The present disclosure relates generally to devices and methods for processing whole blood, and more particularly to devices and methods of separating whole blood into red blood cell and plasma products.
It is well known to collect whole blood from donors using manual collection procedures through blood drives, donor visits to blood centers or hospitals and the like. In such procedures, blood is typically collected by simply flowing it from the donor under the force of gravity and venous pressure into a collection container (e.g., a flexible pouch or bag). Although various blood collection instruments may be used to aid or expedite the collection of blood or blood components.
The collection container in manual collection is often part of a larger pre-assembled arrangement of tubing and containers (sometimes called satellite containers) that are used in further processing of the collected whole blood. More specifically, the whole blood is typically first collected in what is called a primary collection container that also contains an anticoagulant, such as but not limited to a solution of sodium citrate, phosphate, and dextrose (“CPD”).
After initial collection, it is a common practice to transport the collected whole blood to another facility or location, sometimes called a “back lab,” for further processing to separate red blood cells, platelet, and plasma from the whole blood, which may include carrying out additional processes, such as cell washing and plasma cryoprecipitate production and collection. This processing usually entails manually loading the primary collection container and associated tubing and satellite containers into a centrifuge to separate the whole blood into concentrated red cells and platelet-rich or platelet-poor plasma. The separated components may then be expressed from the primary collection container into one or more of the satellite containers, with the red blood cells being combined with an additive or preservative solution pre-filled in one of the satellite containers. After the above steps, the blood components may be again centrifuged, if desired, for example to separate platelets from plasma. The overall process requires multiple large floor centrifuges and fluid expression devices. Because of the multiple operator interactions, the process is labor intensive, time consuming, and subject to human error.
Thus, there have been continuing efforts to automate the apparatus and systems used in the post-collection processing of whole blood, and recently it has been proposed to employ an automated blood component separator for such post-collection processing. The subject matter disclosed herein provides further advances in various aspects of the apparatus, systems and methods that may be employed in whole blood collection and post-collection processing systems by using continuous flow centrifugation in a system that utilizes a programmable controller that is pre-programed to automatically perform selected back lab processes and may also be programmed by the user to meet needs and requirements specific to the user.
There are several aspects of the present subject matter which may be embodied separately or together in the devices, systems, and methods described and/or claimed below. These aspects may be employed alone or in combination with other aspects of the subject matter described herein, and the description of these aspects together is not intended to preclude the use of these aspects separately or the claiming of such aspects separately or in different combinations as set forth in the claims appended hereto or later amended. For purposes of this description and claims, unless otherwise expressly indicated, “blood” is intended to include whole blood and blood components, such as concentrated red cells, plasma, platelets and white cells, whether with or without anticoagulant or additives.
The following summary is to acquaint the reader generally with various potential aspects of the present subject matter, and is non-limiting and non-exclusive with respect to the various possible aspects or combinations of aspects. Additional aspects and features may be found in the detailed description herein and/or in the accompanying figures.
By way of the present disclosure, a method is provided for separating whole blood including executing a priming stage in which a pump system and a valve system of a blood processing device are controlled to prime a processing chamber positioned within a centrifuge of the blood processing device. A blood separation stage is executed in which the pump system, the valve system, and the centrifuge are controlled to separate blood in the processing chamber into at least two blood components. A blood component collection stage is executed in which the pump system and the valve system are controlled to collect at least a portion of one of said at least two blood components. A flow rate stoppage phase is executed to interrupt at least one of the priming, blood separation, and blood component collection stages, the flow rate stoppage phase including: (i) controlling the pumping system and the valve system to prevent fluid flow into and from the processing chamber, (ii) controlling the centrifuge at a selected rate and/or a selected relative centrifugal force; (iii) after a selected time, ending the flow rate stoppage phase; and (iv) resuming the interrupted stage or advancing to a subsequent stage of the method after ending the flow rate stoppage phase.
In another aspect, a blood processing device includes a pump system; a valve system; a centrifuge; and a controller. The controller is configured to execute a blood separation procedure including: executing a priming stage in which the pump system and the valve system are controlled to prime a processing chamber positioned within the centrifuge; executing a blood separation stage in which the pump system, the valve system, and the centrifuge are controlled to separate blood in the processing chamber into at least two blood components; executing a blood component collection stage in which the pump system and the valve system are controlled to collect at least a portion of one of said at least two blood components; and executing a flow rate stoppage phase to interrupt at least one of the priming, blood separation, and blood component collection stages. The flow rate stoppage phase includes: (i) controlling the pumping system and the valve system to prevent fluid flow into and from the processing chamber, (ii) controlling the centrifuge at a selected rate and/or a selected relative centrifugal force; (iii) after a selected time, ending the flow rate stoppage phase; and (iv) resuming the interrupted stage or advancing to a subsequent stage of the blood separation procedure after ending the flow rate stoppage phase.
These and other aspects of the present subject matter are set forth in the following detailed description of the accompanying drawings.
