Abstract: A flexible, disposable centrifuge bag for receiving and holding a fluid sample, comprising one or more tubes and upper and lower flexible sheets having doughnut shaped configurations. The upper and lower sheets are superimposed and completely sealed together at their outer perimeters to define an outer perimeter of the centrifuge bag. The inner perimeter of the bag defines a central core. The tubes are sandwiched between the upper and lower sheets and extend from the central core of the centrifuge bag. The upper and lower sheets are sealed together at their inner perimeters such that the tubes are sealed between said upper and lower sheets at the inner perimeter. The bag may be used to harvest platelet rich plasma from whole blood in either a batch method or while simultaneously infusing additional aliquots of whole blood into the bag during centrifugation.

Abstract: A Platelet Rich Plasma separator assembly is disclosed. The assembly can include a cylindrical outer wall closed at the top by an upper plate and closed at the bottom. A bottom plate having an upper surface sloped down to a central opening. The top edge of the inner wall terminates at a distance from the upper plate to define an annular erythrocyte passageway therebetween. The inner wall has an outer surface and an inner surface that slopes radially inward from its top edge to its bottom at an angle of from 0.2 to 5 degrees with a central axis of the inner wall. A cylindrical depth filter is positioned between the inner surface of the outer wall and the outer surface of the inner wall in communication with the inner wall through the erythrocyte passageway.

Abstract: A centrifugal method, and corresponding system, for processing blood to collect platelet rich plasma. A separation chamber is filled with blood from a fill syringe by rotating the separation chamber at a fill rotation rate and pumping the blood from the fill syringe. A soft spin is used to initially separate red blood cells from platelets by spinning the separation chamber at a soft spin rate. A percentage of the blood is drawn from the separation chamber back into the fill syringe to remove separated red blood cells. A second portion of the separated blood is drawn from the separation chamber until a red blood cell/platelet interface is detected. A hard spin is performed by spinning the separation chamber at a higher rate and connecting tubing is cleared of red blood cells by drawing a predetermined clearing volume. The platelet rich plasma is then collected in the collection syringe.

Abstract: An apparatus that allows for separating and collecting a fraction of a sample. The apparatus, when used with a centrifuge, allows for the creation of at various fractions in the apparatus. A buoy system that may include a first buoy portion and a second buoy member operably interconnected may be used to form at least three fractions from a sample during a substantially single centrifugation process. Therefore, the separation of various fractions may be substantially quick and efficient. Also selected fractions from the sample can be applied to a patient, either alone or as part of a mixture.

Abstract: An apparatus that allows for separating and collecting a fraction of a sample. The apparatus, when used with a centrifuge, allows for the creation of at least three fractions in the apparatus. It also provides for a new method of extracting the buffy coat phase from a whole blood sample and mesenchymal stem cells from bone reaming material. A buoy system that may include a first buoy portion and a second buoy member operably interconnected may be used to form at least three fractions from a sample during a substantially single centrifugation process. Therefore, the separation of various fractions may be substantially quick and efficient.

Abstract: A centrifugal processing bag, system and method for separating the components of a mixed material is presented. The processing bag includes a hub and a first port for receiving the mixed material, where the first port includes an outlet positioned within the processing bag at a perimeter of the bag. The processing bag also including a second port having a second port inlet spaced proximate the hub and away from a central axis of the hub. The second port directs a separated material collected from the second port inlet out of the processing bag.

Abstract: A PRP separator-concentrator comprising a housing, a separation assembly, and a concentration assembly. The concentration assembly has a concentration sump. An axially concentric rigid stationary outlet tube is secured to the housing and extends through the separation assembly to the sump. The separation assembly is attached to and positioned above the concentration assembly to form a combined separator-concentrator assemblage that is rotatable about the outlet tube. The separation assembly includes a separation chamber lined with a depth filter having pores and passageways that are sized to receive and entrap erythrocytes during centrifuging. The concentration chamber has a floor for supporting desiccated beads and a wall with at least one opening closed with a screen. The concentrator can have a distribution of upright screen supports, the upright screen supports having an inner surface and an outer surface, the cylindrical screen being supported on the outer surface of the upright screen supports.

Abstract: Methods for using a centrifuge are presented. A vessel containing a sample and a separator substance is placed within a centrifuge. Upon sufficient centrifugation, the sample separates into two or more fractions separated by the separator substance. The centrifuge exposes the separator substance to a sufficient energy to polymerize the separator substance to produce a hardened barrier between the fractions.

