Patent Grant
7993050
The present invention relates generally to pumping liquids, and more particularly to a two-stage mixing system, apparatus, and method.
Millions of people receive blood transfusions each year. Although helpful in many cases, blood transfusions have associated risks. Among others, there is a risk that microorganisms capable of causing disease (i.e., pathogens) could pass from the donor blood to the ultimate blood recipient. For example, untreated blood used in a blood transfusion could have pathogens causing the West Nile Virus, or AIDS. It thus is critical for the public health to ensure that transfused blood is substantially free of pathogens.
The medical community has responded to this need by developing various techniques for removing known and unknown pathogens from donated blood. One technique involves mixing precise amounts of a diluted anti-pathogen compound with blood. Some time after mixing, a rinsing process removes the anti-pathogen compound from the blood. One complexity with this process, however, is the fact that the diluted anti-pathogen compound has a very short shelf life (e.g., on the order of about four hours). Accordingly, the diluted anti-pathogen compound must be produced a relatively short time before it is mixed with blood.
The anti-pathogen compound is not easy to handle before it is diluted. To the contrary, it has a very high pH (e.g., on the order of 11.0 or higher) and thus, is highly caustic and toxic. Mere contact with the undiluted solution can melt plastic, or burn flesh. Because of these undesirable properties, the undiluted solution typically is manually diluted by highly trained laboratory technicians that necessarily must be protected from direct contact with it. Consequently, laboratory technicians often are required to wear relatively impermeable protective gear while diluting the solution behind a chemical laminar flowhood. Such a process, however, is inherently slow, imprecise, and costly due to the multitude of safety requirements. Moreover, even with safeguards, diluting the undiluted solution still poses a risk to the laboratory technician.
In accordance with one aspect of the invention there is provided a two-stage mixing process to produce a solution including a first substance and a second substance in a predetermined ratio. In a first stage, the first substance is mixed with a first liquid to produce a first solution. In a second stage, the first solution is mixed with the second substance to produce a second solution. This process is particularly useful for mixing two substances that cannot be mixed directly without damaging one of the substances. The first substance is diluted sufficiently in the first solution for it to be directly mixed with the second substance without damaging either of the substances. In exemplary embodiments of the present invention, the two-stage mixing process is used in a blood processing system to produce a solution including a red blood cell concentrate (RBCC) and an anti-pathogen compound for reducing pathogens in the RBCC.
An exemplary two-stage mixing system includes a primary mixing unit for producing batches of the first solution and at least one secondary mixing unit for producing batches of the second solution. Each batch of first solution produced by the primary mixing unit may be sufficient to prepare multiple batches of second solution. Multiple secondary mixing units may operate in parallel to produce second solution from a single batch of first solution. The multiple secondary mixing units may draw the first solution from a common container.
A process controller is typically used to coordinate and control the mixing operations of the primary and secondary mixing units and the actions of the operator. The process controller may be separate from the mixing units or integrated into one of the mixing units (e.g., the process controller may be integrated into the primary mixing unit). The process controller typically includes a user interface (such as a touch screen) for interacting with the operator. Among other things, the process controller coordinates loading, priming, mixing, teardown, maintenance, and calibration functions.
In accordance with another aspect of the invention there is provided apparatus for combining a first substance with a second substance that cannot be mixed directly with the first substance without damaging at least one of the first substance and the second substance. The apparatus includes a primary mixing unit and a secondary mixing unit. The primary mixing unit mixes the first substance with a first liquid to produce a first solution. The first solution has a first predetermined concentration of first substance capable of being mixed directly with the second substance without damaging one of the first substance and the second substance. The secondary mixing unit mixes the first solution with the second substance to produce a second solution having a second predetermined concentration of first substance relative to the second substance. In an exemplary embodiment of the present invention, the first substance is an anti-pathogen compound that is mixed with a buffer solution, and the second substance is a red blood cell concentrate. Other types of diluting solutions can be used to mix with the first substance. Once mixed, the first solution typically has a limited useable lifetime, in which case the first solution is mixed with the second substance during the useable lifetime of the first solution. The apparatus may also include a process controller for controlling the primary and secondary mixing units and coordinating mixing operations of the primary and secondary mixing units. Among other things, the process controller typically monitors the quantity of first solution and prevents the secondary mixing unit from mixing the first solution with the second substance if there is an insufficient quantity of first solution for preparing the second solution. In order to produce the second solution, the process controller coordinates the primary mixing unit to produce a sufficient quantity of first solution for preparing the second solution.