The embodiments disclosed herein are for the purpose of providing an exemplary description of the present subject matter. They are, however, only exemplary and not exclusive, and the present subject matter may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting the subject matter as defined in the accompanying claims.
The present disclosure is directed to devices and methods for whole blood separation using a centrifuge. The device and method includes one or more flow rate stoppage phases during any of the stages of the separation method. During a flow rate stoppage phase, flow of whole blood to the centrifuge and separated blood components from the centrifuge are stopped. While the flows of the whole blood and separated components are stopped, the centrifuge spins at a selected rate. For example, the centrifuge spins a rate between about 500 RPM and about 5500 RPM. In one alternative, the centrifuge spins at a rate of between about 1500 RPM and about 5000 RPM. In yet another alternative, the centrifuge spins at a rate of about 1500, or about 3500, or about 5000 RPM. Independent from or in addition to the spin rate, the relative centrifugal force (G) may be between about 10 Gs and about 1450 Gs. In other words, the relative centrifugal force may be within this range regardless of the spin rate or size of the centrifuge. In one alternative, the relative centrifugal force may be about 100 Gs, and in another alternative about 1140 Gs. After a selected time, the flow rate stoppage phase ends, flow of blood and blood components to and from the centrifuge resumes and the separation process continues. For example, the selected time may be between about 15 seconds and about 45 seconds. In one alternative, the selected time may be about 30 seconds.
The method disclosed herein may be used with any suitable centrifugal blood separation system and/or process. The system and process described and shown relative to
The method includes flowing whole blood from a blood source to a centrifuge and spinning the centrifuge to separate the whole blood into its components. Optionally, the method also may include one or more of stages such as a blood priming stage, an establish separation stage, a collection stage, an air evacuation stage, an additive solution flush stage, or any other suitable stage or process. Periodically and at least once during any point in the method, a flow rate stoppage phase is initiated. During the flow rate stoppage phase, flow to and from the centrifuge is stopped and the blood within the centrifuge is spun at a desired rate for a desired period of time to allow cells to further separate from the plasma fraction of the blood. The flow stoppage phase may include stopping one or more pumps of a pumping system and/or closing one or more valves of a valve system.
Turing now to
More specifically, the illustrated processing device 10 includes a user input and output touchscreen 14, a pump station or system including a first pump 16 (for pumping, e.g., whole blood), a second pump 18 (for pumping, e.g., plasma) and a third pump 20 (for pumping, e.g., additive solution), a centrifuge mounting station and drive unit 22 (which may be referred to herein as a “centrifuge”), and a valve system which includes any suitable type of valves, such as clamps 24a-c. The touchscreen 14 enables user interaction with the processing device 10, as well as the monitoring of procedure parameters, such as flow rates, container weights, pressures, etc. The pumps 16, 18, and 20 (collectively referred to herein as being part of a “pump system” of the processing device 10) are illustrated as peristaltic pumps capable of receiving tubing or conduits and moving fluid at various rates through the associated conduit dependent upon the procedure being performed. An exemplary centrifuge mounting station/drive unit is seen in U.S. Pat. No. 8,075,468 (with reference to
Sterile connection/docking devices may also be incorporated into one or more of the clamps 24a-c. The sterile connection devices may employ any of several different operating principles. For example, known sterile connection devices and systems include radiant energy systems that melt facing membranes of fluid flow conduits, as in U.S. Pat. No. 4,157,723; heated wafer systems that employ wafers for cutting and heat bonding or splicing tubing segments together while the ends remain molten or semi-molten, such as in U.S. Pat. Nos. 4,753,697; 5,158,630; and 5,156,701; and systems employing removable closure films or webs sealed to the ends of tubing segments as described, for example, in U.S. Pat. No. 10,307,582. Alternatively, sterile connections may be formed by compressing or pinching a sealed tubing segment, heating and severing the sealed end, and joining the tubing to a similarly treated tubing segment as in, for example, U.S. Pat. Nos. 10,040,247 and 9,440,396. All of the above-identified patents are incorporated by reference in their entirety. Sterile connection devices based on other operating principles may also be employed without departing from the scope of the present disclosure.
The processing device 10 also includes hangers 26a-d (which may each be associated with a weight scale) for suspending the various containers of the disposable fluid circuit 12. The hangers 26a-d are preferably mounted to a support 28, which is vertically translatable to improve the transportability of the processing device 10. An optical system comprising a laser 30 and a photodetector 32 is associated with the centrifuge 22 for determining and controlling the location of an interface between separated blood components within the centrifuge 22. An exemplary optical system is shown in U.S. Patent Application Publication No. 2019/0201916, which is hereby incorporated herein by reference. An optical sensor 34 is also provided to optically monitor one or more conduits leading into or out of the centrifuge 22.
