Determining cell concentration of a fluid in a facility using cell counters of different configurations

Abstract

A method of measuring the concentration of cells in a fluid in a facility using cell counters of different configurations.SOLUTION: The method of the present invention includes first, for each of a plurality of fluids, illuminating the fluid with light and calculating an uncorrected cell concentration based on the intensity of light transmitted out of the fluid and a correlation curve derived using a first cell counter. Next, the measured cell concentration of each fluid obtained from the second cell counter and the uncorrected cell concentration are plotted to create a curve having a plurality of data points, and an equation representing the curve is selected as a correction equation. Thereafter, the object fluid is irradiated with light, and at least a part of the light emitted through the object fluid is received. An uncorrected cell concentration in the fluid of interest is calculated based on the correlation curve and the intensity of the received light. Finally, a corrected cell concentration in the fluid of interest is calculated by applying the correction equation to the uncorrected concentration.SELECTED DRAWING: None

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of and priority to U.S. Provisional Application No. 63 / 666,370, filed July 1, 2024, the contents of which are incorporated herein by reference.

[0002] [Technical field] The present disclosure relates to optical monitoring of fluids, and more particularly to determining cell concentrations in fluids in a facility using cell counters of different configurations. [Background technology]

[0003] It is known to use optical detection assemblies to monitor the flow of fluid (including biological fluids such as blood) through a fluid flow circuit to determine various characteristics of the flow. A typical optical detection assembly includes a light source (e.g., a laser or light emitting diode) configured to illuminate a fluid-containing vessel in the fluid flow circuit, and a light detector (e.g., a photodiode) configured to receive the light emitted from the vessel. The light detector transmits a signal based on the received light to a controller, which uses the signal to determine one or more characteristics of the fluid.

[0004] Conventional optical detection assemblies can have several drawbacks, depending on their exact configuration. For example, it is common for optical detection assemblies to monitor fluid flow through flexible plastic tubing in a fluid flow circuit. When light enters the plastic tubing, transmission of the light into the lumen of the tubing can vary according to Snell's Law, depending on the refractive index of the material and the angle of incidence formed by the tubing surface. The refractive index of air (approximately 1) and the refractive index of plastic (typically approximately 1.3-1.5) vary significantly. Furthermore, inconsistent tubing surface formation between procedures can alter the angle of incidence, resulting in variations in light transmission into the tubing from procedure to procedure, resulting in inconsistent measurements of fluid properties.

[0005] Another drawback is the configuration of the photodetector in conventional optical detection assemblies, which often consists of a single photodiode. This configuration only captures the amplitude of light emitted from the container at a single location. In contrast, light passing through a turbid medium (e.g., blood or blood components) is scattered and does not travel along a single path, and therefore cannot be fully captured by a single photodiode.

[0006] U.S. Patent Application Publication No. 2023 / 0243746 (the disclosure of which is incorporated herein by reference) describes an optical detection assembly that improves upon conventional optical detection assemblies. The optical detection assembly described in U.S. Patent Application Publication No. 2023 / 0243746 is based on the principle that light emitted from a turbid medium (e.g., blood or blood components) is scattered, and the light is detected at multiple locations using a photodetector array rather than being received at a single location by a single photodetector (e.g., an individual photodiode). Different fluids (e.g., fluids with different concentrations of a target substance) produce emitted light beams with different scattering patterns, and individual photodetectors or light-sensing elements of the photodetector array receive different amounts of light transmitted through the fluid. Based on the maximum intensity of light received by one or more of the individual photodetectors, a controller can determine the concentration of a substance (e.g., platelets) in the target fluid.

[0007] When determining the concentration of a cell or cells in a fluid, the controller can use an empirically derived correlation curve to correlate one or more signals from the photodetector array to corresponding cell concentrations. For example, U.S. Patent Application Publication No. 2025 / 0147003 (the disclosure of which is incorporated herein by reference) describes a correlation curve that correlates the slope of a portion of an optical transmission intensity profile with the platelet concentration in a target fluid. The curve is derived using a cell counter that serves as a cell measurement reference, and is obtained by plotting cell concentration measurements obtained from the cell counter against corresponding signals from an optical detection assembly monitoring the same fluid. One limitation of this approach is the potential for variability in the results reported for a target fluid by cell counters with different configurations. In particular, because cell counters with different configurations (which may include cell counters from different manufacturers or different models from the same manufacturer) may report different cell concentration measurements for a target fluid, an empirically derived correlation curve may only be applicable when used in conjunction with a cell counter with the same configuration as the cell counter used to develop the curve. Summary of the Invention

[0008] The present subject matter includes multiple aspects that may be implemented individually or in combination in the devices and methods described and claimed below. These aspects may be implemented alone or in combination with other aspects described herein, and the description of these aspects together is not intended to preclude them from being used individually or claimed separately as set forth in the appended claims.

[0009] In one embodiment, the optical detection assembly includes a light source, a photodetector, and a controller. The light source is configured and arranged to irradiate the fluid in the container with light, and the photodetector is configured to receive at least a portion of the light emitted from the container and generate a signal indicative of the intensity of the received light. The controller is configured to receive the signal from the photodetector and is programmed with a correlation curve derived using a first cell counter, relating the signal from the photodetector to the cell concentration in the fluid in the container. The controller is further programmed to receive or calculate a correction equation reflecting a comparison between the configuration of the first cell counter and the configuration of a second cell counter used in combination with the optical detection assembly, receive the signal from the photodetector, and determine an uncorrected concentration of cells in the fluid in the container based at least in part on the signal and the correlation curve. The controller then determines the corrected concentration of cells in the fluid in the container by applying the correction equation to the uncorrected concentration of cells in the fluid in the container.

[0010] In another embodiment, the fluid treatment device includes a pump system, a valve system, an optical detection assembly, and a controller. The optical detection assembly includes a light source configured and arranged to illuminate the fluid in the container and a photodetector configured to receive at least a portion of the light emitted from the container and generate a signal indicative of the intensity of the received light. The controller is configured to receive a signal from the photodetector and is programmed with a correlation curve derived using a first cell counter, relating the signal from the photodetector to the cell concentration in the fluid in the container. The controller is also programmed to control operation of the pump system and the valve system to perform a fluid treatment procedure. The controller is further programmed to receive or calculate a correction equation reflecting a comparison between the configuration of the first cell counter and the configuration of a second cell counter used in combination with the fluid treatment device, receive the signal from the photodetector, and determine an uncorrected concentration of cells in the fluid in the container based at least in part on the signal and the correlation curve. The controller then determines the corrected concentration of cells in the fluid in the container by applying the correction equation to the uncorrected concentration of cells in the fluid in the container.

[0011] In yet another aspect, a method for determining a cell concentration in a target fluid in a container is provided. The method includes providing a plurality of fluids having different cell concentrations, irradiating the fluid with light, receiving at least a portion of the light emitted from the fluid container, and determining, for each fluid, an uncorrected concentration of cells in the fluid based at least in part on the intensity of the emitted light and a correlation curve derived using a first cell counter. For each fluid, a measured cell concentration is obtained from a second cell counter, and the uncorrected concentration in the fluid is plotted as data points against the measured cell concentration of the fluid to create a curve having a plurality of data points. A correction equation is then determined to represent the curve. Thereafter, the target fluid in the container is irradiated with light, receiving at least a portion of the light, and determining the uncorrected concentration of cells in the target fluid in the container based at least in part on the intensity of the light emitted from the target fluid and the container and the correlation curve. The corrected concentration of cells in the target fluid in the container is determined by applying the correction equation to the uncorrected concentration of cells in the target fluid in the container. [Brief explanation of the drawings]

[0012] FIG. 1 is a perspective view of hardware components of an example fluid processing system according to one embodiment of the present disclosure.

[0013] FIG. 2 is a schematic diagram of an example of a disposable component that can be attached to the hardware components of FIG. 1 to complete a fluid handling system according to one embodiment of the present disclosure.

[0014] FIG. 3 is a perspective view of an optical detection assembly, an example of a hardware component of FIG. 1, shown with the lid open.

[0015] FIG. 4 is a perspective view of the optical detection assembly of FIG. 3, showing the lid in a closed position.

[0016] FIG. 5 is a perspective view of selected components of the optical detection assembly of FIG.

[0017] FIG. 6 is a schematic diagram illustrating the optical detection assembly of FIG. 3 monitoring a fluid with a low cell concentration.

[0018] FIG. 7 is a schematic diagram illustrating the optical detection assembly of FIG. 3 monitoring a fluid with a high cell concentration.

[0019] FIG. 8 is a chart showing a scattering profile generated using signals from the photodetector array of the optical detection assembly of FIG.

[0020] FIG. 9 is a chart showing a portion of a scattering profile generated using signals from the photodetector array of the optical detection assembly of FIG.

[0021] FIG. 10 is a chart showing an example of the correlation between the slope of a portion of a scattering profile and the platelet concentration in a fluid.

[0022] FIG. 11 is a chart showing the relationship between the platelet concentration in a fluid measured by a cell counter of the type used to generate the chart of FIG. 10 and the platelet concentration predicted by the optical detection assembly.

[0023] FIG. 12 is a chart showing the relationship between platelet concentration in a fluid measured by different configurations of cell counters and the platelet concentration predicted by the optical detection assembly. DETAILED DESCRIPTION OF THE INVENTION

[0024] The embodiments disclosed herein are intended to provide exemplary illustrations of the present subject matter. They are, however, merely examples, and the present subject matter may be embodied in various forms. Accordingly, the specific details disclosed herein should not be construed as limiting the present subject matter, which is defined by the appended claims.

[0025] 1 and 2 illustrate components of a fluid processing system embodying various aspects of the present subject matter. While the use of the system to separate a biological fluid (i.e., blood) into two or more components and collect at least one component is described herein, it should be understood that systems according to the present disclosure can be used to process a variety of fluid types.

