System and method for identifying causes of leukapheresis flow limitation

Abstract

To provide an improved blood separation system, apparatus and method for monitoring pressure in a leukoreduction filter, identifying the cause of flow restriction in the filter, and adjusting fluid processing.SOLUTION: Systems, devices and methods for processing whole blood are disclosed. The system includes a reusable separation device, a disposable fluid flow circuit, and a controller configured to detect a flow restriction in the leukocyte depletion filter and identify a cause of the flow restriction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates generally to blood processing systems, devices, and methods including reusable separation devices and disposable fluid circuits, and more particularly to blood processing systems configured to detect and identify the cause of flow restriction in a leukocyte reduction filter. [Background technology]

[0002] Currently, various blood processing systems allow for the collection of specific blood components (e.g., red blood cells or platelets) rather than whole blood from a blood source. Typically, these systems withdraw whole blood from the blood source, separate, remove, and collect the desired blood components or constituents, and return the remaining blood components to the blood source. Removing only specific components is advantageous when the blood source is a human donor because it may reduce the time required for the donor's body to return to its pre-donation state, allowing for more frequent blood donations than would be possible if whole blood were collected.

[0003] In certain procedures, separated blood components may undergo leukoreduction. Leukoreduction is the removal of white blood cells (WBCs) from blood components. Leukoreduction is typically performed using filters that allow collected blood components, such as red blood cells (RBCs) and platelets (PLTs), to pass through while retaining white blood cells. However, filters are known to clog and restrict component flow. Clogs can be caused by fibrin clots, sickle cells and other amoebocyte types, and platelet aggregation. Leukoreduction is typically achieved by forcing fluid through the filter by gravity. Therefore, when a clog or other flow restriction forms, the flow of blood components is reduced or stopped because the gravitational flow pressure is insufficient to overcome the flow restriction, leading to inadequate or failed leukoreduction.

[0004] U.S. Patent Application Serial No. 17 / 909,799 describes an automated blood or biological fluid processing system in which blood components are forced through a filter by pump-driven flow, whereby the driving pressure may be sufficient to overcome flow restrictions to a much greater extent than gravity-driven flow. However, excessive filter pressure due to flow restrictions may result in failed leukocyte reduction or damage to kit components of the disposable fluid flow circuit. Thus, if leukocyte reduction fails, the collected blood components will contain undesirable leukocytes, potentially including sickle cells and other amorphic cell types, rendering the blood components unusable.

[0005] Therefore, there is a need for improved blood separation systems, devices and methods for monitoring pressure within a leukocyte reduction filter, identifying the cause of flow restriction within the filter, and adjusting fluid treatment. Summary of the Invention

[0006] The subject matter includes multiple aspects that can be implemented individually or in combination in the devices, systems, and methods described and / or claimed below. These aspects can be used alone or in combination with other aspects described herein, and the description of these aspects together is not intended to prevent these aspects from being used individually or from being claimed individually or in different combinations, as described in the appended claims or any later-amended claims. In this specification and claims, unless expressly indicated otherwise, "blood" is intended to include whole blood and blood components such as packed red blood cells, plasma, platelets, and white blood cells, with or without anticoagulants or additives.

[0007] In one embodiment, a system for collecting blood components separated from whole blood is disclosed. The system includes a separation chamber, a source of biological fluid, a container for receiving the separated blood components, and a disposable fluid flow circuit including a flow path between the separation chamber and the container. A leukoreduction filter is disposed downstream of the separation chamber and upstream of the container. The system also includes durable hardware components for receiving the disposable fluid flow circuit. The durable hardware components include a separator configured to receive the separation chamber and a pressure sensor configured to detect pressure within the leukoreduction filter. The system includes a controller configured to automatically perform one or more blood processing procedures selected by an operator, the controller further configured to receive information from the pressure sensor, determine flow restriction within the leukoreduction filter based on the information from the pressure sensor, and identify the cause of the flow restriction.