The face of the processing device 10 includes a nesting module 36 for seating a flow control cassette 50 (
With reference to
In the fluid flow circuit 12 shown in
The processing chamber 52 may be pre-formed in a desired shape and configuration by injection molding from a rigid plastic material, as shown and described in U.S. Pat. No. 6,849,039, which is hereby incorporated herein by reference. The specific geometry of the processing chamber 52 may vary depending on the elements to be separated, and the present disclosure is not limited to the use of any specific chamber design. For example, it is within the scope of the present disclosure for the processing chamber 52 to be configured formed of a generally flexible material, rather than a generally rigid material. When the processing chamber 52 is formed of a generally flexible material, it relies upon the centrifuge 22 to define a shape of the processing chamber 52. An exemplary processing chamber formed of a flexible material and an associated centrifuge are described in U.S. Pat. No. 6,899,666, which is hereby incorporated herein by reference.
In keeping with the disclosure, the controller of the processing device 10 is pre-programmed to automatically operate the system to perform one or more standard blood processing procedures selected by an operator by input to the touchscreen 14, and configured to be further programmed by the operator to perform additional blood processing procedures. The controller may be pre-programmed to substantially automate a wide variety of procedures, including, but not limited to: red blood cell and plasma production from a single unit of whole blood (as will be described in greater detail herein), buffy coat pooling, buffy coat separation into a platelet product (as described in U.S. Patent Application Publication No. 2018/0078582, which is hereby incorporated herein by reference), glycerol addition to red blood cells, red blood cell washing, platelet washing, and cryoprecipitate pooling and separation.
The pre-programmed blood processing procedures operate the system at pre-set settings for flow rates and centrifugation forces, and the programmable controller may be further configured to receive input from the operator as to one or more of flow rates and centrifugation forces for the standard blood processing procedure to override the pre-programmed settings.
In addition, the programmable controller is configured to receive input from the operator through the touchscreen 14 for operating the system to perform a non-standard blood processing procedure. More particularly, the programmable controller may be configured to receive input for settings for the non-standard blood processing procedure, including flow rates and centrifugation forces.
In an exemplary procedure, the processing device 10 and the fluid flow circuit 12 may be used in combination to process a unit of whole blood into a red blood cell product and a plasma product in accordance with the method disclosed herein.
In an initial stage, which is referred to herein as a “blood prime” stage and shown in
During the blood prime stage, whole blood is drawn into the fluid flow circuit 12 from the blood source (the whole blood container 44 in the embodiment of
The centrifuge 22 may be stationary during the blood prime stage or may instead be controlled by the controller of the processing device 10 to spin at a low rotation rate (e.g., on the order of approximately 1,000-2,000 rpm). It may be advantageous for the centrifuge 22 to rotate during the blood prime stage in order to create enough g-force to ensure that the air in the processing chamber 52 (which includes air already present in the processing chamber 52, along with air moved into the processing chamber 52 from lines L1 and/or L2 by the flow of blood) is forced towards the low-g (radially inner) wall of the processing chamber 52. Higher centrifuge rotation rates, such as 4,500 rpm (which is required for steady state separation, as will be described) may be undesirable as air blocks (in which air gets stuck and cannot be forced out of the processing chamber 52, causing pressure to rise) are more likely at higher g-forces.
The blood entering the processing chamber 52 will move towards the high-g (radially outer) wall of the processing chamber 52, displacing air towards the low-g wall. A plasma outlet port of the processing chamber 52 is associated with the low-g wall of the processing chamber 52, such that most of the air will exit the processing chamber 52 via the plasma outlet port and associated line L3, although some air may also exit the processing chamber 52 via a red blood cell outlet port associated with the high-g wall of the processing chamber 52.
Valves 38b and 38d are closed, while the second pump 18 (which may be referred to as the “plasma pump”) is active and the third pump 20 (which may be referred to as the “additive pump”) is inactive. Such an arrangement will direct the air exiting the processing chamber 52 via the red blood cell outlet port through associated line L4 and pressure sensor 40b, into line L5 and then into line L6. Valve 38a is open, such that the air flowing through line L6 will meet up with the air flowing through line L3 (i.e., the air that exits the processing chamber 52 via the plasma outlet port). The combined air will flow through line L7 and open clamp 24c, into the plasma collection container 48. It should be understood that, in
The flow of air out of the processing chamber 52 via either outlet port is monitored by the optical sensor 34, which is capable of determining the optical density of the fluid flowing through the monitored lines and discerning between air and a non-air fluid in lines L3 and L4. When a non-air fluid is detected in both lines L3 and L4, the controller of the processing device 10 will end the blood prime stage and move on to the next stage of the procedure. The amount of blood drawn into the fluid flow circuit 12 from the blood source during the blood prime stage will vary depending on a number of factors (e.g., the amount of air in the fluid flow circuit 12), but may be on the order of approximately 50 to 100 mL. The blood prime stage may take on the order of one to two minutes.