[0026] Generally speaking, the system includes two major components: a durable, reusable fluid treatment device 10 (FIG. 1) and a disposable fluid flow circuit 12 (FIG. 2). The illustrated fluid treatment device 10 includes a spinning membrane separator drive unit 14, a centrifuge or centrifugal separator 16, additional components that control the flow of fluid through the disposable fluid flow circuit 12, and a controller 18 that controls the operation of the other components of the fluid treatment device 10 to carry out the fluid treatment procedure. While the principles described herein are applicable when using the fluid treatment device 10 of FIG. 1, it should be understood that these same principles are also applicable to other fluid treatment devices, including devices that employ a single separation technology or approach.

[0027] I. Durable fluid treatment equipment Fluid treatment device 10 (FIG. 1) is configured as a durable item capable of long-term use. It should be understood that fluid treatment device 10 of FIG. 1 is only one example of a possible configuration, and that fluid treatment devices according to the present disclosure may have different configurations.

[0028] In the illustrated embodiment, fluid treatment device 10 is embodied in a single enclosure or case 20. The illustrated case 20 includes a generally horizontal portion 22 (which may include a sloped or angled top for improved visibility and ergonomics) and a generally vertical portion 24. The spinning membrane separator drive unit 14 and centrifuge 16 are incorporated into the generally horizontal portion 22 of case 20, while the controls 18 are shown incorporated into the generally vertical portion 24.

[0029] A Rotating membrane separator drive unit Fluid treatment device 10 includes a spinner support or rotary membrane separator drive unit 14 for housing a generally cylindrical rotary membrane separator 26 of fluid flow circuit 12. U.S. Pat. No. 5,194,145 (incorporated herein by reference) describes one exemplary rotary membrane separator drive unit suitable for incorporation into fluid treatment device 10, although it should be understood that rotary membrane separator drive unit 14 may be configured differently without departing from the scope of this disclosure.

[0030] The illustrated spinning membrane separator drive unit 14 has a base 28 configured to receive the lower portion of the spinning membrane separator 26 and a top cap 30 for receiving the upper portion of the spinning membrane separator 26. Preferably, the top cap 30 is positioned directly above the base 28 and vertically orients the spinning membrane separator 26 received by the spinning membrane separator drive unit 14, defining a vertical axis about which the spinning membrane separator 26 rotates. While it may be advantageous for the spinning membrane separator drive unit 14 to vertically orient the spinning membrane separator 26, it should be understood that a different orientation of the spinning membrane separator 26 when installed in the fluid treatment device 10 is within the scope of the present disclosure.

[0031] In one embodiment, one of the base 28 and the top cap 30 of the spinning membrane separator drive unit 14 is movable relative to the other, thereby allowing different sized spinning membrane separators 26 to be accommodated by the spinning membrane separator drive unit 14. For example, the top cap 30 is vertically movable relative to the base 28 and can be locked into a number of different positions, each corresponding to a different sized spinning membrane separator 26.

[0032] At least one of the base 28 and the top cap 30 is configured to rotate one or more components of the spinning membrane separator 26 around an axis defined by the spinning membrane separator drive unit 14. The mechanism by which the spinning membrane separator drive unit 14 rotates one or more components of the spinning membrane separator 26 can vary without departing from the scope of the present disclosure. In one embodiment, the components of the spinning membrane separator 26 to be rotated include at least one element (e.g., a metallic material) configured to be acted upon by a magnet, and the spinning membrane separator drive unit 14 includes a magnet (e.g., a series of magnetic coils or semicircular arcs). By modulating the magnetic field acting on the above-mentioned components of the spinning membrane separator 26, the components of the spinning membrane separator 26 can be rotated in different directions and at various speeds. In other embodiments, different mechanisms can be employed to rotate the components of the spinning membrane separator 26.

[0033] Regardless of the mechanism by which the rotating membrane separator drive unit 14 rotates the components of the rotating membrane separator 26, the components of the rotating membrane separator 26 are preferably rotated at a speed sufficient to generate Taylor vortices in gaps between rotating and non-rotating components (or components rotating at different speeds). Fluid being separated in the rotating membrane separator 26 flows through these gaps, and the generation of Taylor vortices can significantly improve filtration performance.

[0034] B. Centrifuge Centrifuge 16 includes a centrifuge compartment 32 that receives a centrifuge chamber 36 of fluid flow circuit 12, as well as other components of centrifuge 16. Further details regarding centrifuges are described in PCT Application WO 2018 / 053217, which is incorporated herein by reference.

[0035] A fluid (e.g., anticoagulated whole blood) is introduced into the centrifuge chamber 36 through the umbilicus, and separated into a layer of less dense components (e.g., platelet-rich plasma when separating blood) and a layer of denser components (e.g., packed red blood cells) within the centrifuge chamber 36 by the action of centrifugal force due to rotation. Components of an interface monitoring system are disposed within the centrifuge compartment 32 and can monitor the separation of the fluid within the centrifuge chamber 36. The interface monitoring system may include a light source 50 and a photodetector 52 positioned and oriented to receive at least a portion of the light emitted from the light source 50.

[0036] The orientation of each component of the interface monitoring system depends, at least in part, on the particular configuration of the centrifuge chamber 36. In general, however, a light source 50 shines a light beam (e.g., a laser light beam) through the separated fluid components within the centrifuge chamber 36 (which may be formed from a material that is substantially transparent to light, or at least certain wavelengths of light, without absorbing it). A portion of the light reaches a photodetector 52, which sends a signal to the controller 18 indicating the location of the interface between the separated fluid components. If the controller 18 determines that the interface is in the wrong location (which may affect the separation efficiency of the centrifuge 16 and / or the quality of the separated fluid components), the controller 18 can issue commands to appropriate components of the fluid processing device 10 to change operation to move the interface to the appropriate location.

[0037] C. Other components of fluid treatment equipment In addition to the spinning membrane separator drive unit 14 and the centrifuge 16, the fluid treatment device 10 may include other components compactly arranged to assist in fluid treatment.

[0038] The generally horizontal portion 22 of the case 20 of the illustrated fluid processing device 10 includes a cassette station 54 that houses a flow control cassette for the fluid flow circuit 12. In one embodiment, the cassette station 54 is configured similarly to the cassette station of U.S. Pat. No. 5,868,696 (incorporated herein by reference), but is modified to include additional components and functionality. The illustrated cassette station 54 includes a plurality of clamps or valves V1-V9 (collectively referred to herein as the "valve system of the fluid processing system 10") that move to a plurality of positions (e.g., between a retracted or lowered position and an activated or raised position) to selectively contact or otherwise interact with corresponding valve stations of the flow control cassette for the fluid flow circuit 12. Depending on the configuration of the fluid flow circuit 12, the cassette may not include a valve station corresponding to each of the valves V1-V9 of the cassette station 54, in which case not all of the valves V1-V9 are used in the fluid processing procedure.

[0039] In the actuated position, valves V1-V9 engage their corresponding valve stations and prevent fluid flow through them (e.g., by closing one or more ports associated with the valve stations, preventing fluid flow through those ports). In the retracted position, valves V1-V9 are spaced from their corresponding valve stations (or do not contact the valve stations as strongly as they do in the actuated position), allowing fluid flow through those valve stations (e.g., by opening one or more ports associated with the valve stations, allowing fluid flow through those ports). Additional clamps or valves V10 and V11 of the valve system may be located outside of cassette station 54 and configured to interact with portions of the valve stations (e.g., portions of tubing) of fluid flow circuit 12 to selectively allow or block fluid flow through those portions. Cassette station 54 and cassette valves V1-V9 and their corresponding valve stations may be configured and operated differently from valves V10 and V11 and valve stations located remote from cassette station 54.

[0040] Cassette station 54 may include additional components, such as pressure sensors A1-A4, that interface with the cassette sensor station to monitor pressure at various locations in fluid flow circuit 12. For example, if the fluid source is a human donor, one or more of pressure sensors A1-A4 may be configured to monitor the donor's venous pressure during blood collection and return. Other pressure sensors A1-A4 may monitor the pressure in spinning membrane separator 26 and centrifuge chamber 36. Controller 18 receives signals from pressure sensors A1-A4 indicative of the pressure within fluid flow circuit 12, and if the signals indicate a low-pressure or high-pressure condition, may initiate an alarm or error condition to notify an operator of the condition and / or attempt to restore the pressure to an acceptable level without operator intervention.

[0041] Fluid processing device 10 may include multiple pumps P1-P6 (collectively referred to herein as the "pump system of fluid processing device 10") for moving fluid through fluid flow circuit 12. Pumps P1-P6 may be of different or similar configurations and / or may have different or similar functions. In the illustrated embodiment, pumps P1-P6 are configured as peristaltic pumps configured according to the general configuration described in U.S. Pat. No. 5,868,696. Each pump P1-P6 engages a different tubing loop extending from the side of a flow control cassette and can be selectively activated by control unit 18 to move fluid through a portion of fluid flow circuit 12. In one embodiment, all or a portion of cassette station 54 is movable toward or away from case 20, allowing tubing loops to be automatically loaded into the corresponding pumps P1-P6. In another exemplary embodiment, a pneumatic pump may be employed instead of a peristaltic pump, with an actuator incorporated into cassette station 54 interacting with an appropriately configured portion of fluid flow circuit 12 (e.g., a pump station of a cassette attached to cassette station 54) to transport fluid through fluid flow circuit 12.

