries. The set of the DeVries patent incorporates a blood collection container that has a somewhat elongated shape similar to those of standard blood collection sets. One embodiment of this combined system is the CS3000 cell separator system marketed by Travenol Laboratories, Inc.
The CS3000 incorporates a dual member centrifuge in combination with a sealed set of the type disclosed in DeVries. This is a continuous system that requires the donor to recei~e two needle punctures. Such systems have been extensively used in blood centers ~or plasma and platelet pheresis.

~31 7~7 The CS3000 is a larye and expensive unit that is not intended to be portable. Further, the DeVries type transfer sets ar~ quite complex to install and use.
They are also an order of magnitude more expensive than a standard, multi-container blood collection set.
A further alternate to the Adams structure is illustrated in United States Patent No. 4,530,691 to Brown entitled "Centrifuge With Movable Mandrel." The centrifuge of this latter Brown patent also is of the Adams-type. However, this latter centrifuge has an exterior member which is hinged for easy opening. When the hinged upper section is pivoted away from the bottom section, it carries the rotatable inner member along with it.
The inner member supports a receiving chamber with a spring biased mandrel which continually presses against a sealed, blood containing container positioned within the receiving chamber. The system o~ this latter Brown patent also discloses the use of two separate electric motors to rotate the inner and outer members.
The motors are coupled to a control system.
; There thus continues to be a need for methods and related apparatus of platelet or plasmapheresis which can readily be used with volunteer donors at various temporary locations. This method and related apparatus should be usable by technicians with a level o~ skill commensurate with the level of skill now ~ound at volunteer-based blood collection centers. Further, both the method and related apparatus should be readily portable to locations such as churches or schools where blood collection centers are temporarily established.
Preferably the apparatus will be essentially sel~-contained. Preferably/ the equipment needed to practice the method will be relatively inexpensive and the blood contacting set will be disposable each time the plasma has been collected from a sinqle donor.

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Summary of the Invention Various aspects of the invention are as follows:
A centrifugation chamber for positioning within A field rotating about an axis comprising, first and second side walls defining a processing chamber, the first side wall, when position~d within the rotating field, being adapted to be disposed closer to the rotational axis than the second side wall and dePining within the processing chamber a low g force region adjacent the first side wall and a high-g force region adjacent the second side wall, a source inlet port in the chamber for conveying source fluid to be processed into the chamber for separation in the rotating field into a first constituent that separates out along the first side wall in the low-g force region of the chamber, a second constituent that separates out along the second side wall in the high-g force region of the chamber, and an interface formed between the first and second constituents in an intermediate-g force region between the first and second side walls, interior wall means that extends into the intermediate-g force region of the processing chamber from one side wall toward the other side wall for directing fluid flow to expose the interface upon the interior wall means for detection through a side wall of the processing chamber, and at least one of the side walls includes a material in the region of the interior wall means that is transmissive to a preselected type of sensing energy for transmitting the sensing energy from outside the processing chamber upon the interior wall means to detect the location of the interface upon the interior wall means.
A centrifugation chamber for positioning within a rotating field comprising ~irst and second side walls defining a generally elongated processing chamber having oppositely spaced ends, the first side wall, when positioned within the rotating field~ being disposed : closer to the rotational axis than the second side wall B

` i~l7~7 8a to define within the processing chamber a low-g force region adjacent the ~irst side wall and a high-g force region adjacent the second side wall, a source inlet port at one end of the chamber for conveyiny source fluid to be pro~essed into the chamber for flow toward the opposite end of the chamber while being separated in the rotating field into a first constituent that flows along the first side wall in the low-g force region of the chamber, a second constituent that flows along the second side wall in the high-g force region of the chamber, and an interface that flows between the first and second constituents in an intermediate-g force region between the first and second side walls, interior wall means extending into the intermediate-g force region of the processing chamber from one of the side walls, the interior wall means being oriented at a non-perpendicular angle relative to the one side wall in the direction of source fluid flow for directing fluid flow away from the one side wall toward the other side wall to expose the interface upon the interior wall means for detection through a side wall of the processing chamber, and at least one of the side walls includes a material in the region of the interior wall means that is transmissive to a preselected type of sensing energy for transmitting the sensing energy from outside the processing chamber upon the interior wall means to detect the locatioll of the interface upon the lnterior wall means.
A system for separating a selected component from a fluid comprising, centri~ugation means including a housing ~or rotation about a select~d axis of rotation, said housing defining an annular slot, sealed fluid flow means including an elongated separation chamber having at least a fluid input port and a separated component output port for defining a fluid f 1QW path therebetween with said separation chamber carried in said slot, the chamher having opposed sidewalls along the fluid flow path that, when the chamber is in the slot, are oriented generally parallel to the axis of rotation, an interface surface , ~3~79~7 8b extending within said fluid ~low path from one of khe sidewalls toward the other sidewall at a selected angle to the fluid flow, and means for detecting the presence of an interface between the separated selected component and the remaining fluid on said interface surface through one of the sidewalls of the separation chamber.
A ~ystem for separating a selected fluid component from a fluid resulting in a residual fluid comprising, centrifugation means including a housing for rotation ahout a selected axis, said housing including an annular slot having a substantially constant radius with respect to said axis, a sealed, elongated, flexible separation chamber having a fluid input port, a selected fluid component output port and a residual fluid output port, said chamber receivable in said annular slot and exhibiting a generally cylindrical, non-spiral shape therein, said chamber defining a fluid flow path between at least said fluid input port and said selected component output port, the chamber having opposed sidewalls along the fluid flow path that, when the chamber is in the slot, are oriented generally parallel to the axis of rotation, one of the sidewalls being transmissive at least in part of radiant energy, a projection, transmissive at least in part of radiant energy, extending within a part of said fluid flow path from one of the sidewalls toward the other sidewall for blocking at least in part said fluid flow path, and means, responsive to radiant energy, for detecting the presence of an interface between the selected fluid component and the residual fluid on said projection through one of the sidewalls of the chamber.
A method of separating a selected component rom a fluid comprising the steps of rotating a processing chamber to create a low g force region adjacent a first side wall of the chamber and a high-g ~orce region adjacent a ~econd side wall of the chamber, conveying source fluid to be processed into the chamber for ~eparation in the rotating field into a first R~
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8c constituent that separates out along the first slde wall in the low-g force region of the chamber, a s0cond constituent that separates out along the second side wall in the hlgh-g force region of the chamber, and an interface ~ormed between the first and second constituents in an intermediate-g force region between the first and second side walls, locating an interior wall in the intermediate-g force region of the processing chamber that extends ~rom one side wall toward the other side wall for directing fluid flow to expose the interface upon the interior wall means, and detecting the interface on the interior wall by transmitting a preselected type of sensing energy from outside the processing chamber upon the interior wall means through a side wall of the processing chamber.
A centrifugation chamber for positioning within a field rotating about an axis comprising first and second side walls defining a processing chamber, the first side wall, when positioned within the rotating field, being adapted to be disposed closer to the rotational axis than the second side wall and defining within the processing chamber a low-g force region adjacent ths first side wall and a high-g force region adjacent the second side wall, a source inlet port in the chamber for conveying source fluid to be processed into the chamb~r ~or separation in the rotatiny field into a first ; con~tituent that æeparates out along the first side wall in the low-g force region o~ the chamber, a second constituent that separates out along the second side wall in the high-g force region o~ the chamber, and an interface formed between the fir~t and second ; constituents in an intermediate-g force region between the first and second side walls, an outlet port adjacent the second side wall for collecting separat~d constituent in the high-g region of the chamber, the inlet source port and the outlet port being located adjacent to each othex in the processing chamber, and ~', i~

