Abstract: Blood processing systems and methods employ two sensors, one to detect a condition of plasma exiting a separation device and another sensor to detect a condition of a cellular component exiting the separation device. The first sensor detects, e.g., contamination of the plasma due to presence of unwanted cellular components. The second sensor detects, e.g., dilution of the cellular component due to presence of plasma. Blood processing parameters are carried out based, at least in part, by conditions detected by one or both of the sensors.

Abstract: An apparatus for carrying out a weight measurement in centrifuges for separating suspensions into their solid and liquid components comprises a machine housing, a drum rotatingly mounted in the machine housing and receiving the suspension, and a filler pipe leading into the drum for feeding the suspension into the drum. The machine housing is mounted for pivotal movement about an axis of rotation, and a force measuring element senses weight-dependent deflections of the machine housing occurring about the axis of rotation and originating from a different degree of filling of the drum with suspension or from a different dewatering of the solid suspension components, and the machine housing deflections are indicated on a measurement value indicator. A pipeline is provided for generating a positive pressure or a negative pressure in the drum.

Abstract: Blood processing systems and methods separate blood into constituents including a plasma constituent that includes a platelet volume. The systems and methods detect the optical density of the plasma constituent and generate a first output indicative of the optical density. A processing element integrates the first output relative to the volume of plasma constituent and generates an integrated output. The integrated output correlates to the platelet volume. A second processing element generates an output based, at least in part, upon the integrated output, which comprises a value indicating a blood volume that needs be processed to obtain a desired platelet volume.

Abstract: An ordinary vacuum blood collection tube assembly is rotated about its longitudinal axis to partition a blood sample into serum and formed elements by centrifugation. While still rotating a higher density, immiscible inert liquid is pumped into the vacuum blood collection tube assembly thereby displacing lower density serum towards the axis of rotation and thence out of the vacuum blood collection tube assembly to a serum receiver vessel. A contaminant detector located on the serum delivery conduit controls a 3 way valve to divert contaminants from the removed serum to a waste vessel so only clean serum is delivered to the serum receiver vessel. The serum delivery conduits, serum cannula, and contaminant detector are washed and dried between successive samples to limit sample carryover effects to acceptably low levels.

Abstract: A method for collecting, from whole blood, platelets suspended in plasma. By centrifuging the blood at a high enough rotational speed, the platelets are separated from the plasma and the red blood cells. In a preferred embodiment, some of the plasma is removed while the centrifuge is being spun to keep the platelets separated from the plasma. Then, the speed of rotation is altered so as to cause the platelets to mix with the remaining plasma. The platelets can then be collected with the remaining plasma.

Abstract: A method is provided to automatically control an infeed gate of a centrifuge to regulate the rate of incoming charge and thereby maintain a desired building rate for a charge wall being formed along inner sidewalls of a rotating centrifugal basket by measuring the charge wall thickness which forms, determining a fill rate at which the charge material enters the basket, and comparing the determined rate to a desired fill rate. Closure of the infeed gate is also controlled to gradually approach a minimum flow rate. A method is also provided for sensing an unstabilizing wobble of the centrifugal basket and closing the infeed gate in response. The automatic control of the opening and closing of the gate not only improves the capacity of the centrifuge, but also allows for remote operation.

Abstract: Red blood cell sensing systems and methods rely upon straightforward measurement geometries. The systems and methods comprise an incident light source, an optical sensor, and a blood collection tube. The systems and methods hold the blood collection tube a predetermined radial distance from the incident light source where a linear relationship exists between sensed reflected light measured by the optical sensor and red blood cell hematocrit in a range of at least 10 to 90. The systems and methods make possible accurate red blood sensing without use of special optical cuvettes, mirrors, or focusing lenses. The systems and methods also make possible the use of standard transparent plastic tubing, without reliance upon special optical cuvettes.

