Dynamic pressure monitoring and adjustment based on pump flow characteristics

Abstract

This disclosure relates to a system and method for monitoring and dynamically adjusting the operation of a pneumatic pump. [Solution] The pump is controlled to draw fluid into the chamber and then transport it out by alternately applying initial negative pressure and initial positive pressure to the flexible diaphragm of the pump chamber. The initial pressure is selected as the minimum negative pressure at which the chamber is expected to be completely filled when negative pressure is applied to the diaphragm during the inflow time, and the minimum positive pressure at which the chamber is expected to be completely discharged when positive pressure is applied to the diaphragm during the outflow time. If complete filling or complete discharge is not achieved, the appropriate initial pressure is increased to reach the minimum pressure at which complete filling and complete discharge are actually achieved.

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application claims the benefit and priority of U.S. Provisional Patent Application No. 63 / 699,925, filed on September 27, 2024, the content of which is incorporated herein by reference.

[0002] [Technical Field] The present subject matter relates to the control of pneumatic pumps. More specifically, the present subject matter relates to using signals from a capacitance sensor to dynamically adjust the pressure applied by a pneumatic pump of a fluid treatment device.

Background Art

[0003] The use of pneumatic pumps in medical devices is well - established and common in multiple devices. By utilizing a control unit, the system can adjust the pressure applied to the pump chamber to induce fluid flow. The basic premise of a pneumatic pumping system is to apply a vacuum (negative pressure) to the pumping chamber to draw back the flexible diaphragm or membrane of the pumping chamber, allowing fluid to flow in. Conversely, to empty the chamber, a positive pressure is applied to move the flexible diaphragm or membrane towards and into the chamber, pushing the fluid out of the chamber and sending it out to the associated fluid path. Current methods of controlling the pneumatic pressure required to operate the pump involve statically setting the pressure to the potentially required maximum level or to a level that has been shown to function well in most procedures. If the pressure is not sufficient and cannot induce proper fluid flow, an alert is generated and the procedure is usually aborted.

[0004] Depending on the viscosity of the fluid, the fluid flow rate / pressure in the relevant fluid path, or other limiting factors (e.g., problems or bends in the donor vein), the inflow and / or outflow of fluid into the pumping chamber may be impaired. To detect such irregularities, the operation of the pneumatic pump may be monitored by relevant sensors, and sensors of different configurations may be used to assist in pump control. One type of sensor that may be used to monitor the operation of a pneumatic pump is a capacitive sensor, which measures whether the pump is properly filled (indicating no limitations on the upstream side) and whether it is properly discharged (indicating no limitations on the downstream side). An example of such a system using a pneumatic pump and a capacitive sensor is described in U.S. Patent Application Publication 2 006 / 0161092, which is incorporated herein by reference.

[0005] If an upstream limitation is detected, current methodologies involve increasing the time the pumping chamber remains open (i.e., the time a vacuum or negative pressure is applied to the chamber's flexible diaphragm or membrane) to allow more fluid to flow in over time, or calculating the volume assumed to have been moved by the pump (i.e., the stroke volume) as being less than normal. However, one potential drawback of each of these methods is that they significantly limit the maximum speed at which the pump can operate.

[0006] Instead of increasing the time the pumping chamber remains open or adjusting the stroke volume, an alternative approach involves applying a stronger vacuum or negative pressure to the flexible diaphragm or membrane of the pumping chamber. This has been shown to increase the pull force into the chamber, allowing for faster filling without compromising the maximum velocity. However, one potential drawback of such an approach is the risk of generating excessively large shear stresses, which could be harmful to the treatment / product (e.g., red blood cells).

[0007] Regarding downstream limitations, if detected, current methodologies either increase the time the pumping chamber remains closed (i.e., the time positive pressure is applied to the chamber's flexible diaphragm or membrane) to allow more fluid to flow out over time, or calculate the volume assumed to have been moved by the pump (i.e., stroke volume) as being less than normal. As with conventional approaches to detecting upstream limitations, one potential drawback of each of these methods is that they significantly limit the maximum speed at which the pump can operate.