[0008] In another aspect, a method for separating whole blood into its constituent blood components is disclosed. The method includes separating the whole blood in a whole blood separation system. The whole blood separation system includes a disposable fluid flow circuit, a separation chamber, a fluid flow control cassette in fluid communication with the separation chamber, a plurality of containers in fluid communication with the fluid flow control cassette, and a leukoreduction filter disposed downstream of the separation chamber. The system further includes durable hardware components, including a separator configured to receive the separation chamber and a pressure sensor configured to detect pressure within the leukoreduction filter. A controller is included, configured to control the system to automatically perform one or more blood processing procedures selected by an operator. The controller is further configured to receive information from the pressure sensor, determine flow restriction within the leukoreduction filter based on the information from the pressure sensor, and identify a cause of the flow restriction. The method further includes measuring the pressure within the leukoreduction filter and detecting the flow restriction based on the pressure within the leukoreduction filter. According to the method, if the pressure within the leukoreduction filter exceeds a predetermined threshold, the flow of separated blood components to the leukoreduction filter may be restricted or bypassed.

[0009] These and other aspects of the present subject matter are disclosed in the accompanying detailed description of the drawings. [Brief explanation of the drawings]

[0010] FIG. 1 is a perspective view of an example of reusable hardware components of a blood processing system configured to receive a disposable fluid flow circuit.

[0011] FIG. 2 is a plan view of one example of a disposable fluid flow circuit used in combination with the durable hardware components of FIG.

[0012] FIG. 2A is a plan view of the cassette of the disposable fluid flow circuit, showing the internal flow paths and other components of the system.

[0013] FIG. 3 is a schematic diagram of another example fluid flow circuit installed in the processing device of FIG. 1, in a first configuration in which separated blood components pass through a leukoreduction filter.

[0014] FIG. 4 is a schematic diagram of the fluid flow circuit of FIG. 3 in a second configuration in which separated blood products flow bypassing the leukoreduction filter.

[0015] FIG. 5 is a flow chart illustrating a method for identifying the cause of flow restriction in a leukoreduction filter.

[0016] 6A-C are graphs showing trends / profiles representative of different flow limitations. DETAILED DESCRIPTION OF THE INVENTION

[0017] The embodiments disclosed herein are intended to provide exemplary explanations of the subject matter. However, these are merely examples and are not limiting, as the subject matter may be embodied in various forms. Therefore, the specific details disclosed herein should not be construed as limiting the subject matter defined by the appended claims.

[0018] FIG. 1 illustrates an example of a reusable, durable hardware component (e.g., processor) 10 of a blood processing system, and FIG. 2 illustrates an example of a disposable or single-use fluid flow circuit 12 used in combination with the hardware component 10 to process collected whole blood. By way of example, the reusable, durable hardware component 10 may be the device described in International Patent Publication No. WO 2021 / 194824, the entire contents of which are incorporated herein by reference. The illustrated processor 10 includes pumps, valves, sensors, displays, and other devices for configuring and controlling fluid flow through the fluid flow circuit 12, which are described in detail below. The blood processing system may be controlled by a controller 13 integrated into the processor 10. The controller 13 includes a programmable microprocessor for automatically controlling the operation of the pumps, valves, sensors, etc. The system may also include wireless communication capabilities for transferring data from the device to an operator's quality control system.

[0019] More specifically, the illustrated processing device 10 includes a touchscreen 14 for user input and output, a pumping station including a first blood pump 16 (e.g., for pumping whole blood), a second pump 18 (e.g., for pumping plasma), a third pump 20 (e.g., for pumping additive solutions), a separator / centrifuge 22 (which may include or be associated with a centrifuge mounting station and drive unit), and tubing clamps 24a-c. The touchscreen 14 allows user interaction with the processing device 10 and allows monitoring of processing parameters such as flow rate, vessel weight, and pressure. The pumps 16, 18, and 20 are illustrated as peristaltic pumps capable of accepting tubing and moving fluids through associated conduits at various flow rates depending on the processing procedure. An exemplary centrifuge mounting station / drive unit is disclosed in U.S. Patent No. 8,075,468 (see Figures 26-28), the entire contents of which are incorporated herein by reference. Clamps 24a-c are capable of opening and closing the flow path through the tubing or conduit and may incorporate an RF sealer to complete a heat seal against the tubing or conduit placed within the clamp to seal the tubing leading to the product container upon completion of the processing procedure.

[0020] The processor 10 also includes hangers 26a-d, each of which may be associated with a weighing scale, for suspending the various containers of the disposable fluid flow circuit 12. The hangers 26a-d are preferably mounted on a vertically movable support 28 to enhance the portability of the processor 10.