In accordance with another aspect of the invention there is provided a method for combining a first substance with a second substance that cannot be mixed directly with the first substance without damaging at least one of the first substance and the second substance. The method involves mixing the first substance with a first liquid to produce a first solution so as to have a first predetermined concentration of first substance capable of being mixed directly with the second substance without damaging one of the first substance and the second substance, and mixing the first solution with the second substance to produce a second solution having a second predetermined concentration of first substance relative to the second substance. In an exemplary embodiment of the present invention, the first substance is an anti-pathogen compound that is mixed with a buffer solution, and the second substance is a red blood cell concentrate. Other types of diluting solutions can be used to mix with the first substance. Once mixed, the first solution typically has a limited useable lifetime, in which case the first solution is mixed with the second substance during the useable lifetime of the first solution. The method may also involve monitoring the quantity of first solution and preventing said mixing of the first solution with the second substance if there is an insufficient quantity of first solution for preparing the second solution. In order to produce second solution, the method may involve preparing a sufficient quantity of first solution for preparing the second solution and enabling said mixing of the first solution with the second substance when there is a sufficient quantity of first solution for preparing the second solution.
In accordance with another aspect of the invention there is provided a mixing system including a primary mixing unit for mixing a first substance with a first liquid to produce a first solution, which is stored in a container, and multiple secondary mixing units coupled to the container. Each of the secondary mixing units mixes first solution from the container with a second substance to produce a second solution having a second predetermined concentration of first substance relative to the second substance. In an exemplary embodiment of the present invention, the first substance is an anti-pathogen compound that is mixed with a buffer solution, and the second substance is a red blood cell concentrate. Other types of diluting solutions can be used to mix with the first substance. Once mixed, the first solution typically has a limited useable lifetime, in which case the first solution is mixed with the second substance during the useable lifetime of the first solution. The mixing system may include a process controller for controlling the primary and secondary mixing units and coordinating mixing operations of the primary and secondary mixing units. The process controller typically monitors the quantity of first solution and prevents the secondary mixing units from mixing the first solution with the second substance if there is an insufficient quantity of first solution for preparing the second solution. In order to produce second solutions, the process controller typically coordinates the primary mixing unit to produce a sufficient quantity of first solution for preparing the second solution by the plurality of secondary mixing units. The plurality of secondary mixing units may be coupled to the container of first solution via a single connection to the container. Each of the secondary mixing units typically requires priming with first solution prior to mixing the first solution with the second substance, in which case the process controller coordinates priming of the plurality of secondary mixing units from the container of first solution. The process controller may coordinate priming of the plurality of secondary mixing units symmetrically outward from the middle of the plurality of secondary mixing units. For example, in an embodiment having an odd number of secondary mixing units including a middle unit, the process controller typically begins priming with the middle unit and continues priming outward from the middle unit with successive pairs of units.
The mixing system may include a management rack for holding multiple second substance containers and multiple second solution receptacles for use by the secondary mixing units. The management rack typically includes a multiple compartment tray for holding the plurality of second solution receptacles. The tray is typically removable from the rack and may be stackable with other trays while holding the second solution receptacles.
In order to avoid operator confusion, the process controller typically focuses the operator on one task at a time. The process controller may control at least one visual indicator (e.g., LEDs) on each mixing unit for focusing the operator on one task at a time, and the process controller may provide a graphical display to the operator including a representation of the at least one visual indicator of at least one mixing unit. The process controller may provide a graphical display to the operator including a representation of at least one mixing unit and further including a highlighting icon for indicating any mixing unit associated with the task.
In the accompanying drawings:
Embodiments of the present invention utilize a two-stage mixing process to produce a solution including a first substance and a second substance in a predetermined ratio. In a first stage, the first substance is mixed with a first liquid to produce a first solution. In a second stage, the first solution is mixed with the second substance to produce a second solution. This process is particularly useful for mixing two substances that cannot be mixed directly without damaging one of the substances. The first substance is diluted sufficiently in the first solution for it to be directly mixed with the second substance without damaging either of the substances.
Thus, an exemplary two-stage mixing system includes a primary mixing unit for producing batches of the first solution and at least one secondary mixing unit for producing batches of the second solution. In a typical embodiment of the present invention, each batch of first solution produced by the primary mixing unit is sufficient to prepare multiple batches of second solution. Multiple secondary mixing units may operate in parallel to produce second solution from a single batch of first solution. The multiple secondary mixing units may draw the first solution from a common container.
A process controller is typically used to coordinate and control the mixing operations of the primary and secondary mixing units and the actions of the operator. The process controller may be separate from the mixing units or integrated into one of the mixing units (e.g., the process controller may be integrated into the primary mixing unit). The process controller typically includes a user interface (such as a touch screen) for interacting with the operator. Among other things, the process controller coordinates loading, priming, mixing, teardown, maintenance, and calibration functions, as described below.