~:ll7~17 8~
ramp means extending along the second side wall toward the outlet port for urging constituent separated in the high-g region to flow along the ramp means toward the outlet port in a direction opposite to the flow direction of source fluid through the inlet source port.
In accordance with another aspect of the invention, a method is provided of continuously separating a selected component from a fluid. The method includes providing an elongated flexible separation chamber which has an input port. The separation chamber or member has at least one output port.
A first fluid flow conduit, a plastic tubing member for example, is coupled at one end to the input port. A second fluid flow conduit, also a plastic tubing member, is coupled to the output port.
A centrifuge is provided which has ~ hollow cylindrical receiving chamber. The separation member is placed in the receiving chamber adjacent an interior curved peripheral wall thereof. Distal ends of the two tubing members are brought out to a fixed location.
The centrifuge, including the receiving chamber is then rotated at predetermined first and second rates.
Simultaneously, an input ~luid flow is provided at the fixed distal end of the first fluid flow conduit. The input fluid flow partly fills the separation member. The input fluid is separated in the separation member by centrifugal forces. An interface is formed between a portion of the separated fluid component and a portion of the '.

13~l7~7 g residual fluid. The interface is formed adjacent a selectively oriented surface of the receiving chamber.
The location of the interface on the ~urface is sensed. A portion o~ the separated component is withdrawn through the output port via the second fluid f~ow conduit and out the fixed distal end thereof in response to the interface being sensed at a predetermined location.
The withdrawing ~tep can include pumping the separated~fluid component through the ~econd fluid flow conduit. The separa~ed component can then be accumulated in a component container.
In one embodiment of the invention, a blood collection and component ~eparation set is provided.
The set includes an elongated flexible separa~ion chamber which is ormed with at least one interface region thereon The interface re~ion is, at least in part, transmissive of radiant energy. The chamber has a whole blood input port, a separated component output port and a residual fluid output port. The separated component can be for example plasma or platelets.
First, ~econd and third fluid flow ~onduits are provided, each of which, for example being a pla~tic tubular member. Each fluid flow conduit has ~ proximal end coupl'ed to a respective input or output port of the ~eparation chamber.
The f irst f luid f low conduit is coupl d to the whole blood input port~ A dis'cal end there~f can O in turn be coup}ed to donor collection means which c:an include a piercing cannula. The second fluid flow conduit i~ coupled to the selected component output port. A distal end thereof can be coupled to a collection container. ~he third fluid flow conduit 35 is coupled to the re~idual fluid o~ltpUt port~, 13179~7 In accordance with this embodiment of the invention, a quantity of whole blood can be withdrawn from a donor and drawn into the separation chamber~
The whole blood can be separated into plasma or platelets and packed red blood cells in the separation.chamber. The plasma or platelets can be drawn of f or puinped into the component collection container. The packed red blood cells can then be collected or returned to the donor. The process can then be repeated 2 number of times until the desired quantity of plasma or platelets has been collected.
This embodiment requires that ~he donor only receive a single needle puncture. In addition, if the concentrated red blood cells and plasma are to be returned to the donor, the donor is never physically disconnected f rom the pheresis ~ystem until that return process has been completed.
In yet another embodiment of the invention, platelets can be separated from the plasma and collected in a second component collection container. In this embodiment, the platelets can be accumula~ed in the ~eparati~n chamber while the pla~ma i~ being drawn off.' Subsequently, after the plasma has been drawn off the platelets can be drawn off and collected.
The blood ~ollection set can be formed with a ~ingle cannula which is used for both drawing whole blood and returning packed red blood cells to the donor. ~lternately, if desired, the ~e~ can be configured as a ~wo cannula ~et with one cannula used for withdrawing whole blood and a second cannula used for returning packed red blood cells to the donor.
In yet another embodiment of the invention, the separatio~ chamber can be formed in two parts.
The fir t part can include the whole blood inpu~ port " 13~7~ 7 and the packed red blood cell output port. This first part is in fluid flow communication with sec~nd part. Platelet rich plasma separated from the whole blood in the first part flows into the ~ec~nd part and is in turn ~eparated from the platelets therein. The plasma can then be drawn off into a collection container or returned to the donor along with the red blood cells. ~he platelets can continue to accumuiate in t~e second part. Additional quantities of whole blood can be drawn from the donor and passed through the separation chamber.
Subseguen~ly, the collected platelet concentrate can be sealed in the ~econd part.
The receiving chamber in the du~l ~ember lS centrifuge can be formed with an ~nnular ~lotO The slot receives and supports the elongated ~epara~ion chamber.
Numerous o~her advantag~s and features of the present invention will become readily apparent from the following detailed description of the invention and the embodiments thereof, from the claims and from the accc>mpanying drawings in which the details ~f the invention are fully and completely disclosed as a part of thi~ specification.

