Patent Application
20250222187
The present disclosure relates generally to blood processing systems including a reusable separation device and a disposable fluid circuit. More particularly, the present disclosure relates to a blood processing system for expelling air from multiple product containers.
A wide variety of fluid processing systems are presently in practice and allow for a fluid to be fractionated or separated into its constituent parts. For example, various blood processing systems make it possible to collect particular blood constituents, rather than whole blood, from a blood source. Typically, in such systems, whole blood is drawn from a blood source, the particular blood component or constituent is separated, removed, and collected, and the remaining blood constituents are returned to the blood source in a process commonly referred to as “apheresis.” Removing only particular constituents is advantageous when the blood source is a human donor or patient because potentially less time is needed for the donor's body to return to pre-donation levels and donations can be made at more frequent intervals than when whole blood is collected.
When blood is being collected or separated in an apheresis procedure into its various components (such as red blood cells, plasma, platelet-rich plasma, white blood cells), some amount of air invariably is forced into the collection container for the blood or its separated constituents. As is well known, exposure of blood and blood products to air can result in a degradation of the blood/blood product due to, e.g., clotting, coagulation, etc., as well as create an environment conducive to bacterial growth. Additionally, residual air in the blood product may also adversely affect any subsequent processing of the blood product. Consequently, when blood/blood product is being stored in a container for later treatment extracorporeal or for reinfusion to the donor or transfusion to a patient, it is desirable to minimize, and preferably eliminate, any interface within the storage container between the air and the blood/blood product contained therein.
Typically, the residual air will be expelled from the circuit in a process sometimes referred to as “burping.” In particular, after collection, product containers associated with a disposable fluid circuit may be burped to ensure residual air is not stored in the product container. If a flexible collection container is used, the air in the collection container is burped by manually squeezing the collection container to force the air back into the disposable fluid circuit.
Certain blood processing procedures include collecting multiple units of a separated blood component. During a multiple unit collection, each unit may be collected in a separate product container. In such instances, each product container would be burped individually. Thus, burping procedures can require several steps such as placing the disposable fluid circuit in varying configurations by clamping particular lines/tubes and tilting and/or inverting containers to suitably burp each product container individually.
Therefore, there exists a need for improved disposable fluid circuits and systems to expel air from multiple product containers.
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.
In one aspect, a system for collecting red blood cells is provided. The system includes a reusable separation device, and the separation device includes a separator. The system also includes a disposable fluid circuit. The disposable fluid circuit includes a leukoreduction filter with a leukoreduction filter inlet and a leukoreduction filter outlet. The disposable fluid circuit also includes a first product container including a first product container inlet and a first product container outlet. The first product container inlet is in fluid communication with the leukoreduction filter outlet. The disposable fluid circuit also includes an openable flow control device located between the leukoreduction filter and the first product container. Additionally, the disposable fluid circuit includes a second product container including a second product container inlet and a second product container outlet. The second container outlet is in fluid communication with the leukoreduction filter outlet. The disposable fluid circuit also includes a one-way flow control device located between the leukoreduction filter outlet and the second product container, wherein the one-way flow control device is configured to allow fluid flow from the second product container towards the leukoreduction filter. The disposable circuit additionally includes overflow tubing placing the first product container in direct fluid communication with the second product container.
In another aspect, a method of removing air from multiple containers of a collected red blood cell product is provided. The method includes flowing a double unit of separated red blood cell product through a disposable circuit. The disposable circuit includes a leukoreduction filter with a leukoreduction filter inlet and a leukoreduction filter outlet. The disposable circuit also includes a first product container including a first product container inlet and a first product container outlet, and the first container inlet is in fluid communication with the leukoreduction filter outlet. The disposable fluid circuit also includes an openable flow control device configured to be located between the leukoreduction filter and the first product container. The disposable fluid circuit additionally includes a second product container including a second product container inlet and a second product container outlet, and the second product container outlet is in fluid communication with the leukoreduction filter outlet. Additionally, the disposable fluid circuit includes a one-way flow control device located between the leukoreduction filter outlet and the second product container. The one-way flow control device is configured to allow fluid flow from the second product container towards the leukoreduction filter. The disposable fluid circuit also includes overflow tubing placing the first product container in direct fluid communication with the second product container. The method further includes collecting the separated red blood cell product in the first product container, flowing the separated red blood cell product from the first product container to the second product container via the overflow tubing, stopping flow of the red blood cell product to the first product container with the openable flow control device, and flowing the collected red blood cell product in the second product container towards the leukoreduction filter until the red blood cell product reaches the one-way flow control device.
