System and method for collecting plasma

Abstract

To provide a system and method for collecting a plasma preparation.SOLUTION: A method for collecting plasma includes determining the weight and hematocrit of a donor, and puncturing the donor with a venous-access device. The method includes then withdrawing blood from the donor through a draw line connected to a blood component separation device, and introducing an anticoagulant into the withdrawn blood. The blood component separation device separates the blood into a plasma component and a second blood component, and the plasma component is collected from the blood component separation device into a plasma collection container. The method includes then calculating (1) a percentage of the anticoagulant in the collected plasma component, and (2) a volume of pure plasma collected into the plasma collection container. The volume of pure plasma may be based, at least in part, on the calculated percentage of the anticoagulant. The method may include continuing until a target volume of pure plasma is collected into the plasma collection container.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] This patent application claims priority to U.S. patent application Ser. No. 15 / 608,183, filed May 30, 2017, assigned attorney docket number 1611 / C80, entitled “PLASMA COLLECTION SYSTEM AND DEVICE,” which names Michael Ragusa as an inventor, the disclosure of which is incorporated herein by reference in its entirety.

[0002] The present invention relates to systems and methods for blood apheresis, and more particularly, to systems and methods for collecting plasma products. [Background technology]

[0003] Apheresis is a procedure by which individual blood components can be separated and collected from whole blood temporarily drawn from a subject. Typically, whole blood is drawn through a needle inserted into a vein in the subject's arm into a cell separator, such as a centrifuge bowl. Once the whole blood has been separated into its various components, one or more of the components (e.g., plasma) can be removed from the centrifuge bowl. The remaining components can be returned to the subject, along with optional compensation fluid to make up for the volume of the removed components. The process of removal and return continues until the desired amount of component has been collected, at which point the process is stopped. A central feature of an apheresis system is that the processed but undesired components are returned to the donor. The separated blood components may include, for example, high density components such as red blood cells, intermediate density components such as platelets or white blood cells, and low density components such as plasma.

[0004] Many jurisdictions have regulations regarding the amount of whole blood and / or blood components that may be removed from a donor. For example, the U.S. Food and Drug Administration ("FDA") sets both an upper limit on the volume of plasma that may be collected (e.g., 800 ml for adult males weighing more than 175 pounds) as well as an upper limit on the total collection volume (e.g., 880 ml for adult males weighing more than 175 pounds). Prior art plasma collection systems are unable to determine the total amount of plasma collected (e.g., because the product collected is a mixture of plasma and anticoagulant) and therefore collect based on the total collection volume even if the total amount of plasma collected is less than the limits set by the FDA. Summary of the Invention

[0005] According to some embodiments of the present invention, a plasma collection method includes determining a donor's weight and hematocrit and injecting a venous access device into the donor. Once the venous access device has been inject, the method may draw whole blood from the donor via a draw line connected to the venous access device and a blood component separation device. The method may then introduce an anticoagulant into the drawn whole blood via an anticoagulant line, and may use a blood component separation device to separate the drawn whole blood into a plasma component and at least one second blood component. Once separated, the plasma component may be collected from the blood component separation device into a plasma collection container. During processing, the method may calculate (1) the percentage of anticoagulant in the collected plasma component, and (2) the volume of pure plasma collected in the plasma collection container. The volume of pure plasma may be based, at least in part, on the calculated percentage of anticoagulant in the collected plasma component. The method may continue this process (e.g., drawing whole blood, introducing anticoagulant into the whole blood, separating the blood, collecting the plasma, and calculating the percentage of anticoagulant and the volume of pure plasma) until a volume of pure plasma is collected in the plasma collection container.

[0006] In some embodiments, the method may determine a volume change in an anticoagulant container, and the calculated percentage of anticoagulant in the collected plasma may be based, at least in part, on the volume change in the anticoagulant container. Additionally or alternatively, the method may determine a volume of anticoagulant introduced into the whole blood based on the rotational speed of the anticoagulant pump. In such embodiments, the calculated percentage of anticoagulant in the collected plasma may be based, at least in part, on the rotational speed of the anticoagulant pump. The method may also determine a volume of anticoagulant in a blood component separation device, and the calculated percentage of anticoagulant in the collected plasma may be based, at least in part, on the volume of anticoagulant in the blood component separation device.