[0021] An optical system including a laser 30 and a photodetector 32 is associated with the centrifuge 22 and is used to identify and control the location of interfaces between separated blood components within the centrifuge 22. An example optical system is disclosed in U.S. Patent Application Publication No. 2019 / 0201916, the entirety of which is incorporated herein by reference. An optical sensor 34 is also provided and is used to optically monitor one or more conduits leading to and from the centrifuge 22.

[0022] The front of the processing device 10 includes a nesting module 36 for mounting flow control cassettes 50 (FIG. 2) in fluid flow circuit 12 (described in more detail below). Cassette nesting module 36 is configured to accept a variety of disposable cassette designs, allowing the system to perform different types of fluid processing procedures. Included within the illustrated cassette nesting module 36 are valves 38a-d for opening and closing fluid flow paths within flow control cassette 50, and pressure sensors 40a-c capable of measuring pressure at various locations in fluid flow circuit 12.

[0023] 2, the illustrated fluid flow circuit 12 includes a plurality of vessels 42, 44, 46, and 48, a flow control cassette 50, and a processing / separation chamber 52 configured to be received in the centrifuge 22, all interconnected by conduit or tubing segments to enable continuous-flow centrifugation. The flow control cassette 50 directs fluid flow through three tubing loops 54, 56, and 58, each of which is positioned to engage one of the pumps 16, 18, and 20. The conduits or tubing may extend through the cassette 50, or the cassette 50 may have preformed flow paths for directing fluid flow.

[0024] In fluid flow circuit 12 shown in Figure 2, container 42 may be pre-filled with an additive solution, container 44 may be filled with whole blood and connected to fluid flow circuit 12 during use, container 46 may be an empty container for receiving red blood cells (RBCs) separated from the whole blood, and container 48 may be an empty container for receiving plasma separated from the whole blood. While Figure 2 shows whole blood container 44 as the blood source (e.g., configured as a blood pack unit), it is within the scope of this disclosure for the blood source to be a living donor.

[0025] Additionally, fluid flow circuit 12 includes a leukoreduction filter 62 through which blood, such as separated red blood cells, passes before entering red blood cell collection container 46. The fluid flow circuit may optionally include an air trap 60 (shown in FIGS. 3 and 4) through which whole blood passes before entering the separation chamber.

[0026] The processing chamber 52 may be pre-molded into the desired shape and configuration or may be formed by injection molding from a rigid plastic material, as shown and described in U.S. Pat. No. 6,849,039, the entire disclosure of which is incorporated herein by reference. The specific shape of the processing chamber 52 may vary depending on the elements being separated, and the present disclosure is not limited to the use of any particular chamber design. For example, it is within the scope of the present disclosure for the processing chamber 52 to be formed from a generally flexible material rather than a generally rigid material. If the processing chamber 52 is formed from a generally flexible material, the shape of the processing chamber 52 is defined by the centrifuge 22. An example processing chamber and associated centrifuge formed from a flexible material is described in U.S. Pat. No. 6,899,666, the entire disclosure of which is incorporated herein by reference.

[0027] Fluid flow circuit 12 can have a variety of configurations without departing from the scope of this disclosure. The circuit may include additional containers, filters, and / or different configurations of tubing / conduits depending on the processing procedure. For example, for collection of red blood cell, plasma, and buffy coat products, the disposable circuit includes an additional buffy coat collection container 64 (shown in FIGS. 4 and 5). Different configurations of disposable fluid flow circuit 12 and blood processing procedures (including collection of red blood cell and plasma products, collection of red blood cell, plasma, and buffy coat products, and washing of the red blood cell product) are described in more detail in International Patent Publication No. WO 2021 / 194824, incorporated by reference above.

[0028] In accordance with the present disclosure, the controller 13 of the processing device 10 may be preprogrammed to automatically operate the system to perform one or more standard blood processing procedures selected by operator input on the touchscreen 14, and may be further configured to be programmed by the operator to perform additional blood processing procedures. The controller 13 may be preprogrammed to substantially automate various procedures, including, but not limited to, the generation of red blood cells and plasma from a single unit of whole blood, buffy coat pooling, buffy coat separation into a platelet product (as described in U.S. Patent Application Publication No. 2018 / 0078582, the entire disclosure of which is incorporated herein by reference), the addition of glycerol to red blood cells, washing red blood cells, washing platelets, and pooling and separation of cryoprecipitate.