Abstract: A centrifuge for continuously separating the various constituents of blood or other biological fluids includes a rotating bowl having high-G and low-G walls. An inwardly directed ramped surface on the high-G wall interacts with an interface region between the separated fluid constituents to provide an optically detectable indication of the position of the interface between the high-G and low-G walls. An optical sensor sensing each passage of the ramped surface past a point develops a changing signal indicative of the interface position. Signal processing circuitry responsive to the signal measures such signal parameters as peak amplitude, signal area and signal shape. By so monitoring these signal parameters, a better indication of actual interface position between the high-G and low-G walls can be obtained. This, in turn, results in better control over centrifuge operation and improved separation of the desired fluid components.

Abstract: A method and an apparatus for the automatic control of a blood centrifuge, including a controller that processes four input values and two output parameters. The four input values include the hematocrit value of the input blood, the volume of the red cells present in the centrifuge, the filling level of the centrifuge, and, selectively, the hematocrit value for collected blood at the end of the filling step and the time required for the filling step. The two output parameters include the flow rate of the blood into the centrifuge and either the time required for the filling step (when the hematocrit value is provided as input) or the predicted hematocrit value (when the time for the filling step is provided as input).

Abstract: Apparatus for separating a biological component from a biological fluid are disclosed. The apparatus includes a chamber for receiving a biological fluid including a biological component, and a rotor for creating a centrifugal field within the chamber. A source of particles may be included wherein the particles have a binding site for selectively binding to the biological component. The particles may be aseptically introduced into the chamber. The apparatus may withdraw whole blood from a donor, separate the whole blood to obtain a target cell population and return a selected one of either the target cell population or at least a portion of the whole blood remainder to the donor or patient. A disposable separation inset for use in conjunction with a rotatable separation device such as the apparatus described above may also be provided.

Abstract: A method and apparatus for measuring the thickness of sludge being deposited on the sidewall of a rotating turbine can in a centrifuge by measuring the electrical admittance (capacitance or conductance) between the sidewall of the turbine can and the base, shaft, or body of the centrifuge which is electrically isolated from the turbine can. An electrical circuit is coupled to the sidewall of the turbine can to measure a change in the thickness of the sludge being deposited on the inner surface of the sidewall by measuring a change in voltage, admittance, capacitance, or conductance between the turbine can and the base, shaft or body of the centrifuge which are all at ground potential. The apparatus of the invention includes a typical centrifuge which is modified by adding a pair of insulating rings to the structure of the centrifuge to electrically isolate the turbine can from the rest of the centrifuge structure.

Abstract: Blood processing systems and methods separate whole blood into red blood cells and a plasma constituent within a rotating centrifugal separation device. The systems and methods convey whole blood into the separation device through an inlet path including a pump operable at a prescribed rate. The systems and methods remove plasma constituent from the separation device through an outlet path including a pump operable at a prescribed rate. The systems and methods derive a value Hb representing an apparent hematocrit of whole blood entering the separation device, where: H b = H rbc ⁡ ( Q b - Q p ) Q b and where Hrbc is a value relating to hematocrit of red blood cells in the separation device.

Abstract: Blood processing systems and methods separate blood into constituents including a plasma constituent that includes a platelet volume. The systems and methods detect the optical density of the plasma constituent and generate a first output indicative of the optical density. A processing element integrates the first output relative to the volume of plasma constituent and generates an integrated output. The integrated output correlates to the platelet volume. A second processing element generates a third output based, at least in part, upon the integrated output, which comprises parameters for storing the platelet volume.

Abstract: The present invention is a centrifuge essentially comprised of a rotor and a transparent cover which can be fixed to the rotor. The cover is provided with a plurality of spaced concentration lines each extending around the cover and a plurality of different graduated scales extending radially from the center of the cover across the concentration lines at spaced angular intervals. The rotor and the cover also have opposing snap lock elements at a central portion of the rotor and the cover.

Abstract: Computerized (e.g., "intelligent") systems for monitoring, diagnosing, operating and controlling various parameters and processes of continuous feed centrifuges is presented. The computer control system actuates at least one of a plurality of control devices based on input from one or more monitoring sensors so as to provide real time continuous operational control. The monitoring sensors may sense process and other parameters located both inside the centrifuge (e.g., inside the bowl) and outside or exterior to the centrifuge (e.g., outside the bowl) including machine operation parameters and parameters related to the input and output streams of the centrifuge.