[0007] In further embodiments, the method may monitor (e.g., using a weight sensor) the volume and / or weight of the plasma component collected in the plasma collection container, and the calculated volume of pure plasma collected in the plasma collection device may be based, at least in part, on the monitored volume and / or weight of the collected plasma component. Additionally or alternatively, determining the donor's hematocrit may include monitoring the volume of red blood cells collected in the blood separation device. In such embodiments, the determined donor's hematocrit may be based, at least in part, on the monitored volume of red blood cells collected in the blood separation device and the volume of whole blood drawn from the donor.

[0008] The target volume of pure plasma may be based, at least in part, on the weight of the donor. The proportion of the anticoagulant component in the collected plasma may include at least a portion of the anticoagulant introduced into the drawn blood and at least a portion of the volume of anticoagulant added to the system during the priming phase. After collecting at least a portion of the target volume of pure plasma, the method may return the second blood component to the donor via the return line.

[0009] According to additional embodiments, the plasma collection system includes a venous access device for drawing whole blood from a subject and returning blood components to the subject, and a blood component separation device for separating the drawn blood into a plasma component and a second blood component. The blood component separation device has an outlet and is configured to deliver the plasma component to a plasma container. The system may also include a blood draw line fluidly connected to the venous access device and an anticoagulant line connected to a source of anticoagulant. The blood draw line conveys the drawn whole blood to the blood component separation device, and flow through the blood draw line may be controlled by a blood draw pump. The anticoagulant line may introduce an anticoagulant into the drawn whole blood.

[0010] Additionally, the system may include a controller that controls operation of the centrifuge bowl. The controller may also calculate (1) the percentage of the anticoagulant component in the collected plasma, and (2) the volume of pure plasma collected in the plasma container. The volume of pure plasma may be based, at least in part, on the percentage of the anticoagulant component in the collected plasma. The controller may stop the blood draw pump when a target volume of pure plasma (e.g., based, at least in part, on the donor's weight) has been collected in the plasma container. In some embodiments, the percentage of the anticoagulant component in the collected plasma may be based, at least in part, on the volume of anticoagulant added to the collected whole blood and the subject's hematocrit.

[0011] The system may also include an anticoagulant source weight sensor that measures the weight of the anticoagulant source. The controller may monitor a volume change in the anticoagulant container based on the measured weight of the anticoagulant source, and the calculated percentage of anticoagulant in the collected plasma may be based, at least in part, on the volume change in the anticoagulant source. Additionally or alternatively, the controller may monitor the rotational speed of the anticoagulant pump to determine the volume of anticoagulant introduced into the whole blood. In such an embodiment, the calculated percentage of anticoagulant in the collected plasma may be based, at least in part, on the rotational speed of the anticoagulant pump.

[0012] In some embodiments, the system can include an optical sensor disposed in the blood component separation device that can monitor the contents of the blood component separation device and determine whether a volume of anticoagulant remains in the blood component separation device. The calculated percentage of anticoagulant in the collected plasma can be based, at least in part, on the volume of anticoagulant in the blood component separation device.

[0013] In additional embodiments, the system may also include a plasma container weight sensor that monitors the volume and / or weight of the plasma component collected in the plasma collection container. The calculated volume of pure plasma collected in the plasma collection container may be based, at least in part, on the monitored volume and / or weight of the collected plasma component. The system may also include an optical sensor disposed in the blood component separation device. The optical sensor may monitor the volume of red blood cells collected in the blood separation device. The controller may then determine the subject's hematocrit based, at least in part, on the monitored volume of red blood cells collected in the blood separation device and the volume of whole blood collected from the donor. The proportion of the anticoagulant component in the collected plasma may include at least a portion of the anticoagulant introduced into the collected blood and at least a portion of the volume of anticoagulant added to the system during the priming phase. [Brief description of the drawings]

[0014] The foregoing features of the present invention will be more readily understood by consideration of the following detailed description in light of the accompanying drawings, in which:

[0015] FIG. 1 illustrates a schematic perspective view of a blood processing system according to some embodiments of the present invention.

[0016] FIG. 2 illustrates a schematic top view of the blood processing system of FIG. 1 according to some embodiments of the present invention.

[0017] FIG. 3 shows a schematic of a disposable set installed within the blood processing system of FIG. 1 according to some embodiments of the present invention.

[0018] FIG. 4 is a flow chart illustrating a plasma collection method according to an embodiment of the present invention.