In exemplary embodiments of the present invention, the two-stage mixing process is used in a blood processing system to produce a solution including a red blood cell concentrate (RBCC) and an anti-pathogen compound for reducing pathogens in the RBCC. For convenience, this solution may be referred to hereinafter as an “incubation solution.” The anti-pathogen compound is preferably a caustic anti-pathogen compound known as PEN 110™ or INACTINE™, which is an organic solvent with a pH over 11 that is distributed by V.I. Technologies, Inc. of Watertown, Mass. Because of its high pH, this anti-pathogen compound will damage the RBCC if added directly to the RBCC. Therefore, the anti-pathogen compound is first mixed with a buffer solution of sodium phosphate to a predetermined concentration (e.g., 1 part anti-pathogen compound to 99 parts buffer solution) to form an anti-pathogen working solution. For convenience, this mixing of anti-pathogen compound with buffer solution to produce working solution may be referred to hereinafter as “compounding,” and an apparatus that performs such compounding may be referred to hereinafter as a “compounder” or “compounder pump.” The working solution is then mixed with the RBCC to a predetermined concentration (e.g., 1 part working solution to 9 parts RBCC) to form the incubation solution. For convenience, this mixing of working solution with RBCC to produce incubation solution may be referred to hereinafter as “blood processing,” and an apparatus that performs such blood processing may be referred to hereinafter as a “blood pump.” The working solution has a limited useable lifetime, so blood processing is coordinated to occur within the useable lifetime of the working solution. The incubation solution is typically allowed to incubate for some period of time, after which it is rinsed to remove the anti-pathogen compound to produce a pathogen reduced blood product.
System Overview
The compounder pump 102 pumps buffer solution from a buffer solution container 110 into a vial of anti-pathogen compound 108, and the resulting working solution is pumped into a working solution container 112. Each compounding cycle preferably produces a sufficient quantity of working solution for each of the ten blood pumps 104 to run one blood processing cycle. Each of the blood pumps 104 mixes working solution from the working solution container 112 with red blood cell concentrate (RBCC) from a RBCC container 106 to form an incubation solution that is pumped into an incubation bag 118. The blood processing system 100 typically also includes two sterile docks 114 that are used by the operator to splice together plastic tubing as necessary for various blood processing operations. The blood processing system 100 is controlled through a user interface 116.
The process controller 120 coordinates the actions of the compounder pump 102, the blood pumps 104, and the operator throughout the various mixing operations. The process controller 120 initiates high level embedded commands within the pumps to move and mix the fluids. The process controller 120 instructs the operator through the setup and teardown of each process through the user interface 116. The user interface 116 is also used to inform the operator of any anomalies that may occur during mixing operations.
In an exemplary embodiment of the present invention, the process controller 120 coordinates blood processing for an entire bank of five blood pumps 104 at a time. Specifically, the process controller 120 ensures that there is a sufficient quantity of working solution for operating five blood pumps 104, and coordinates preparation of a batch of working solution if there is an insufficient quantity of working solution. The process controller 120 then coordinates operation of a bank of blood pumps 104 for mixing working solution with RBCC from a respective RBCC bag 106. The process controller is described in greater detail below.
Each of the pumps preferably employs disposable pump cassettes that are operated pneumatically. The pump cassette acts as an interface between the liquids being pumped and the pump unit itself so that no liquids come into direct contact with the pump unit. A compounder disposable set includes a single pump cassette coupled through a vial cap to a working solution bag, and is used to pump buffer solution from a buffer solution container through a vial of anti-pathogen compound to the working solution bag. An exemplary compounder disposable set is described in Application D84. A blood disposables set includes five pump cassettes connected to a single working solution inlet tube and to a respective incubation solution bag. The five pump cassettes are installed respectively in the five blood pumps 104 of a bank of blood pumps 104, and are used for mixing working solution with RBCC from a respective RBCC bag 106. An exemplary blood disposables set is described in Application D85.
In order to facilitate blood processing, a portable management rack is typically used to prepare and hold the blood disposables set for use in a bank of blood pumps 104.
In order to prepare for a blood processing cycle, five RBCC bags 106 are hung on the hooks 502, and a blood disposables set is placed in the tray 503. The five RBCC bags 106 are connected respectively to the five pump cassettes using a sterile docking device. This is typically done at a preparation or staging area away from the actual blood processing workstation.
For actual blood processing operations, the management rack is maneuvered in front of a bank of five blood pumps 104, and the locking casters 505 are locked in order to hold the rack 500 in place. The working solution inlet tube of the blood disposables set is connected to the working solution bag using a sterile docking device 114 at the blood processing workstation. The five pump cassettes are loaded respectively into the five blood pumps 104, leaving the incubation bags in the tray 503.
After blood processing operations are complete for a bank of blood pumps, the incubation bags are sealed and separated from the pump cassettes. The management rack 500 can then be wheeled to an incubation or staging area for unloading of the incubation bags. In a typical embodiment of the invention, the entire tray 503 is removed from the rack 500, and the incubation bags remain in the tray 503 during incubation. The trays may be designed to stack with the incubation bags in their respective compartments. Among other things, this stacking reduces the amount of space needed for incubation. The rack 500 is recycled by removing all remaining disposables and installing a new tray 503.