[0029] The pre-programmed blood processing protocol operates the system based on set values ​​for flow rate and centrifugal force, and the programmable control unit 13 may be further configured to accept input from the operator regarding one or more of the flow rate and centrifugal force and override the pre-programmed set values ​​for standard blood processing protocols.

[0030] Additionally, the programmable controller 13 is configured to accept input from an operator via the touch screen 14 to operate the system to perform non-standard blood processing procedures. More specifically, the programmable controller 13 may be configured to accept input from an operator regarding settings (including flow rates and centrifugal forces) for non-standard blood processing procedures.

[0031] Further in accordance with the present disclosure, controller 13 is configured to monitor flow through leukoreduction filter 62 associated with disposable fluid flow circuit 12 and detect and identify causes of flow restriction in leukoreduction filter 62. For example, controller 13 may be associated with pressure sensors 40a-c of processing device 10. In particular, controller 13 receives information from pressure sensors associated with leukoreduction filter 62 of disposable fluid flow circuit 12.

[0032] 3 and 4, pressure sensor 40b is configured to measure the pressure within leukoreduction filter 62. As shown in FIG. 3, pressure sensor 40b may be located downstream of centrifuge 22 and upstream of leukoreduction filter 62. As an example, pressure sensor 40b measures the pressure within a tube / conduit leading to leukoreduction filter 62. The pressure within the tube / conduit correlates with the pressure within leukoreduction filter 62.

[0033] The controller 13 can perform various actions based on the information received from the pressure sensor 40b. For example, the controller may be programmed to automatically switch the flow of separated blood components to bypass the leukoreduction filter 62 for the remainder of the process if the pressure detected within the leukoreduction filter 62 exceeds a predetermined / preprogrammed pressure threshold. Switching the fluid flow to bypass the leukoreduction filter 62 can prevent damage or failure of the leukoreduction filter 62.

[0034] 3 and 4 illustrate an example of fluid flow within fluid flow circuit 12 before and after a threshold pressure within leukocyte reduction filter 62 is exceeded during a blood processing procedure. In particular, FIGS. 3 and 4 illustrate fluid flow circuit 12 in a configuration suitable for red blood cell, plasma, and buffy coat product collection procedures, which is described in more detail in International Patent Publication No. WO 2021 / 194824, previously incorporated by reference. Due to similarities between the fluid flow circuit of FIG. 2 and the fluid flow circuit of FIGS. 3 and 4, components in the fluid flow circuit of FIGS. 3 and 4 that correspond to components described above in the fluid flow circuit of FIG. 2 are labeled with the same reference numerals. However, components that are new or configured differently are labeled with new reference numerals. In summary, the primary difference between the fluid flow circuit of FIG. 2 and the fluid flow circuit of FIGS. 3 and 4 is that fluid flow circuit 12 of FIGS. 3 and 4 includes buffy coat collection container 64 and associated tubing / conduit L9.

[0035] Referring to Figure 3, whole blood is drawn into the fluid flow circuit from a blood source (whole blood container 44 shown in Figure 3) via line L1 by operation of whole blood pump 16. Valve 38c is closed, directing the blood past pressure sensor 40c and into line L2. The blood passes through air trap 60, pressure sensor 40a, and optical sensor 34 before entering processing chamber 52, which is located within centrifuge 22 of processing device 10.

[0036] During the separation process, the centrifuge is rotated at a rotational speed (for example, in the range of about 4,500 to 5,500 rpm) sufficient to separate the blood into packed red blood cells and platelet-poor plasma and form a buffy coat between the two.

[0037] Once steady-state separation is established, controller 13 advances the procedure to the collection step. The valve system of the processor is activated and controlled to direct the separated plasma and red blood cells to their respective containers. During this time, additional whole blood may be drawn into fluid flow circuit 12 until a total of one unit of whole blood has been drawn into fluid flow circuit 12. Clamp 24b may be closed, and the buffy coat may remain in processing chamber 52 during the collection step.

[0038] Specifically, during the collection step, valve 38c is closed, causing whole blood pump 16 to draw additional blood from the blood source through line L1 and direct it from line L1 to line L2. The blood passes through air trap 60, pressure sensor 40a, and optical sensor 34 before entering processing chamber 52, where it is separated into plasma, red blood cells, and buffy coat.