Abstract: A rotatable rotor for separating components contained in a fluid, comprising an annular base having a first annular channel and an annular cover having a second annular channel for holding a flexible doughnut-shaped centrifuge bag therebetween. The cover has one or more radially spaced apart concentric indicator lines for monitoring the separation of the components. When the base and cover are superimposed, the first and second channels define an annular interior chamber having an off-centered figure eight configuration. The base and cover each comprise a grooved column axially centered and extending from the base top surface and the cover bottom surface, respectively. The flexible bag comprises inner and outer tubes extending from the core of the bag and which are seated in the column grooves to ensure that the bag is fixably rotatable with the rotor.

Abstract: A test object receptacle, capable of measuring a test object in a wide range of concentrations with good accuracy and within a short time, contains a plurality of fine protruding portions inside grooves. The test object receptacle can fix antigens, antibodies and test objects faster than without the protruding portions. Furthermore, the protruding portions are so formed that the surface area thereof increases gradually to the downstream with respect to the movement direction of the test object in the grooves, the detection intensity (intensity of color development) of the test object is not saturated downstream of the grooves even when the test object has a high concentration. For this reason, the test object can be detected within a short time and the measurements can be conducted within a wide concentration range.

Abstract: A blood separation chamber is provided for separating blood into its constituent parts by rotation about an axis. The chamber has a central hub coinciding with the axis and spaced apart high-G and low-G walls which define therebetween a separation channel. The chamber further includes a plurality of parallel radial walls extending outwardly from the central hub and defining a radial fluid flow passage between each adjacent pair of walls. Each fluid flow passage communicates between the central hub and the separation channel. One of the radial walls includes a radially outer end portion defining a barrier in the separation channel intermediate the low-G and high-G walls and having generally parallel upstream and downstream sides. The separation channel has a recessed portion located radially outward of the high-G wall and extending between the upstream and downstream sides of the barrier.

Abstract: An apparatus is disclosed that allows for separating and collecting a fraction of a sample. The apparatus, when used with a centrifuge, allows for the creation of at least three fractions in the apparatus. It also provides for a new method of extracting the buffy coat phase from a whole blood sample. A buoy system that may include a first buoy portion and a second buoy member operably interconnected may be used to form at least three fractions from a sample during a substantially single centrifugation process. Therefore, the separation of various fractions may be substantially quick and efficient.

Abstract: An apparatus and method for centrifugally separating particles by both weight and size include a rotating drum rotating about a second rotating axis disposed perpendicularly to a first rotating axis, and includes an inlet, at least one rotating plate and an outlet. The inlet injects a test material. The rotating plate extends radially outward toward an inner surface of the rotating drum from the second rotating axis and has one or more configurations of protruded and recessed portions formed on a surface thereof. The rotating plate receives the test material on a surface thereof. The outlet discharges separated test material.

Abstract: A method and apparatus for obtaining various components of a multi-component material. Generally, a component of a whole blood sample may be concentrated from a patient and re-introduced to the same patient. For example, a clotting component, such as thrombin, from a whole blood sample may be extracted and concentrated in an apparatus and collection to be reapplied or reintroduced into a patient.

Abstract: A system for automatically collecting and separating whole blood into its components is described. The system includes a console, which contains all motors, pumps, sensors, valves and control circuitry, and a unique disposable set that includes a cassette supporting a centrifuge with an improved design, pump interfaces with an improved design, component and solution bags, and tubing. Various processes are implemented using a specific disposable set for each process which allows automatic identification of the process to be performed the console.

Abstract: A transportation system for transporting a biological material container between a sterile field and a nonsterile field and substantially maintaining sterility of the biological material container includes a housing assembly that removably houses the biological material container. The system also includes a port defined by the housing assembly, and the port provides communication into the biological material container from outside the housing assembly. The housing assembly includes a first member that covers a first portion of the biological material container such that a second portion of the biological material container extends from the first member. The housing assembly also includes a second member that covers the second portion of the biological material container. The second member is removably coupled to the first member to expose the second portion of the biological material container. A keying member that keys the transportation system in a centrifuge is also disclosed.

Abstract: The present invention is directed to a method and system that separates first particles from second particles, or white blood cells from red blood cells, by sedimentation in a fluid chamber with debulking of one of the first or second particles or red blood cells through the inlet of the fluid chamber. The method and system further includes fractionation of the remaining particles or white blood cells into selected subsets. In one embodiment of the instant invention a blood product containing white blood cells is loaded in a separation chamber, a diluting or sedimenting agent is added to encourage rouleaux formation of any red blood cells, the cells are sedimented and the red blood cells are removed.