The various components used in the blood processing system are designed specifically to work in certain proximities to one another. For example, it is desirable for the working solution lines between the working solution container and the pump cassettes in each bank of five blood pumps to be relatively short so that the pump cassettes can be efficiently primed and the lines do not contain an excessive amount of residual working solution after blood processing operations are complete. Therefore, the blood pumps 104 in each bank of blood pumps are typically situated in close proximity to one another (e.g., side-by-side), the compounder 102 is typically located between and in close proximity to both banks of blood pumps, and the blood disposables set is designed so that the working solution lines are not excessively long. The sterile docks 114 are typically located on either side of the compounder 102 to facilitate joining the working solution line between the working solution bag and the blood disposables set.
In certain embodiments of the present invention, specialized tables are used to hold the various components of the blood processing workstation. The tables are designed to allow different workstation configurations to be formed using different combinations and orientations of the tables. In an exemplary embodiment of the invention, a workstation is formed from three different tables, specifically a trapezoidal shaped center table and two types of end tables that are essentially mirror images of one another. A single workstation can be formed in a linear (horizontal) configuration or a corner (L-shaped) by merely orienting the end tables differently. Multiple workstations can be combined to form more complex workstation configurations.
Each workstation can be run very efficiently using two people, one to work the staging area preparing the management racks and handling the resulting incubation solutions, and the other to operate the pumps to prepare working solution and incubation solutions. The staging operator prepares management racks by hanging five RBCC bags, placing the incubation bags and pump cassettes respectively in the tray compartments, and connecting each RBCC bag to a corresponding pump cassette. The staging operator wheels the management rack to a workstation operator, who controls compounding and blood process operations. The staging operator can prepare another management rack while the workstation operator is coordinating blood process operations using the previous management rack. When a blood processing cycle is complete, the workstation operator seals the incubation bags and provides the management rack with incubation bags to the staging operator.
Process Controller
As described above, the process controller 120 coordinates the actions of the compounder pump 102, the blood pumps 104, and the operator throughout the various mixing operations. The process controller 120 initiates high level embedded commands within the pumps to move and mix the fluids. The process controller 120 instructs the operator through the setup and teardown of each process through the user interface 116. The user interface 116 is also used to inform the operator of any anomalies that may occur during mixing operations. The process controller 120 preferably coordinates blood processing for an entire bank of five blood pumps 104 at a time.
More specifically, the process controller 120 is the primary interface between the operator and the workstation. The process controller 120 interacts with the operator through the user interface in order to provide information to the operator and received inputs from the operator. The process controller 120 interacts with the pumps to send control commands to the pumps and receive status and alarm information from the pumps. The process controller 120 also receives inputs from the bar code reader and the swipe card reader.
The process controller 120 maintains various timers, including a system time and date, a running timer for the process controller, and various process timers associated with the pumps. When the process controller 120 is powered on, the operator is instructed to confirm the system time and date. The operator is required to restart the process controller if the process controller has been running continuously for more than 48 hours. The process controller 120 keeps track of the age of working solution, and prevents blood processing operations if the working solution becomes too old. Each of the pumps includes a tick counter, and the process controller compares the system clock with the tick counters to verify proper system operation.
The process controller 120 maintains an open-case file for each batch of working solution and for each unit of RBCC processed. The process controller 120 typically creates an open-case file at the time the process controller instructs the operator to load disposables into the pump. For each batch of working solution, the process controller typically maintains in the open-case file such things as a working solution batch identifier, an operator identifier, the serial number of the compounder, the working solution creation time and date (i.e., the time when the compounding operation begins), the status of the compounding operation (success or failure), and any anomalies generated during compounding. For each unit of RBCC, the process controller typically maintains in the open-case file such things as a blood bag identifier, an incubation bag identifier, the serial number of the blood pump, an operator identifier, a working solution batch identifier, the volume of RBCC processed, the volume of working solution delivered, the time and date the blood processing was completed, the status of blood processing (success or failure), and any anomalies generated during blood processing. The process controller verifies and correlates various pieces of information to ensure that the blood processing operations are valid. For example, the process controller typically verifies that all disposables were installed correctly by the operator (e.g., by scanning bar codes on the various bags and pumps, and ensuring that each blood pump is associated with an RBCC bag and an incubation bag having identical identifiers). The process controller stores the open-case files in non-volatile storage, and includes mechanisms for detecting corruption or unauthorized modification of the open-case files.
The process controller 120 also maintains a closed-case file for each batch of working solution and for each unit of RBCC processed. The process controller 120 typically creates an RBC closed-case file when the blood pump disposables are removed from the blood pump, and creates a working solution closed-case file when compounding is complete. For each batch of working solution, the process controller typically maintains in the closed-case file such things as a working solution batch identifier, an operator identifier, the serial number of the compounder, the working solution creation time and date (i.e., the time when the compounding operation begins), the status of the compounding operation (success or failure), and any anomalies generated during compounding. For each unit of RBCC, the process controller typically maintains in the closed-case file such things as a blood bag identifier, an incubation bag identifier, the serial number of the blood pump, an operator identifier, a working solution batch identifier, the volume of RBCC processed, the volume of working solution delivered, the time and date the blood processing was completed, the status of blood processing (success or failure), and any anomalies generated during blood processing. The process controller stores the closed-case files in non-volatile storage, and includes mechanisms for detecting corruption or unauthorized modification of the closed-case files.