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Figure 1 is a schema~cic view, f ragmented and partly in ~ection of a system and ~ethod of pheresis in accordance with the present invention;
Figure 2 is ~n enlarged sectional YieW of the receiving ch~mber of Figure 1;
Figures 3~ and 3B illus~rate schematically a particular transfer set and method of pheresi~ in accordance with the present invention;
Figure 4 i~ a section~l view taken along 3~ plane 4-4 of Figure 3B;

~3:179~7 Figure 5A is a top plan view of a separation chamber in accordance with the present invention illustrating the pheresis process;
Figure 5B is a perspective view of the separation chamber and pheresis process illustrated in Figur~ 5A;
~ Figure 5C is a perspective view of an alternate embodiment of the r-eparation chamber illustrat~ng the pheresis process therein;
Figure 6 is a graph of varying hematocrit of fluid in a rotating separation chamber as ~ unction of di~tance along the separation chamber in accordance with the present invention;
Figure 7A is a top plan view of an alternate separation chamber in accordance with the present invention;
Figure 7~ is a perspective view ~f the alternate separation chamber of Figure 7A;
Figure 8 is a schematic fluid flow circuit illustrating an alternative fluid flow transfer ~et and method of practiciny the present invention, Figure 9 is a schem~ti perspective view of a ~wo part ~eparation chamber;
Figure 10 is a 8chematic fluid flow circuit illu~trating ~n alternative fluid ~low transfQr ~et and method of practicing the present invention; ~nd ~ igure 11 is a schematic fluid flow ~ircuit illustra~ing an alternative fluid $10w tran~fer ~et and method of practicing the present invention.
Detailed Description of the Preferred Embodiment -Whil~ this invention is su~ceptible of embodime~t in many different forms, there is shown in the drawing and will be described herein in detail ~pecific embodiments thereof wi~h the understanding 35 that the pres2nt disclosure i~ to be considered as an ' ~3~7~17 , . .

exemplification of the principles of the invention and are not intended to limit the invention to the specific embodiments illustrated.
Figure 1 ill~strates a readily transportable system 10 in accordance with the present inventionO
The system 10 i.ncludes a relatively light-weight dual member centrifuge 12 and an associated fluid flow transfer set 14.
~he dual member centrifuge 12 is of the Adams type having a stati~nary support 20 on which is mounted a first motor 22. The first motor 22 has a rotary output ~haft 24 which rotates at a first angular velocity conventionally referred to as one omega. Fixed}y attached to th~ rotary 6haft 24 is a yoke 26. The yoke 26 supports a second electric motor 28. The electric motor 28 has a rotary output shaft 30. The ~haft 30 rot~tes at an angular velocity twice that of the shaft 24, conventionally referred to as two omega. The motor 28 is pivotably 20 attached to the yoke 26 at pivot points 36 and 38.
Afixed to the xotating shaft 3Q is a cylindrical re~eiving chamber 40. The details of the chamber 40 are illustrated in detail in Figure 2.
The receiving chamb~r 40 i~ rotated by the shaf t 30.
The chamber 4~ includes a region 40a that is tran~parent to selected, incident radiant energy.
The chamber 40 has ~ cylindrical ex~erior peripheral region 42. Spaced apart from the exterior region 42 is a generally cylindrical interior peripheral region 44. Be~ween the exterior region 42 and ~he interior region 44 is a selectively shaped ~nnular slot 46 The slot 46 has a closed end 46a~ ~he slot 46 slidably receives a separation chamber 50~ The chamber 40 has an ex~erior diame~er on the order of six inches and an ~nternal length on the order ~f 2O3 13~7917 inches. The slot 46 has a length on the order o~ 2.1 inches. The width of the slot 46 is on the order of .2 inchesO
The separation chamber 50 is in fluid flow communication via a flexible multi-channel conduit 52 with the remainder of the set 14. A proximal end 54 of the flexible fluid flow conduit 52 is coupled to the separation chamber 50.
The fluid flow conduit 52 is supported by a ~tationary torque arm 56. The use of such tor~ue arms is well known to those skilled in the use of dual member centrifuges of the Adams type. A distal end 60 of the fluid flow conduit 52 separates into a plurality of discrete flexible conduits 6Da, 60b and 15 60c. The distal ends 60a, 60b and 60c are each in fluid ~low communication with a respective container as ~een in Figures 3a and 3b.
The conduits 60a, 60b and 60c could be formed of various flexible, medical grade plastics.
The system 10 also includes a control ~ystem 66 which is coupled to the motors 22 and 28. Control systems for u~e with dual member centrifuge~ o~ the Adams type are known in the art. One type of ~uitable control system is a proportional-integral-dif~erential control sys~em. Various of ~he above noted patents disclose a variety of ways to rotate and coTItrol dual member centrifuges.
The control ~ystem 6$ receives feedback ~rom vibration and fluid leak sensor~ 68 and 70. The 30 sensor~ 68 and 70 are f ixedly supported by a stationary suspension system 72. The system 72 can be connected to re ilient member~ 74 to tabili~e the centrifug2 12 during operation.
A ~ource of radian~ energy 76 is affixed ~o the ~motor 28. The source 76 direct~ ~ beam of .... .

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radiant energy 76a toward the radiant energy transmitting region 40a of the rotatable chaMber 40.
The region 40a permits the beam of radiant energy 76a to inpinge on an interface region of the separatiDn chamber 50. A portion 76b of the beam 76a will pass through ~he inter~ace region of the separation chamber 50 and emerge to be detected at an interface sensor 80.
The source 76 could be any emitter of radiant energy such as infrared-or incandescent lightO The sensor 80 could be any compatible energy ~ensitive detector. The interface ~ensor 80 can be used to detect the location of the interface between the separated plasma and packed red blood cells in the separation chamber 50 during the centrifugation process. The sensor 80 is also coupled to the control system 66.
Figure 2 illustrates the shape of the slot 46 in the receiving chamb~r 40. The slot 46 has two spaced apart annular surfaces 46b, 4~c. This spacing is on ~he order of ~2 inches. The slot 46 has a downwardly oriented opening 46d. The æeparation chamber 50 is slid into the ~lo~ 46 via the opening 46d. If necessary, ~he opening 46d can be covered by a metal cover to ~nitially retain the separation chamber 50 in position. Once the chamber 40 is rotated and the chamber 50 has ~e~n filled with fluid, the rotational forces set up adeguate frictional forces ~uch that ~he separation chamber 50 will be locked in p~ace~
The chamber 40 can be mo}ded of polycarbonate, a transparent plastic. The radiant energy beam 76a readily passes through this material. The chamber 40 can ~e selectively painted .