Referring to
During the flow rate stoppage phase, the centrifuge 22 is spun at a selected rate and/or at a selected centrifugal force (G). For example, the centrifuge spins at a rate between about 500 RPM and about 5500 RPM. In one alternative, the centrifuge spins at a rate of between about 1500 RPM and about 5000 RPM. In yet another alternative, the centrifuge spins at a rate of about 1500, or about 3500, or about 5000 RPM. Independent from or in addition to the spin rate, the relative centrifugal force may be between about 10 Gs and about 1450 Gs. In one alternative, the relative centrifugal force may be 100 Gs, and in another alternative about 1140 Gs. After a selected time, flow of blood and blood components to and from the centrifuge assembly resumes and the blood separation method continues. For example, at the end of the selected time, the flow rate stoppage phase ends and one or more of pumps 16, 18, 20 may be activated and one or more of the valves 24a, 24c and 38a-38d may be opened to resume flow. When flow resumes, the current stage may resume or the method may be moved on to the next stage of the method. In one alternative, the selected time may be between about 15 seconds and about 45 seconds. In one alternative, the selected time may be about 30 seconds.
The next stage (shown in
As the blood source includes (in the case of a whole blood container) or provides (in the case of a living donor) only a single unit of whole blood (approximately 500 mL), the system must work with a finite fluid volume. To avoid product loss or quality issues, the plasma and red blood cells initially separated from the blood in the processing chamber 52 and removed from the processing chamber 52 are not directed to their respective collection containers, but are instead mixed together to form recombined whole blood and recirculated back into the processing chamber 52.
More particularly, during the establish separation stage, separated plasma will exit the processing chamber 52 via the plasma outlet port and associated line L3. Clamp 24c is closed during this stage, while valve 38a remains open, which directs the plasma from line L3 into line L6. Separated red blood cells exit the processing chamber 52 via the red blood cell outlet port and associated line L4. In the illustrated embodiment, there is no pump associated with line L4, such that the red blood cells exit the processing chamber 52 at a rate that is equal to the difference between the rate of the whole blood pump 16 and the rate of the plasma pump 18. In alternative embodiments, there may be a pump associated with the red blood cell outlet line instead of the plasma outlet line or a first pump associated with the plasma outlet line and a second pump associated with the red blood cell outlet line.
The additive pump 20 is inactive during this stage, thereby directing the red blood cells from line L4 into line L5. The plasma flowing through line L6 is mixed with the red blood cells flowing through line L5 at a junction of the two lines L5 and L6 to form recombined whole blood. Valve 38d is closed, which directs the recombined whole blood into line L8. Valve 38b is also closed, which directs the recombined whole blood from line L8 into line L9 and through open valve 38c. The whole blood pump 16 draws the recombined whole blood into line L2 from line L9 (rather than drawing additional blood into the fluid flow circuit 12 from the blood source), with the recombined blood passing through air trap 60, pressure sensor 40a, and optical sensor 34 before flowing back into the processing chamber 52, where it is again separated into plasma and red blood cells.
The establish separation stage continues until steady state separation has been achieved, which may take on the order of approximately one to two minutes. As used herein, the phrase “steady state separation” refers to a state in which blood is separated into its constituents in the processing chamber 52, with the radial position of the interface between separated components within the processing chamber 52 being at least substantially maintained (rather than moving radially inwardly or outwardly). The position of the interface may be determined and controlled according to any suitable approach, including using an interface detector of the type described in U.S. Patent Application Publication No. 2019/0201916.
Preferably, steady state separation is achieved with the interface between separated components within the processing chamber 52 at a target location. The target location may correspond to the location of the interface at which separation efficiency is optimized, with the precise location varying depending on a number of factors (e.g., the hematocrit of the whole blood). However, in an exemplary embodiment, the target location of the interface may be the position of the interface when approximately 52% of the thickness or width (in a radial direction) of the channel defined by the processing chamber 52 is occupied by red blood cells. In the illustrated embodiment, the position of the interface within the processing chamber 52 may be adjusted by changing the flow rate of the plasma pump 18, with the flow rate being increased to draw more separated plasma out of the processing chamber 52 (which decreases the thickness of the plasma layer within the processing chamber 52) and move the interface toward the low-g wall or decreased to draw less plasma out of the processing chamber 52 (which increases the thickness of the plasma layer within the processing chamber 52) and move the interface toward the high-g wall.
In an exemplary procedure, the controller of the processing device 10 will control the whole blood pump 16 to operate at a constant rate, with the plasma pump 18 initially operating at the same rate, which will quickly increase the thickness of the red blood cell layer within the processing chamber 52 and move the interface toward the low-g wall. The rate of the plasma pump 18 is gradually decreased as the thickness of the red blood cell layer increases and the location of the interface approaches the target location. As described above, the target location of the interface may depend upon the hematocrit of the whole blood, meaning that the rate of the plasma pump 18 (which controls the position of the interface) may also depend on the hematocrit of the whole blood. In one embodiment, this relationship may be expressed as follows:
Theoretical plasma pump rate=whole blood pump rate−((whole blood hematocrit*whole blood pump rate)/hematocrit of separated red blood cells) [Equation 1]
The hematocrit of the whole blood may be measured before the procedure begins or by the optical sensor 34 during the procedure, while the hematocrit of the separated red blood cells may be determined during the procedure by the optical sensor 34 monitoring line L4. In practice, the plasma pump rate will typically not remain at the theoretical rate once steady state separation has been achieved, with the interface at the target location, but rather the plasma pump rate will instead tend to “flutter” around the theoretical rate.