Abstract: A two-tube centrifuge separates light material and heavy material from an input mixture. A hollow drive shaft rotates a central body member about an axis of rotation. Two hollow arm assemblies, each having circular cross-section, are mounted on diametrically opposite sides of the central body. Each arm assembly includes an outer housing tube, an intermediate tube, and an inner tube that is longer than the intermediate tube. An end cap having a removable plug is mounted on the outer end of the housing-tube of each arm assembly. The inner ends of all three tubes are mechanically interlocked in a manner to cantilever mount the inner and intermediate tubes to the central-body with their outer ends spaced from the internal surface of the end cap. An input-mixture path extends through the hollow drive shaft, through the central-body, and into a cylindrical space between the inner and intermediate tubes of each arm assembly.

Abstract: A system for automatically processing blood components is described. The system includes a console, which contains all motors, pumps, sensors, valves and control circuitry, and a unique disposable set that includes a cassette supporting a centrifuge with an improved design, pump interfaces with an improved design, component and solution bags, and tubing. Various processes are implemented using a specific disposable set for each process which allows automatic identification of the process to be performed the console.

Abstract: The filter removes volatile, particulate and water-based contaminants from a fluid, such as lubricating oil, of a different density than the contaminants. The device has a cone shaped, jet-propelled, helical-spiral wiper rotor creating centrifugal forces that separate the volatile and heavier particulate matter. Ports in a base assembly facilitate removal of the separated contaminants. A settling tank with vertical grid filter minimizes turbulence for further separation of heavier particulate matter. A volatile tank with vertical grid filter and flow restrictor minimizes turbulence to allow volatiles to rise from the fluid. A filter tank filters out remaining particulate matter from the fluid. A combination of flow restrictors and baffles minimize cross-contamination, thereby maximizing purity of oil returned to the engine. The collection tanks are easily cleaned and reused. The compact design minimizes oil volume necessary for purification.

Abstract: The present invention provides an apparatus for separating components of a fluid having an outer housing containing a core wherein three separate fluid pathways are provided to allow continuous separation of biological fluids.

Abstract: The teachings of the present disclosure provide methods and apparatus for removing substances from a process fluid. The system may include a centrifuge body rotatable around a longitudinal axis, the centrifuge body having a first end and a second end. The first end may be configured for receiving a process fluid. The second end may be configured for dispensing a clarified fluid. The centrifuge body may include a first working space and a second working space. The working diameter of the second working space may be greater than the working diameter of the first working space.

Abstract: A blood processing centrifuge comprising: a rotor having an axis of rotation and being controllably spun around the axis, a mechanism for processing whole blood within the rotor while spinning, a computer controlling blood processing operations, the computer being mounted to the rotor and spinning therewith.

Abstract: A system for the production of a blood component composition is provided. The system includes a centrifuge having a blood reservoir for receiving and separating a blood sample into multiple components; a dispenser disposed outside of the centrifuge having a first collection chamber containing an activation agent and a second collection chamber containing one or more medicinal agents; means for removing a first portion at least one separated blood component from the centrifuge to the first container and a second portion to the second collection chamber, wherein the first collection chamber activates the first portion and stores the resulting clot and thrombin; a filter for separating the thrombin from the clot; and a nozzle for entraining and mixing the thrombin with the second portion containing the one or more medicinal components.

Abstract: An apparatus that allows for separating and collecting a fraction of a sample. The apparatus, when used with a centrifuge, allows for the creation of at least three fractions in the apparatus. It also provides for a new method of extracting the buffy coat phase from a whole blood sample. A buoy system that may include a first buoy portion and a second buoy member operably interconnected may be used to form at least three fractions from a sample during a substantially single centrifugation process. Therefore, the separation of various fractions may be substantially quick and efficient.

Abstract: A blood-collection system configured to permit selection of either collection and disposal of shed blood from a patient or collection and processing of shed blood for autologous transfusion back to the patient includes an automated blood-processing machine. The system may also include a blood-collection reservoir, a separation chamber, and a fluid conduit. The blood-collection reservoir may be engageable with the blood-processing machine so that the machine can identify and report the presence of blood in the reservoir. The separation chamber may also be engageable with the blood processing machine. The fluid conduit may be configured to selectively join the reservoir to the separation chamber by a quick-connect coupling.