[0019] Exemplary embodiments of the present invention provide a blood processing system and method for collecting a target volume of pure plasma. The system and method calculates the percentage of anticoagulant collected in a plasma collection container based on the amount of anticoagulant added to the system and the donor's hematocrit (e.g., in addition to the plasma collected in the container). The system / method then calculates the volume of pure plasma (e.g., plasma without anticoagulant) collected in the container. Details of the exemplary embodiments are described below.

[0020] As shown in Figures 1 and 2, blood processing system 100 includes a cabinet 110 that houses the main components (e.g., non-disposable components) of system 100. Within cabinet 110, system 100 may include a first / blood pump 232 that draws whole blood from a subject, and a second / anticoagulant pump 234 that pumps anticoagulant through system 100 and into the drawn whole blood. In addition, system 100 may include several valves that can be opened and / or closed to control the flow of fluids through system 100. For example, system 100 may include donor valve 120, which may be opened or closed to selectively block or allow fluid flow through donor line 218 (e.g., inlet line; Figure 3), and plasma valve 130, which selectively block or allow fluid flow through outlet / plasma line 222 (Figure 3). Some embodiments may also include a saline valve 135 , which selectively blocks or allows saline to flow through the saline line 223 .

[0021] To facilitate connection and installation of the disposable set and to support corresponding liquid containers, the system 100 may include an anticoagulant pole 150, on which an anticoagulant solution container 210 (FIG. 3) may be suspended, and a saline pole 160, on which a saline solution container 217 (FIG. 3) may be suspended (e.g., if the procedure to be performed requires the use of saline). Additionally, in some applications, it may be necessary and / or desirable to filter whole blood drawn from the subject for processing. To that end, the system 100 may include a blood filter holder 170, in which a blood filter (located in the disposable set) may be placed.

[0022] As described in more detail below, an apheresis system 100 according to an embodiment of the invention uses a blood pump 232 to draw whole blood from a subject via a venous access device 206 (FIG. 3). As the system 100 draws whole blood from the subject, the whole blood flows into a blood component separation device 214, such as a Latham-type centrifuge (other types of separation chambers and devices can be used, including, but not limited to, one-piece blow molded centrifuge bowls such as those described in U.S. Pat. Nos. 4,983,158 and 4,943,273, which are incorporated herein by reference). The blood component separation device 214 separates the whole blood into its components (e.g., red blood cells, white blood cells, plasma, and platelets). Thus, to facilitate operation of the separation device 214, the system 100 may also include a well 180, in which the separation device 214 may be placed and in which the separation device 214 rotates (e.g., to generate the centrifugal force necessary to separate whole blood).

[0023] To enable a user / technician to monitor the operation of the system and control / set various parameters of the procedure, the system 100 may include a user interface 190 (e.g., a touch screen device) that displays the operating parameters, any alarm messages, and buttons that the user / technician can press to control the various parameters. Additional components of the blood processing system 100 are described in more detail below (e.g., in connection with the operation of the system).

[0024] 3 is a schematic block diagram of a blood processing system 100 and a disposable collection set 200 (including an inlet disposable set 200A and an outlet disposable set 200B) that can be loaded onto / into the blood processing system 100 in accordance with the present invention. The collection set 200 includes a venous access device 206 (e.g., a venous needle) for drawing whole blood from a donor's arm 208, an anticoagulant container 210, a centrifuge bowl 214 (e.g., a blood component separator), a saline container 217, and a final plasma collection bag 216. A blood / inlet line 218 connects the venous access device 206 to an inlet port 220 of the bowl 214, a plasma / outlet line 222 connects an outlet port 224 of the bowl 214 to the plasma collection bag 216, and a saline line 223 connects the outlet port 224 of the bowl 214 to the saline container 217. An anticoagulant line 225 connects the anticoagulant container 210 to the inlet line 218. 3, the blood processing system 100 includes a controller 226, a motor 228, and a centrifuge chuck 230. The controller 226 is coupled to operate two pumps 232 and 234, and the motor 228, which in turn drive the chuck 230. The controller 226 may be coupled to operate, and may be in communication with, the user interface 190.