Abstract: An apparatus is adapted to centrifuge and furthermore automatically handle a container (10) for separating a component, such as fibrin monomer, from plasma. The container (10) comprises a cylindrical member (11) and a piston (25) displaceable therein and comprising a tubular piston rod (12), which extends through the top wall. The piston (25) divides the cylindrical member (11) into a first chamber positioned above said piston (25) between said piston and said top wall and a second chamber positioned below said piston (25). The apparatus comprises a supporting turntable (1) with means for releasably retaining the cylindrical member (11), said supporting turntable being connected to a first activating mechanism (5) for rotating the supporting turntable (1) with the container (10) about the central axis thereof. The apparatus comprises furthermore a rotatably journalled piston activating mechanism (13, 15, 16) adapted to activate the piston by means of a second activating means (21).

Abstract: A system for separating a fluid having heavier and lighter components. The system includes a rotor having a rigid mounting member and an elastic diaphragm attached to the mounting member, the diaphragm defining a chamber. The system also includes a chuck for holding the rigid mounting member of the rotor and for spinning the rotor around an axis. The pressure of a control fluid, preferably a control gas, disposed adjacent the rotor's diaphragm is varied in order to control the volume of the rotor. Pressurizing the control gas causes fluid to flow out of the rotor; applying a vacuum to the diaphragm draws fluid into the rotor.

Abstract: Systems and methods obtain a platelet suspension with reduced number of leukocytes by centrifugally separating whole blood into red blood cells, a suspension of platelets, and an intermediate layer comprising leukocytes. The systems and methods convey the suspension of platelets from the centrifugal separation chamber to a filter, while maintaining the intermediate layer containing leukocytes inside the centrifugal separation chamber. The systems and methods filter remaining leukocytes from the platelet suspension in the filter.

Abstract: A computerized system for monitoring, diagnosing, operating, and controlling various parameters and processes of basket centrifuges is presented. The computer control system actuates at least one of a plurality of control devices based on input from one or more monitoring sensors so as to provide real time, continuous, operational control of certain parameters. In a preferred embodiment, the apparatus comprises a basket centrifuge with at least one sensor for providing input which is analyzed to provide information regarding cake moisture at a given time. As a result of the analysis, at least one output may be generated to activate a control device that effects changes or adjustments in the operation of the centrifuge.

Abstract: A system for a clinical lab that is capable of automatically processing, including sorting, of multiple specimen containers. The system comprises a central controller, a workstation, one or more analyzers, and an automated centrifuge. The workstation has automatic detectors for detecting the presence of a holder holding specimen containers. The workstation has a bar code reader for reading bar codes on the containers. The system has a transport subsystem, preferably a workstation robotic arm and an analyzer robotic arm for transporting the specimen containers, moving them to and from the workstation, to and from the analyzers, and to and from the centrifuge. The centrifuge is loaded with buckets containing specimen containers. The workstation can be provided with a balance system for balancing the weight of the buckets used. The workstation can also have a decapper for automatically removing caps from the specimen containers.

Abstract: The instant invention relates to a method and the apparatus for collecting a hyperconcentrated platelet product. A fluid containing platelets and other particles flows into a fluid chamber at a flow rate. The flow rate of the fluid is selected to retain the majority of the platelets in the fluid chamber in a saturated bed. The platelets are collected from the fluid chamber without collecting the other particles to form a hyperconcentrated other particle reduced platelet product.

Abstract: Apparatus for measurement concerning fluids in a rotor or container (2) during rotation, comprising an electric or magnetic sensor (4) mounted internally on a wall in the container (2), and means (5A, 5B) for contact-free and intermittent transmission of measurement signals from the sensor (4) to a stationary measuring unit (7) outside the container. The sensor (4) comprises an active electronic circuit (8) adapted to store measurement values that are recorded during at least a portion of a revolution of the container (2), before said transmission of corresponding measurement signals to the measuring unit (7). Electric power supply to the electronic circuit (8) is provided for by generator means comprising a stationary magnet (11) near the container (2) and a coil (12) mounted in the container so that a voltage is induced in the coil (12) during movement past the magnet (11) during the rotation of the container (2).