[0042] The illustrated fluid processing device 10 also includes a spinner inlet sensor M1 mounted within the spinning membrane separator drive unit 14 for determining one or more characteristics of the fluid entering the spinning membrane separator 26. If the fluid entering the spinning membrane separator 26 is whole blood (which may include anticoagulated whole blood), the spinner inlet sensor M1 may be configured to determine the hematocrit of the blood entering the spinning membrane separator 26. If the fluid entering the spinning membrane separator 26 is platelet-rich plasma, the spinner inlet sensor M1 may be configured to determine the platelet concentration of the platelet-rich plasma entering the spinning membrane separator 26. The spinner inlet sensor M1 may detect one or more characteristics of the fluid by optically monitoring the fluid flowing through the tubing of the fluid flow circuit 12 or by other suitable methods. The controller 18 can receive a signal from the spinner inlet sensor M1 indicative of one or more characteristics of the fluid entering the spinning membrane separator 26 and use the signal to optimize the fluid processing procedure based on the characteristics. If the characteristic is outside of an acceptable range, the controller 18 may initiate an alarm or error condition to notify an operator of the condition. Suitable devices and methods for monitoring hematocrit and / or platelet concentration are described in U.S. Patent No. 6,419,822, which is incorporated herein by reference, although it should be understood that other methods may be employed to monitor one or more characteristics of the fluid or fluid components entering the spinning membrane separator 26.

[0043] The illustrated fluid processing device 10 further includes a spinner outlet sensor M2 that receives the tubing of the fluid flow circuit 12 as the separated fluid components from the spinning membrane separator 26 exit through the tubing. The spinner outlet sensor M2 monitors the separated fluid components to determine one or more characteristics of the separated fluid components, which may be determined by optically monitoring the separated fluid components flowing through the tubing or by other suitable methods. In one embodiment, when separated plasma flows through the tubing, the spinner outlet sensor M2 may be configured to determine the amount of cellular blood components in the plasma and / or whether the plasma is hemolytic and / or lipemic. This determination may be made by measuring the optical density of the fluid in the associated tubing using an optical monitor of the type described in U.S. Pat. No. 8,556,793 (incorporated herein by reference) or by other suitable devices and / or methods.

[0044] The illustrated fluid treatment device also includes an air detector M3 (e.g., an ultrasonic air bubble detector) that houses the tubing of fluid flow circuit 12 through which fluid flows toward the receiver. Because it may be advantageous to prevent air from reaching the receiver, whether the receiver is human (e.g., the same person from whom the blood is sourced) or non-human (e.g., a storage bag or container), air detector M3 may send a signal to controller 18 indicating whether air is present in the tubing. If the signal indicates the presence of air in the tubing, controller 18 may initiate an alarm or error condition to notify an operator of the condition and / or take corrective action (e.g., reversing the flow of fluid in the tubing or diverting the flow to a vent location) to prevent the air from reaching the receiver.

[0045] The generally vertical portion 24 of the case 20 may include a plurality of volume measurement systems W1-W6 (six are shown, but more or fewer may be included), each configured to be associated with one or more fluid containers F1-F7 (see FIG. 2 ) of the fluid flow circuit 12. Each volume measurement system W1-W6, in conjunction with the controller 18, is configured to measure the current volume of fluid in the corresponding fluid container F1-F7 and calculate the change in volume at two or more points in time. The individual volume measurement systems W1-W6 may have various configurations, and two or more of W1-W6 may have different configurations, without departing from the scope of this disclosure. In one example embodiment, the volume measurement systems W1-W6 may be configured as weigh scales configured to support and measure the weight of the fluid in the corresponding fluid container F1-F7, with the measured weight being converted to volume by components of the volume measurement systems W1-W6 or the controller 18. In another exemplary embodiment, volume measurement systems W1-W6 may include one or more sensors configured to detect the volume and / or volume change of fluid within the corresponding fluid containers F1-F7. Volume measurement systems including components that include both a scale and a sensor, and / or other alternative components, may also be employed without departing from the scope of this disclosure.

[0046] Regardless of its configuration, volume measurement systems W1-W6 transmit signals to the controller 18 indicative of the volume of fluid in the corresponding vessels F1-F7 to track volume changes over the course of a process. This enables the controller 18 to process the volume increases and decreases to derive fluid process volumes and flow rates and to generate signals to control process events based at least in part on the derived process volumes. For example, the controller 18 can diagnose and notify an operator of leaks or blockages in the fluid flow circuit 12.

[0047] The illustrated case 20 is also provided with a plurality of hooks or supports H1 and H2 for supporting various components of the fluid flow circuit 12 or other objects of suitable size and configuration.

[0048] D Control section According to one aspect of the present disclosure, fluid treatment device 10 includes a controller 18 suitably configured and / or programmed to control the operation of fluid treatment device 10. In one embodiment, controller 18 may comprise a main processing unit (MPU) including, for example, an Intel Corporation Pentium™-type microprocessor, although other types of conventional microprocessors may also be used. In one embodiment, controller 18 may be mounted within a generally vertical portion 24 of case 20 adjacent to or as part of an operator interface station (e.g., a touchscreen). In other embodiments, controller 18 and the operator interface station may be associated with a generally horizontal portion 22 of case 20 or may be incorporated into a separate device connected to fluid treatment device 10 physically (e.g., by cable) or wirelessly.

[0049] Controller 18 is configured and / or programmed to perform at least one fluid processing procedure, but more preferably is configured and / or programmed to perform a plurality of different fluid processing procedures. For example, controller 18 may be configured and / or programmed to perform one or more of the following processing procedures: a two-unit red blood cell collection procedure, a plasma collection procedure, a plasma / red blood cell collection procedure, a red blood cell / platelet / plasma collection procedure, a platelet collection procedure, and a platelet / plasma collection procedure.

[0050] More specifically, in carrying out these fluid processing procedures, the controller 18 is configured and / or programmed to control one or more of the following operations: drawing fluid into a fluid flow circuit 12 attached to the fluid processing device 10; transporting the fluid through the fluid flow circuit 12 to a location for separation (i.e., the spinning membrane separator 26 or centrifuge chamber 36 of the fluid flow circuit 12); separating the fluid into two or more components as desired; and transporting the separated components to a storage container, to a second location for further separation (e.g., a spinning membrane separator 26 or centrifuge chamber 36 not used in the initial separation step), or to a receiver (which may be the source from which the fluid was originally collected).

[0051] This may include instructing the spinning membrane separator drive unit 14 and / or the centrifuge 16 to operate at a particular rotational speed, or instructing the pumps P1-P6 to convey fluid at a particular flow rate through a portion of the fluid flow circuit 12. Thus, although a particular component of the fluid processing arrangement 10 (e.g., the spinning membrane separator drive unit 14 or the centrifuge 16) is described herein as performing a particular function, it should be understood that the component is controlled to perform that function by the controller 18.

[0052] Before, during, and after processing, controller 18 can receive signals from various components of fluid processing device 10 (e.g., pressure sensors A1-A4) to monitor various aspects of the operation of fluid processing device 10 and the properties of the fluid and separated fluid components as they flow through fluid flow circuit 12. If the operation of the fluid processing device components and / or one or more properties of the fluid or separated fluid components are outside of acceptable ranges, controller 18 can initiate an alarm or error condition to notify an operator of the condition and / or take action to correct the condition. The appropriate corrective action will vary depending on the particular error condition and may be performed with or without operator involvement.

[0053] For example, the controller 18 may include an interface control module that receives a signal from the optical detector 52 of the interface monitoring system. The signal that the controller 18 receives from the optical detector 52 indicates the location of the interface between the separated fluid components within the centrifuge chamber 36. If the controller 18 determines that the interface is in an incorrect location, the controller 18 can issue commands to appropriate components of the fluid processing device 10 to modify their operation to move the interface to the appropriate location. For example, the controller 18 can instruct one of the pumps P1-P6 to modify the flow rate of fluid entering the centrifuge chamber 36 and / or to modify the flow rate at which the separated fluid components are discharged from the centrifuge chamber 36 and / or to modify the rotation speed of the centrifuge 16 to rotate the centrifuge chamber 36.

[0054] If an operator interface station is provided associated with the control unit 18, the operator may view information regarding the operation of the system (in alphanumeric form and / or as graphical images) on a screen or display. The operator interface station may also allow the operator to select applications run by the control unit 18 and to modify certain system functions and performance criteria. If the operator interface station is configured as a touchscreen, the screen may accept input from the operator via touch operation. Alternatively, if the screen is not a touchscreen, the operator interface station may accept input from the operator via a separate input device, such as a computer mouse or keyboard. It is also within the scope of this disclosure for the operator interface station to accept input from both the touchscreen and a separate input device, such as a keypad.

[0055] II. Disposable Fluid Flow Circuit Fluid flow circuit or flow set 12 (FIG. 2) is intended to be sterile and single-use, disposable. Prior to initiating a given fluid processing procedure, an operator associates fluid flow circuit 12 with fluid processing device 10 and loads each component of fluid flow circuit 12 into case 20. Controller 18 executes the procedure based on a pre-established protocol, taking into account other inputs from the operator. Once the procedure is complete, the operator removes fluid flow circuit 12 from its association with fluid processing device 10. The portion of fluid flow circuit 12 holding the collected fluid components (e.g., collection container or bag) is removed from case 20 and retained for storage, transfusion, or further processing. The remaining portion of fluid flow circuit 12 is removed from case 20 and discarded.

[0056] In the illustrated embodiment, fluid flow circuit 12 includes a cassette to which other components of fluid flow circuit 12 are connected by flexible tubing. These other components may include multiple fluid containers F1-F7. In the context of the present disclosure, these containers include an anticoagulant container F1, a saline container F2, an in-process container F3, a blood return container F4, a plasma collection container F5, a platelet collection container F6, and an (optional) additive container F7. The illustrated fluid path circuit 12 further includes one or more fluid source access devices (e.g., a connector or a blood collection needle for accessing blood in the fluid containers), a spinning membrane separator 26, and a centrifuge chamber 36.

[0057] The flow control cassette provides a centralized, programmable, integrated platform for all pumping functions and many of the valve functions required for a given fluid processing procedure. In one embodiment, the cassette is configured similarly to the cassette of U.S. Patent No. 5,868,696, but modified to include additional components (e.g., more tubing loops) and functions.