[0025] In operation, disposable collection sets 200 (e.g., inlet disposable set 200A and outlet disposable set 200B) may be loaded onto / into blood processing system 100 prior to blood processing. Specifically, blood / inlet line 218 is routed through blood / first pump 232, and anticoagulant line 225 from anticoagulant container 210 is routed through anticoagulant / second pump 234. Centrifuge bowl 214 may then be fixedly loaded into chuck 230. Once bowl 214 is fixedly positioned, a technician may install outlet disposable set 200B. For example, a technician may connect bowl connector 300 to outlet 224 of bowl 214, place plasma container 216 in weight sensor 195, place saline line 223 through valve 135, and place plasma / outlet line 222 through valve 130 and line sensor 185. Once disposable set 200 is installed and anticoagulant and saline containers 210 / 217 are connected, system 100 is ready to begin blood processing.

[0026] FIG. 4 is a flow chart illustrating an exemplary method for collecting plasma according to various embodiments of the present invention. Prior to connecting a donor to the blood processing device 100, it is beneficial (and in some cases perhaps necessary) to obtain / determine several pieces of information about the donor, namely the donor's weight (step 410) and hematocrit (step 415). Not only does such information help determine whether the individual is suitable to be a donor and the volume of blood components that can be withdrawn / collected (e.g., in accordance with FDA guidelines), but the hematocrit can be used during processing to help collect a target volume of plasma. A technician may obtain / determine the donor's weight by weighing the donor (e.g., on a scale). To obtain / determine the donor's hematocrit, the technician may take a blood sample from the donor and test the blood sample. Additionally or alternatively, the system may determine the hematocrit during blood processing, as described in more detail below. For example, the blood processing device 100 may include a hematocrit sensor (not shown) that determines the hematocrit of blood flowing into the blood processing device 100, and / or the system 100 may determine the hematocrit based on the volume of red blood cells collected in the bowl 214.

[0027] Once the lines 222 / 223 are in place and the technician has determined the donor's weight and / or hematocrit (if necessary), the user / technician may insert the venous access device 206 into the donor's arm 208 (step 420). The controller 226 then activates the two pumps 232, 234 and the motor 228. The activation of these two pumps 232, 234 results in the collection of whole blood from the donor (step 425), the introduction of anticoagulant from the container 210 into the collected whole blood (step 430), and the delivery of the anticoagulated whole blood to the inlet port 220 of the bowl 214.

[0028] It should be noted that the anticoagulant line 225 may also include a bacterial filter (not shown), which prevents any bacteria present in the anticoagulant source 210, the anticoagulant, or the anticoagulant line 225 from entering the system 100 and / or the subject. Additionally, the anticoagulant line 225 may include an air detector 140, which detects the presence of air in the anticoagulant. The presence of air bubbles within any of the system 100 lines can be problematic for the operation of the system 100 and also harmful to the subject if air bubbles get into the bloodstream. Thus, the air detector may be connected to an interlocking device that stops the flow in the anticoagulant line 225 (e.g., by stopping the anticoagulant pump 234) if air bubbles are detected, thereby preventing air bubbles from getting into the subject.

[0029] Once anticoagulated whole blood is drawn from the subject and contained within the blood component separator 214, the blood component separator 214 separates the whole blood into several blood components (step 435). For example, the blood component separator 214 may separate the whole blood into a first, second, third, and possibly a fourth blood component. More specifically, the blood component separator 214 (and the centrifugal force generated by the rotation of the separator 214) may separate the whole blood into plasma, platelets, red blood cells ("RBCs"), and possibly white blood cells ("WBCs"). The denser components, i.e., RBCs, are forced toward the outer walls of the bowl 214, while the less dense plasma resides near the core. Between the plasma and the RBCs, a buffy coat is formed. The buffy coat is made up of an inner layer of platelets, a transition layer of platelets and WBCs, and an outer layer of WBCs. Plasma is the component closest to the exit port and is the first fluid component to exit bowl 214 through exit port 224 as additional anticoagulated whole blood enters bowl 214 through inlet port 220.

[0030] 3, system 100 may also include an optical sensor 213 that may be applied to a shoulder portion of bowl 214 to monitor each layer of blood components as they are gradually advanced coaxially from the outer wall toward the core of bowl 214. Optical sensor 213 may be located in a position (e.g., within well 180) that can detect when the buffy coat and / or red blood cells reach a particular radius, and the steps of withdrawing whole blood from the subject / donor and introducing the whole blood into bowl 12 may be modified and / or terminated in response to the detection.