[0008] Instead of increasing the time the pumping chamber remains closed or adjusting the stroke volume, an alternative approach involves applying stronger positive pressure to the flexible diaphragm or membrane of the pumping chamber. This has been shown to increase the expulsion force into the chamber, allowing for faster discharge without compromising maximum velocity. However, one potential drawback of such an approach is the risk of generating excessively large shear stresses, which could be harmful to the treatment / product (e.g., red blood cells).

[0009] Since none of the above approaches are without significant drawbacks, it is desirable to provide a method for controlling the operation of a pneumatic pump that avoids the shortcomings of conventional approaches. [Overview of the project]

[0010] Several aspects of the subject matter may be embodied individually or as a whole in the apparatus and methods described and claimed below. These aspects may be used alone or in combination with other aspects described herein, and the joint description of these aspects is not intended to prevent the use of these aspects alone or the claim of these aspects alone, as described in the claims attached to the end of this specification.

[0011] In one embodiment, a fluid processing device is provided for use in combination with a fluid flow circuit comprising a pump chamber including a flexible diaphragm and electrodes. The fluid processing device includes a control unit programmed to perform fluid flow processing, a pneumatic pump, and a capacitance sensor. The pneumatic pump is operationally coupled to the control unit and is operated by the control unit during fluid flow processing, and is configured to alternately apply negative pressure to the flexible diaphragm of the pump chamber during the inflow period to draw fluid into the pump chamber, and apply positive pressure to the flexible diaphragm of the pump chamber during the outflow period to transport fluid out of the pump chamber. The capacitance sensor is operationally coupled to the control unit and is configured to be electrically coupled to the electrodes of the pump chamber, and is configured to transmit an inflow signal to the control unit indicating the inflow volume of fluid drawn into the pump chamber while the pneumatic pump is applying negative pressure to the flexible diaphragm of the pump chamber during the inflow period. The control unit is programmed to operate the pneumatic pump to apply an initial negative pressure to the flexible diaphragm of the pump chamber during the inflow period when negative pressure is first applied to the flexible diaphragm of the pump chamber during fluid flow processing. This initial negative pressure is selected as the minimum negative pressure at which the pump chamber is expected to be fully filled while negative pressure is applied to the flexible diaphragm of the pump chamber during the inflow period. Based at least partially on the inflow signal, the control unit determines whether the pump chamber has been fully filled while the initial negative pressure is applied to the flexible diaphragm of the pump chamber during the inflow period. If it determines that the pump chamber has not been fully filled, the control unit operates the pneumatic pump to apply a second negative pressure, greater than the initial negative pressure, to the flexible diaphragm of the pump chamber during the inflow period when negative pressure is next applied to the flexible diaphragm of the pump chamber during fluid flow processing.

[0012] In another embodiment, a method is provided, implemented by a control unit, for performing fluid flow processing using a fluid flow circuit having a pump chamber including a flexible diaphragm and electrodes. This method involves operating a pneumatic pump to alternately draw fluid into the pump chamber by applying negative pressure to the flexible diaphragm of the pump chamber during the inflow period, and to transport fluid out of the pump chamber by applying positive pressure to the flexible diaphragm of the pump chamber during the outflow period. The pneumatic pump is operated to apply an initial negative pressure to the flexible diaphragm of the pump chamber during the inflow period when negative pressure is first applied to the flexible diaphragm of the pump chamber during fluid flow processing, and this initial negative pressure is selected as the minimum negative pressure at which the pump chamber is expected to be fully filled while negative pressure is applied to the flexible diaphragm of the pump chamber during the inflow period. While the pneumatic pump is applying negative pressure to the flexible diaphragm of the pump chamber during the inflow period, an inflow signal indicating the inflow volume of fluid drawn into the pump chamber is received from a capacitive sensor electrically coupled to the electrodes of the pump chamber. Next, based at least partially on the inflow signal, it is determined whether the pump chamber is fully filled while an initial negative pressure is being applied to the flexible diaphragm of the pump chamber during the inflow period. If it is determined that the pump chamber is not fully filled, the pneumatic pump is activated to apply a second negative pressure, greater than the initial negative pressure, to the flexible diaphragm of the pump chamber during the inflow period when applying negative pressure to the flexible diaphragm of the pump chamber during the next application of negative pressure to the flexible diaphragm of the pump chamber during the fluid flow processing.