Abstract: Numerous embodiments of a system and method for treating cardiac tissue are described. In one embodiment, bone marrow cells are extracted from a patient. The cells are then processed to isolate mononuclear cells, which can then be delivered back near the cardiac tissue of the patient.

Abstract: A rotatable rotor for separating components contained in a fluid, comprising an annular base having a first annular channel and an annular cover having a second annular channel for holding a flexible doughnut-shaped centrifuge bag therebetween. The cover has one or more radially spaced apart concentric indicator lines for monitoring the separation of the components. When the base and cover are superimposed, the first and second channels define an annular interior chamber having an off-centered figure eight configuration. The base and cover each comprise a grooved column axially centered and extending from the base top surface and the cover bottom surface, respectively. The flexible bag comprises inner and outer tubes extending from the core of the bag and which are seated in the column grooves to ensure that the bag is fixably rotatable with the rotor.

Abstract: A centrifuge includes at least two centrifugal drums, each drum including a disc stack and each drum being rotatable about first and second axes of rotation. The first axis of rotation extends through a center of gravity of and is within each drum. The second axis of rotation is situated outside each drum.

Abstract: In a centrifugal oil separator in an internal combustion engine including a centrifuge housing which is placed in a rotationally fixed manner onto a rotating centrifuge shaft, the centrifuge housing is manufactured from plastic and a metal bushing is integrated into the centrifuge housing and is slipped onto the centrifuge shaft.

Abstract: A centrifugal method, and corresponding system, for processing blood to collect platelet rich plasma. A separation chamber is filled with blood from a fill syringe by rotating the separation chamber at a fill rotation rate and pumping the blood from the fill syringe. A soft spin is used to initially separate red blood cells from platelets by spinning the separation chamber at a soft spin rate. A percentage of the blood is drawn from the separation chamber back into the fill syringe to remove separated red blood cells. A second portion of the separated blood is drawn from the separation chamber until a red blood cell/platelet interface is detected. A hard spin is performed by spinning the separation chamber at a higher rate and connecting tubing is cleared of red blood cells by drawing a predetermined clearing volume. The platelet rich plasma is then collected in the collection syringe.

Abstract: A separation apparatus and method are employed using a separation channel for rotation about an axis. Such channel includes radially spaced apart inner and outer side wall portions and an end wall portion. An inlet conveys fluid into the channel. A barrier is located in the channel intermediate of the inner and outer side wall portions. A first flow path communicates between upstream and downstream sides of the barrier. A collection region may be located downstream of the barrier for communication with the first flow path. An outer side wall section of the channel may be positioned radially outward of an upstream section thereof. The barrier may join the outer side wall portion along a substantial portion of an axial length of the channel. First and second exit flow paths may allow communication with the channel either upstream or downstream of the barrier or both.

Abstract: An apparatus and method for centrifugally separating particles by both weight and size include a rotating drum rotating about a second rotating axis disposed perpendicularly to a first rotating axis, and includes an inlet, at least one rotating plate and an outlet. The inlet injects a test material. The rotating plate extends radially outward toward an inner surface of the rotating drum from the second rotating axis and has one or more configurations of protruded and recessed portions formed on a surface thereof. The rotating plate receives the test material on a surface thereof. The outlet discharges separated test material.

Abstract: A centrifugal method, and corresponding system, for processing blood to collect platelet rich plasma. A separation chamber is filled with blood from a fill syringe by rotating the separation chamber at a fill rotation rate and pumping the blood from the fill syringe. A soft spin is used to initially separate red blood cells from platelets by spinning the separation chamber at a soft spin rate. A percentage of the blood is drawn from the separation chamber back into the fill syringe to remove separated red blood cells. A second portion of the separated blood is drawn from the separation chamber until a red blood cell/platelet interface is detected. A hard spin is performed by spinning the separation chamber at a higher rate and connecting tubing is cleared of red blood cells by drawing a predetermined clearing volume. The platelet rich plasma is then collected in the collection syringe.

Abstract: An apparatus and method for collecting whole blood and then separating it into components for subsequent use or storage. A self-contained bag set is used to collect the sample, which may then be placed into container adapted to fit into a centrifuge for separation of components. Each component is then sequentially extracted according to density, with a sensor present in the container to control the operation of valves directing the collection of each component. Each component may then be separated into its own storage container.