[0039] The separated plasma exits the processing chamber 52 via the plasma outlet and associated line L3. With valve 38a closed, pump 18 directs the plasma from line L3 to line L7, through open clamp 24c, and into the plasma collection container 48.

[0040] The separated red blood cells are discharged from the processing chamber 52 via the red blood cell outlet and associated line L4. The additive solution pump 20 is operated by the control unit 13 to draw additive solution (which may be ADSOL® or another additive solution for red blood cells) from the additive solution container 42 via line L10. The red blood cells flowing through line L4 are mixed with the additive solution flowing through line L10 at the junction of lines L4 and L10, and the resulting mixture continues into line L5. When the clamp 24a is open, the mixture is ultimately directed to the red blood cell collection container 46, but first passes through the leukocyte reduction filter 62.

[0041] The leukocyte removal filter 62 is associated with a pressure sensor 40b, which measures the pressure within the leukocyte removal filter 62. The pressure within the leukocyte removal filter 62 may be measured indirectly by measuring the pressure within a line L5 leading to the leukocyte removal filter 62, or the pressure sensor 40b may be configured to directly measure the pressure within the leukocyte removal filter 62. As red blood cells pass through the pressure sensor 40b, the pressure measurement is recorded and stored by the control unit 13.

[0042] Cassette 50, as shown schematically in FIG. 2A, includes multiple internal flow paths (e.g., L1-L5, L7-L8, and L10-L12). Cassette 50 includes a flexible polymer sheet or membrane on at least one side, isolating the internal flow paths and other components from the valves and sensors of cassette nesting module 36. As noted above, pressure sensor 40b detects pressure in flow path L5, more specifically, leukocyte reduction filter 62. (As shown in FIG. 2A, lines L4 and L5 are fluidly connected. When these lines are filled with an incompressible fluid, such as one containing separated blood components, pressure changes caused by flow restriction in filter 62 in line L5 also occur in line L4, where pressure sensor 40b may be located.)

[0043] Positive pressure can cause the membrane to expand toward the sensor hardware, which may include a force-sensing resistor, load cell, strain gauge, or other suitable means for measuring changes in the force exerted by the membrane on the sensor hardware or changes in membrane displacement due to changes in pressure. Once the system reaches a steady state, the pressure in line L5 typically changes only due to changes in the fluid level in the red blood cell container 46 and changes in filter pressure. Potential hydrostatic pressure changes throughout the procedure are typically small (e.g., less than 15 mmHg after the red blood cell container 46 is full), and such changes can be ignored. Larger pressure changes in line L5 are likely due to changes in the flow path through the leukocyte reduction filter 62.

[0044] When the controller 13 detects that the pressure within the leukocyte reduction filter 62, as measured by pressure sensor 40b, exceeds a predetermined threshold, the controller 13 can automatically configure the system to bypass the leukocyte reduction filter 62, as shown in FIG. 4. The predetermined threshold may be preprogrammed into the controller 13, or the operator may input the value into the system using the touchscreen 14 before the procedure begins. While maintaining valves 38a and 38c closed, the controller 13 activates the device to close valve 38d and open valve 38b. Thus, red blood cells (including additive solution, if present) are switched to flow from line L5 to line L8, through the open valve 38b, and via lines L12 and L11 to the red blood cell container 46.

[0045] The collection process continues until one unit of whole blood has been drawn from the blood source into the fluid flow circuit. If a whole blood container 44 is used as the blood source, as in the illustrated embodiment, the collection process ends when the whole blood container 44 is empty. If the blood source is a live donor (or if the whole blood container 44 contains more than one unit of blood), the volumetric flow rate of the whole blood pump 16 can be used to determine when one unit of whole blood has been drawn into the fluid flow circuit 12.

[0046] Once the collection step is complete, the control unit 13 can transition the system through multiple post-collection steps, including red blood cell recovery, buffy coat collection, additive solution flush, air evacuation, and various post-processing steps, which are described in more detail in International Patent Publication No. WO 2021 / 194824, previously incorporated herein by reference.