[0031] Additionally, in some embodiments, optical sensor 213 may be used to determine the donor's hematocrit during processing. For example, if bowl 214 fills with red blood cells and optical sensor 213 detects a layer of red blood cells, system 100 (e.g., a controller) can determine the volume of red blood cells that are within bowl 214 based on the location of the red blood cell layer and the fixed / known bowl volume. System 100 can then calculate the donor's hematocrit based on the volume of red blood cells that are inside the bowl and the volume of whole blood that has been processed to that point.

[0032] Once the blood component separation device 214 has separated the blood into its various components, one or more of the components may be removed from the blood component separation device 214. For example, plasma may be removed (step 440) via line 222 to a plasma container 216 (e.g., a plasma bottle). As mentioned above, some embodiments of the system 100 may include a weight sensor 195 (FIG. 1) that measures the amount of plasma collected. The plasma collection process may continue until a target volume of pure plasma (described in more detail below) is collected in the plasma collection container 216. Although not shown, if the blood processing system 100 and / or disposable set 200 includes a platelet bag, a red blood cell bag, and / or a white blood cell bag, each of these bags / containers may include a similar weight sensor (e.g., a load cell).

[0033] In some embodiments, system 100 may also include line sensor 185 (described above), which can determine the type of fluid (e.g., plasma, platelets, red blood cells, etc.) exiting blood component separation device 214. Specifically, line sensor 185 consists of an LED that emits light that passes through the blood components exiting bowl 214, and a photodetector that receives the light after it has passed through the components. The amount of light received by the photodetector is correlated to the density of the fluid flowing through the line. For example, if plasma is exiting bowl 214, line sensor 185 can detect when the plasma exiting bowl 214 becomes cloudy with platelets (e.g., the fluid exiting bowl 214 is changing from plasma to platelets). System 100 can then use this information to stop the removal of blood components from bowl 214, stop the collection of whole blood from the subject, or change the flow direction, for example, by closing one valve and opening another.

[0034] It is important to note that during processing, the osmotic pressure of red blood cells prevents anticoagulant introduced into the whole blood from entering / remaining within the red blood cells (e.g., in bowl 214). Rather, the anticoagulant mixes with the plasma components. Thus, the anticoagulant flows out of bowl 214 along with the plasma and is collected together with the plasma in collection container 216. In other words, the weight of the product measured by weight sensor 195 is the weight of plasma and any anticoagulant mixed with the plasma - the weight provided by weight sensor 195 is not the weight of pure plasma.

[0035] In addition, the amount of plasma that whole blood contains is variable, as determined by the donor's hematocrit. A typical donor's hematocrit can vary from 38% to 54%, meaning that for 100 ml of whole blood, the volume of plasma can vary from 36 ml to 62 ml. Furthermore, the amount of anticoagulant added to the collected whole blood is fixed (e.g., it is independent of the donor's hematocrit), meaning that for donor hematocrits between 38% and 54%, the percentage of anticoagulant in the collected plasma can vary from 9.7% to 12.7%, respectively. Thus, not only does the volume measured by weight sensor 195 include the volume of anticoagulant, but the volume of anticoagulant can vary from donor to donor based on the hematocrit.

[0036] As discussed above, some embodiments of the present invention continue the blood processing / separation procedure until a target volume of pure plasma (e.g., only plasma, not including any volume of anticoagulant mixed with the plasma) is collected in the plasma collection container 216. To do so, some embodiments of the present invention may calculate the volume of pure plasma in the plasma collection container 216. For example, the technician or the system 100 (e.g., a controller) may calculate the percentage of anticoagulant in the collected plasma (e.g., plasma contained in the plasma collection container 216) based on the amount of anticoagulant added / metered into the whole blood and the donor's hematocrit (step 455). The technician and / or system may calculate the percentage of anticoagulant according to the following formula, where AC is the amount of anticoagulant added to the system 100: As discussed above, the osmotic pressure of red blood cells prevents the anticoagulant from mixing with the red blood cells, so essentially all of the anticoagulant flows out of the bowl 214 and is collected in the plasma collection container 216 along with the plasma.

number

[0037] The amount of anticoagulant added to the system 100 can be determined in a number of ways. For example, the system 100 can base the amount of anticoagulant (e.g., the value of "AC" in the formula above) on a predetermined ratio of anticoagulant per unit of anticoagulated whole blood. In some embodiments, the value of "AC" can be the inverse of this predetermined ratio (e.g., if the ratio of anticoagulant to anticoagulated whole blood is 1:16, then "AC" is 16). Additionally or alternatively, the technician / system 100 can monitor the volume of anticoagulant added to the system. In such an embodiment, the technician / system can monitor the volume of anticoagulant added to the system 100 based on the number of revolutions of the anticoagulant pump (e.g., each revolution of the anticoagulant pump introduces a set volume of anticoagulant into the system 100) and / or based on the change in weight of the anticoagulant container 210 as measured by a weight sensor (described in more detail below).