Abstract: A centrifuge for separating particulate matter from circulating fluid includes a centrifuge enclosure including a housing and a base joined together so as to define a hollow interior. A rotor is positioned in the hollow interior and is supported by the base in a manner to permit rotary motion of the rotor relative to the centrifuge enclosure. A coalescing filter assembly is secured to the rotor and is constructed and arranged for removing oil aerosol from a blowby gas which is introduced into the centrifuge. A roller bearing, press fit into the centrifuge housing, receives a portion of the coalescing filter assembly.

Abstract: The present invention provides an apparatus for separating components of a fluid having an outer housing containing a core wherein three separate fluid pathways are provided to allow continuous separation of biological fluids.

Abstract: The present invention is directed to a method and system that separates first particles from second particles, or white blood cells from red blood cells, by sedimentation in a fluid chamber with debulking of one of the first or second particles or red blood cells through the inlet of the fluid chamber. The method and system further includes fractionation of the remaining particles or white blood cells into selected subsets. In one embodiment of the instant invention a blood product containing white blood cells is loaded in a separation chamber, a diluting or sedimenting agent is added to encourage rouleaux formation of any red blood cells, the cells are sedimented and the red blood cells are removed.

Abstract: The present invention relates to systems, methods and apparatus for improving the yield for separating components of fluids, for example biological or sensitive fluids such as blood, and improving the component yield, for example, from donated whole blood by separating its components by density in a centrifuge bowl with a multi-axial lumen. The apparatus, system, and method eliminate the need to batch-type separate blood and can reduce the time needed to treat patients suffering from T-cell or white blood cell mediated diseases or conditions to less than 70 minutes. In one aspect, the invention is a centrifuge bowl (10) comprising an outer housing (100); a core (200); a lower plate (300); a lumen (400); a first bowl channel (420) within said lumen (400) for inflowing said fluid (800); a second bowl channel (410) for removing a first separated fluid component (810); and a third bowl channel (740) for removing a second separated fluid component (820).

Abstract: An apparatus that allows for separating and collecting a concentrated fraction of a fluid, such as a whole blood sample, adipose tissue, or a bone marrow sample. The apparatus, when used with a centrifuge, allows for the creation of at least three fractions in the apparatus. It also provides for a new method of extracting the buffy coat phase from a whole blood sample. The apparatus includes a container to be placed to a centrifuge after being filled with a whole blood sample. A buoy or fraction separator, which has a density less than that of red blood cells of a whole blood sample, is disposed in the container. During the centrifuge process the buoy separates the red blood cells from another fraction of the whole blood. After the centrifuge process is finished a plunger is used to produce at least two other fractions, including a plasma fraction and a buffy coat. Then, the buffy coat may be removed from the container without commingling the fractions of the sample.

Abstract: A centrifugal debris trap includes a cylindrical chamber bound by an inner surface of a continuous wall radially disposed about a center axis at a first inner diameter, and having a first wall end and a second wall end; and a plurality of grooves between the first and second wall ends, extending radially outward from the inner surface into a portion of the continuous wall, and each having a groove outer diameter that is greater than the first inner diameter. The cylindrical chamber is sealed at the first wall end by a back plate attached about a circumference of the first wall ends, and is open at the second wall end through a ring attached thereto about a circumference of the second wall end. The ring has a ring opening radially disposed about the center axis, and a second inner diameter less than the first inner diameter.

Abstract: A method for centrifugally separating whole blood into red blood cells and a plasma constituent rotates about a rotational axis a separation zone having radially spaced apart walls with a high-G side and a low-G side located closer to the rotational axis than the high-G side. Whole blood enters the rotating separation zone in an entry region to begin separation. Separation is halted by a terminal wall that is circumferentially spaced from the entry region. The whole blood separates into red blood cells toward the high-G side and plasma constituent toward the low-G side. The method directs red blood cells separated in the separation zone in a circumferential flow direction toward the terminal wall. The method directs separated red blood cells from the rotating separation zone through a second path that extends, at least in part, radially beyond the high-G wall.