The process controller also coordinates workstation operations during exception conditions. For example, when the blood processing system 100 is operating from the uninterruptible power supply 128 and at other appropriate times, the process controller 120 will prevent compounding and other pump operations from starting, although the pumps will generally be allowed to complete any ongoing operations. The pumps have internal logic for safely completing or terminating any ongoing operations in case the process controller fails or communication is lost with the process controller. The process controller provides an emergency stopping mechanism that the operator can invoke to stop all pumping operations (e.g., in case of a fluid leak).
As described above, the process controller 120 includes a user interface for interacting with the operator. The user interface is typically a touch screen that can be used both for displaying information to the operator and receiving inputs from the operator. The operator is typically presented with various menus for controlling workstation operations. A graphical display is also used to help focus the operator on a particular operation.
In an exemplary embodiment of the present invention, the graphical display is logically partitioned into at least two sections (windows). A graphical window is used to show a graphical representation of the status of one or more pumps, including representations of the three LEDs on the front of the pump, the physical configuration of the pump (e.g., whether disposables are loaded), and the status of the pump (e.g., currently pumping). A dialog/status window is used to display operator instructions and pump anomalies and to display the most recent pump command or operator instruction administered by the process controller. The graphical display may include action “buttons” that can be pressed or selected by the operator for performing certain functions (e.g., there may be a button for indicating that an action has been completed by the operator).
In order to focus the operator on a specific task, the process controller is generally able to control the status of the LEDs on the front of the pumps. Specifically, for each LED, the process controller can cause the LED to be turned on, turned off, or flashed at various rates. The LED states for an exemplary embodiment of the present invention are shown in Table 5 below. The process controller typically displays a representation of the pump LEDs on the graphical display so that the representation of the LEDs on the graphical display substantially match the actual status of the pump LEDs. The process controller can manipulate the LEDs on both the pumps and the graphical display to focus the operator on a specific task. For example, if multiple pumps require assistance due to a category 3 anomaly, the process controller can cause only one of those pumps to flash the red LED at a time so that the operator will focus only on one pump at a time.
In order to further focus the operator on a specific task, the graphical display preferably uses a highlighting icon to highlight one or more pumps in the graphical window 901. An exemplary highlighting icon is described in Application D76. The process controller 120 uses the highlighting icon to highlight one or more pumps that require attention. The required action is typically displayed in the dialog/status window 902.
Main Process
Once a compounding or blood processing operation is in process, the process controller typically prevents the operator from accessing the main menu.
If at any time both blood pump banks become idle with no disposables loaded in them, and there is a batch of working solution ready for mixing, then the process controller gives the operator the option to process blood, tear down the compounder disposables, or print closed case files.
Compounding and Blood Processing
The process starts in block 1201. In block 1202, the process controller instructs the operator to load and scan a compounder disposable set. After the compounder disposable set is loaded into the compounder, the process controller instructs the compounder to run a dry cassette integrity test (CIT) in block 1203. Assuming the dry CIT is acceptable, the process controller instructs the operator to hang, scan, and connect the buffer solution bag so that the buffer solution bag is connected to the inlet port of the pump cassette, in block 1204. The process controller then instructs the compounder to prime the compounder disposable set, in block 1205. The process controller then instructs the compounder to run a wet CIT, in block 1206. Assuming the wet CIT is acceptable, the process controller then instructs the operator to scan and load the vial assembly and spike receptacle into the vial spike assembly, in block 1207. The process controller then instructs the compounder to spike the vial, in block 1208. Once spiking is completed, the process controller instructs the compounder to perform the compounding operation, in block 1209.
As discussed above, compounding involves drawing buffer solution from the buffer solution container and pumping the buffer solution to the vial to dilute the anti-pathogen compound and pump the working solution to the working solution container. The compounder measures the volume of buffer solution pumped to the vial so that the resulting working solution will have a predetermined concentration of anti-pathogen compound, within predetermined limits. After compounding is complete, the vial will contain some amount of fluid including buffer solution and perhaps a very small amount of anti-pathogen compound.
After compounding is complete, the process controller coordinates “teardown” of the compounder for removal and disposal of the compounder disposable set from the compounder. Specifically, with reference again to
After compounder “teardown” is complete, the process controller coordinates the blood processing operations in which the RBCC is mixed with working solution by the blood pumps 104 in order to produce the incubation solutions. Specifically, in block 1210, the process controller 120 instructs the operator to load and scan a blood disposables set in one of the banks of blood pumps 104. The process controller 120 may instruct the operator to scan, for each blood pump, the RBCC bag 106, the blood pump 104, and the incubation bag 118. The process controller 120 stores this information so that there is a correlation between each blood pump 104 and the solutions processed and produced by it. This information can be used, for example, to identify all incubation solutions produced by a particular blood pump 104 if the blood pump 104 is found to be defective.