[0058] In use, the cassette is installed in cassette station 54 of fluid processing device 10 such that each sensor station aligns with a corresponding pressure sensor A1-A4 in cassette station 54 and each valve station aligns with a corresponding valve V1-V9. Each valve station may define one or more ports that allow fluid communication between that valve station and other internal spaces (e.g., flow paths) within the cassette. As described above, each valve V1-V9 is movable to a plurality of positions (e.g., a retracted or lowered position and an actuated or raised position) under command of controller 18 and is configured to selectively contact a valve station of the cassette. In the actuated position, valve V1-V9 engages its corresponding valve station, closing one or more ports therein to block fluid flow. In the retracted position, valve V1-V9 is spaced from (or does not contact as strongly as in the actuated position) its corresponding valve station, thereby opening one or more ports associated with that valve station and allowing fluid flow.

[0059] Multiple tubing loops extend from the side of the cassette and are adapted to interface with pumps P1-P6 of fluid processing device 10. While different pumps P1-P6 may interact with the cassette's tubing loops to perform different tasks during processing, in the context of the present disclosure, each pump P1-P6 may be configured as an anticoagulant pump P1, a source pump P2, a centrifugal pump P3, an output pump P4, a recirculation pump P5, and a plasma pump P6, respectively. If pumps P1-P6 are configured differently (e.g., configured as pneumatic pumps), the cassette may also be configured differently (e.g., with a pumping station that aligns with the actuator of the pneumatic pump) to enable pumps P1-P6 to transport fluid through the cassette.

[0060] Extending from the sides of the cassette are additional tubes that connect to other components of the fluid flow circuit 12, namely the various fluid reservoirs F1-F7, the spinning membrane separator 26, and the centrifuge chamber 36. The tubes connected to the centrifuge chamber 36 (including one inlet tube and two outlet tubes) may be collectively configured as an umbilicus.

[0061] Various additional components may be incorporated into the tubing extending from the cassette or into some of the space within the cassette, such as a manual clamp 56 associated with the line to the fluid source, a blood return line filter 58 (e.g., a microaggregate filter) associated with the line to the fluid receiver, and / or an air trap 62 located in the line upstream of the centrifuge chamber 36.

[0062] III. Exemplary Fluid Processing Procedures An exemplary fluid processing procedure according to the present disclosure is described below.

[0063] Before processing begins, the operator selects the desired protocol (e.g., using an operator interface station, if provided). This selection informs the controller 18 of how to control other components of the fluid processing device 10 during processing. This selection may include first selecting one of several procedures the system can perform, then selecting the nature of the procedure, and then selecting one or more parameters to be in effect during processing. For example, this may include selecting a platelet collection procedure from several blood separation procedures, then selecting the total volume of blood to be processed and the target volume of platelets to be collected during processing. If the fluid source is a living organism (e.g., a donor or patient), the operator may input various parameters of the source, such as the gender, height, and weight of the source. In one embodiment, the operator may also input one or more characteristics of the fluid to be processed (e.g., a pre-count of platelets).

[0064] Once the controller 18 receives the necessary input, it can instruct the operator to attach the fluid flow circuit 12 to the fluid processing device 10. If some fluid containers (e.g., platelet additive solution containers) are not integrally formed with the fluid flow circuit 12, they may be connected to the fluid flow circuit 12 (e.g., by puncturing a septum in the tubing of the fluid flow circuit 12 or by connecting via a Luer connector). The fluid flow circuit 12 is then attached to the fluid processing device 10 (including associating fluid containers F1-F7 with volume measurement systems W1-W6, as appropriate). In one exemplary embodiment, each volume measurement system W1-W6 may include a weigh scale associated with a hook for hanging the fluid container. In another exemplary embodiment, at least one of the volume measurement systems W1-W6 may include a weigh scale associated with a horizontal platform or surface, and the weigh scale sends signals indicative of the weight of the container (and its contents) to the controller 18 throughout the process while the container is resting on and supported on the platform or surface. In other embodiments, the fluid container may be associated with a volume measurement system that does not include a weigh scale, and in that case may include other means (e.g., one or more sensors) for measuring the volume of fluid in the container.

[0065] Once fluid flow circuit 12 is fully installed in fluid processing device 10, controller 18 may perform an integrity check to ensure that each component of fluid flow circuit 12 is properly connected and functioning properly. Upon successful completion of the integrity check, a fluid source may be connected to fluid flow circuit 12 (e.g., by connecting to a container containing previously collected fluid or by drawing blood from a donor), and fluid flow circuit 12 may then be primed (e.g., by pumping saline from saline container F2 by operating one or more of pumps P1-P6).

[0066] Once priming of fluid flow circuit 12 is complete, fluid processing begins. The first step in an exemplary platelet collection procedure involves drawing blood from a blood source into fluid flow circuit 12. If the blood source is a donor, blood is drawn into fluid flow circuit 12 through a single needle, which is connected to the cassette through line L1. Line L1 may include a manual clamp 56, which may be initially in a closed position, preventing fluid flow through line L1. To begin processing, an operator moves manual clamp 56 from the closed position to an open position, allowing fluid flow through line L1.

[0067] Blood is drawn into line L1 by source pump P2 of fluid treatment device 10. Anticoagulant from anticoagulant container F1 is drawn through line L2 by operation of anticoagulant pump P1 and added to the blood at the junction of lines L1 and L2.

[0068] In the illustrated embodiment, valve V10 is open, allowing anticoagulated blood to flow through line L3 and the cassette's sensor station associated with pressure sensor A1, while valve V11 is closed, preventing fluid flow through line L4. If the blood source is a living organism (e.g., a donor), pressure sensor A1 can communicate with controller 18 to monitor the pressure within the source's veins.

[0069] The cassette includes two valve stations downstream of source pump P2: valve V2 is closed to prevent flow through line L5, and valve V1 is open to allow flow through line L6. A portion of the blood is transported to in-process container F3 via line L7 and the cassette's sensor station associated with pressure sensor A3, while the remainder is transported via line L8 to centrifugal pump P3. Centrifugal pump P3 controls the amount of blood transported to centrifuge chamber 36 rather than in-process container F3. In particular, the flow rate of source pump P2 is greater than the flow rate of centrifugal pump P3, and the difference between the two corresponds to the flow rate of blood entering in-process container F3. The flow rates may be selected so that in-process container F3 is partially or completely filled with blood at the end of the collection phase.

[0070] Blood transported by centrifugal pump P3 through line L8 passes through line L19, air trap 62, and the cassette's sensor station associated with pressure sensor A2 (which monitors the pressure within centrifuge chamber 36 in conjunction with controller 18 of fluid processing device 10) before reaching centrifuge chamber 36 of fluid flow circuit 12. Centrifuge 16 of fluid processing device 10 operates centrifuge chamber 36 to separate the blood therein into platelet-rich plasma and packed red blood cells. In one embodiment, centrifuge chamber 36 nominally rotates at 4,500 rpm, although the specific rotational speed may vary depending on the flow rates of fluids entering and leaving centrifuge chamber 36.

[0071] Packed red blood cells are discharged from the centrifuge chamber 36 through line L10 and flow into the blood return container F4 through line L11. Platelet-rich plasma is withdrawn from the centrifuge chamber 36 through line L12 by the coordinated operation of the recirculation pump P5 and the discharge pump P4 of the fluid processing device 10. The platelet-rich plasma travels through line L12 to a junction where it branches into lines L13 and L14. The recirculation pump P5 is associated with line L13 and transports a portion of the platelet-rich plasma back to the junction with line L8. Line L8 carries blood delivered to the centrifuge chamber 36 by the centrifugal pump P3, where the two are mixed. By recirculating a portion of the platelet-rich plasma back into the centrifuge chamber 36 along with the incoming blood, the hematocrit of the blood entering the centrifuge chamber 36 may be reduced, potentially improving separation efficiency. With this configuration, the flow rate of fluid entering the centrifuge chamber 36 is equal to the sum of the flow rates of the centrifugal pump P3 and the recirculation pump P5. The platelet-rich plasma drawn into line L13 by recirculation pump P5 is immediately returned to the centrifuge chamber 36, so that the net or net flow rate of platelet-rich plasma from the centrifuge chamber 36 is equal to the flow rate of discharge pump P4.

[0072] Line L14 terminates at a junction where it branches into lines L15 and L16. Valve V6 is closed, preventing fluid flow through line L16, thereby transporting the separated platelet-rich plasma through line L15 toward the spinning membrane separator 26. Before reaching the spinning membrane separator 26, a portion of the platelet-rich plasma transported through line L15 passes through a sensor station on the cassette associated with a spinner inlet sensor M1 and a pressure sensor A4. Spinner inlet sensor M1 can detect the platelet concentration of the platelet-rich plasma entering the spinning membrane separator 26, and pressure sensor A4 can monitor the pressure of the spinning membrane separator 26.

[0073] Valve V6 is normally closed, but can be selectively opened as needed to divert all or part of the platelet-rich plasma to blood return container F4 via lines L14 and L16. One example is when separation is initialized at the start of processing and platelets have not yet been discharged from centrifuge chamber 36. In such a case, the fluid transported by discharge pump P4 through line L14 may be diverted to blood return container F4.

[0074] The spinning membrane separator drive unit 14 of the fluid processing device 10 operates the spinning membrane separator 26 to separate the platelet-rich plasma into platelet-poor plasma ("plasma") and platelet concentrate ("platelets"). The plasma is discharged from the spinning membrane separator 26 via line L17 by the plasma pump P6 of the fluid processing device 10. Valves V5, V6, V8, and V9 are closed, and the separated plasma is transported via line L18 through valve V4 to the blood return container F4 along with the separated red blood cells. On its way to the blood return container F4, the plasma passes through the spinner outlet sensor M2. The spinner outlet sensor M2, in conjunction with the controller 18, can determine one or more characteristics of the plasma, such as the amount of cellular blood components in the plasma and / or whether the plasma is hemolytic and / or lipemic.