These and other aspects of the present subject 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.
Generally, the system 10 may include two principal components, a durable and reusable hardware unit (i.e., blood separation device) 12 and a disposable fluid flow circuit 14. The blood separation device 12 includes a separator 16, additional components that control fluid flow through the disposable fluid circuit 14, and a controller 18, which controls and/or directs the operation of the other components of the blood separation device 12 to perform a blood processing and collection procedure selected by the operator.
Referring to
In an embodiment, blood separation device 12 may be a portable device configured to rest on an elevated, generally horizontal support surface, (e.g., a countertop or a tabletop), but it is also within the scope of the present disclosure for the device 12 to include a support base to allow the device to be appropriately positioned and oriented when placed onto a floor or ground surface. While it may be advantageous for the blood separation device 12 to be portable, it is also within the scope of the present disclosure for the blood separation device 12 to be installed in a single location and remain in that location for an extended period of time.
As shown in
Additionally, as described above, separation device 12 includes a controller 18. In an example, the controller 18 can be housed within the separation device 12. Alternatively, the controller 18 can be an external device associated with the separation device 12. The controller 18 controls the interaction between the components of the device 12 and the components of the disposable fluid circuit 14 to perform a blood processing procedure selected by the operator. Furthermore, in some examples, the separation device 12 can include an interactive user interface 19, which allows the operator to view and comprehend information regarding the operation of the system 10. As shown in
Blood separation device 12 also includes a cassette station 20, which is configured to accommodate a cassette of the disposable fluid circuit 14. In one embodiment, the cassette station 20 is similarly configured to the cassette station of U.S. Pat. No. 7,282,154 (which is incorporated herein by reference), but it can be adapted to include additional components and functionality. The cassette station 20 includes a plurality of clamps or valves, which move between a plurality of positions (e.g., between a retracted or lowered position and an actuated or raised position) to selectively contact or otherwise interact with corresponding valve stations of the cassette of the disposable fluid circuit 14. In an example, as shown in
Furthermore, blood separation device 12 can include a variety of sensors configured to monitor the procedures carried out by blood separation device 12. For instance, blood separation device 12 can include weigh stations 22 configured to monitor containers of the disposable fluid circuit 14. As shown in
In use, containers are suspended and/or placed on weigh stations 22. As blood or fluids are received into and/or dispensed from the containers during processing, the weigh stations 22 provide output reflecting weight changes over time. This output is conveyed to the controller 18. The controller 18 processes the incremental weight changes to derive fluid processing volumes. The controller 18 generates signals to control processing events based, in part, upon the derived processing volumes.
Additionally, blood separation device 12 can include other sensors such as flow sensors, temperature sensors, a separation interface sensor, and other suitable sensors to monitor a blood processing procedure without departing from the scope of the disclosure.
Blood separation device 12 can also include other retaining elements configured to hold components of the disposable fluid circuit 14. For example, the blood separation device 12 can include a filter holder 24. For instance, depending on the blood separation procedure, the disposable circuit 14 can include a leukoreduction or other type of filter. Filter holder 24 is configured to hold the filter during a blood separation procedure.
Moreover, the blood separation device 12 includes a product container retaining element 26. In an example, as shown in
The disposable fluid circuit 14 is intended to be a sterile, single use, disposable item. Before beginning a selected blood processing and collection procedure, the operator mounts the various components of the disposable fluid circuit 14 onto device 12 (as
The disposable fluid circuit 14 includes a blood processing chamber, a fluid actuated pump and valve cassette, and an array of associated processing containers and flow tubing coupled to the chamber and cassette. In an example, the disposable fluid circuit 14 includes a blood processing chamber designed for use in association with the separator 16. For instance, the blood processing chamber is loaded into the separation chamber within the separation station 15. In one embodiment, the separator 16 may be a centrifuge. The separation chamber rotates the processing chamber. When rotated the processing chamber centrifugally separates whole blood received from a donor into its component parts, principally, red blood cells, plasma, and intermediate layer called the buffy coat, which is populated by platelets and leukocytes. The configuration of the chamber can vary according to the intended blood separation objectives.