~317~ 7 or masked so as to limit those regions through which the radiant energy 76a can pass.
Figures 3a and 3b schematically illustrate the details of the fluid ~ransfer ~et 14 as well as one mode o$ using ~ame. In Figures 3a and 3~ arrows along a conduit or tubing member indicate a direction of fluid flow~
The set 14 in addition to the ~eparation chamber 50 and the multi-channel conduit ~2 includes a whole blood collection container 86. A~ached to the collection container 86 i~ a draw condui~ 88 which terminates at a free end in a draw cannula 88a. The draw cannula 88a is intended to be inserted into a vein of a donor. The set 14 al50 includes a plasma collection container 90 and a red blood cell nutritive ~ontainer 9~.
The solution in the container 92 is of a known type which provides nutrients to packed red blood cell~ ~ubsequent ~o the plasma pheresi~
process. Conten~s of such solutions include dextrose, ~odium chloride, mannitol and adenine. One appropriate solution is marketed by Travenol Laboratories, Inc~ under the trademark ADSOL. The container 92 is ~ealed with a frangible member ~2a which can be broken at an appropriate point in the plasma pheresis process7 The set 14 i~ initially used to co~lect a unit vf blood in the whole blood collec~ion container B6 using standard pro~edures. Onc:e the unit of whole 30 blood 86 has l:)een collected, the cannula 88a is removed from the arm of the donor and ~he tubing 88 i8 clo~ed by heat ~ealing. The 6et 14 is now a closed sterile system~ ~he ~eparation chamber 50 is po~itioned in the 510t within the rotatable receiving 35 chamber 40. The separation ~hamber 50 can then be .
rotated.

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~317~17 A whole blood pump 94 can be u~ilized to meter whole blood from the container 86 into the chamber 50 for separation into concentrated ~ed blood cells and plasma. The plasma can be withdrawn after separation into the container 90. A ~econd pump ~6 can be used to pump the concentrated red blood cells into the container 92 containing the nutritive solution. The ~ontainers 90 and 92 can then be closed by heat sealing and separated from the remainder of the set lg.
While the set and method illustrated in Figures 3a and 3b are primarily ~ited for procecsing of whole bl~od on a ba~ch basis9 one of ~he advantages of the present inven~ion lies in the fact that it should be possible to separate to a ~reat ex~cent the white cells from the pl~sma. It is known that from time to time the white cell~ from a donor infused into a receipient can cause an adverse reaction. Hence, removal of these white cells would ~0 be both desirable and beneficial.
In a preferred mode, the separation ehamber 50 has a volume on the order cf 30 to 90 ml. The preferred separation centrifugation speeds are in a range on the order of 38~0 to 4200 rpm.
Figure 4, a sectional view taken along plan 4-~ 4 of Figure 3b, illustrates the overall shape of the chamber 50 prior ~o the cen~rifu~ation process.
The chamber 50 can be formed of a ~ingle plastic sheet member. That member is folded on itself and sealed in a region 51~ An internal volume 51a results. The fluid being separated flows in this vol~me.
Figures SA ~hrough 5C ~chematically il~ustrate the Beparation process as the separation 35 chamber 50 is being rota~ed. As is illus'crat2d in .

13~7~17 Figures 5A-5C the chamber 40 and the separation chamber 50 are rotated in a direction 100. Whole blood is infused at the input port 50a and flows into the separation chamber 50 in a direction 102. The whole blood input port 50a is positioned centrally with respect to the centrifugal force field F.
Under the influence of the centrifugal force field F, the whole blood ~eparates into high density packed red blood cells in an outer annular region 104 adjacent the maximum centrifugal force region 42 of the rotatable chamber 40. Lower density plasma ~eparates out into an inner annular region 106 adjacent a relatively lower centrifugal force region adja~ent the inner region 44. Between the outer annular region 104 of packed red blood cells and the inner annular region 106 of plasmar a ~ubstantially smaller layer 108 of platelets forms.
A surface 110 can be provided which is at a predetermined ~ngle with respect to the direction of flow 102. The surface 110 provides ~ very sharp and highly transmissive interface between the region of plasma 106 and the region of packed red blood cells 104. The incident radiant energy 76a passes through the surface member 110, which is essentially transparent thereto, and out the transparent region 40a of the chamber 40 as the output radiant energy beam 76b. When sensed by the inter~ace sensor 80 the preci~e location of ~he interface between the pl~sma in the region 106 and the packed red blood ~ells in the region 104 can be determined.
The output port 50b for the platele~ rich plasma is located adjacent ~he low force inner : surface 50d of ~he separation chamber 50. Platelet poor plasma can be withdrawn therefrom under the control of the control sy~tem 66 in response to the 13~7~7 sen~ed position of the interface between the red blood cells and the plasma on the surface llOo The residual fluid output por~ 50c from which the packed red blood cells can be withdrawn is positioned adjacent the relatively high for~e outer surface o~ the separation chamber 50 adjacent the outer peripheral surface 40a.
The transparent ~urface 110 can be formed as part of the separation chamber 50. Alternatively, the surface llQ can be affixed to the rotatable chamber 40. In this instance, a region of the chamber 50 can be positioned adjacent thereto.
Depending on the location of the annular region 108 of platelets with respect to the surface 110, the system 10 can operate in several different modes.
If the location of the region 108 has moved adjacent an interior end llOa of the ~urface 110, the platelets will spill through the port 50b resulting 20 in platelet rich plasma as the separated ~luid component.
If the region 108 is centrally located as in Figure 5A, platelets will accumulate in the chamber.
Platelet poor plasma will then flow out the port 50b. In this mode, the plasma continually flows inwardly through the platelet region 108. ~his fluidizes the platelets and minimize~ ~edimenting and aggregating of the platelet concentrste~
In a third mode of opera~ion ~ ~he platele~c region 108 can be posi~ioned adjacent an outer regon llOb. In this instance, the platelets will be ~wept out ~f the chamb~r, via the port 50c with the packed red blood cells.
As illustrated in Figure 5C, a dam 112 can also be provided adjacent the plasma output por~

.

3~7~7 50b. As is discussed ~ubsequently, the dam 112 is effective to re~ain a fluid, such as air, in the chamber 50 during start up of the centrifugation process.
As was the case with the surface 110, the dam 112 c~n be integrally formed with either the separation chamber 50 or can be formed as part of the rotatable chamber 40.
~t will be understood that Figures 5a through 5c are ~chematic in nature and are intended to illustrate the separation process. The ~hape of the separation chamber 50 during the pheresis operation will be determined by the shape o the slot 4~.
The gxaph of ~igure 6 illustrates the expected change of hema~ocri~ as whole blood is infused ~hrough the input port 50a and travels along the rotating separation chamber 50. Assuming an input hematocrit on the order of .45, the hematocrit of the outp~t packed red blood cells ranges between .80 and 1Ø One o~ ~he func~ions of the nutritive mixture provided in the con~ainer 92 is to restore the hematocrit of the packed red blood cells to a value ~uch that infusion into a receipient is possible.
Figures 7A and 7~ illustrate ~chematically an alternate ~eparation chamber 51. In ~he ~eparation chamber 51, whole blood is injected into the chamber at a centrally located input port 51a.
Unlike the ~eparation chamber 50, an output port 51c for the concen~rated red blood cells is provided at the same end of ~he chamber 51 as is ~he whole blood input port 51a~ In this embodiment, ~he ~ed blood cells are withdrawn in the opposite direction as the : 35 input flow of the whole blood. The output port 51c , ~, . , ~ .