Abstract: A viewing area in a blood separation chamber is monitored for the presence of an interface region between plasma and cellular blood components. Sensed optical density values for the viewing area are compared to a calibrated threshold value to generate a time pulse output. A calibration element derives the calibrated threshold value based upon either (i) a comparison of a sensed reference optical density value in the viewing area to an expected optical density value for the reference material, or (ii) a sensed optical density value of plasma exiting the blood separation chamber, or both.

Abstract: Blood processing systems and methods separate blood into constituents including a plasma constituent that includes a platelet volume. The systems and methods detect the optical density of the plasma constituent and generate a first output indicative of the optical density. A processing element integrates the first output relative to the volume of plasma constituent and generates an integrated output. The integrated output correlates to the platelet volume. A second processing element generates a third output based, at least in part, upon the integrated output, which comprises parameters for storing the platelet volume.

Abstract: Centrifuges having a rotating bowl and associated computerized systems for monitoring, diagnosing, operating and controlling various parameters and processes of the centrifuges are presented. The computerized control system actuates at least one out of a plurality of control devices based on input from one or more monitoring sensors so as to provide real time continuous operational control. The monitoring sensors may sense process and other parameters and may be located both inside the centrifuge or bowl and outside the centrifuge or bowl and may monitor machine operation parameters and parameters related to the input and output streams of the centrifuge.

Abstract: An adapter for use in a fixed angle centrifuge rotor has, in use, a radially inboard and a radially inboard portion. An opening is formed in the radially inboard portion of the adapter. The opening is sized so that substantially no part of the inboard portion of the adapter is exposed during centrifugation to a load that exceeds the ability of the material of the adapter to support itself. The material of the inboard portion of the adapter surrounding the opening has sufficient strength to support itself while under centrifugation. The adapter is fabricated from a light transmissive material. A plug that is slidably disposed and selectably positionable within the opening in the inboard segment of the adapter. The inside surface of the plug having a sealing material thereon that is biased into contact with a tube carried within the adapter.

Abstract: A separator and a method for quickly separating an aliquot of plasma or serum from cells in a sample of blood is provided herein. The separator includes a housing which defines a separation container, an outlet aperture, a valve which selectively seals the outlet aperture, and a spinner. Initially, the spinner rotates the housing at a separation speed which causes the heavier cells to separate from the serum or plasma. Subsequently, the spinner rotates the housing at a faster, expellant speed which causes the valve to open and the cells to be expelled through the outlet aperture. After the cells have been expelled from the separation container, rotation of the housing is stopped and the serum or plasma is collected from the separation container. Since the separator provided herein does not use a separation gel, the separator is easy to clean and reusable.

Abstract: A centrifuge such as a continuous solid bowl centrifuge, for example, includes a rotatable bowl for receiving a slurry, and defines a zone in which the slurry is accelerated. The centrifuge includes a device such as a slurry feed tube for delivering slurry to the acceleration zone and a device for delivering a plurality of individual streams of flocculant solution coterminating with the slurry delivery device in order to uniformly distribute flocculant solution to the slurry.

Abstract: A system for separating flowable media into its components includes a pump delivering a flowing stream of the media, a separation tube through which the stream of the flowable media is passed, a mechanism for spinning the stream of flowable media about the axis of the separation tube at sufficient rotational speed that centrifugal force within the stream causes the media components to separate into component radial layers, according to their specific gravities, an extraction conduit for selectively extracting one or more of the radial layers from the separation tube, and monitoring and automatic feed back elements for measuring the component content as the media enters and exits the separation tube and for adjusting the rotational speed of the media.