[0047] Additionally, the controller may identify the cause or source of the flow limitation. For example, the controller 13 may be configured to identify the cause of flow limitation by comparing pressure sensor data collected during a procedure with known flow limitation profiles, according to method 65 shown in FIG. 5. In particular, during a blood processing procedure, such as the red blood cell, plasma, and buffy coat collection procedures described above, the controller 13 measures and stores the pressure of the leukocyte reduction filter measured by the pressure sensor 40b (step 66). The controller may compare the measurement to a predetermined pressure threshold (step 68). In some embodiments, the predetermined threshold may be preprogrammed into the controller 13, selected by the user, and / or empirically derived from past data and selected or entered by the user. If the measured pressure does not exceed the predetermined threshold, the controller may compare the measured and stored data with a database of known pressure / flow limitation profiles (step 72). If the measured pressure exceeds a predetermined pressure threshold, the controller 13 may automatically configure the system to bypass the fluid flow around the leukoreduction filter 62 (step 70), as described above. After switching the fluid flow, the controller may proceed to step 72 to identify the cause of the increased pressure / flow restriction.

[0048] The controller 13 can access a database of known flow limitation profiles by either pre-programming the database or, optionally, by being configured to access an external database (e.g., located on the Internet or on another storage device) via a wired or wireless connection. When a flow limitation is detected (i.e., when the pressure sensor detects an increase in pressure in the leukocyte reduction filter 62), the controller 13 can compare the stored pressure data with the database to identify the cause of the flow limitation. The system can notify / warn the user of the detected flow limitation and its cause (step 76). For example, information notifying / warning the user of the flow limitation and its cause may be displayed on the touchscreen 14.

[0049] Generally, the leukocyte reduction filter 62 is expected to exhibit a known pressure increase during the course of the filtration process. For example, the pressure is expected to gradually increase over time during the process, as shown in the graph of FIG. 6A. Baseline pressure data such as that shown in FIG. 6A may be included in a database of known flow limitations. Thus, if the controller 13 determines during the process that an increase in leukocyte reduction filter pressure is due to the predicted baseline pressure increase, the controller 13 may continue the process without making any changes.

[0050] As resistance increases due to increased flow restriction, the pressure profile changes. This increased resistance could be caused, for example, by the presence of sickle cells or fibrin clots. Understanding the cause or reason for the flow restriction allows the user / system operator to determine how to proceed with a particular collected component or product. Figure 6B shows an example of a flow restriction profile caused by the presence of sickle cells. The sickle cell profile exhibits a greater increase in pressure over time (indicated by a steeper slope) as an increasing amount of sickle cells are sequestered by the filter. If the system determines that the filter's flow is restricted by sickle cells or another type of anemia, the user will likely discard the unit.

[0051] FIG. 6C illustrates a flow limitation profile caused by a fibrin clot. The fibrin clot profile exhibits a momentary and significant pressure increase from the baseline profile due to the clot entering the filter. If the system determines that the flow limitation is due to a fibrin clot, the user may attempt secondary, offline filtration to recover viable red blood cells. As another example, if the system detects that the flow limitation is due to aggregated platelets, the user may wish to allow the unit to rest for a period of time to allow the platelets to return to a non-aggregated state before attempting secondary, offline filtration.

[0052] Thus, the flow limitation profiles described above may be included in the flow limitation database. Additionally, various other pressure profiles (e.g., exponential, cyclic, etc.) representing known causes of flow limitation may also be included in the flow limitation database without departing from the scope of the disclosure.

[0053] As described herein, a blood processing system including a hardware component 10 with a controller 13 configured to detect a flow restriction, switch fluid flow in response to the detection of the flow restriction, and identify the cause of the flow restriction may be used in combination with a variety of fluid flow circuits to perform a variety of blood processing procedures without departing from the scope of the disclosure.

[0054] [Other aspects] There are additional aspects to the methods and systems described herein, including but not limited to the following aspects.

[0055] Aspect 1: A system for collecting and separating blood components from whole blood, comprising: a disposable fluid flow circuit; and durable hardware components for receiving the disposable fluid flow circuit, the disposable fluid flow circuit comprising a separation chamber, a biological fluid source, a container for receiving separated blood components, a flow path between the separation chamber and the container, and a leukoreduction filter positioned downstream of the separation chamber and upstream of the container, the durable hardware components comprising: a separator configured to receive the separation chamber; and a pressure sensor configured to detect pressure within the leukoreduction filter. The system is configured to automatically operate the system to perform one or more blood processing procedures selected by an operator, and the controller is further configured to receive information from the pressure sensor, measure flow restriction within the leukoreduction filter based on the information from the pressure sensor, and identify the cause of the flow restriction.