-21- 1 3 1 ~1 9 ~ r~
is located adjacent the high force outer peripheral wall of the separation chamber 51. Thus, there are two directions of 10w of fluid within the chamber 51.
The chamber 51 also includes a supplemental ramp 111 to urge or p~sh the packed cells towards the packed c~ll removal port 51c. This flow is opposi~e the flow of whole blood 51a. The ramp 111 may be integrally ~ormed as part of the separation chamber 51, Al~erna~ely, the ramp 111 can be formed as part of the rotatable member 40.
Fi~ure 8 illustrates yet another ~ys~em 120 which incorp~rates the elongated flexible separation chamber 50. The system 120 is a centrifugely based pheresis 6ystem which can provide as a ~eparated 1~ component from whole blood either platelet poor plasma or platelet concentrate.
The system 120 includes a fluid flow transfer set 122 which is useable in conjunction with the dual me~ber centrifuge 12. The tran~fer ~et 122 includes the draw conduit 88 with the a~sociated cannula R8aO In the set 122, the cannula ~8a is used ~or drawing whole blood from a donox and ~or returning concentrated red blood cells and/or plasma to the donor during the pheresis operation. The system 120 i~ intended to be csupled to the donor continuou~ly throughout the entire pher2sis oper~tion.
The draw/return conduit 88 i~ coupled ~t junction ~onnector 124 to respective tubing lines 126, 128 and 130. The tubing member 126 i~ coupled via an anticoagulant pump 132 to a container of anticoagulant 134. ~he tubing member 128 is coupled via a connec~or 136 and a feed blood pump 13B to the whole blood input port 50a of he separation chamber 50.

~3~7~ ~

The separated component output port 50b of ~he separation chamber 50 is coupled via a tubing member 140 to a plasma pump 141. A tubing member 142 is coupled alternately either to a 6eparated component container 144 or a tubing member 146. The member 146 feeds either a reservoir 148 or a bubble trap/bubble detector, 150 in the return conduit line 13~. Clamps 1 through 6 would be manually opened and closed to regulate the desired directions of flow.
The residual output port 5Dc is coupled via a tubing member 147 and a junction member 14g to the bubble trap~bubble detector 150.
In operation, the ~et 122 would be cou~led to the donor by means of the cannula 88a. The chamber 50, as previously discussed t would be positioned in the receiving chamber of the dual member centrifuge 12. Clamps 1, 4, and ~ would be opened. Cl~mps 2, 3 and 6 would be closed.
Whole blood would be drained from the donor via conduit 128. Anticoagulant would be simultaneously infused into the whole blood via ~he conduit 126. ~he feed blood pump 138 would dr~w the blood from the donor a~ approximately a 70ml per minu'ce rate. The pump 138 would also supply the drawn blood to ~he input port 50a of the rotating separation chamber 50 at the same rate.
The rotating separation chamber 50 would separate ~he whole blood into platelet poor plasma at the output port 50b and red blood cells at the ou~put port 50c. ~ed blood cells from the output port 50c would be accumulated in th~ reservoir 148 simultaneously with platelet poor plasma beang accumulated in the container 144.
When the volume and weight detector ass~ciated with the reservoir 148 indicates that a :~317~17 maximum extracorporeal volume has been acc~mulated therein, clamps 1, 4 and 5 would be closed. Clamps 2, 3 and 6 would be opened.
The concentrated cells in the reservoir 148 would be pumped, via the feed pump 138, through the separati~ chamber 50 a second time. Output f rom the separation chamber 50 via conduits 140 and 147 would be passed through the bubble trap 150 and, via ~he conduit 130, returned through the cannula 88a to ~he donor. When the weight and volume detector indicated that the reservoir 148 was sufficien ly empty, the draw process would be reinitiated.
Hence, the system 120 would be capable of accumulating platelet poor plasma in the container 144. In addition, the platelets would be accumulated in the region lOB of the separation chamber 50.
Subsequen~ to the plasma having been collected, the container 144 can be replaced and the platelets could be drawn off and accumulated in the replacement container.
~ ensities of platelets which could be accumulated and drawn off in this fashion range from 200 billion to 300 billi~n ~ells in 100 ml of ~luidv Such densities might take 3 to 4 cycles of whole 25 blood drawn ~rom the donor ts:~ build up the neceæsary pla~elet concentration in ~he ~eparation chamber 50.
Alternately, the platele~ poor plasma could be pumped into the reservoir 142 and returned after the ~econd pass to the donor. The platelet concentrate can then be accumulated in the container 144.
Figure 9 illus~rates yet another separa~ion chamber 160. The separation chamber 160 ha~ ~WQ
fluid separa~ing portions 162 and 164, ~he fluid ~eparating portion 162 includes a whole blood input ' . . .~

13~79~7 port 162a centrally located at an input end of the portion 162. A concentra~ed red blood cell outp~t port 162c is also provided adjacent the input port 162a. The portion 162 thus includes whole blood flowing into the region and packed red blood ~ells flowing ou.t of the region~ The portion 162 co~ld have a relatively small volume on the order of 20-30 ml.
Separated platelet rich plasma can be drawn out of the portion 162 via a conduit 166. The platelet rich plasma can then be separa~ed in th~
second portion 164 into pl~telet poor plasma and platelets. The platelets accumulate in the second portion lS4 along the outer, high for~e, wall 164a.
15 The second portion 164 includes an output port 162b.
The platelet poor plasma can be returned to the donor. The portion 164 can have a volume on th2 order of 50-60 ml.
Figure 10 illustrates a system 170 usable 20 for platelet pheresis. The system 170 incorporates a single use disposable fluid transfer ~et }72. The ~et 172 includes the ~wo part ~eparation chamber 160 of Figure 9. Other elemen~s of the ~et 172 which correspond to elements of the previously dificus0ed 25 set 122 have been given iden~ical identification numerals .
The two p~rt chamber 160 would be po~itioned in the receiving chamber of the dual member ~en~rifuge 12. }amps 1, 4 and 6 would be opened.
Clamps 2, 3 and 5 would be closed. The set 172 could be mounted on an automaked fixture whi~h could automatically operate the clamp~ 1-6.
In ~perationt the set 172 would be coupled to the donor by means of the cannula 8~a. Whole blood would be draw~ from the donor by the cannula 1317~7 88a. The whole blood will flow through the conduit B8, the conduit 128 and; via the feed blood p~mp 132, would be pumped into the input port 162a of the separation chamber 160 at a 70 ml per minute rate.
Concentrated red blood cells from the output port 162c would flow into the reservoir 14B via ~he conduit 147. Platelet rich plasma, via the tubing member 166, will ~low into the rotating platelet ~epara~io'n chamber 1647 Output from the platelet separation chamber 154, via the output port 162b will be platelet poor plasma. The platelet poor plasma will be pumped via the plasma pump 141 in the conduit 145 into the reservoir 148. While the whole blood is passing through the separation chamber portion 162 and the platele~ poor plasma is being separated in the platelet chamber 164, platele~s will continue to accumulate in the chamber 164.
When the volume and weiqht detector associate with the reservoir 148 indicates that a maximum extracorporeal volume of drawn blood has accumulated in the set 172, the appropriate detector signal will be generated. The operator or fixture will then close clamps 1 and 4. The operator or fixture will open clamps 2 and 3. Fluid in ~he re~ervoir 148 will be pumped via the f~ed pump 138 through the ~eparation chamber 160 a second time.
This fluid includes plasma and packed red blood cells which had previously accumula~ed therein ~hus providing a second opportunity ~o collect ~hose platelets not collected with the f~rst pa~s.
However, with cla~p 4 closed, output fluid on the line 147 and the line 166 will pass through the bubble trap/bubble de~ector 150 through the line 130 and be retu~ned to the donor via conduit 88 and cannula 88a.