[0038] Once the technician / system 100 has calculated the percentage of anticoagulant in the plasma collection container 216, the technician / system 100 may then use that information to calculate the volume of pure plasma in the plasma collection container 216 (step 465). For example, the technician / system 100 may determine the volume of anticoagulant in the container (based on the percentage of anticoagulant in the container 216) and subtract this volume from the total volume of fluid in the container 216 measured by the weight sensor 195. The system 100 may continue to monitor the volume of pure plasma collected in the container 216 and may continue to process the whole blood (e.g., continue to perform steps 425, 430, 435, 440, 455, 460, and 465) until a target volume of pure plasma has been collected in the plasma collection container 216 (e.g., 800 ml for an adult male weighing more than 175 pounds, or other limit set by the FDA or similar government agency) (step 470).

[0039] Once system 100 has collected a target volume of pure plasma in plasma collection container 216, system 100 may return the remaining components (e.g., components remaining in bowl 214) to the subject (step 475). For example, once all the plasma has been removed and bowl 214 is filled with RBCs (and any other blood components that were not collected), controller 226 may stop drawing whole blood from the subject and reverse the direction of blood / first pump 232 to draw RBCs (and other components) from bowl 214 and return them directly to the subject. Alternatively, if system 100 is so configured, the system may return the components to the subject via a dedicated return line.

[0040] In addition to blood components that are not collected (e.g., components remaining in bowl 214), system 100 may also return saline to the patient / subject. Saline may be used as a compensation fluid to make up for the volume of blood components (e.g., plasma) that were removed and collected and not returned to the patient. To that end, during the return step (e.g., step 475), saline valve 135 may be opened, thus allowing saline from saline container 217 to flow through saline line 223 and into bowl 214 (via outlet 224), where it can be returned to the patient / donor with or after the remaining blood components.

[0041] It should be noted that in some embodiments, several additional and optional steps may be performed to help determine the volume of pure plasma in the plasma collection container 216. For example, as described above, in some embodiments, the weight change of the anticoagulant container 210 (e.g., as measured by a weight sensor / load cell of the anticoagulant container 210) may be monitored (step 445). This measurement provides an indication of the volume of anticoagulant added to the system 100 and may be used to help determine the proportion of anticoagulant in the plasma collection container 216. Additionally or alternatively, in some embodiments, the change in weight and / or volume of the plasma and anticoagulant collected in the plasma collection container 216 may be monitored (e.g., via the weight sensor 195) (step 450). This measurement may be used to calculate the total volume of pure plasma collected in the plasma collection container 216 (e.g., to obtain a total weight from which to subtract the calculated volume of anticoagulant).

[0042] Some embodiments may also (optionally) monitor the volume of anticoagulant remaining in bowl 214 (e.g., anticoagulant that is not mixed with the plasma and / or otherwise remains in the bowl) (step 460). For example, system 100 may utilize an optical sensor applied to bowl 214 to determine whether any anticoagulant remains in bowl 214. If so, method 400 / system 100 may modify the calculation of the amount of pure plasma collected in the plasma collection container (e.g., increase the calculated amount or decrease the calculated amount) based on the volume of anticoagulant remaining in bowl 214.