Referring back to
During flow rate stoppage phase, the centrifuge 22 is spun at a selected rate and/or a selected relative centrifugal force. For example, the centrifuge spins a rate between about 500 RPM and about 5500 RPM. In one alternative, the centrifuge spins at a rate of between about 500 RPM and about 5500 RPM. In another alternative, the centrifuge spins at a rate of between about 1500 RPM and about 5000 RPM. In yet another alternative, the centrifuge spins at a rate of about 1500, or about 3500, or about 5000 RPM. Independent from or in addition to the spin rate, the relative centrifugal force may be between about 10 Gs and about 1450 Gs. In one alternative, the relative centrifugal force may be 100 Gs, and in another alternative about 1140 Gs. After a selected time, flow of blood and blood components to and from the centrifuge assembly resumes and the method continues. For example, at the end of the selected time, the flow rate stoppage phase ends and one or more of pumps 16, 18, 20 may be activated and one or more of the valves 24a, 24c and 38a-38d may be opened to resume flow. When flow resumes, the establish separation stage may resume or the procedure may be moved on to the next stage. In one alternative, the selected time may be between about 15 seconds and about 45 seconds. In one alternative, the selected time may be about 30 seconds.
Regardless of the particular manner in which the controller of the processing device 10 executes the establish separation stage and arrives at steady state separation, once steady state separation has been established, the controller ends the establish separation stage and advances the procedure to a “collection” stage, which is illustrated in
More particularly, during the collection stage, valve 38c is closed, which causes the whole blood pump 16 to draw additional blood into line L1 from the blood source (which is the whole blood container 44 in the illustrated embodiment, but may be a living donor). The whole blood pump 16 draws the blood from the blood source into line L2 from line L1, with the blood passing through air trap 60, pressure sensor 40a, and optical sensor 34 before flowing into the processing chamber 52, where it is separated into plasma and red blood cells. Most of the platelets of the whole blood will remain in the processing chamber 52, along with some white blood cell populations (much as mononuclear cells), while larger white blood cells, such as granulocytes, may exit with the packed red blood cells.
The separated plasma exits the processing chamber 52 via the plasma outlet port and associated line L3. Valve 38a is closed, which directs the plasma from line L3 into line L7, through open clamp 24c, and into the plasma collection container 48.
As for the separated red blood cells, they exit the processing chamber 52 via the red blood cell outlet port and associated line L4. The additive pump 20 is operated by the controller to draw an additive solution (which is ADSOL® in one exemplary embodiment, but may be some other red blood cell additive) 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 a junction of the two lines L4 and L10 to form a mixture that continues flowing into and through line L5. The mixture is ultimately directed into the red blood cell collection container 46, but may first be conveyed through a leukoreduction filter 62 (if provided), as shown in
In the configuration of
In the configuration of
As described above, the mixture may be routed through the leukoreduction filter 62 at the beginning of the collection stage (as in
Regardless of whether the collected red blood cells have been leukoreduced (or only partially leukoreduced), the collection stage continues until one unit of whole blood has been drawn into the fluid flow circuit 12 from the blood source. In the case of a whole blood container 44 being used as a blood source (as in the illustrated embodiment) the collection stage will end when the whole blood container 44 (which is initially provided with one unit of whole blood) is empty, with different approaches possibly being employed to determine when the whole blood container 44 is empty. For example, in one embodiment, pressure sensor 40c monitors the hydrostatic pressure of the whole blood container 44. An empty whole blood container 44 may be detected when the hydrostatic pressure measured by pressure sensor 40c is at or below a threshold value. Alternatively (or additionally), the weight of the whole blood container 44 may be monitored by a weight scale, with an empty whole blood container 44 being detected when the weight is at or below a threshold value. In the case of a living donor (or in the event that the whole blood container 44 is provided with more than one unit of blood), the volumetric flow rate of the whole blood pump 16 may be used to determine when one unit of whole blood has been drawn into the fluid flow circuit 12.
Referring back to
During flow rate stoppage phase, the centrifuge 22 is spun at a selected rate and/or a selected relative centrifugal force. For example, the centrifuge spins a rate between about 500 RPM and about 5500 RPM. In one alternative, the centrifuge spins at a rate of between about 1500 RPM and about 5000 RPM. In yet another alternative, the centrifuge spins at a rate of about 1500, or about 3500, or about 5000 RPM. Independent from or in addition to the spin rate, the relative centrifugal force (G) may be between about 10 Gs and about 1450 Gs. In one alternative, the relative centrifugal force may be 100 Gs, and in another alternative about 1140 Gs. After a selected time, flow of blood and blood components to and from the centrifuge assembly resumes and the method continues. For example, at the end of the selected time, the flow rate stoppage phase ends and one or more of pumps 16, 18, 20 may be activated and one or more of the valves 24a, 24c and 38a-38d may be opened to resume flow. When flow resumes, the collection stage may resume or the procedure may be moved on to the next stage. In one alternative, the selected time may be between about 15 seconds and about 45 seconds. In one alternative, the selected time may be about 30 seconds.