~317~7 When the reservoir 148 has been sufficiently emptied, the volume weight detector will again generate a indicator signal. The operator or ~ixture will reclose clamps 2 and 3 and reopen clamps 1 and 4 5 to reinitiate the draw cycle. Whole blot~d will again be drawn.from the donor at the 70 ml per minute rate. This process may be repeated as many times as desired so-as to accumulate the desired quantity of . platelets-in the chamber 164.
Subseguent to the desired quantity of platelets having been accumulated in chamber 164, clamps 1, 3 ~nd 6 can be closed and clamp 5 can be opened. The platelets must then be resuspended, for example, by ~haking the platelet ~hamber 164~
Platelets can be pumped from the chamber 164 by the pump 141 into the platelet accumulation container 174. By means of this process, platelets on ~he order of 4xlO 1 cells can be accumulated from a single donor. This represents approximately 90 percent of the platelets whioh were in the blood drawn fr~m the donor.
Figure 11 illustrate~ an alternate system 180 which incorporate6 a di.posable fluid flow transfer ~et 182. The transfer set 182 includes the draw return cannula 88a and associa~ed conduit 88.
Whole blood is drawn through and concentrated cells are returned through a ~onduit member 184 which i8 coupled to an input ~o ~he bubble trap/bubble detector 150. Output ~rom ~he bubble trap/bubble detector 150 via a ~idirectional pump l~S flows into a reservoir 18B at an input port 18Bbo ~ deflector member 188d in the container 188 directs ~nd re~ulates the flow of fluid among the ports 188a, 188b and 188c.

~ 3~r~ ~7 During the draw cycle, whole blood which flows through the conduit 184, the conduit lB4a and into the input port 18BB of the reservoir 18B is deflected by the member 188D and flows out the port S 188A. Output whole blood ~low from the por~ 188A via a conduit l89 is pumped ~y the feed pump 190 at a f;ow rate of 70-80 ml per minute into the input port 162a of the two part separation chamber 160.
Red blood ce}ls ~epara~ed in the chamber 162 flow via conduit 192 into the input port lB8C of the reservoir 188 and are accumula~Pd ~herein. A~suminy clamp 2 is closed and clamp 1 i~ open, platelet poor plasma separated in the p~atelet chamber 164 flows via the ou~put port 162b and ~he pump 141 through a fluid flow conduit 194 also into the reservoir 188.
In operation, set 182 would be coupled to the donor by means of the cannula 88a. The chamber 160 would be positioned in the receiving chamber of the dual member centrifuge 12. Clamp 1 would be opened and clamp 2 would be clo~ed.
Whole blood would then be drained through the conduit lB4 as discussed absv~ at a 70 to 80 ml per minute rate. When the reservoir 18B is filled with a predetermined maximum ex~racorporeal volume, ~5 the volume~weight detector will generate an appropriate signal. At uch time, the bidirectional donor pump 186 will be reversedO Fluid will then be dr~wn from the reservoir 188 out the port 188B via the fluid flow condui~ 184a and the bubble trap/bubble detector 150 ~o the fluid ~low condui~
184. The fluid will then be returned to the donor via the conduit B8 and the cannula BBa.
The return ra'ce of ~he concentrated cells, including red blood cells and plasma, is on the order of 130 ~o 150 ml per minu~e. This substantially 11 31~917 increased return fluid flow rate provides the important advantage in that ~he time necessary ts return the concentrated cells to the donor is approximately half of the time required for the draw cycle. While the concentrated cells are being returned to the donor, fluid continues to be pumped from the reservoir 188 via the p~rt lB8a via the feed pump 190 through the separation chamber 160 and back to the donor Yia the port 188c. Additional volume ~low rate can come directly from the reservoir 188.
Platelets ~ontinue to accumulate in the chamber 164.
~ he draw çycle can then be reinitiated and an additional quantity ~f blood drawn from the donor. When the desired quantity of platelets has been accumulated in ~he ~hamber 164, clamp 1 can be closed and clamp 2 can be opened. The platelets then need to be resuspended. By means of the pump 141, the platelets in the chamber 164 can then be pumped into the container 198. Quantities of pl3telets on the order o~ 4xlO11 cells can be accumulated using the system and apparatus in Figure 11 in ~ time in~erval on the order of 50 minutes.
With respect to the embodiment o~ Figure 5C, the use of the dam or shim 112 illustrated ~herein allows priming of a dry ~luid transfer system with whole blood and prevents the occurence of potential air locks whi~h would hinder the flow of plasma and/or platelets in the fluid flow conduits during high ~peed centrifugation. The shim or dam 112, a~
noted previously, ~an be formed as par~ of the separation chamber S0c Alternately, it can be formed as part of the rotatable receiving ~hamber 40.
Many of the known cell separation syste~s require saline priming of the separation chambers prior ~o ~he pheresis operation~ As a resul~, it is ~3~791~
-29~
necessary to ~upply a container of sterile ~aline as part of the transfer set~ During set up, a frangible in the saline container is broken permiting the saline to flow into the separation chamber driving out any air present therein and providing a liquid filled s~paration chamber.
: The separation chamber 50 of Figure 5C does not require the use of saline for priming. The various ports have been lo ated on the separation chamber 50, taking into account different fluid densities. The ports are located in different planes he centrifugal force field F. For example, the input whole blood port 50A is centrally located with respect to the ~orce field. The plasma output p~rt 50B is located adjacent the relatively low force interior wall of the separation chamber 50., The residual :Eluid output por t 50C f~r the concentra'ced or packed red blood cells is located adjacent the maximum force exterior wall of the separation chamber 50.
Directing of ~he fluids ~o the various e:utput ports i5 ac~omplished by means o~ essentially rigid deflecting member~ such as the shim or dam 112 adjacent the separated component or plasma output port 50B. A ~him or dam 112A is ~ssociated with the concentrated red blood ce}l output port 50C. The interface sur~ace 110 which is illustrated in Figure 5C ~ormed as part of the outer wall 40a of ~he receiving chamber 40 directs ~he ~low of separa~ed plasma cells.
~ he dams or shims ~12 and 112A are also ef~ective to prevent the flow of air through ~he plasma por ~ Since air has a lower density then plasma, a cer~in amount of air will remain in the inner most region of the separation chamber 50. This air is also ~ompressed at higher centrifuge speeds~