[0043] Various embodiments of the present invention provide many advantages over prior art plasma collection systems. In particular, as discussed above, prior art plasmapheresis devices terminate plasma collection based on the total volume of anticoagulated plasma (e.g., pure plasma plus added anticoagulant). While this is the simplest method since it only requires weighing the product collection container, the amount of true product - pure plasma - is dependent on the hematocrit of the donor. In other words, prior art systems collect more plasma from donors with low hematocrits than donors with high hematocrits due to the varying percentage of anticoagulant in the product. Various embodiments of the present invention address this issue in prior art systems by collecting a standard volume (e.g., a target volume) of pure plasma from each donor. As discussed above, embodiments of the present invention accomplish this by using knowledge of the donor's hematocrit and knowledge of the amount of anticoagulant collected in the plasma collection container 216 (e.g., by counting pump revolutions and / or using a weigh scale / weight sensor, etc.) to determine the percentage of anticoagulant in the formulation. Additionally, by stopping the plasma collection process based on the volume of pure plasma collected, embodiments of the present invention are able to collect a greater volume of plasma compared to prior art systems that stop based on a plasma / anticoagulant mixture.

[0044] Also, while the various embodiments described above relate to blood processing systems that collect plasma, it is important to note that the features described herein may be applied to any type of blood processing system. For example, the features described herein may be implemented on blood processing systems that collect and / or process red blood cells, platelets, and / or white blood cells.

[0045] The above-described embodiments of the invention are intended to be merely exemplary; many variations and modifications will be apparent to those skilled in the art. All such variations and modifications are intended to be within the scope of the invention as defined in any appended claims.

Claims

1. 1. A method of collecting plasma comprising: (a) inserting a venous access device into a donor; (b) drawing whole blood from a donor through a venous access device and a draw line, the draw line being fluidly connected to a blood component separation apparatus; (c) introducing an anticoagulant into the collected whole blood via an anticoagulant line; (d) separating the collected whole blood using a blood component separation device into a plasma component and at least a second blood component; (e) collecting the plasma component from the blood component separation device into a plasma collection container; and (f) calculating a volume of pure plasma collected in the plasma collection container based, at least in part, on the volume of the plasma component collected in the plasma collection container, the ratio of anticoagulant added to the collected whole blood, and the donor's hematocrit.

2. The method of claim 1, further comprising calculating the percentage of anticoagulant in the collected plasma component.

3. 3. The method of claim 2, wherein the calculated percentage of anticoagulant in the collected plasma component is based, at least in part, on the proportion of anticoagulant added to the collected whole blood and the hematocrit of the donor.

4. 3. The method of claim 2, wherein the calculated volume of pure plasma collected in the plasma collection container is based, at least in part, on the calculated percentage of anticoagulant in the collected plasma component.

5. 2. The method of claim 1, further comprising calculating a volume of anticoagulant in the collected plasma component based, at least in part, on the hematocrit of the donor, wherein the calculated volume of pure plasma collected in the plasma collection container is based, at least in part, on the calculated volume of anticoagulant in the collected plasma component.

6. 6. The method of claim 5, further comprising determining a volume change in an anticoagulant container, wherein the calculated volume of anticoagulant in the collected plasma component is based at least in part on the volume change in the anticoagulant container.

7. 10. The method of claim 1, further comprising monitoring the volume of plasma component collected in the plasma collection container.

8. 10. The method of claim 1, further comprising monitoring a weight of the plasma component collected in the plasma collection container, wherein the calculated volume of pure plasma collected in the plasma collection device is based, at least in part, on the monitored weight of the collected plasma component.

9. 2. The method of claim 1, further comprising monitoring a volume of red blood cells collected in the blood component separation device, wherein the determined hematocrit of the donor is based at least in part on the monitored volume of red blood cells collected in the blood component separation device and the volume of whole blood drawn from the donor.

10. 10. The method of claim 1, further comprising continuing steps (b) through (f) to collect a target volume of pure plasma and / or a target volume of plasma components in a plasma collection container.

11. 11. The method of claim 10, wherein the target volume of pure plasma and / or the target volume of the plasma component is based, at least in part, on the body weight of the donor.

12. 11. The method of claim 10, further comprising returning the second blood component to the donor via a return line after collecting at least a portion of the target volume of pure plasma and / or the target volume of the plasma component.

13. 1. A plasma collection system comprising: a venous access device for withdrawing whole blood from a subject and returning blood components to the subject; a blood component separation device for separating collected blood into a plasma component and a second blood component, the blood component separation device having an outlet and configured to deliver the plasma component to a plasma collection container; a blood draw line fluidly connected to the venous access device and configured to transport collected whole blood to the blood component separation device, wherein flow through the blood draw line is controlled by a blood draw pump; an anticoagulant line fluidly connected to the anticoagulant source, the anticoagulant line configured to introduce anticoagulant into the collected whole blood; and 1. A system comprising: a controller configured to control operation of a blood component separation device and a blood draw pump, the controller configured to calculate a volume of pure plasma collected in the plasma collection container based, at least in part, on a volume of plasma components collected in the plasma collection container, a ratio of anticoagulant added to the collected whole blood, and a hematocrit of the subject.