As described above, the disposable fluid circuit also includes a processing cassette, such as a pressure-actuated cassette. In an example, the cassette is the cassette described in U.S. Pat. No. 7,282,154, previously incorporated herein. During a procedure, the cassette is housed within cassette station 20. The cassette provides a centralized, programmable, integrated platform for all pumping and valving functions required for a given blood processing procedure. For example, the cassette includes positive and negative pneumatic pressure, although other types of fluid pressure can be used.
The disposable fluid circuit 14 also includes an array of tubes and containers in flow communication with the cassette and the chamber. The arrangement of tubes and containers can vary according to the processing objectives. For example, the disposable flow circuit can include an array of processing containers such as, but not limited to, an anticoagulant container, a processing fluid (e.g., saline) container, and a plasma collection container, as described in U.S. Pat. No. 7,282,154, which has been previously incorporated by reference herein.
In an example, the system 10 with the disposable fluid circuit 14 is configured to collect a double unit of a separated blood component. Referring to
As shown in
Referring to
Leukoreduction filter 36 can be variously constructed without departing from the scope of the disclosure. For instance, leukoreduction filter 36 can include a housing enclosing a filtration medium that can include a membrane or be made from a fibrous material, such as melt blown or spun bonded synthetic fibers (e.g., nylon or polyester or polypropylene), semi-synthetic fibers, regenerated fibers, or inorganic fibers. If fibrous, the medium removes leukocytes by depth filtration. If a membrane, the medium removes leukocytes by exclusion. The housing can include rigid plastic plates sealed about their peripheries. Alternatively, the housing can comprise flexible sheets of medical grade plastic material, such as polyvinyl chloride plasticized with di-2-ethylhexyl-phtalate (PVC-DEHP).
Product inlet line 34 is further in fluid communication with a branch member 38 including a first branch 38a and a second branch 38b. In an example, branch member 38 can be a Y-connector or a T-connector. In another example, branch member 38 can be branched tubing that is integral with the disposable fluid circuit 14.
First product container 30 is in fluid communication with first branch 38a via first product container tubing 40. More particularly, first product container tubing 40 connects the branch 38a to a first product container inlet 31. Additionally, first product container tubing 40 includes an openable flow control device 42. Openable flow control device 42 is configured to stop fluid flow through first product container tubing 40. In an example, openable flow control device 42 can be, but is not limited to, a clamp, roller clamp, or other suitable openable flow control device.
Similarly, second product container 32 is in fluid communication with second branch 38b via a second product container tubing 44. Second product container tubing 44 connects second branch 38b to a second product container outlet 33. Additionally, second product container tubing 44 includes a one-way flow control device 46. One-way flow control device 46 can be, but is not limited to, a check valve. In one embodiment, one-way flow control device 46 is located between second branch 38b and second product container outlet 33. For example, one-way flow control device 46 is located about 1.5 in. from second branch 38b. One-way flow control device 46 is configured to restrict fluid flow from the second branch 38b towards the second product container 32 and allows fluid flow from second product container 32 towards branch member 38.
Disposable fluid circuit 14 further includes overflow tubing 48 connecting first product container 30 to second product container 32 and placing first product container 30 and second product container 32 in direct fluid communication with one another. In particular, overflow tubing 48 connects a first product container outlet 41 to a second product container inlet 43. Excess overflow tubing 48 can be coiled and temporarily attached to itself to ease handling of the disposable fluid circuit 14. For example, excess tubing can be attached to itself with an adhesive tape 49, or other suitable temporary connection. Additionally, overflow tubing 48 can be configured to function as sample collection tubing as will be described herein.
The lengths of the tubing of disposable fluid circuit 14 can vary without departing from the scope of the disclosure. For example, product inlet line 34 between the leukoreduction filter 36 and the branch member 38 can be about 7.125 in., first product container line can be about 10 in., second product container line can be about 9.5 in., and overflow tubing can be about 102.375 in. Additionally, when overflow tubing is sealed and severed to provide sample tubing, each portion of the overflow tubing remaining with either first product container 30 and second product container 32 can be about 51.1875 in.
First product container 30 and second product container 32 can also include various other ports 50. Ports 50 can be used to connect first and second product containers 30, 32 to other tubing, processing circuits, or to access the fluid product within each respective container.