[0075] Platelet concentrate is transported from spinning membrane separator 26 through line L19. Because line L19 has no associated pump, the flow rate of platelets out of spinning membrane separator 26 is equal to the difference between the flow rates of output pump P4 and plasma pump P6. Valve V8 is closed, preventing fluid flow through line L20 and transporting platelet flow through line L19 and valve V7 toward platelet collection container F6. If desired, valve V8 may be selectively opened to allow fluid flow through line L20 to a junction where it meets with plasma being transported to blood return container F4 through line L18.

[0076] Depending on the volume of platelets to be collected, the above-described blood collection step may be repeated, or blood collection and blood return steps may be alternated. During the blood return step, blood from container F3 is separated in centrifuge chamber 36 during processing, while collected blood components in container F4 are returned to the blood source. During this blood return step, the separated red blood cells and platelet-rich plasma are variously transported within fluid flow circuit 12, and typically an additional volume of platelets separated from platelet-poor plasma in spinning membrane separator 26 is collected in platelet collection container F6 (as in the blood collection step). Before the end of processing, platelet additive solution from additive container F7 may be added to the collected platelets in platelet collection container F6.

[0077] IV. Determination of cell concentration As discussed above, spinner inlet sensor M1 may be used in combination with controller 18 to determine one or more characteristics of the fluid entering spinning membrane separator 26. Meanwhile, spinner outlet sensor M2 may be used to determine one or more characteristics of the fluid exiting spinning membrane separator 26. FIGS. 3-5 illustrate an exemplary optical detection assembly 100 that may be incorporated into fluid treatment device 10 to perform the functions of spinner inlet sensor M1 or spinner outlet sensor M2. In one embodiment, two optical detection assemblies 100 may be incorporated into fluid treatment device 10, one functioning as spinner inlet sensor M1 and the other functioning as spinner outlet sensor M2. While optical detection assembly 100 shown in FIGS. 3-5 is described as a component of fluid treatment device 10 of FIG. 1, it should be understood that optical detection assemblies according to the present disclosure may be incorporated into fluid treatment devices of different configurations or may be provided as stand-alone devices without being incorporated into a fluid treatment device.

[0078] In the illustrated embodiment, optical detection assembly 100 includes a light source 102 and a photodetector array 104, spaced apart to accommodate a container "B" therebetween. When optical detection assembly 100 is used as spinner inlet sensor M1, container B may be line L15 of fluid flow circuit 12, and when optical detection assembly 100 is used as spinner outlet sensor M2, container B may be line L17 of fluid flow circuit 12. It should be understood that the configuration of container B used in conjunction with optical detection assembly 100 can vary without departing from the scope of this disclosure, provided that container B is capable of containing a fluid (including a configuration in which fluid flows through container B) and is formed of a material that is transparent to light emitted from light source 102.

[0079] The illustrated optical detection assembly 100 includes a base 106 defining a slot or channel 108 for receiving a container B. The channel 108 is configured to secure the container B in a desired orientation relative to the light source 102 and the photodetector array 104. The optical detection assembly 100 may further include a lid 110 to prevent external light from interfering with the analysis of the fluid in the container B (in FIGS. 3 and 4, the lid 110 is shown hinged or rotatably coupled to the base 106).

[0080] Light D emitted from light source 102 (which may be configured in various ways without departing from the scope of this disclosure) passes through the fluid in container B, enters container B, and then exits container B. FIGS. 6 and 7 show the transmitted light exiting container B, with photodetector array 104 positioned and oriented to receive at least a portion of the transmitted light. Photodetector array 104 is comprised of multiple photodetectors or light-sensing elements (e.g., 256 photodiodes arranged in a linear array). As discussed above, light passing through a turbid medium (e.g., blood or blood components) is dispersed, so that light may not be detected by a single photodetector (e.g., individual photodiodes) at a single location, but may be detected at multiple locations. It has been found that different fluids (e.g., fluids with different concentrations of a substance of interest) exhibit different dispersion patterns of the exiting light beam. For example, FIG. 6 shows a fluid "f" with a relatively low platelet concentration, while FIG. 7 shows a fluid "F" with a high platelet concentration. Light D (eg, a narrowly focused laser beam) passing through the fluid in vessel B is dispersed, with different individual photodetectors receiving different portions of the transmitted light.

[0081] A controller associated with the photodetector array 104 (which may be the controller 18 of the fluid processing device 10 or a separate, dedicated controller) receives signals from each individual photodetector in the photodetector array 104. Each signal, which indicates the intensity of light received by that individual photodetector, is transmitted from that photodetector to the controller. FIGS. 6 and 7 include charts (hereinafter referred to as "scattering profiles") generated by the controller based on the signals from the photodetector array 104, reflecting the intensity of the signal received by the controller from each individual photodetector. The results are ordered according to the relative position of the individual photodetectors within the photodetector array 104 (i.e., the signal from the leftmost photodetector in the photodetector array 104 is displayed at the left edge of the chart, the signal from the adjacent photodetector is displayed to the right of it, and so on, until the signal from the rightmost photodetector in the photodetector array 104 is displayed at the right edge of the chart). As shown in Figures 6 and 7, photodetectors located in the center of the photodetector array 104 tend to receive the most light, while photodetectors located at the ends of the photodetector array 104 tend to receive little or no light.

[0082] In the illustrated embodiment, platelets in the fluid scatter light, causing it to deviate from its original direction of travel rather than passing directly through the fluid and container B. Because fluid F in FIG. 7 contains more cells, more light is scattered, resulting in more individual photodetectors receiving at least some of the light. However, the maximum intensity is relatively low compared to the maximum intensity of light received by the individual photodetectors in FIG. 6. In other words, light passing through low-concentration fluid f in FIG. 6 has a narrow distribution or scattering profile, while light passing through high-concentration fluid F in FIG. 7 has a broader or more widespread distribution or scattering profile. Thus, by providing a photodetector array 104, one or more characteristics of the fluid of interest, such as the concentration of a substance (e.g., platelets) in the fluid, can be determined by evaluating the light intensity (i.e., the light distribution or scattering profile) received by multiple individual photodetectors. This configuration potentially improves measurement accuracy compared to conventional optical detection assemblies having a single photodetector and a controller configured to evaluate only the intensity of light received by the single photodetector.

[0083] Once the controller generates the scattering profile, various techniques can be used to extract data from the scattering profile that can be used to determine characteristics of the fluid of interest. For example, the scattering profile has an apex at a location corresponding to the individual photodetector that received the most light that passed through container B and the fluid therein. The scattering profile has a "rising edge" to the left of the apex and a "falling edge" to the right of the apex. The rising edge includes signals from individual photodetectors located to the left of the center photodetector, and the falling edge includes signals from individual photodetectors located to the right of the center photodetector. As mentioned above, photodetectors located near the center of the photodetector array 104 tend to receive more light than photodetectors located farther from the center, so the rising edge has a positive slope (this slope tends to be different at different points in the scattering profile) and the falling edge has a negative slope (this slope also tends to be different at different points in the scattering profile).

[0084] Because the slopes of the rising and falling edges of a scattering profile tend to vary at different points along the profile, the controller can use different techniques to calculate the slope of a portion of the rising or falling edge. For example, FIG. 6 illustrates a portion of a rising edge of a scattering profile, which can be analyzed to calculate the slope of the rising edge. Meanwhile, FIG. 7 illustrates a portion of a falling edge of a scattering profile, which can be analyzed to calculate the slope of the falling edge. In one example technique, the controller selects two points on the rising or falling edge of the scattering profile. These two points correspond to signals from two individual photodetectors in the photodetector array 104. The controller calculates the slope of the edge by dividing the change in detector response (the voltage of the signal transmitted from the left detector minus the voltage of the signal transmitted from the right detector) by the change in detector position (the difference in the relative positions of the two detectors within the photodetector array 104). In the example illustrated in FIG. 8, the controller analyzes the falling edge of the scattering profile to calculate its slope. The "L" signal from the left detector (detector position 290) of the two selected detectors has a voltage of 2.1 dV, and the "R" signal from the right detector (detector position 350) has a voltage of 0.7 dV. In this example, the slope of the falling edge is approximately -0.023 ((0.7 dV - 2.1 dV) / (350 - 290)).

[0085] According to another approach, the controller can use linear regression to calculate the slope of the rising or falling edge of the scattering profile. Figure 9 shows a regression line (line "C") for calculating the slope of a portion of the rising edge of the scattering profile, and a regression line (line "E") for calculating the slope of the falling edge of the scattering profile.

[0086] When calculating the slope of a rising or falling edge of a scattering profile, any two points on that edge can be selected. According to one exemplary approach, the two selected points correspond to individual photodetectors that generated signals equivalent to two predetermined percentages of the signal at apex "A" of the scattering profile. In one example, the two selected percentages are 35% and 65% of the signal at the apex of the scattering profile. When analyzing the rising edge of the scattering profile, the left detector of the two selected photodetectors is the detector with a signal equivalent to 35% of the signal at the apex, and the right detector is the detector with a signal equivalent to 65% of the signal at the apex. However, when analyzing the falling edge of the scattering profile, as shown in FIG. 8, the left detector is the detector with a signal equivalent to 65% of the signal at the apex, and the right detector is the detector with a signal equivalent to 35% of the signal at the apex.

[0087] Regardless of the method for calculating the leading edge slope or trailing edge slope, the magnitude of the leading edge slope and trailing edge slope, respectively, in the scattering profile has been found to be indicative of the cell concentration of the fluid monitored by the optical detection assembly 100. A library or database correlating each slope value with the substance concentration may be programmed into the controller or stored elsewhere and remotely accessed by the controller. For example, FIG. 10 is a chart showing an empirically derived correlation between the leading edge slope or trailing edge slope and the platelet concentration in a fluid. In the example shown in FIG. 8, the magnitude of the trailing edge slope is approximately 0.023, which corresponds to a platelet concentration of approximately 2,250×10 3 Equivalent to particles / μL.