The problem posed by air in the system is a result of pressures induced by the centrifugal force field F~ These forces are proportional to the &quare of the radius of the receiving chamber as well ~s the 6quare of the rotational velocity o~ the receiving chamber a~ the separation chamber 50 along with the density of the fluid. If air gets into the fluid flow conduit associated wîth the outpu~ port 50~, a pressure arop will occur in that line. This pressure drop may force the plasma pump to clamp the tubing shut and stop the flow of plasma by requiring too high a vacuum in the conduit. Aiternately, the pump may degas the plasma.
Overcoming this condition requires that the receiving chamber 40 and separating chamber 50 be slowed down until the plasma pump can overcome this pressure drop. Hence, the use of the saline in the known devices to drive all of the ai~ ou~ of the separation chamber and the related ~luid flow conduits. On the other hand, ~n the embodiment of Figure 5C the shims or dams 112 and 112a preve~t movement of the air out of the separation chamber 50 by creating a reservoir which will trap the air within the chamber during a low speed prime with blood. At high speed operation, the centrifugal induced pressure will compress this air away from the dam 112. The presence of a small ~mount of air in the chambex will not interfere with the pheresis process as long as the air i~ not permi~ted ~o escape into the fluid flow conduits associated wi~h the output port of ~he chamber.
From the foregoingl it will be observed that numerous varia~ions and modifications may be effected without departing from the true spiri~ and scope of the novel concept of the invention. I~ is to be 13179~7 understood tha~ no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. It is, of course t intended to cover by the appended claims all such modifications 5 as fall within the ~cope of the claims.

~0 ' - . . ,~ :;, ~

Claims

1. A centrifugation chamber for positioning within a field rotating about an axis comprising:
first and second side walls defining a processing chamber, the first side wall, when positioned within the rotating field, being adapted to be disposed closer to the rotational axis than the second side wall and defining within the processing chamber a low-g force region adjacent the first side wall and a high-g force region adjacent the second side wall, a source inlet port in the chamber for conveying source fluid to be processed into the chamber for separation in the rotating field into a first constituent that separates out along the first side wall in the low-g force region of the chamber, a second constituent that separates out along the second side wall in the high-g force region of the chamber, and an interface formed between the first and second constituents in an intermediate-g force region between the first and second side walls, interior wall means that extends into the intermediate-g force region of the processing chamber from one side wall toward the other side wall for directing fluid flow to expose the interface upon the interior wall means for detection through a side wall of the processing chamber, and at least one of the side walls includes a material in the region of the interior wall means that is transmissive to a preselected type of sensing energy for transmitting the sensing energy from outside the processing chamber upon the interior wall means to detect the location of the interface upon the interior wall means.

2. A chamber according to claim 1 wherein the side wall material is transmissive to radiant energy.

3. A chamber according to claim 1 wherein the interior wall means includes a material that is also transmissive to the sensing energy.

4. A chamber according to claim 3 wherein the interior wall means material is transmissive to radiant energy.

5. A chamber according to claim 3 wherein both side walls are transmissive in the region of the transmissive interior wall means to transmit the sensing energy in a path that enters one side wall, passes through the interior wall means, and exits the other side wall.

6. A chamber according to claim 5 wherein the material of the side walls and the interior wall means is transmissive to radiant energy.

7. A chamber according to claim 1 and further including an outlet port adjacent the first side wall for collecting separated constituent in the low-g region of the chamber.

8. A chamber according to claim 1 or 7 and further including an outlet port adjacent the second side wall for collecting separated constituent in the high-g region of the chamber.

9. A chamber according to claim 1 and further including a first outlet port adjacent the first side wall for collecting separated constituent in the log-g region of the chamber, a second outlet port adjacent the second side wall for collecting separated constituent in the high-g region of the chamber, and at least one of the first and second outlet ports is located, relative to the direction of source fluid flowing through the inlet source port, downstream of the region of the interior wall means.

10. A chamber according to claim 9 wherein both the first and second outlet ports are located, relative to the direction of source fluid flow, downstream of the region of the interior wall means.

11. A chamber according to claim 9 wherein one of the outlet ports is located, relative to the direction of source fluid flow, downstream of the region of the interior wall means, and wherein the other outlet port is located, relative to the direction of the source of fluid flow, upstream of the region of the interior wall means.

12. A chamber according to claim 11 wherein the first outlet port is located downstream of the region of the interior wall means, and the second outlet port is located upstream of the region of the interior wall means.

13. A chamber according to claim 1 and further including an outlet port adjacent the second side wall for collecting separated constituent in the high-g region of the chamber, and wherein the inlet source port and the outlet port are located adjacent to each other in the processing chamber.

14. A chamber according to claim 13 wherein the inlet source port enters the processing chamber at a location that is adapted to be closer to the axis of rotation than the outlet port.

15. A chamber according to claim 1 and further including a first outlet port adjacent the first side wall for collecting separated constituent in the low-g region of the chamber, a second outlet port adjacent the second side wall for collecting separated constituent in the high-g region of the chamber, and wherein the inlet source port enters the processing chamber at a location that is adapted to be farther from the axis of rotation than the first outlet port while being closer to the axis of rotation than the second outlet port.

16. A chamber according to claim 1 and further including an outlet port that is located adjacent one of the first and second side walls and that communicates with a second processing chamber.