Once a total of one unit of whole blood has been drawn into the fluid flow circuit 12, the controller will transition the procedure to a “red blood cell recovery” stage, which is shown in
In the illustrated embodiment, the whole blood pump 16 is deactivated, while the plasma pump 18 is operated in a reverse direction (with respect to its direction of operation up to this stage of the procedure). This draws the air from the plasma collection container 48 and into line L7. Valve 38a is closed, while clamp 24c is open, which directs the air through line L7, into and through line L3, and into the processing chamber 52 via the plasma outlet port. On account of the air flowing through the plasma outlet port, it will enter the processing chamber 52 at the low-g side. As additional air is introduced into the processing chamber 52, it will move from the low-g wall towards the high-g wall, thus displacing any liquid content through the red blood cell outlet port at the high-g side and into line L4. During this stage, the centrifuge 22 may be operated at a slower rate (e.g., in the range of approximately 1,000-2,000 rpm) to decrease the risk of an air blockage (as during the blood prime stage).
The additive pump 20 continues its operation, drawing additive solution from the additive solution container 42 and through line L10, to be mixed with the contents of the processing chamber 52 flowing through line L4 at the junction of the two lines L4 and L10. The mixture continues flowing into and through line L5. If the valve system was arranged in the configuration of
Regardless of whether the mixture is filtered, it flows into line L12, through open clamp 24a, and into the red blood cell collection container 46. The red blood cell recovery stage continues until all of the air is removed from the plasma collection container 48. In one exemplary embodiment, the weight of the plasma collection container 48 may be monitored by a weight scale, with an empty plasma collection container 48 being detected when the weight is at or below a threshold value. Other approaches may also be employed to determine when to end the red blood cell recovery stage, such as using the optical sensor 34 to detect plasma flowing through line L3.
Referring back to
During flow rate stoppage phase, the centrifuge 22 is spun at a selected rate and/or a selected relative centrifugal force. For example, the centrifuge spins a rate between about 500 RPM and about 5500 RPM. In one alternative, the centrifuge spins at a rate of between about 1500 RPM and about 5000 RPM. In yet another alternative, the centrifuge spins at a rate of about 1500, or about 3500, or about 5000 RPM. Independent from or in addition to the spin rate, the relative centrifugal force may be between about 10 Gs and about 1450 Gs. In one alternative, the relative centrifugal force may be 100 Gs, and in another alternative about 1140 Gs. After a selected time, flow of blood and blood components to and from the centrifuge assembly resumes and the method continues. For example, at the end of the selected time, the flow rate stoppage phase ends and one or more of pumps 16, 18, 20 may be activated and one or more of the valves 24a, 24c and 38a-38d may be opened to resume flow. When flow resumes, the red blood cell recovery stage may resume or the procedure may be moved on to the next stage. In one alternative, the selected time may be between about 15 seconds and about 45 seconds. In one alternative, the selected time may be about 30 seconds.
Once the red blood cell recovery stage is complete, the procedure will transition to an “additive solution flush” stage. During the additive solution flush stage, additive solution from the additive solution container 42 is conveyed into the red blood cell collection container 46 until a target amount of additive solution is in the red blood cell collection container 46. The only change in transitioning from the red blood cell recovery stage to the additive solution flush stage involves deactivating the plasma pump to prevent plasma from being removed from the plasma collection container 48 (though it is also possible for the additive pump 20 to operate at a different rate). Thus, if the valve system was arranged to direct flow through the leukoreduction filter 62 at the end of the red blood cell recovery stage (as in
The additive solution flush stage will continue until a target amount of additive solution has been added to the red blood cell collection container 46. In one exemplary embodiment, the weight of the additive solution container 42 may be monitored by a weight scale, with a particular change in weight corresponding to the target amount of additive solution having been conveyed to the red blood cell collection container 46. Alternatively (or additionally), the weight of the red blood cell collection container 46 may be monitored by a weight scale, with a particular change in weight corresponding to the target amount of additive solution having been conveyed to the red blood cell collection container 46.
When the additive solution flush stage is complete, the system will transition to an “air evacuation” stage, as shown in
The air evacuation stage will continue until all of the air is removed from the red blood cell collection container 46, which may be determined (for example) by detecting a change in the weight of the red blood cell collection container 46 (e.g., using a weight scale).
Upon completion of the air evacuation stage, any of a number of post-processing stages may be executed. For example,
Aspect 1. A method for separating whole blood, comprising: executing a priming stage in which a pump system and a valve system of a blood processing device are controlled to prime a processing chamber positioned within a centrifuge of the blood processing device; executing a blood separation stage in which the pump system, the valve system, and the centrifuge are controlled to separate blood in the processing chamber into at least two blood components; executing a blood component collection stage in which the pump system and the valve system are controlled to collect at least a portion of one of said at least two blood components; and executing a flow rate stoppage phase to interrupt at least one of the priming, blood separation, and blood component collection stages, the flow rate stoppage phase including: (i) controlling the pumping system and the valve system to prevent fluid flow into and from the processing chamber, (ii) controlling the centrifuge at a selected rate and/or a selected relative centrifugal force; (iii) after a selected time, ending the flow rate stoppage phase; and (iv) resuming the interrupted stage or advancing to a subsequent stage of the method after ending the flow rate stoppage phase.