After the blood disposables set is loaded, the process controller 120 instructs the blood pumps 120 to perform a dry CIT, in block 1212. The dry CIT operation is described in more detail with reference to
After the break-away closures are opened, the process controller 120 instructs the blood pumps 104 to mix the RBCC with the working solution to produce the incubation solutions, in block 1219. The blood mixing operation is described in more detail with reference to
After blood mixing is complete, the process controller 120 instructs the operator to heat seal the incubation solution outlet tubes 206, in block 1220, and to heat seal the working solution distribution tubes 212, in block 1221. The process controller 120 then instructs the blood pumps 104 to test the heat seal on the incubation solution outlet tubes 206, in block 1223. Assuming the tubes are sealed, the process controller 120 instructs the blood pumps 104 to release their respective doors, in block 1224. The process controller 120 then instructs the operator to remove the incubation bags 118, in block 1225, and to tear down the blood disposables set, in block 1226.
If there is enough working solution remaining for another blood processing cycle, then the process may recycle to block 1210 to coordinate blood processing operations for another bank of blood pumps. If and when the working solution has expired or there is not enough working solution remaining for another blood processing cycle, then the process controller typically instructs the operator to remove the working solution bag, in block 1236. The process ends in block 1234.
If the bank is configured properly, then a determination is made as to whether there is a sufficient quantity of working solution and a sufficient amount of time for performing the blood processing operation, in block 1404. If there is no working solution, then the compounder setup and process operation is performed as described in Application D70, in block 1408. If there is an insufficient amount of working solution, then the compounder teardown operation is performed as described in Application D70, in block 1405, and, in block 1406, the operator is given the option to either terminate the blood processing operation, in which case the process ends in block 1433, or continue the blood processing operation, in which case the compounder setup and process operation is performed as described in Application D70, in block 1408.
If there is a sufficient quantity of working solution in block 1404, or after working solution is prepared in block 1408, the blood disposables set is loaded into the blood pumps 104. If the occluders are engaged, in block 1409, then the door is unsealed, in block 1410. Once the door is unsealed, the operator is instructed to load the blood disposables set, in block 1411, and to close the door. When the door is confirmed to be closed, in block 1414, the operator is instructed to scan the RBCC bags, blood pumps, and incubation solution bags, in block 1413. When scanning is complete, in block 1414, the blood pumps 104 are instructed to seal their respective doors, in block 1415. If a door is unable to be sealed, then the process enters anomaly handling, in block 1416, which typically includes instructing the operator to reload the pump cassette. If the door is able to be sealed, then the blood pumps 104 are instructed to perform the dry CIT, in block 1417. If the dry CIT fails, then the process enters anomaly handling, in block 1418, which typically involves instructing the operator to reload the pump cassette and running the dry CIT again. If the dry CIT passes, then the operator is instructed to connect the working solution inlet tube 210 to the working solution bag 112 using the sterile dock and to open the break-away closure on the working solution line, in block 1419. The blood pumps 104 are then instructed to perform the priming process, in block 1420. If the priming process fails, then the process enters anomaly handling, in block 1420. If priming is successful, then the blood pumps 104 are instructed to perform the wet CIT, in block 1422. If the wet CIT fails, then the process enters anomaly handling, in block 1423. If the wet CIT passes, then the operator is instructed to open the break-away closures on the RBCC inlet tubes, in block 1424. The blood pumps 104 are then instructed to mix the RBCC and the working solution to form incubation solution, in block 1425. If there is a failure during mixing, then the process enters anomaly handling, in block 1426.
Assuming blood processing is successful, the operator is instructed to heat seal the incubation and working solution lines, in block 1427. The blood units 104 are then instructed to test the seal on the incubation line, in block 1428. If the test fails, then the process enters anomaly handling, in block 1429. Assuming the incubation line is sealed, then the blood pumps 104 are instructed to release their respective doors, in block 1430, after which the operator is instructed to teardown the blood disposables set, in block 1431. A closed-case file is prepared, in block 1432. The process ends in block 1433.
Blood Pump Dry Cassette Integrity Test
The dry cassette integrity test (CIT) is used to identify air leaks in the cassette membranes prior to pumping any fluids. Identifying a cassette with a membrane hole will protect the RBCC from being contaminated by a potentially non-sterile cassette, and will reduce the potential of pumping fluid into the blood unit itself. Also, at the time of the dry CIT, an internal pressure transducer calibration check is performed in order to ensure that none of the transducers have failed or drifted out of calibration. Also during the dry CIT, the fluid valve leading to the air vent on the cassette is tested by closing the valve, pressurizing the pump chamber, and observing the pressure decay.