[0088] Because a scattering profile has both a rising edge and a falling edge, the slope of either edge can be calculated and compared against a library or correlation database to determine a fluid characteristic correlated with that slope. Scattering profiles are often substantially symmetrical about their apex, and the slope of a portion of a rising edge tends to be approximately equal to the slope of a corresponding portion of a falling edge. In this case, both slopes correlate to the same fluid characteristic value. However, it is within the scope of this disclosure to use both slopes when determining the fluid characteristic value. According to one exemplary approach, both the rising edge slope and the falling edge slope are calculated, and the controller calculates an average value of both slopes, and then compares the average value with a library or database to determine the fluid characteristic value. According to another exemplary approach, both the rising edge slope and the falling edge slope are calculated, and the controller compares each slope with a library or database to determine the fluid characteristic value correlated with each slope. The controller then calculates the average value of these two fluid characteristic values ​​and sets this average value as the fluid characteristic value of the target fluid. It should be noted that other techniques for determining fluid property values ​​using the slopes of the rising and falling edges of the scattering profile (e.g., weighting one slope more than the other) may also be employed without departing from the scope of this disclosure.

[0089] As described above, the controller can use various techniques to extract data from the scattering profile to determine the characteristics of the target fluid, and it should be understood that the present disclosure is not limited to a correlation between the slope of a portion of the scattering profile and cell concentration. For example, cell concentration may be correlated in an empirically derived correlation curve with the maximum intensity of light received by an individual photodetector, the sum of the intensities of light received by at least two individual photodetectors, or the width of the scattering profile (corresponding to the number of individual photodetectors that receive a certain amount of light or more). Details of these are described in U.S. Patent Application Publication No. 2023 / 0243746.

[0090] When a correlation curve defines the relationship between a certain aspect of the scattering profile and the predicted cell concentration, that relationship and the correlation curve are specific to the configuration of the cell counter used to generate the correlation curve. Therefore, if the cell counter used in a certain facility (e.g., a blood center) has the same configuration as the cell counter used to generate the correlation curve, there will be a 1:1 relationship between the cell concentration predicted by the controller using the correlation curve and the cell concentration measured by the cell counter (as shown in FIG. 11 , where the x-axis represents the platelet concentration predicted by the controller and the y-axis represents the platelet concentration measured by the cell counter). On the other hand, if the cell counter used in a facility has a different configuration (e.g., a different manufacturer or a different model from the same manufacturer) than the cell counter used to generate the correlation curve, there may not be a 1:1 relationship between the cell concentration predicted by the controller using the correlation curve and the cell concentration measured by the cell counter (as shown in FIG. 12 and discussed below).

[0091] Thus, before using the fluid processing device's controller to predict the concentration of a cell or group of cells in a fluid, an operator can work with the fluid processing device to determine whether a correction factor is needed to correct the predicted value if the correlation curve used by the controller differs between the cell counter configuration used at the operator's facility and the cell counter configuration used to generate the correlation curve. This approach requires the operator to use the fluid processing device's optical detection assembly and controller (as described above) to predict the cell concentrations of multiple fluids having different cell concentrations and then measure the cell concentrations of the same fluids using the facility's cell counter. While the number of fluids analyzed by the optical detection assembly and cell counter can vary without departing from the scope of this disclosure, it is desirable to use a sufficient number of samples with a relatively wide range of cell concentrations in order to derive a reliable correction factor.

[0092] For each fluid, a correlation curve of the type shown in FIG. 12 is generated by plotting the cell concentration predicted by the controller against the cell concentration measured by the cell counter. FIG. 12 shows correlation curves corresponding to three different cell counter configurations (identified in FIG. 12 as "Cell Counter 1," "Cell Counter 2," and "Cell Counter 3"). In addition to the correlation curves corresponding to these three cell counters, FIG. 12 also includes a "benchmark equivalent" curve, which shows a 1:1 relationship between the cell counter used to generate the correlation curve used by the controller and the cell concentration measured by a cell counter of the same configuration (the "benchmark equivalent" curve in FIG. 12 is the same as the correlation curve shown in FIG. 11). The plotting of predicted and measured values ​​may be performed by the controller or by any other suitable computer or computing device.

[0093] Once a curve showing the correlation between the cell concentration predicted by the controller and the corresponding cell concentration measured by the cell counter is generated, an equation representing the curve (sometimes referred to herein as a "correction equation") may be generated by the controller or other suitable computer or computing device. The form of the correction equation (e.g., linear, quadratic, cubic, etc.) can be changed without departing from the scope of the present disclosure, and the shape of the correction equation depends on the data points generated by the controller and the cell counter. In one embodiment, a linear equation representing a best-fit straight line may be generated using the data points generated by the controller and the cell counter using least squares or linear regression, etc., and the correction equation includes a variable representing the slope of the line and a variable representing the point where the line intersects the y-axis (intercept). Figure 12 illustrates this approach, showing that the curve corresponding to "Cell Counter 2" is represented by a linear equation (y = 0.9091x + 45.455) with a slope of 0.9091 and a y-intercept of 45.455, while the curve corresponding to "Cell Counter 3" is represented by a linear equation (y = 0.9474x + 296.51) with a slope of 0.9474 and a y-intercept of 296.51. For "Cell Counter 1," on the other hand, the best-fit line coincides with the "benchmark equivalent" curve, indicating that "Cell Counter 1" is either identical in construction to the cell counter used to generate the correlation curve used by the controller, or at least that the two operate to provide identical results. In this case, the linear equation is (y = x) with a slope of 1 and a y-intercept of 0.

[0094] Regardless of the form of the correction equation generated for a particular cell counter, the correction equation is used by the controller to correct the predicted cell concentration. This may involve the controller itself obtaining or calculating the correction equation (or at least the constant values ​​of the correction equation) or an operator providing the correction equation (or at least the constant values ​​of the correction equation) to the controller. After the controller has the correction equation, the fluid processing procedure can be performed as usual, including using a pre-programmed correlation curve to control the optical detection assembly to predict cell concentration in the fluid. However, after the cell concentration is predicted using the correlation curve, the controller applies the correction equation (or at least the constant values ​​of the correction equation) to generate a corrected predicted value to compensate for differences between the cell counter configuration used in the facility and the cell counter configuration used to generate the correlation curve.

[0095] The manner in which the controller applies the correction equation (or at least its constant values) may vary without departing from the scope of the present disclosure. For example, if the correction equation is provided as a linear formula, the controller substitutes the predicted (uncorrected) cell concentration into the correction equation as the "x" value, and the resulting "y" value is the corrected cell concentration value for the fluid. For "Cell Counter 1," the correction equation is y=x, which means that "Cell Counter 1" is configured identically to the cell counter used to generate the pre-programmed correlation curve, or at least that the two operate to provide identical results, and the cell concentration value ultimately reported by the controller will be the same as the uncorrected cell concentration value. In light of this result, according to one embodiment, the controller may prompt the operator to confirm whether the cell counter used in the operator's facility is the same model as the cell counter used to generate the pre-programmed correlation curve, before the operator performs the aforementioned steps to derive the correction equation. If the operator confirms that the cell counter used in the facility is the same model, the controller may present the operator with the option of skipping the step of deriving the correction equation. In this case, the correction formula is y = x, and it is assumed that correction of the predicted value by the control unit is unnecessary. However, even if the cell counters used in the facility are the same model, it may be desirable to perform the above-mentioned procedure to confirm that correction is unnecessary for the cell concentration predicted by the control unit.

[0096] For "cell counter 2" and "cell counter 3," the controller each has a correction formula that corrects at least a portion of the cell concentration predicted by the controller using the correlation curve. For example, if the uncorrected cell concentration value is 2,150 e3 / μL, the controller applies the correction formula for "cell counter 2" (y = 0.9091x + 45.455) to derive a corrected cell concentration value of 2,000 e3 / μL, and applies the correction formula for "cell counter 3" (y = 0.9474x + 296.51) to derive a corrected cell concentration value of 2,333 e3 / μL. After calculating the corrected cell concentration value, the controller reports or records the corrected cell concentration value instead of the uncorrected cell concentration value.

[0097] It will be appreciated that the approach described herein is more practical than an alternative approach in which the manufacturer of the fluid processing device predetermines correction equations for all available cell counters, programs all of these correction equations into the device's controller, and the end user or operator informs the controller of the model of cell counter they are using, which then selects the appropriate correction equation to apply to the predicted value. However, as noted above, it is also within the scope of this disclosure for the controller to query the operator whether the cell counter used in the operator's facility is the same model cell counter used to derive the pre-programmed correlation curve, and present the operator with the option of proceeding with the fluid processing procedure (including the process in which the controller uses the correlation curve to predict the cell concentration of the fluid) without taking the steps to derive the correction equation.

[0098] V. Aspect Aspect 1 10. An optical detection assembly for monitoring a fluid in a vessel, the optical detection assembly comprising: a light source constructed and arranged to illuminate the fluid in the vessel; a photodetector configured to receive at least a portion of the light exiting the vessel and generate a signal indicative of the intensity of the at least a portion of the light; and a controller; wherein the controller is configured to receive a signal from the photodetector and is programmed with a correlation curve derived using a first cell counter, the correlation curve relating the signal from the photodetector to a cell concentration in the fluid in the vessel; the controller is further programmed to: receive or calculate a correction equation based on a comparison of a configuration of the first cell counter and a configuration of a second cell counter used in combination with the optical detection assembly; receive the signal from the photodetector; calculate an uncorrected cell concentration in the fluid in the vessel based at least in part on the signal and the correlation curve; and apply the correction equation to the uncorrected cell concentration in the fluid in the vessel to calculate a corrected cell concentration.