14. The system of claim 13 , wherein the controller is further configured to calculate a percentage of anticoagulant in the collected plasma component.

15. 15. The system of claim 14, wherein the calculated percentage of anticoagulant in the collected plasma component is based, at least in part, on the proportion of anticoagulant added to the collected whole blood and the hematocrit of the subject.

16. 15. The system of claim 14, wherein the calculated volume of pure plasma collected in the plasma collection container is based, at least in part, on the calculated percentage of anticoagulant in the collected plasma component.

17. 14. The system of claim 13, wherein the controller is further configured to calculate a volume of anticoagulant in the collected plasma component based, at least in part, on the subject's hematocrit, and wherein the volume of pure plasma collected in the plasma collection container is based, at least in part, on the volume of anticoagulant in the collected plasma component.

18. 20. The system of claim 17, further comprising an anticoagulant source weight sensor configured to measure a weight of the anticoagulant source, the controller further configured to monitor a volume change in the anticoagulant source based on the measured weight of the anticoagulant source, and the calculated volume of anticoagulant in the collected plasma component is based at least in part on the volume change in the anticoagulant source.

19. 14. The system of claim 13, wherein the controller is configured to monitor operation of the anticoagulant pump to determine a total volume of anticoagulant introduced into the system.

20. 14. The system of claim 13, further comprising a plasma collection container weight sensor configured to monitor a volume of plasma component collected in the plasma collection container.

21. 14. The system of claim 13, further comprising a plasma collection container weight sensor configured to monitor a weight of the plasma component collected in the plasma collection container, wherein the calculated volume of pure plasma collected in the plasma collection container is based at least in part on the monitored weight of the collected plasma component.

22. 14. The system of claim 13, wherein the controller is configured to control the plasma collection process to collect a target volume of pure plasma and / or a target volume of plasma components in the plasma collection container.

23. 23. The system of claim 22, wherein the target volume of pure plasma and / or the target volume of the plasma component is based, at least in part, on the subject's body weight.

24. 1. A plasma collection system comprising: a venous access device for withdrawing whole blood from a subject and returning blood components to the subject; a blood component separation device for separating collected blood into a plasma component and a second blood component, the blood component separation device having an outlet and configured to deliver the plasma component to a plasma collection container; a blood draw line fluidly connected to the venous access device and configured to transport collected whole blood to the blood component separation device, wherein flow through the blood draw line is controlled by a blood draw pump; an anticoagulant line fluidly connected to the anticoagulant source, the anticoagulant line configured to introduce anticoagulant into the collected whole blood; and 1. A system comprising: a controller configured to control operation of a blood component separation device and a blood draw pump, the controller configured to calculate a volume of pure plasma to be collected in the plasma collection container based, at least in part, on a volume of plasma component to be collected in the plasma collection container, a ratio of anticoagulant to be added to the collected whole blood, and a hematocrit of the subject.

25. 25. The system of claim 24, wherein the controller is configured to control the plasma collection process to collect a target volume of pure plasma and / or a target volume of plasma components in the plasma collection container.

26. 26. The system of claim 25, wherein the target volume of pure plasma and / or the target volume of the plasma component is based, at least in part, on the subject's body weight.

27. 25. The system of claim 24, wherein the controller is configured to calculate the percentage of anticoagulant collected in the plasma component.

28. 30. The system of claim 27, wherein the calculated percentage of anticoagulant collected in the plasma component is based, at least in part, on the rate of anticoagulant added to the collected whole blood and the hematocrit of the subject.

29. 30. The system of claim 27, wherein the calculated volume of pure plasma to be collected in the plasma collection container is based, at least in part, on the calculated percentage of anticoagulant to be collected in the plasma component.

30. 25. The system of claim 24, wherein the controller is further configured to calculate a volume of anticoagulant collected in the collected plasma component based, at least in part, on the subject's hematocrit, and wherein the volume of pure plasma collected in the plasma collection container is based, at least in part, on the volume of anticoagulant collected in the collected plasma component.

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