Blood Pump Priming
The working solution priming process operates on an entire bank of five blood pumps, where all blood pumps share a single working solution line. The working solution priming process is coordinated by the process controller 120 so as to prevent one pump from drawing in air that is being expelled by another pump, specifically by priming the operating the blood pumps symmetrically from the middle blood pump outward. Each blood pump is responsible for detecting “no flow” conditions during priming and also for detecting air in the working solution chamber of the pump cassette 202 after the priming operation is complete. The priming process uses two operations, namely a “put” operation and a “get” operation. The “put” operation involves pumping the contents of the working solution chamber of the pump cassette 202 (air and/or working solution) out through the working solution inlet 304 to the working solution bag, specifically by applying a positive pressure to the working solution chamber. The “get” operation involves drawing from the working solution inlet 304, specifically by applying a negative pressure to the working solution chamber. For convenience, the five blood pumps 104 in a bank are referred to numerically from one to five, where pump three is the middle pump of the bank, pumps two and four are the pumps adjacent to the middle pump, and pumps one and five are the outside pumps.
Blood Pump Wet Cassette Integrity Test
The wet cassette integrity test (CIT) is used to identify defects within the injection-molded body of the cassette. The wet CIT involves testing the functionality of all of the fluid valves within the cassette as well as testing for “cross-talk” between the fluid paths and fluid pump chambers within the cassette. The wet CIT is performed on a partially primed cassette, after priming the working solution pump chamber, but before priming the RBC pump chamber. Therefore, a complete wet CIT is performed on the working solution pump chamber, but the RBC pump chamber is tested using air pressure and decay. Priming and wet testing of the RBC pump chamber is performed during blood mixing, as discussed below.
Compounder Pump Teardown
Compounder Pump Manual Teardown
During normal compounder teardown, the compounder receives commands from the process controller to release pressure against the pump door so that the door can be opened by the operator. The pressure against the door comes from both the door piston bladder and the tubing occluder. While the door piston bladder is pressurized and the tubing occluder is engaged, it is virtually impossible for the operator to open the pump door and remove the pump cassette. If communication between the process controller and the compounder is lost, then the operator will need to relieve this pressure manually in order to remove the cassette. Among other things, this involves the operator pressing the manual door release valve on the back of the pump to deflate the bladder in the door assembly. The operator may also manually retract the occluder if necessary.
Blood Pump Manual Teardown
During normal blood pump teardown, the blood pump 104 receives commands from the process controller 120 to release pressure against the pump door so that the door can be opened by the operator. The pressure against the door comes from both the door piston bladder and the occluders. While the door piston bladder is pressurized and the tubing occluders are engaged, it is virtually impossible for the operator to open the pump door and remove the pump cassette. If communication between the process controller 120 and the blood pump 104 is lost, then the operator will need to relieve this pressure manually in order to remove the cassette. Among other things, this involves the operator pressing the manual door release valve on the back of the pump to deflate the bladder in the door assembly. The operator may also manually retract the occluders if necessary.
Volumetric Calibration
Each pump is typically calibrated periodically to verify its ability to accurately measure volumes of pumped fluids. In exemplary embodiments of the invention, this calibration is done by running test measurements with two different test cassettes having different but known chamber volumes.
Anomaly Handling
In an embodiment of the present invention, there are three categories of anomaly conditions. Category 1 anomalies are fully recoverable anomalies from which it may be possible to resume normal processing if recovery is done in a timely manner. Category 2 anomalies are those from which it is not possible to resume processing blood or working solution without discarding and replacing the disposable set—if mixing has started, then the blood or working solution being processed will be lost. Category 3 anomalies indicate failures that prevent any further processing by the affected subsystem without that workstation subsystem being reset or serviced. In general, the operator is given an opportunity to cancel a process on a pump after a category 1 anomaly is detected on that pump. If a second anomaly occurs while the operator is in the process of mitigating a prior anomaly, then the operator is typically not shown the new anomaly until the process for the prior anomaly has been completed (except for certain category 3 anomalies).
Tables 1-4 describe the handling of various anomaly conditions described with reference to
Table 1 shows anomaly conditions in which there is no immediate loss of working solution or RBCC.
Unseal Compounder Door
Seal Compounder Door
Unseal Compounder Door
Seal Compounder Door
Compounder Dry CIT
Compounder Prime
Compounder Prime
Unseal Blood Pump Door
Seal Blood Pump Door
Unseal Blood Pump Door
Seal Blood Pump Door
Blood Pump Dry CIT
Unseal Blood Pump Door (entire bank)
Wait for Compounder to finish
Repeat Working Solution Prime Sequence (entire
bank)
Repeat Working Solution Prime Sequence (entire
bank)
Unseal Blood Pump Door (entire bank)
Unseal Blood Pump Doors
(Wait for rest of bank to finish blood process)
Unseal Blood Pump Door
Unseal Blood Pump Doors
Mix Blood
(Follow Normal Process Path)
Test Seal On Incubation Bag Line
Table 2 shows anomaly conditions in which there is a loss of working solution.