[0056] Aspect 2: The system of aspect 1, wherein the control unit is configured to flow the separated blood components through the disposable fluid flow path circuit, and wherein the separated blood components are configured to bypass the leukocyte reduction filter if the control unit measures that the flow restriction exceeds a predetermined threshold.

[0057] Embodiment 3 The system of embodiment 1 or embodiment 2, wherein the control unit is preprogrammed to include pressure information including a baseline filtration profile and profiles representative of other sources of flow limitation.

[0058] Aspect 4 The system of any one of Aspects 1 to 3, wherein the control unit includes a touchscreen, the touchscreen configured to receive input from an operator and display procedural information.

[0059] Aspect 5 The system of any one of Aspects 1 to 4, wherein the pressure sensor is positioned upstream of the leukocyte reduction filter.

[0060] Aspect 6 The system of any one of Aspects 1 to 4, wherein the leukoreduction filter includes a pressure sensor configured to detect the pressure of the separated blood components flowing into the leukoreduction filter.

[0061] Embodiment 7 The system of any one of embodiments 1 to 6, wherein the blood processing procedure includes separating red blood cells, collecting plasma and buffy coat from a unit of whole blood, pooling the buffy coat, separating the buffy coat into a platelet product, adding glycerol to the red blood cells, washing the red blood cells, washing the platelets, and pooling and separating the cryoprecipitate.

[0062] Aspect 8: The system of any one of aspects 3 to 7, wherein the control unit is preprogrammed to include profiles representing other causes of flow limitation, including a sickle cell flow limitation profile and a fibrin clot flow limitation profile.

[0063] Embodiment 9 The system of any one of embodiments 1 to 8, wherein the disposable fluid flow path circuit further comprises a control cassette in fluid communication with the separation chamber.

[0064] Embodiment 10: The durable hardware components include one or more pumps for generating flow through the fluid flow circuit. The system of any one of embodiments 1 to 9.

[0065] Aspect 11: A method for separating whole blood into its constituent blood components, the method comprising: separating the whole blood in a whole blood separation system configured to perform a blood processing procedure and including a leukoreduction filter; measuring the pressure in the leukoreduction filter using a pressure sensor; detecting a flow restriction in the leukoreduction filter based on the pressure in the leukoreduction filter; and restricting or bypassing the flow of the separated blood components to the leukoreduction filter when the pressure in the leukoreduction filter exceeds a predetermined threshold.

[0066] Embodiment 12: The method of embodiment 11, further comprising identifying a cause of the flow limitation.

[0067] Embodiment 13 The method of embodiment 11 or embodiment 12, further comprising storing the pressure measured within the leukocyte depletion filter.

[0068] Example 14 The method of any one of Examples 11 to 13, comprising accessing a database of flow limitation profiles.

[0069] Embodiment 15 The method of any one of embodiments 12 to 14, comprising comparing information from the pressure sensor to a database of flow limitation profiles to identify a cause of the flow limitation.

[0070] Example 16 The method of example 14, wherein the database comprises a flow limitation profile of a sickle cell and a flow limitation profile of a fibrin clot.

[0071] Embodiment 17 The method of any one of embodiments 12 to 16, comprising alerting a user to the cause of the flow limitation.

[0072] Embodiment 18. The method of any one of embodiments 11 to 16, wherein the blood processing procedure comprises separating red blood cells, collecting plasma and buffy coat from a unit of whole blood, pooling the buffy coat, separating the buffy coat into a platelet product, adding glycerol to the red blood cells, washing the red blood cells, washing the platelets, and pooling and separating the cryoprecipitate.

[0073] Example 19 The method of any one of Examples 15 to 17, wherein the database comprises reference flow limitation profiles.

[0074] Embodiment 20. The method of embodiment 19, comprising continuing the blood processing procedure after detecting that the flow limitation is a baseline flow limitation.