[0099] Aspect 2 2. The optical detection assembly of claim 1, wherein the control unit is programmed to calculate an uncorrected cell concentration in the fluid in the container based at least in part on a signal reflecting a maximum intensity of light received by the photodetector.

[0100] Aspect 3 The optical detection assembly of embodiment 1, wherein the optical detector is configured as a photodetector array including a plurality of photosensitive elements, and the control unit is programmed to receive from the photodetector array a signal indicating the intensity of at least some of the light received by each of the plurality of photosensitive elements, generate a scattering profile based at least in part on the signal from the photodetector array, and calculate an uncorrected cell concentration in the fluid in the container based at least in part on the scattering profile and the correlation curve.

[0101] Aspect 4 4. The optical detection assembly of claim 3, wherein the scattering profile includes a rising edge and a falling edge, and the controller is programmed to calculate a slope of the rising edge or the falling edge of the scattering profile and calculate an uncorrected cell concentration in the fluid in the container based at least in part on the slope and the correlation curve.

[0102] Aspect 5 The optical detection assembly of aspect 3, wherein the control unit is programmed to calculate an uncorrected cell concentration in the fluid in the container based at least in part on a sum of the intensities of at least some of the light received by at least two of the plurality of light-sensing elements.

[0103] Aspect 6 4. The optical detection assembly of embodiment 3, wherein the controller is programmed to calculate an uncorrected cell concentration in the fluid in the vessel based at least in part on the width of the scattering profile.

[0104] Aspect 7 7. The optical detection assembly of any one of aspects 1 to 6, wherein the controller is programmed to receive an input from an operator reflecting whether the second cell counter is of the same configuration as the first cell counter, and to proceed with applying the correction formula to the uncorrected cell concentration to calculate the uncorrected cell concentration in the fluid in the container only if the controller receives an input indicating that the second cell counter is of a different configuration than the first cell counter.

[0105] Aspect 8

[0023] Embodiment 8. The optical detection assembly of any one of embodiments 1 to 7, wherein the controller is programmed to calculate a correction equation.

[0106] Aspect 9 The optical detection assembly of embodiment 8, wherein the control unit is programmed to calculate an uncorrected cell concentration for each of a plurality of fluids having different cell concentrations, and to calculate a correction equation for each of the plurality of fluids by plotting the uncorrected cell concentration in the fluid and the cell concentration of the fluid measured by the second cell counter as data points, creating a curve having the plurality of data points, and determining a correction equation as an equation representing the curve.

[0107] Aspect 10

[0023] Embodiment 8. The optical detection assembly of any one of embodiments 1 to 7, wherein the controller is programmed to receive a correction formula from an operator.

[0108] Aspect 11 10. A fluid treatment device comprising: a pump system; a valve system; an optical detection assembly; and a controller; the optical detection assembly including a light source constructed and arranged to illuminate a fluid in a vessel; and a photodetector configured to receive at least a portion of the light emitted from the vessel and generate a signal indicative of an intensity of at least a portion of the light; the controller configured to receive the signal from the photodetector and programmed with a correlation curve derived using a first cell counter, the correlation curve relating the signal from the photodetector to a cell concentration in the fluid in the vessel; and programmed to control operation of the pump system and the valve system to perform a fluid treatment procedure; the controller further programmed to: receive or calculate a correction equation based on a comparison of a configuration of the first cell counter and a configuration of a second cell counter used in combination with the fluid treatment device; receive the signal from the photodetector; calculate an uncorrected cell concentration in the fluid in the vessel based at least in part on the signal and the correlation curve; and apply the correction equation to the uncorrected cell concentration in the fluid in the vessel to calculate a corrected cell concentration.

[0109] Aspect 12 12. The fluid treatment device of embodiment 11, wherein the controller is programmed to calculate an uncorrected cell concentration in the fluid within the container based at least in part on a signal reflecting a maximum intensity of light received by the photodetector.

[0110] Aspect 13 12. The fluid treatment device of claim 11, wherein the light detector is configured as a light detector array including a plurality of light sensing elements, and the control unit is programmed to receive from the light detector array a signal indicating the intensity of at least some of the light received by each of the plurality of light sensing elements, generate a scattering profile based at least in part on the signal from the light detector array, and calculate an uncorrected cell concentration in the fluid in the container based at least in part on the scattering profile and the correlation curve.

[0111] Aspect 14 14. The fluid treatment device of embodiment 13, wherein the scattering profile comprises a rising edge and a falling edge, and the controller is programmed to calculate a slope of the rising edge or the falling edge of the scattering profile and calculate an uncorrected cell concentration in the fluid in the vessel based at least in part on the slope and the correlation curve.

[0112] Aspect 15 14. The fluid treatment device of claim 13, wherein the control unit is programmed to calculate an uncorrected cell concentration in the fluid in the container based at least in part on a sum of the intensities of at least some of the light received by at least two of the plurality of light-sensing elements.

[0113] Aspect 16 14. The fluid treatment device of embodiment 13, wherein the controller is programmed to calculate an uncorrected cell concentration in the fluid in the vessel based at least in part on the width of the scattering profile.

[0114] Aspect 17 17. The fluid processing device of any one of aspects 11 to 16, wherein the control unit is programmed to receive an input from an operator reflecting whether the second cell counter is of the same configuration as the first cell counter, and to proceed with applying the correction formula to the uncorrected cell concentration to calculate the uncorrected cell concentration in the fluid in the container only if the control unit receives an input indicating that the second cell counter is of a different configuration than the first cell counter.

[0115] Aspect 18

[0033] Aspect 18. The fluid treatment device of any one of aspects 11 to 17, wherein the controller is programmed to calculate a correction formula.

[0116] Aspect 19 19. The fluid processing device of claim 18, wherein the control unit is programmed to calculate an uncorrected cell concentration for each of a plurality of fluids having different cell concentrations, and to calculate a correction equation for each of the plurality of fluids by plotting the uncorrected cell concentration in the fluid and the cell concentration of the fluid measured by the second cell counter as data points to create a curve having the plurality of data points, and to determine a correction equation as an equation representing the curve.

[0117] Aspect 20

[0033] Embodiment 18. The fluid treatment device of any one of embodiments 11 to 17, wherein the controller is programmed to receive a correction formula from an operator.

[0118] Aspect 21 10. A method for calculating a cell concentration in a target fluid in a container, the method comprising: providing a plurality of fluids having different cell concentrations; for each of the plurality of fluids, irradiating the fluid with light and receiving at least a portion of the light exiting the container; calculating an uncorrected cell concentration in the fluid based at least in part on a correlation curve derived using a first cell counter and the intensity of at least some of the light exiting the fluid; obtaining a measured cell concentration of the fluid from a second cell counter; plotting the uncorrected cell concentration in the fluid against the measured cell concentration of the fluid as data points to create a curve having the plurality of data points; and determining a correction equation as an equation representing the curve; irradiating the target fluid in the container with light; receiving at least a portion of the light exiting the container; calculating an uncorrected cell concentration in the target fluid in the container based at least in part on the correlation curve and the intensity of at least some of the light exiting the container; and applying the correction equation to the uncorrected cell concentration to calculate a corrected cell concentration in the target fluid in the container.

[0119] Aspect 22 22. The method of embodiment 21, wherein the calculation of the uncorrected cell concentration in the subject fluid within the container is based at least in part on a maximum intensity of at least some of the light exiting the subject fluid and the container.

[0120] Aspect 23 22. The method of claim 21, wherein at least a portion of the light emitted from the subject fluid and the container is received by a photodetector array including a plurality of light-sensing elements, and the calculation of the uncorrected cell concentration in the subject fluid in the container is based at least in part on a scattering profile of at least a portion of the light received by the photodetector array.

[0121] Aspect 24 24. The method of embodiment 23, wherein the scattering profile comprises a rising edge and a falling edge, and wherein the calculation of the uncorrected cell concentration in the fluid of interest in the vessel is based at least in part on the slope of the rising edge or the falling edge.

[0122] Aspect 25 24. The method of embodiment 23, wherein the calculation of the uncorrected cell concentration in the target fluid in the container is based at least in part on a sum of the intensities of at least some of the light received by at least two of the plurality of light-sensing elements.

[0123] Aspect 26 24. The method of embodiment 23, wherein the calculation of the uncorrected cell concentration in the fluid of interest in the vessel is based at least in part on the width of the scattering profile.

[0124] Aspect 27 27. The method of any one of aspects 21 to 26, further comprising a step of determining whether the second cell counter is of the same configuration as the first cell counter, and wherein the correction equation is applied to the uncorrected cell concentration in the target fluid in the container to calculate a corrected cell concentration in the target fluid only if it is determined that the second cell counter is of a different configuration than the first cell counter.

[0125] Aspect 28 Aspect 28. The method of any one of aspects 21 to 27, wherein the correction formula is calculated by a controller of the fluid processing device.

[0126] Aspect 29 The method of embodiment 28, wherein the uncorrected cell concentrations in each fluid and in the target fluid in the container are calculated by the control unit of the fluid processing device, and a correction formula is applied by the control unit of the fluid processing device to the uncorrected cell concentrations in the target fluid in the container to calculate the corrected cell concentration in the target fluid in the container.

[0127] Aspect 30 28. The method of any one of aspects 21 to 27, wherein the correction formula is provided to a controller of the fluid processing device, and uncorrected cell concentrations in each fluid and in the target fluid in the vessel are calculated by the controller of the fluid processing device, and the correction formula is applied by the controller of the fluid processing device to the uncorrected cell concentrations in the target fluid in the vessel to calculate a corrected cell concentration in the target fluid in the vessel.

[0128] It will be understood that the above-described embodiments are illustrative of some of the applications of the principles of the present invention. Numerous modifications may be made by those skilled in the art without departing from the spirit and scope of the claimed subject matter of this application, including combinations of features that are individually disclosed or claimed herein. For these reasons, it is understood that the scope of the present application is not limited to the above description, but is instead defined by the following claims, which claims may be directed to configurations incorporating combinations of features individually disclosed or claimed herein.