Abstract: A method and apparatus for controlling the density of the solids separated from a feed slurry by selectively recirculating the separated liquid component of the feed slurry to change the feed slurry's density when an unwanted density of the separated solids is detected. Further, the efficiency of the separation is increased by recirculating and recharging unused catalyst into the feed slurry where it is used to assist in the separation of the solids.

Abstract: An ultrasonic probe is mounted in a centrifugal machine within close proximity to a maximum charge wall which is to be formed within a charge basket of the centrifugal machine. The probe comprises a tubular member which extends from an upper portion of an outer shell which surrounds the basket into the basket. A sensing head of the probe includes an ultrasonic transmitter and receiver which are mounted within a capsule formed of ultrasonic energy and vibration damping material. The transmitter and receiver are directed toward an inner surface of the charge basket of the centrifugal machine to monitor build up of a charge wall within the basket by directing bursts or pulses of ultrasonic energy toward the inner surface of the basket and receiving reflections or echoes of the pulses which are reflected from the charge wall building within the basket.

Abstract: Centrifuged material layer volumes are measured and quantified during centrifugation of the material layers. The material layers are differentially highlighted, preferably by means of one or more fluorescent dyes or stains which are admixed with the sample being analyzed. This kinetic quantification procedure is particularly useful in performing differential blood cell and platelet counts. The blood sample is centrifuged while being subjected to a strobed light source. At least one photometric cell layer compaction measurement is made in conjunction with the light flashes so as to record a degree of cell layer compaction as the sample is being centrifuged. In certain cases, after several successive cell layer compaction readings are derived, a compaction curve is identified and the ultimate degree of cell layer compaction is calculated from the derived compaction curve prior to the achievement of the ultimate degree of cell layer compaction.

Abstract: A centrifuge apparatus is used for collecting white blood cells, primarily mononuclear cells, from whole blood stratified into layers. A thin mononuclear (MNC) layer is formed at the interface of red blood cells and plasma. A barrier is positioned in the separation vessel of the centrifuge at a location to intercept the thin layer. An MNC collect port is positioned in front of the barrier to collect the thin layer. MNC fluid is allowed to pool behind the barrier to surround the collect port before collection is started. Collection ceases when the pool is removed and allowed to build again. By operating the collect in an intermittent fashion, improvements in purity and collect volume are achieved. The intermittent collection procedure can be useful for harvesting granulocytes and, in general, any sparse stratified component of a centrifuged solution where the sparse component is layered between more dense and less dense strata.

Abstract: A centrifuge apparatus is used for collecting white blood cells (WBC), primarily mononuclear cells, from whole blood stratified into layers. A thin mononuclear (MNC) layer is formed at the interface of red blood cells and plasma. A barrier is positioned in the separation vessel of the centrifuge at a location to intercept the thin layer. MNC fluid is allowed to pool behind the barrier before collection is started. To collect the MNC pool, the stratified red blood cell layer is raised from below the interface level by slowing or reversing flow in the RBC exit line thereby causing the MNC pool to spill over the barrier into a well in which a collect line is positioned. Collection ceases when a desired percentage of the pool is removed and the normal position of the interface is re-established; thereafter the pool builds again. By raising the MNC pool from below, improvements in purity and collect volume are achieved.

Abstract: A processor (9) within an apparatus for managing a centrifuge by operation results (8) identifies an ID card of a user who operates a centrifuge (1) through a card reader (12). Further, a rotation signal (7) that will serve as operation result data of the centrifuge is received through a counter (10), and a rotation start time and a rotation stop time of a drive section (3) are read by a real-time clock. Still further, the processor (9) calculates the operation result data, displays the calculated data on a display section (16), stores the operation result data in a memory (15), and outputs the operation result data to a printer (13) as may be required by the user.

Abstract: A protocol record database is used in conjunction with operating a centrifuge device. Each protocol record includes information relevant to the centrifugation of a certain specimen. The user can search the database for a protocol on the basis of the specimen and/or the type of separation desired. The database has an interface to one or more centrifuges via a controller. The controller, operates a centrifuge in accordance with the run program of a selected protocol record. In a preferred embodiment, the protocol records have links to additional files which supplement the information contained in the protocol records. These supplemental files include information related to the availability and compatibility of the various hardware needed to perform a centrifugation. The supplemental files can also be used to provide general information to assist the user in setting up a centrifuge for an experiment.