Aspect 2. The method of Aspect 1, wherein the blood comprises whole blood and the at least two blood components comprise red blood cells and plasma.
Aspect 3. The method of any one of Aspects 1 and 2, wherein the controlling the centrifuge at a selected rate during the flow rate stoppage phase includes spinning at a rate of between 500 and 5500.
Aspect 4. The method of any one of Aspects 1-3, wherein the controlling the centrifuge at a selected rate during the flow rate stoppage phase includes spinning at a rate of about 1500, about 3500 or about 5000.
Aspect 5. The method of any one of Aspects 1-4, wherein the selected time of the flow rate stoppage phase comprises between 15 seconds and 45 seconds.
Aspect 6. The method of any one of Aspects 1-5, wherein the selected time of the flow rate stoppage phase comprises about 30 seconds.
Aspect 7. The method of any one of Aspects 2-6, wherein the blood component collection stage further includes: (i) whole blood being conveyed from a blood source to the processing chamber until a total of one unit of whole blood has been conveyed from the blood source to the processing chamber, and (ii) the centrifuge being controlled to separate the whole blood in the processing chamber into plasma and red blood cells, the separated plasma is conveyed out of the processing chamber and into a plasma collection container, the separated red blood cells are conveyed out of the processing chamber, and an additive solution is conveyed out of an additive solution container of a fluid flow circuit, with the separated red blood cells and the additive solution being combined as a mixture and conveyed into a red blood cell collection container of the fluid flow circuit.
Aspect 8. The method of Aspect 7, further including executing an additive solution flush stage with the pump system and the valve system in which additive solution is conveyed from the additive solution container to the red blood cell collection container until a target amount of additive solution has been conveyed into the red blood cell collection container.
Aspect 9. The method of any one of Aspects 7-8, wherein the fluid flow circuit includes a whole blood container containing one unit of whole blood, and the blood source is the whole blood container.
Aspect 10. The method of any one of Aspects 7-9, wherein said executing blood component collection stage includes measuring a weight of the whole blood container, and ending the blood component collection stage based at least in part on the weight of the whole blood container.
Aspect 11. The method of Aspect 10, wherein the blood source is a living donor.
Aspect 12. The method of any one of Aspects 7-11, wherein said executing the blood component collection stage further includes measuring hydrostatic pressure of the whole blood container, and ending the blood component collection stage based at least in part on the hydrostatic pressure of the whole blood container.
Aspect 13. The method of any one of Aspects 7-12, wherein said executing the blood component collection stage includes conveying the mixture through a leukoreduction filter before being conveyed into the red blood cell collection container during at least a portion of the blood component collection stage.
Aspect 14. The method of any one of Aspects 2-13, wherein the priming stage comprises conveying whole blood from the blood source to a processing chamber to remove air from the processing chamber.
Aspect 15. The method of any one of Aspect 1-14, wherein said executing the priming stage includes monitoring fluid exiting the processing chamber, and ending the priming stage when a non-air fluid is detected exiting the processing chamber.
Aspect 16. The method of any one of Aspect 2-15, wherein the blood separation stage comprises conveying the separated plasma and red blood cells out of the processing chamber and recombing the plasma and red blood cells as recombined whole blood, and conveying the recombined whole blood into the processing chamber.
Aspect 17. The method of any one of Aspects 1-16, further including executing an air flush stage with the pump system and the valve system in which air is conveyed into the processing chamber to convey separated at least one of the separated blood components out of the processing chamber.
Aspect 18. The method of any one of Aspects 1-17, wherein the pump system comprises a plurality of pumps, and executing a flow rate stoppage phase comprises stopping one or more of the plurality of pumps.
Aspect 19. The method of any one of Aspects 1-18, wherein the valve system comprises a plurality of clamps, and executing a flow rate stoppage phase comprises closing one or more of the plurality of clamps.
Aspect 20. The method of any one of Aspects 1-19, wherein in the selected relative centrifugal force is between about 10 Gs and about 1450 Gs.
Aspect 21. The method of any one of Aspects 1-20, wherein the selected relative centrifugal force is about 100 Gs or about 1140 Gs.
Aspect 22. A blood processing device, comprising: a pump system; a valve system; a centrifuge; and a controller, wherein the controller is configured to execute a blood separation procedure including executing a priming stage in which the pump system and the valve system are controlled to prime a processing chamber positioned within the centrifuge; executing a blood separation stage in which the pump system, the valve system, and the centrifuge are controlled to separate blood in the processing chamber into at least two blood components; executing a blood component collection stage in which the pump system and the valve system are controlled to collect at least a portion of one of said at least two blood components; and executing a flow rate stoppage phase to interrupt at least one of the priming, blood separation, and blood component collection stages, the flow rate stoppage phase including: (i) controlling the pumping system and the valve system to prevent fluid flow into and from the processing chamber, (ii) controlling the centrifuge at a selected rate; (iii) after a selected time, ending the flow rate stoppage phase; and (iv) resuming the interrupted stage or advancing to a subsequent stage of the blood separation procedure after ending the flow rate stoppage phase.