To collect a double unit of red blood cells, disposable fluid circuit 14 is mounted onto the separation device 12. For instance, the processing chamber is loaded into the separation station 15, the cassette is mounted onto cassette station 20, filter 36 is placed into filter holder 24, and various containers are hung or placed on weigh stations 22. Prior to commencing collection, the first and second product containers 30, 32 are placed in association with product container retaining element 26. In particular, the first product container 30 is placed into compartment 28 of retaining element 26 and second product container 32 is hung on hooks 29 of retaining element. When placed in/on product container retaining element 26, the first and second product containers 30, 32 are oriented in an upright configuration such that tubing and ports extend from the top of the containers. Additionally, openable flow control device 42 in the first product container line 40 is placed in an open configuration.
After loading the disposable fluid circuit 14 onto separation device 12, the operator may instruct the pre-programmed controller 18 to carry out a double unit red blood cell collection procedure via interface 19. A more detailed description of loading the disposable fluid circuit 14 and of a double unit red blood cell collection procedure is described in U.S. Pat. No. 7,282,154, which has been incorporated herein.
After whole blood has been separated into its components, a double unit of separated red blood cells can be flowed towards the product containers 30 and 32. In particular, the red blood cells are flowed through product inlet line 34 and through the leukoreduction filter 36 (if present), towards the branch member 38. Because second product container line 44 includes one-way flow control device 46 configured to restrict flow from the second branch 38b towards the second product container 32, the red blood cells flow through branch 38a, through first product container line 40, and into first product container 30.
As the first product container 30 becomes filled, the red blood cells push any residual air out of the first product container 30 and into overflow tubing 48. After the first product container 30 is filled, red blood cells will continue to flow into first product container 30, thus pushing the collected red blood cells (and any residual air) into overflow tubing 48 and into second product container 32.
After second product container 32 is filled with a unit of separated red blood cells, openable flow control device 42 can be placed in a closed configuration to stop fluid flow through first product container line 40. At this point, the second product container 32 can be tilted in a manner to direct residual air in second product container 32 towards the second product container outlet 33 and second product container line 44. Optionally, a second flow control device (not shown), such as, but not limited to, a clamp, can be placed on overflow tubing 48 to restrict fluid flow from the second product container 32 through overflow tubing 48. The second product container 32 can then be (gently) squeezed to expel air out of second product container 32 and into second product container line 44. The second product container 32 is squeezed until the red blood cells reach the one-way flow control device 46, pushing the air through the one-way flow control device 46.
After burping/expelling the air out of the product containers 30 and 32, first product container line 40 and second product container line 44 can be sealed, and the product containers can be removed from the disposable fluid circuit 14. The tubing can be sealed by, for example, welding, heat sealing, or by any other suitable manner. In some instances, the first product container 30 and second product container 32, while still connected by overflow tubing 48, can be hung port-side down (for example, on weigh scales of the separation device 12), allowing for the volume of fluid between the product containers 30, 32 to equalize.
In addition to placing the first product container 30 directly in fluid communication with the second product container 32, overflow tubing 48 can also function as sample collection tubing. After collection, overflow tubing 48 can be sealed and severed at its midpoint, providing the first product container 30 connected to a portion of the overflow tubing 48 and the second product container 32 connected to the remaining portion of the overflow tubing 48. Alternatively, the overflow tubing 48 can be constructed with two printed tube segments joined equidistantly from product containers 30 and 32 with a bushing (not shown). In this instance, the overflow tubing can be sealed and severed at each end of the bushing to provide sample collection tubing connected to the first and second product containers 30, 32.
Not only is disposable fluid circuit 14 configured to expel air from multiple product containers by burping a single product container, but also, disposable fluid circuit 14 reduces the volume of unrecoverable fluid produced during the burping process. In a study, the volume of unrecoverable fluid in a disposable fluid circuit without a one-way flow control device 46 and overflow tubing 48 was compared to the volume of unrecoverable fluid in a disposable fluid circuit 14 as described herein.
As shown in
The study was conducted using the ALYX Centrifugal Blood Processing System sold by Fenwal, Inc. of Lake Zurich, III., disclosed in more detail in U.S. Pat. No. 7,282,154. The separation device was calibrated with calibrated weights and set with the parameters shown in Table 1 below:
The disposable fluid circuit 100 was loaded onto the separation device. A plastic beaker was filled with 750 ml of water and a short AV fistula was placed inside to simulate the venipuncture of a donor's arm. The separation device prompts were then followed to initiate a double red blood cell collection procedure. After the procedure, the disposable fluid circuit 100 was burped. To burp the disposable fluid circuit 100, the flow control device 116a was placed in a closed configuration between the branch member 108 and the leukoreduction filter 110. The flow control devices 116b and 116c located on the first product container line 112 and second product container line 114, respectively, were placed in an open configuration. The first product container 102 was then squeezed to expel air towards the second product container 104 through the first product container line 112 and branch member 108. The first product container 102 was squeezed until the first product container line 112 was filled with fluid up to the branch member 108. The first product container line 112 and second product container line 114 were then shut with the flow control devices 116b and 116c, respectively.