Claims

1. 1. An optical detection assembly for monitoring a fluid in a container, comprising: a light source constructed and arranged to illuminate the fluid in the container; a photodetector configured to receive at least a portion of the light exiting the container and to generate a signal indicative of an intensity of the at least a portion of the light; a control unit; the controller is configured to receive the signal from the photodetector and is programmed with a correlation curve derived using a first cell counter, the correlation curve relating the signal from the photodetector to a cell concentration in the fluid within the vessel; The control unit further includes: receiving or calculating a correction formula based on a comparison of the first cell counter configuration and a second cell counter configuration used in combination with the optical detection assembly; receiving the signal from the photodetector; calculating an uncorrected cell concentration in the fluid within the vessel based at least in part on the signal and the correlation curve; an optical detection assembly programmed to apply the correction equation to the uncorrected cell concentration in the fluid in the vessel to calculate a corrected cell concentration.

2. 2. The optical detection assembly of claim 1, wherein the control unit is programmed to calculate the uncorrected cell concentration in the fluid in the container based at least in part on a signal reflecting a maximum intensity of light received by the light detector.

3. the photodetector is configured as a photodetector array including a plurality of photosensitive elements; The control unit receiving a signal from the photodetector array indicative of an intensity of the at least some of the light received by each of the plurality of light-sensing elements; generating a scattering profile based at least in part on the signals from the photodetector array; The optical detection assembly of claim 1 , programmed to calculate the uncorrected cell concentration in the fluid within the vessel based at least in part on the scattering profile and the correlation curve.

4. the scattering profile includes a rising edge and a falling edge; The control unit calculating the slope of the rising edge or the falling edge of the scattering profile; The optical detection assembly of claim 3 , programmed to calculate the uncorrected cell concentration in the fluid in the vessel based at least in part on the slope and the correlation curve.

5. 4. The optical detection assembly of claim 3, wherein the control unit is programmed to calculate the uncorrected cell concentration in the fluid in the container based at least in part on a sum of intensities of the at least some of the light received by at least two of the plurality of light-sensing elements.

6. 4. The optical detection assembly of claim 3, wherein the controller is programmed to calculate the uncorrected cell concentration in the fluid in the vessel based at least in part on a width of the scattering profile.

7. The control unit receiving input from an operator reflecting whether the second cell counter is of the same configuration as the first cell counter; 7. The optical detection assembly of claim 1, wherein the optical detection assembly is programmed to apply the correction formula to the uncorrected cell concentration to proceed with calculating the uncorrected cell concentration in the fluid in the container only if the optical detection assembly receives input indicating that the second cell counter is configured differently from the first cell counter.

8. The optical detection assembly of claim 1 , wherein the control unit is programmed to calculate the correction formula.

9. The control unit calculating the uncorrected cell concentration for each of a plurality of fluids having different cell concentrations; for each of the plurality of fluids, plotting the uncorrected cell concentration in the fluid and the cell concentration of the fluid measured by the second cell counter as data points to generate a curve having the plurality of data points; The optical detection assembly of claim 8 , programmed to calculate the correction equation by determining the correction equation as an equation that represents the curve.

10. The optical detection assembly of claim 1 , wherein the control unit is programmed to receive the correction formula from an operator.

11. 1. A fluid treatment device comprising: A pump system; a valve system; an optical detection assembly; a control unit; The optical detection assembly includes: a light source constructed and arranged to illuminate the fluid in the container; a photodetector configured to receive at least a portion of the light exiting the container and to generate a signal indicative of an intensity of the at least a portion of the light; the controller is configured to receive the signal from the photodetector and is programmed with a correlation curve derived using a first cell counter, the correlation curve relating the signal from the photodetector to a cell concentration in the fluid within the vessel, and is programmed to control operation of the pump system and the valve system to perform a fluid processing procedure; The control unit further includes: receiving or calculating a correction formula based on a comparison of the configuration of the first cell counter and the configuration of a second cell counter used in combination with the fluid processing device; receiving the signal from the photodetector; calculating an uncorrected cell concentration in the fluid within the vessel based at least in part on the signal and the correlation curve; a fluid processing device programmed to apply the correction formula to the uncorrected cell concentration in the fluid in the vessel to calculate a corrected cell concentration.

12. 12. The fluid treatment device of claim 11, wherein the controller is programmed to calculate the uncorrected cell concentration in the fluid in the vessel based at least in part on a signal reflecting a maximum intensity of light received by the light detector.

13. the photodetector is configured as a photodetector array including a plurality of photosensitive elements; The control unit receiving a signal from the photodetector array indicative of an intensity of the at least some of the light received by each of the plurality of light-sensing elements; generating a scattering profile based at least in part on the signals from the photodetector array; The fluid treatment device of claim 11 , programmed to calculate the uncorrected cell concentration in the fluid in the vessel based at least in part on the scattering profile and the correlation curve.

14. the scattering profile includes a rising edge and a falling edge; The control unit calculating the slope of the rising edge or the falling edge of the scattering profile; 14. The fluid treatment device of claim 13, programmed to calculate the uncorrected cell concentration in the fluid in the vessel based at least in part on the slope and the correlation curve.

15. 14. The fluid treatment device of claim 13, wherein the control unit is programmed to calculate the uncorrected cell concentration in the fluid in the container based at least in part on a sum of the intensities of the at least some of the light received by at least two of the plurality of light-sensing elements.

16. 14. The fluid treatment device of claim 13, wherein the controller is programmed to calculate the uncorrected cell concentration in the fluid in the vessel based at least in part on the width of the scattering profile.

17. The control unit receiving input from an operator reflecting whether the second cell counter is of the same configuration as the first cell counter; 17. The fluid processing device of claim 11, wherein the device is programmed to apply the correction formula to the uncorrected cell concentration to proceed with calculating the uncorrected cell concentration in the fluid in the vessel only if the device receives input indicating that the second cell counter is configured differently from the first cell counter.

18. The fluid processing device according to any one of claims 11 to 17, wherein the control unit is programmed to calculate the correction formula.

19. The control unit calculating the uncorrected cell concentration for each of a plurality of fluids having different cell concentrations; for each of the plurality of fluids, plotting the uncorrected cell concentration in the fluid and the cell concentration of the fluid measured by the second cell counter as data points to generate a curve having the plurality of data points; 20. The fluid treatment device of claim 18, programmed to calculate the correction equation by determining the correction equation as an equation that represents the curve.

20. 18. A fluid processing apparatus according to any one of claims 11 to 17, wherein the control unit is programmed to receive the correction formula from an operator.

21. 1. A method for calculating a cell concentration in a target fluid in a container, comprising: Providing a plurality of fluids having different cell concentrations; for each of the plurality of fluids, irradiating the fluid with light, receiving at least a portion of the light exiting the vessel, calculating an uncorrected cell concentration in the fluid based at least in part on the correlation curve derived using a first cell counter and the intensity of the at least a portion of the light exiting the fluid, obtaining a measured cell concentration of the fluid from a second cell counter, plotting the uncorrected cell concentration in the fluid as data points against the measured cell concentration of the fluid, creating a curve having a plurality of the data points, and determining a correction equation as an equation representing the curve; irradiating the target fluid in the container with light; receiving at least a portion of the light emitted from the target fluid and the container; calculating an uncorrected cell concentration in the target fluid in the vessel based at least in part on the correlation curve and the intensities of the target fluid and the at least some of the light exiting the vessel; and applying the correction formula to the uncorrected cell concentration to calculate a corrected cell concentration in the subject fluid in the vessel.

22. 22. The method of claim 21, wherein the calculation of the uncorrected cell concentration in the subject fluid in the container is based at least in part on a maximum intensity of the at least some of the light exiting the subject fluid and the container.

23. at least a portion of the light exiting the target fluid and the container is received by a photodetector array including a plurality of light-sensing elements; 22. The method of claim 21, wherein the calculation of the uncorrected cell concentration in the fluid of interest in the vessel is based at least in part on a scattering profile of the at least some of the light received by the photodetector array.

24. the scattering profile includes a rising edge and a falling edge; 24. The method of claim 23, wherein the calculation of the uncorrected cell concentration in the subject fluid in the vessel is based at least in part on the slope of the rising edge or the falling edge.

25. 24. The method of claim 23, wherein the calculation of the uncorrected cell concentration in the target fluid in the container is based at least in part on a sum of the intensities of the at least some of the light received by at least two of the plurality of light-sensing elements.

26. 24. The method of claim 23, wherein the calculation of the uncorrected cell concentration in the fluid of interest in the vessel is based at least in part on the width of the scattering profile.

27. 27. The method of claim 21, further comprising determining whether the second cell counter is of the same configuration as the first cell counter, and applying the correction formula to the uncorrected cell concentration in the subject fluid in the container to calculate the corrected cell concentration in the subject fluid only if it is determined that the second cell counter is of a different configuration than the first cell counter.

28. 28. The method of any one of claims 21 to 27, wherein the correction formula is calculated by a controller of a fluid processing device.

29. the uncorrected cell concentrations in each fluid and in the target fluid in the container are calculated by the controller of the fluid processing device; 29. The method of claim 28, wherein the correction equation is applied by the control unit of the fluid processing device to the uncorrected cell concentration in the target fluid in the container to calculate the corrected cell concentration in the target fluid in the container.

30. the correction formula is provided to the controller of the fluid processing device; the uncorrected cell concentrations in each fluid and in the target fluid in the container are calculated by the controller of the fluid processing device; 28. The method of claim 21, wherein the correction equation is applied by the control unit of the fluid processing device to the uncorrected cell concentration in the target fluid in the container to calculate the corrected cell concentration in the target fluid in the container.

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