17. A chamber according to claim 1 and further including an outlet port adjacent the second side wall for collecting separated constituent in the high-g region of the chamber, the inlet source port and the outlet port being located adjacent to each other in the processing chamber, and ramp means joined to the interior wall means and extending therefrom along the second side wall toward the outlet port for urging constituent separated in the high-g region to flow along the ramp means from the interior wall means toward the outlet port in a direction opposite to the flow direction of source fluid through the inlet source port.

18. A chamber according to claim 17 wherein the inlet source port enters the processing chamber at a location that is adapted to be closer to the axis of rotation than the outlet port.

19. A centrifugation chamber for positioning within a rotating field comprising first and second side walls defining a generally elongated processing chamber having oppositely spaced ends, the first side wall, when positioned within the rotating field, being disposed closer to the rotational axis than the second side wall to define within the processing chamber a low-g force region adjacent the first side wall and a high-g force region adjacent the second side wall, a source inlet port at one end of the chamber for conveying source fluid to be processed into the chamber for flow toward the opposite end of the chamber while being separated in the rotating field into a first constituent that flows along the first side wall in the low-g force region of the chamber, a second constituent that flows along the second side wall in the high-g force region of the chamber, and an interface that flows between the first and second constituents in an intermediate-g force region between the first and second side walls, interior wall means extending into the intermediate-g force region of the processing chamber from one of the side walls, the interior wall means being oriented at a non-perpendicular angle relative to the one side wall in the direction of source fluid flow for directing fluid flow away from the one side wall toward the other side wall to expose the interface upon the interior wall means for detection through a side wall of the processing chamber, and at least one of the side walls includes a material in the region of the interior wall means that is transmissive to a preselected type of sensing energy for transmitting the sensing energy from outside the processing chamber upon the interior wall means to detect the location of the interface upon the interior wall means.

20. A chamber according to claim 19 wherein the side wall material is transmissive to radiant energy.

21. A chamber according to claim 19 wherein the interior wall means includes a material that is also transmissive to the sensing energy.

22. A chamber according to claim 21 wherein the interior wall means material is transmissive to radiant energy.

23. A chamber according to claim 21 wherein both side walls are transmissive in the region of the transmissive interior wall means to transmit the sensing energy in a path that enters one side wall, passes through the interior wall means, and exits the other side wall.

24. A chamber according to claim 23 wherein the material of the side walls and the interior wall means is transmissive to radiant energy.

25. A chamber according to claim 19 and further including a first outlet port adjacent the first side wall for collecting separated constituent in the low-g region of the chamber, and a second outlet port adjacent the second side wall for collecting separated constituent in the high-g region of the chamber.

26. A system for separating a selected component from a fluid comprising:
centrifugation means including a housing for rotation about a selected axis of rotation, said housing defining an annular slot, sealed fluid flow means including an elongated separation chamber having at least a fluid input port and a separated component output port for defining a fluid flow path therebetween with said separation chamber carried in said slot, the chamber having opposed sidewalls along the fluid flow path that, when the chamber is in the slot, are oriented generally parallel to the axis of rotation, an interface surface extending within said fluid flow path from one of the sidewalls toward the other sidewall at a selected angle to the fluid flow, and means for detecting the presence of an interface between the separated selected component and the remaining fluid on said interface surface through one of the sidewalls of the separation chamber.

27. A system as in claim 26 wherein the interface detection means includes a source of radiant energy.

28. A system as in claim 26 wherein the interface detection means includes means for detecting radiant energy.

29. A system for separating a selected fluid component from a fluid resulting in a residual fluid comprising:
centrifugation means including a housing for rotation about a selected axis, said housing including an annular slot having a substantially constant radius with respect to said axis, a sealed, elongated, flexible separation chamber having a fluid input port, a selected fluid component output port and a residual fluid output port, said chamber receivable in said annular slot and exhibiting a generally cylindrical, non-spiral shape therein, said chamber defining a fluid flow path between at least said fluid input port and said selected component output port, the chamber having opposed sidewalls along the fluid flow path that, when the chamber is in the slot, are oriented generally parallel to the axis of rotation, one of the sidewalls being transmissive at least in part of radiant energy, a projection, transmissive at least in part of radiant energy, extending within a part of said fluid flow path from one of the sidewalls toward the other sidewall for blocking at least in part said fluid flow path, and means, responsive to radiant energy, for detecting the presence of an interface between the selected fluid component and the residual fluid on said projection through one of the sidewalls of the chamber.

30. A method of separating a selected component from a fluid comprising the steps of rotating a processing chamber to create a low-g force region adjacent a first side wall of the chamber and a high-g force region adjacent a second side wall of the chamber, conveying source fluid to be processed into the chamber for separation in the rotating field into a first constituent that separates out along the first side wall in the low-g force region of the chamber, a second constituent that separates out along the second side wall in the high-g force region of the chamber, and an interface formed between the first and second constituents in an intermediate-g force region between the first and second side walls, locating an interior wall in the intermediate-g force region of the processing chamber that extends from one side wall toward the other side wall for directing fluid flow to expose the interface upon the interior wall means, and detecting the interface on the interior wall by transmitting a preselected type of sensing energy from outside the processing chamber upon the interior wall means through a side wall of the processing chamber.

31. A method according to claim 30 wherein, in detecting the interface, radiant energy is transmitted through a side of the processing chamber.

32. A method according to claim 30 and further including the step of collecting the first and second constituents.

33. A method according to claim 32 and further including the step of controlling the collection of the first and second constituent at least in part by a signal generated in response to detecting the interface on the interior wall.

34. A centrifugation chamber for positioning within a field rotating about an axis comprising first and second side walls defining a processing chamber, the first side wall, when positioned within the rotating field, being adapted to be disposed closer to the rotational axis than the second side wall and defining within the processing chamber a low-g force region adjacent the first side wall and a high-g force region adjacent the second side wall, a source inlet port in the chamber for conveying source fluid to be processed into the chamber for separation in the rotating field into a first constituent that separates out along the first side wall in the low-g force region of the chamber, a second constituent that separates out along the second side wall in the high-g force region of the chamber, and an interface formed between the first and second constituents in an intermediate-g force region between the first and second side walls, an outlet port adjacent the second side wall for collecting separated constituent in the high-g region of the chamber, the inlet source port and the outlet port being located adjacent to each other in the processing chamber, and ramp means extending along the second side wall toward the outlet port for urging constituent separated in the high-g region to flow along the ramp means toward the outlet port in a direction opposite to the flow direction of source fluid through the inlet source port.

35. A chamber according to Claim 34 wherein the inlet source port enters the processing chamber at a location that is adapted to be closer to the axis of rotation than the outlet port.