Table 3 shows anomaly conditions in which there is a loss of RBCC.
(Wait for rest of bank to finish heat-seal test and
tear down with them)
(Wait for rest of bank to finish heat-seal test and
tear down with them)
(Wait for rest of bank to finish heat-seal test and
tear down with them)
(Wait for rest of bank to finish heat-seal test and
tear down with them)
(Wait for rest of bank to finish heat-seal test and
tear down with them)
(Wait for rest of bank to finish heat-seal test and
tear down with them)
(Wait for rest of bank to finish heat-seal test and
tear down with them)
(Follow Normal Process Path)
(Follow Normal Process Path)
(Wait for rest of bank to finish heat-seal test and
tear down with them)
Release Door (whole bank)
Unseal Blood Pump Doors
(Wait for rest of bank to finish heat-seal test and
tear down with them)
(Wait for rest of bank to finish heat-seal test and
tear down with them)
Table 4 shows anomaly conditions in which there is an immediate loss of working solution or RBCC in process on the affected pump.
If bank is in process, wait for rest of bank to finish
heat-seal tests.
If bank is in process, wait for rest of bank to finish
heat-seal tests.
Release Door
Release Door
Upon detection of anomalies, the process controller typically executes the pump LED states shown in Table 5.
In the exemplary embodiments described above, the primary and secondary mixing operations are performed by physically separate mixing units under the control of a separate process controller. It should be noted, however, that the present invention is in no way limited to a mixing system having separate primary and secondary mixing devices operating under control of a separate process controller. Thus, for example, primary and secondary mixing operations could be performed in a single device capable of performing both operations. Also, the process controller functions could be integrated into one of the mixing units such as, for example, the primary mixing unit (e.g., compounder pump).
It should also be noted that the flow diagrams are used herein to demonstrate various aspects of the invention, and should not be construed to limit the present invention to any particular flow or implementation. In some cases, certain process steps can be omitted or performed in a different order than shown without changing the overall results or otherwise departing from the true scope of the invention.
The present invention may be embodied in other specific forms without departing from the true scope of the invention. The described embodiments are to be considered in all respects only as illustrative and not restrictive.
This application is a division of U.S. application Ser. No. 10/696,818 filed on Oct. 30, 2003, now U.S. Pat. No. 7,354,190, issued Apr. 8, 2008, and entitled TWO-STAGE MIXING SYSTEM, APPARATUS, AND METHOD, herein incorporated by reference. The present application may also include subject matter related to one or more of the following commonly-owned United States patent applications or patents, each of which was filed on even date herewith and is hereby incorporated herein by reference in its entirety: U.S. patent application Ser. No. 10/696,969, filed Oct. 30, 2003, published May 5, 2005 as U.S. Publication No. US-2005-0095576, and entitled SYSTEM, DEVICE, AND METHOD FOR MIXING A SUBSTANCE WITH A LIQUID (referred to herein as “Application D70”); U.S. patent application Ser. No. 10/696,893, filed Oct. 30, 2003, now U.S. Pat. No. 7,461,968, issued Dec. 9, 2008 and entitled SYSTEM, DEVICE, AND METHOD FOR MIXING LIQUIDS (referred to herein as “Application D71”); U.S. patent application Ser. No. 10/697,176, filed Oct. 30, 2003, published May 5, 2005 as U.S. Publication No. US-2005-0095141, and entitled SYSTEM AND METHOD FOR PUMPING FLUID USING A PUMP CASSETTE (referred to herein as “Application D73”); U.S. patent application Ser. No. 10/696,984, filed Oct. 30, 2003, published May 5, 2005 as U.S. Publication No. US-2005-0095152, and entitled DOOR LOCKING MECHANISM (referred to herein as “Application D74”); U.S. patent application Ser. No. 10/697,450, filed Oct. 30, 2003, now U.S. Pat. No. 7,632,080, issued Dec. 15, 2009 and entitled BEZEL ASSEMBLY FOR PNEUMATIC CONTROL (referred to herein as “Application D75”); U.S. patent application Ser. No. 29/192,835, filed Oct. 30, 2003 and entitled ICON FOR A PORTION OF A COMPUTER SCREEN, now abandoned (referred to hereinafter as “Application D76”); U.S. patent application Ser. No. 10/697,862, filed Oct. 30, 2003, now U.S. Pat. No. 7,662,139, issued Feb. 16, 2010 and entitled PUMP CASSETTE WITH SPIKING ASSEMBLY (referred to herein as “Application D84”); and U.S. patent application Ser. No. 10/696,990, filed Oct. 30, 2003, now U.S. Pat. No. 7,632,078, issued Dec. 15, 2009 and entitled PUMP CASSETTE BANK (referred to herein as “Application D85”).
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| Number | Date | Country | |
|---|---|---|---|
| 20080112258 A1 | May 2008 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10696818 | Oct 2003 | US |
| Child | 11926891 | US |