Abstract: Many areas in the world already suffer shortages of water, and others will suffer from it in the coming years. Therefore more efficient water sweetening is essential for our survival on this planet. The most commonly used water sweetening methods are: Reversed osmosis, distillation, electrodyalisis, and partial freezing. However, these methods suffer from low efficiency and high energy consumption, thus making them significantly more expensive than naturally obtained water. The present invention describes a system & method for efficient and low energy sweetening of water, based on borderline fast fluctuation between liquid to gaseous state and back, by using centrifugal forces to make water droplets fly at a high speed, so that they evaporate for a split second, the salt is separated, and they condense again. The present invention tries to make the process energy-efficient by enabling the use of lower speeds and smaller droplet sizes and solving various problems involved with that.

Abstract: An apparatus for use in separating, at least in part, a mixture, including at least one chamber and at least one microwave generation device configured for communicating microwave energy into the at least one chamber is disclosed. The rotor assembly may comprise an electric generator for generating electricity for operating the microwave generation device. At least one microwave generation device may be positioned within a tubular interior shaft extending within the rotor assembly. At least a portion of the tubular interior shaft may be substantially transparent to microwave energy. Microwave energy may be emitted in an outward radial direction or toward an anticipated boundary surface defined between a mixture and a separated constituent thereof. A method including flowing a mixture through at least one chamber and communicating microwave energy into the at least one chamber while rotating same is disclosed. Methods of operating a centrifugal separator and design thereof are disclosed.

Abstract: A system for automatically collecting and separating whole blood into its components is described. The system includes a console, which contains all motors, pumps, sensors, valves and control circuitry, and a unique disposable set that includes a cassette supporting a centrifuge with an improved design, pump interfaces with an improved design, component and solution bags, and tubing. Various processes are implemented using a specific disposable set for each process which allows automatic identification of the process to be performed the console.

Abstract: The filter removes volatile, particulate and water-based contaminants from a fluid, such as lubricating oil, of a different density than the contaminants. The device has a cone shaped, jet-propelled, helical-spiral wiper rotor creating centrifugal forces that separate the volatile and heavier particulate matter. Ports in a base assembly facilitate removal of the separated contaminants. A settling tank with vertical grid filter minimizes turbulence for further separation of heavier particulate matter. A volatile tank with vertical grid filter and flow restrictor minimizes turbulence to allow volatiles to rise from the fluid. A filter tank filters out remaining particulate matter from the fluid. A combination of flow restrictors and baffles minimize cross-contamination, thereby maximizing purity of oil returned to the engine. The collection tanks are easily cleaned and reused. The compact design minimizes oil volume necessary for purification.

Abstract: A centrifugal processing bag, system and method for separating the components of a mixed material is presented. The processing bag includes a hub and a first port for receiving the mixed material, where the first port includes an outlet positioned within the processing bag at a perimeter of the bag. The processing bag also including a second port having a second port inlet spaced proximate the hub and away from a central axis of the hub. The second port directs a separated material collected from the second port inlet out of the processing bag.

Abstract: An apparatus is adapted to centrifuge a container for separating a component, such as fibrin monomer, from blood or plasma. The container includes a cylindrical member, and a piston displaceable therein and a tubular piston rod, which extends through a top wall of the cylindrical member. The piston divides the cylindrical member into a first chamber positioned above the piston between the piston and the top wall, and a second chamber positioned below the piston. The apparatus includes a supporting turntable which releasably retains the cylindrical member. The supporting turntable is connected to a first activator for rotating the supporting turntable with the container about the central axis thereof. The apparatus also includes a rotatably journalled piston activating mechanism adapted to activate the piston by a second activator.

Abstract: A process includes coating a cylinder having an inner wall and a cylinder axis with a gel coating on the inner wall. Then a specimen mixture including solvent is made to flow through the cylinder while the cylinder is being continuously rotated. The specimen mixture is initially directed to flow along the cylinder axis and such that specimen particles from the specimen mixture are accelerated off the cylinder axis toward the inner wall, so as to form a film of specimen particles embedded into the gel coating.

Abstract: A centrifugal method, and corresponding system, for processing blood to collect platelet rich plasma. A separation chamber is filled with blood from a fill syringe by rotating the separation chamber at a fill rotation rate and pumping the blood from the fill syringe. A soft spin is used to initially separate red blood cells from platelets by spinning the separation chamber at a soft spin rate. A percentage of the blood is drawn from the separation chamber back into the fill syringe to remove separated red blood cells. A second portion of the separated blood is drawn from the separation chamber until a red blood cell/platelet interface is detected. A hard spin is performed by spinning the separation chamber at a higher rate and connecting tubing is cleared of red blood cells by drawing a predetermined clearing volume. The platelet rich plasma is then collected in the collection syringe.