[0075] It will be understood that the above-described embodiments and examples are illustrative of some applications or principles of the present subject matter. Numerous modifications, including those involving combinations of features individually disclosed or claimed herein, may be made by those skilled in the art without departing from the spirit and scope of the claimed subject matter. Accordingly, it will be understood that the scope of the present invention is not limited to the above description, but is instead defined by the following claims, which claims are directed to configurations incorporating combinations of features individually disclosed or claimed herein.

Claims

1. a disposable fluid flow circuit and durable hardware components for receiving said disposable fluid flow circuit; The disposable fluid flow circuit comprises: A separation chamber; a biological fluid source; a container for receiving the separated blood components; a flow path between the separation chamber and the container; a leukocyte reduction filter disposed downstream of the separation chamber and upstream of the container; The durability hardware components include: a separator configured to receive the separation chamber; a pressure sensor configured to detect pressure within the leukocyte reduction filter; a controller configured to automatically operate the system to perform one or more blood processing procedures selected by an operator, the controller further configured to receive information from the pressure sensor, measure a flow restriction in the leukocyte reduction filter based on the information from the pressure sensor, and identify a cause of the flow restriction.

2. 2. The system of claim 1, wherein the controller is configured to, when the controller determines that the flow restriction exceeds a predetermined threshold, cause the separated blood components to flow through the disposable fluid flow path circuit such that the separated blood components bypass the leukocyte reduction filter.

3. 3. The system of claim 1 or claim 2, wherein the control unit is preprogrammed to include pressure information including a baseline filtration profile and profiles representative of other sources of flow limitation.

4. the control unit includes a touch screen; The system of claim 1 , wherein the touchscreen is configured to receive input from an operator and display procedural information.

5. The system of claim 1 , wherein the pressure sensor is located upstream of the leukocyte reduction filter.

6. 5. The system of claim 1, wherein the leukocyte reduction filter includes a pressure sensor configured to detect the pressure of the separated blood components flowing into the leukocyte reduction filter.

7. 7. The system of claim 1, wherein the blood processing procedure includes separating red blood cells, collecting plasma and buffy coat from a unit of whole blood, pooling the buffy coat, separating the buffy coat into a platelet product, adding glycerol to the red blood cells, washing the red blood cells, washing the platelets, and pooling and separating the cryoprecipitate.

8. 8. The system of claim 3, wherein the controller is preprogrammed to include profiles representative of other causes of flow limitation, including a sickle cell flow limitation profile and a fibrin clot flow limitation profile.

9. The system of claim 1 , wherein the disposable fluid flow path circuit further comprises a control cassette in fluid communication with the separation chamber.

10. the durable hardware components include one or more pumps for generating flow through the fluid flow circuit; A system according to any one of claims 1 to 9.

11. 1. A method for separating whole blood into its constituent blood components, comprising: separating whole blood in a whole blood separation system configured to perform a blood processing procedure, the whole blood separation system including a leukoreduction filter; measuring the pressure in the leukocyte reduction filter using a pressure sensor; detecting a flow restriction within the leukocyte reduction filter based on a pressure within the leukocyte reduction filter; restricting or bypassing the flow of separated blood components to the leukoreduction filter when the pressure within the leukoreduction filter exceeds a predetermined threshold.

12. The method of claim 11 further comprising identifying the cause of the flow limitation.

13. 13. The method of claim 11 or claim 12, further comprising storing the pressure measured within the leukocyte reduction filter.

14. 14. A method according to any one of claims 11 to 13, including accessing a database of flow restriction profiles.

15. 15. A method according to any one of claims 12 to 14, comprising comparing information from the pressure sensor with the database of flow limitation profiles to identify the cause of the flow limitation.

16. The method of claim 14 , wherein the database includes a flow limitation profile of a sickle cell and a flow limitation profile of a fibrin clot.

17. 17. A method according to any one of claims 12 to 16, including the step of alerting a user to the cause of the flow limitation.

18. 17. The method of any one of claims 11 to 16, wherein the blood processing procedure comprises separating red blood cells, collecting plasma and buffy coat from a unit of whole blood, pooling the buffy coat, separating the buffy coat into a platelet product, adding glycerol to the red blood cells, washing the red blood cells, washing the platelets, and pooling and separating the cryoprecipitate.

19. 18. The method of any one of claims 15 to 17, wherein the database includes reference flow restriction profiles.

20. 20. The method of claim 19, further comprising continuing the blood treatment procedure after detecting that the flow limitation is a baseline flow limitation.

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