Abstract: An apparatus is provided for centrifuging and further automatically handling a container (110) for separating a component, such as fibrin monomer, from blood. The container (110) comprises a cylindrical member (27) and a piston displaceable in said cylindrical member, said piston comprising a tubular piston rod (8) extending through a top wall (73). The piston divides the cylindrical member (27) into a first chamber (70) positioned above said piston between said piston and the top wall (73), and a second chamber positioned below said piston. The top wall (73) of the container comprises an extension (90) defining a circumferential slit surrounding the outer side of the piston rod (8), whereby one end of said slit communicates in the axial direction with the first chamber. In addition, the first chamber communicates through a plurality of channels with the second chamber.

Abstract: A centrifuge has a drive unit, a separation chamber which can be inserted into the drive unit, and a scanning device for recognizing the position of the separation chamber which is rotated by the drive unit. The separation chamber is constructed as a disposable chamber and is provided with a marker element which is arranged in a scanning region extending annularly around the rotation axis of the chamber. The position of a phase boundary window is detected by sensing the position of the marker with a phase boundary detector portion of the scanning device whereby the chamber can be inserted into the drive unit in any position.

Abstract: Blood separation systems and methods separate mono nuclear cells from whole blood. The systems and methods introduce whole blood into a rotating chamber for separation into red blood cells, a plasma constituent, and an interface carrying mono nuclear cells between the red blood cells and the plasma constituent. The systems and methods convey whole blood into the chamber while removing red blood cells and the plasma constituent and while maintaining the interface at a set location within the chamber. At an appropriate processing time, the systems and methods move the interface from the set location for removal from the chamber through an outlet path. The outlet path includes a sensing element to locate mono nuclear cells in the outlet path outside the chamber.

Abstract: Systems and methods separate whole blood containing leukocytes in a first separation chamber into a first layer comprising red blood cells, a second layer comprising a suspension of platelets, and an interface between the first and second layers. The systems and methods convey the suspension of platelets into a second separation chamber while simultaneously filtering the suspension of platelets to reduce the number of leukocytes. The systems and methods separate the filtered suspension of platelets in the second separation chamber into a platelet-rich concentrate and platelet-poor component.

Abstract: Apparatus and a method for detecting imbalance and for identifying rotors in centrifuges is disclosed. An accelerometer measures the vibration of a rotating drive system as it accelerates from rest to a predetermined speed, and a signal processing system monitors changes in the magnitude of measured vibration energy. The processing system determines the power spectrum density of the measured values and from this the frequency spectrum and the total energy spectrum of the measured vibration are determined. These values may be used to provide an identifying profile which can be used as a reference for later identification of drive systems and rotors in operating systems, and for monitoring and controlling such operating systems.

Abstract: Method and equipment for monitoring a centrifugal separator, with a separation chamber (6), a radially inner outlet (18, 19, 20) connected to the separation chamber (6), which is connected to an outlet conduit (21), a flow sensor (28) in the outlet conduit (21) being arranged to indicate a flow in the outlet conduit, an intermittently operable radially outer outlet (7) connected to the separation chamber (6), the flow of the separated component in the outlet conduit (21) ceasing temporarily until the separation chamber (6) has been refilled. In order to monitor the centrifugal separator in a reliable and easy manner the time for the refilling of the separation chamber (6) is measured and is compared with a shortest allowable time for the refilling of the separation chamber (6) stored and a signal is given if the measured time is shorter than the shortest allowable time stored in the memory.

Abstract: A method and structure for analysis of the size and/or distribution of low-density particles by centrifugal sedimentation in a centrifuge chamber containing a fluid where the particles to be tested are delivered to the bottom of the centrifuge chamber and allowed to float upwards in the higher density fluid within the centrifuge chamber to be analyzed.