Aspect 23. The blood processing device of Aspect 22, wherein the blood comprises whole blood and the at least two blood components comprise red blood cells and plasma.
Aspect 24. The blood processing device of any one of Aspects 22 and 23, wherein the controlling the centrifuge at a selected rate during the flow rate stoppage phase includes spinning at a rate of between 500 and 5500.
Aspect 25. The blood processing device of any one of Aspects 23-24, wherein the controlling the centrifuge at a selected rate during the flow rate stoppage phase includes spinning at a rate of about 1500, about 3500 or about 5000.
Aspect 26. The blood processing device of any one of Aspects 22-25, wherein the selected time of the flow rate stoppage phase comprises between 15 seconds and 45 seconds.
Aspect 27. The blood processing device of any one of Aspects 22-26, wherein the selected time of the flow rate stoppage phase comprises about 30 seconds.
Aspect 28. The blood processing device of any one of Aspects 23-27, wherein the blood component collection stage further includes: (i) whole blood being conveyed from a blood source to the processing chamber until a total of one unit of whole blood has been conveyed from the blood source to the processing chamber, and (ii) the centrifuge being controlled to separate the whole blood in the processing chamber into plasma and red blood cells, the separated plasma is conveyed out of the processing chamber and into a plasma collection container, the separated red blood cells are conveyed out of the processing chamber, and an additive solution is conveyed out of an additive solution container of a fluid flow circuit, with the separated red blood cells and the additive solution being combined as a mixture and conveyed into a red blood cell collection container of the fluid flow circuit.
Aspect 29. The blood processing device of Aspect 28, further including executing an additive solution flush stage with the pump system and the valve system in which additive solution is conveyed from the additive solution container to the red blood cell collection container until a target amount of additive solution has been conveyed into the red blood cell collection container.
Aspect 30. The blood processing device of any one of Aspects 28-29, wherein the fluid flow circuit includes a whole blood container containing one unit of whole blood, and the blood source is the whole blood container.
Aspect 31. The blood processing device of any one of Aspects 28-30, wherein said executing the blood component collection stage includes measuring a weight of the whole blood container, and ending the blood component collection stage based at least in part on the weight of the whole blood container.
Aspect 32. The blood processing device of Aspect 31, wherein the blood source is a living donor.
Aspect 33. The blood processing device of any one of Aspects 28-32, wherein said executing the blood component collection stage further includes measuring hydrostatic pressure of the whole blood container, and ending the blood component collection stage based at least in part on the hydrostatic pressure of the whole blood container.
Aspect 34. The blood processing device of any one of Aspects 28-32, wherein said executing the blood component collection stage includes conveying the mixture through a leukoreduction filter before being conveyed into the red blood cell collection container during at least a portion of the blood component collection stage.
Aspect 35. The blood processing device of any one of Aspects 23-34, wherein the priming stage comprises conveying whole blood from the blood source to a processing chamber to remove air from the processing chamber.
Aspect 36. The blood processing device of any one of Aspect 22-35, wherein said executing the priming stage includes monitoring fluid exiting the processing chamber, and ending the priming stage when a non-air fluid is detected exiting the processing chamber.
Aspect 37. The blood processing device of any one of Aspect 23-36, wherein the blood separation stage comprises conveying the separated plasma and red blood cells out of the processing chamber and recombing the plasma and red blood cells as recombined whole blood, and conveying the recombined whole blood into the processing chamber.
Aspect 38. The blood processing device of any one of Aspects 22-37, further including executing an air flush stage with the pump system and the valve system in which air is conveyed into the processing chamber to convey separated at least one of the separated blood components out of the processing chamber.
Aspect 39. The blood processing device of any one of Aspects 22-8, wherein the pump system comprises a plurality of pumps, and executing a flow rate stoppage phase comprises stopping one or more of the plurality of pumps.
Aspect 40. The blood processing device of any one of Aspects 22-39, wherein the valve system comprises a plurality of clamps, and executing a flow rate stoppage phase comprises closing one or more of the plurality of clamps.
Aspect 41. The blood processing device of any one of Aspects 22-40, wherein in the selected relative centrifugal force is between about 10 Gs and about 1450 Gs.
Aspect 42. The blood processing device of any one of Aspect 22-41, wherein the selected relative centrifugal force is about 100 Gs or about 1140 Gs.
This application claims the benefit and priority of U.S. Provisional Patent Application Ser. No. 63/300,895, filed Jan. 19, 2022, the contents of which are incorporated by reference herein.
Number | Date | Country | |
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63300895 | Jan 2022 | US |