Product inlet line 106 was then sealed with a heat seal 118a between the leukoreduction filter 110 and the branch member 108. In particular, the product inlet line 106 was heat sealed between the branch member 108 and the flow control device 116a. After heat sealing product inlet line 106, the first and second product containers 102, 104 were hung on hangers associated with the separation device and the prompts from the device were followed.
The first product container line 112 and the second product container line 114 were then sealed with a heat seal 118b near the branches 108a and 108b, respectively, and the branch member 108 was removed. Additionally, the second product container line 114 was sealed with a heat seal 118c near the second product container 104 and the heat-sealed segment (from the branch member 108 to the second product container 104) was removed.
Disposable fluid circuit 14, as described herein, was prepared similarly. The disposable fluid circuit 14 was loaded onto the separation device. In particular, the first product container 30 and the second product container 32 were placed in association with product container retaining element 26 as described herein. A plastic beaker was filled with 750 ml of water and a short AV fistula was placed inside to simulate the venipuncture of a donor's arm. The separation device prompts were then followed to initiate a double red blood cell collection procedure. After the procedure, the disposable fluid circuit 14 was burped.
To burp the disposable fluid circuit 14, openable flow control device 42 on first product container line 40 was placed in a closed configuration and the filter holder 24 was opened. The second product container 32 was held at an angle such that any trapped air would move towards the one-way flow control device 46. The second product container 32 was then gently squeezed to expel any air into the leukoreduction filter 36. The second product container 32 was squeezed until the fluid reached the one-way flow control device 46.
The first product container line 40 was then sealed with a heat seal 120b between the first branch 38a and the first product container 30, about 3 inches from branch 38a. The first product container line 40 was further sealed with a heat seal 120a at or near first branch 38a. The heat-sealed segment (from branch 38a to about 3 inches from first branch 38a) was then removed from disposable fluid circuit 14. The second product container line 44 was sealed with a heat seal 120c between the one-way flow control device 46 and the second product container 32 at a location near the one-way flow control device 46 (depicted in
The heat-sealed segments from disposable fluid circuit 100 and disposable fluid circuit 14 were then compared. The lengths and weights of each of the segments were measured and recorded. After obtaining the lengths and weights of the segments, a small portion of each segment was cut on each side of the segments, making sure none of the tubing was lost. An air source was used to expel any fluid out of the segments, and the empty segments were then re-weighed.
Theoretical and actual values of fluid loss were calculated as shown in Tables 2a and 2b below:
As shown in Tables 2a and 2b above, fluid processing with disposable fluid circuit 14 including one-way flow control device 46 and overflow tubing 48 resulted in less fluid loss as compared to the configuration of disposable fluid circuit 100, in terms of grams of fluid expelled from the tubing segments. Fluid loss of disposable fluid circuit 14, as described herein was 0.20 g, while fluid loss from the disposable fluid circuit 100 was 0.90 g, providing a reduction in fluid loss by 77.8%. By including the one-way flow control device 46 in the second product container line 44 in disposable fluid circuit 14, the disposable fluid circuit 14 increases ease of expelling air and reduces fluid loss by eliminating the need to hold the product container(s) at a certain compression and closing of clamp(s) while holding the product container(s) at a particular compression.
There are additional aspects to the methods and systems described herein including, without limitation, the following aspects.
It will be understood that the embodiments and examples described above are illustrative of some of the applications or principles of the present subject matter. Numerous modifications may be made by those skilled in the art without departing from the spirit and scope of the claimed subject matter, including those combinations of features that are individually disclosed or claimed herein. For these reasons, the scope hereof is not limited to the above description but is as set forth in the following claims, and it is understood that the claims may be directed to the features thereof, including as combinations of features that are individually disclosed or claimed herein.
This application claims the benefit of and priority to U.S. Provisional Patent Application Ser. No. 63/617,641, filed Jan. 4, 2024, the disclosure of which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63617641 | Jan 2024 | US |