Abstract: An automated centrifuge includes a weighing station to weigh sample holding racks which arrive at the centrifuge and a rack handling robot to transfer the weighed racks to and from the centrifuge. A controller, which operates the rack handling robot, employs a novel balance method to have the rack handling robot load the sample holding racks in the centrifuge to obtain a best balance arrangement of the sample holding racks. If the balance method determines that the best balance arrangement will exceed one or more predefined balance thresholds, appropriate remedial action is taken by substituting a selected balance rack for a loaded sample holding rack.

Abstract: A fixed-angle rotor, having a centrifuge tube inclined at a predetermined gradient angle with respect to a rotational axis, is used to obtain a sedimentation coefficient of sample particles. In one method, a distance in the centrifugal direction is corrected by the gradient angle .theta. of centrifuge tube 1. Sedimentation coefficient S.sub.20,W is calculated based on the corrected distance, and then the sedimentation coefficient S.sub.20,W is multiplied with sin(.theta.) to obtain a corrected sedimentation coefficient. In another method, a distance in the centrifugal direction is corrected by the gradient angle .theta., and also an angular acceleration .omega..sup.2 is corrected by dividing it by sin(.theta.). And then, the sedimentation coefficient S.sub.20,W is calculated based on thus corrected distance and corrected angular acceleration.

Abstract: A centrifuge rotor overspeed protection system which can operate with rotors of at least two speed ranges. A set of coding elements are provided on the rotors coded to represent the actual maximum safe speed rating of the rotor. An additional set of coding elements coded to correspond to the maximum speed in the lower speed range are also provided such that the rotor can be operated at the maximum speed possible in a prior art centrifuge designed for operation in the lower speed range. The detection circuit for the coding elements automatically adjusts the detection threshold depending on the average values of the sensor output peaks corresponding to the codes.

Abstract: A centrifugal separator comprising: a rotor for containing a sample; a rotating unit; a detection circuit for detecting a distance between a reference position and a position of the rotor and generating a distance detection signal; a rectifying circuit for half-wave rectifying the distance detection signal; a judging circuit for judging the distance detection signal from the rectifying circuit; and a controller for controlling the rotating unit in accordance with a judging result of the judging circuit and a corresponding method are disclosed. The judging circuit judges whether the distance is in a balanced condition of or an unbalance condition of the rotor.

Abstract: An operating parameter of a centrifuge is determined by converting vibration of the machine frame of the centrifuge on rotation of the drum thereof to electrical signals having a frequency spectrum which is analyzed. Variations of the peak amplitudes and frequency locations on frequency analysis, e.g. by Fast Fourier Transmissions, is used to signal the parameter, e.g. a parameter representing the degrees of filling the centrifuge, termination of filtration, etc.

Abstract: Blood collection systems and methods minimize citrate toxicity in donors. The systems and methods convey whole blood at a prescribed rate Q.sub.b into a separation device for separation into red blood cells and a plasma constituent. The systems and methods add anticoagulant including citrate to the whole blood. The systems and methods control Qb (in ml/min or equivalent) based upon a citrate equivalent blood flow rate EqQB.sub.CIR, where: ##EQU1## where: CIR is a selected nominal a-symptomatic citrate infusion rate (in mg/kg/min or equivalent),AC is a selected anticoagulant ratio,Wgt is the donor's weight (in kg or equivalent), andCitrateConc is the citrate concentration in the anticoagulant (in mg/ml or equivalent).

Abstract: A device for performing a weight measurement in centrifuges which serve to process chemical substances of different weights and in which fluctuating gas pressures cause different interfering forces which have an interfering effect on the weight measurement. The centrifuge is mounted so as to swivel in a vertical plane, a force measuring element senses the weight-dependent swivel movements of the machine, and a compensation means equalizes the interfering forces caused by the fluctuating gas pressures such that the weight measurement remains unaffected hereby. The compensation means comprises a sensor sensing the gas pressure in the centrifuge, this sensor correspondingly correcting a weight display as a function of changes sensed in the gas pressure.