[0013] In yet another embodiment, a fluid processing device is provided for use in combination with a fluid flow circuit comprising a pump chamber including a flexible diaphragm and electrodes. The fluid processing device includes a control unit programmed to perform fluid flow processing, a pneumatic pump, and a capacitance sensor. The pneumatic pump is operationally coupled to the control unit and is operated by the control unit during fluid flow processing, and is configured to alternately apply negative pressure to the flexible diaphragm of the pump chamber during the inflow period to draw fluid into the pump chamber, and apply positive pressure to the flexible diaphragm of the pump chamber during the outflow period to transport the fluid out of the pump chamber. The capacitance sensor is operationally coupled to the control unit and is configured to be electrically coupled to the electrodes of the pump chamber, and is configured to transmit an outflow signal to the control unit indicating the outflow volume of fluid transported from the pump chamber while the pneumatic pump is applying positive pressure to the flexible diaphragm of the pump chamber during the outflow period. The control unit is programmed to operate the pneumatic pump to apply an initial positive pressure to the flexible diaphragm of the pump chamber during the outflow period when positive pressure is first applied to the flexible diaphragm of the pump chamber during fluid flow processing. This initial positive pressure is selected as the minimum positive pressure at which the pump chamber is expected to become completely empty while positive pressure is being applied to the flexible diaphragm of the pump chamber during the outflow period. Based at least partially on the outflow signal, the control unit determines whether the pump chamber has become completely empty while the initial positive pressure is being applied to the flexible diaphragm of the pump chamber during the outflow period. If it determines that the pump chamber has not become completely empty, the control unit operates the pneumatic pump to apply a second positive pressure, greater than the initial positive pressure, to the flexible diaphragm of the pump chamber during the outflow period when positive pressure is next applied to the flexible diaphragm of the pump chamber during fluid flow processing.

[0014] In another embodiment, a method is provided, implemented by a control unit, for performing fluid flow processing using a fluid flow circuit having a pump chamber including a flexible diaphragm and electrodes. This method involves operating a pneumatic pump to alternately draw fluid into the pump chamber by applying negative pressure to the flexible diaphragm of the pump chamber during the inflow period, and to transport the fluid out of the pump chamber by applying positive pressure to the flexible diaphragm of the pump chamber during the outflow period. The pneumatic pump is operated to apply an initial positive pressure to the flexible diaphragm of the pump chamber during the outflow period, when it first applies positive pressure to the flexible diaphragm of the pump chamber during fluid flow processing, and this initial positive pressure is selected as the minimum positive pressure at which the pump chamber is expected to be completely empty while positive pressure is applied to the flexible diaphragm of the pump chamber during the outflow period. While the pneumatic pump is applying positive pressure to the flexible diaphragm of the pump chamber during the outflow period, an outflow signal indicating the outflow volume of fluid transported from the pump chamber is received from a capacitive sensor electrically coupled to the electrodes of the pump chamber. Next, based at least partially on the discharge signal, it is determined whether the pump chamber has become completely empty while an initial positive pressure is being applied to the flexible diaphragm of the pump chamber during the discharge period. If it is determined that the pump chamber has not become completely empty, the pneumatic pump is activated to apply a second positive pressure, greater than the initial positive pressure, to the flexible diaphragm of the pump chamber during the discharge period when applying positive pressure to the flexible diaphragm of the pump chamber next during fluid flow processing. [Brief explanation of the drawing]

[0015] Figure 1 is a perspective view of an exemplary fluid processing apparatus, including components of a fluid processing system according to one aspect of the present disclosure.

[0016] Figure 2 is a schematic diagram of an exemplary disposable fluid flow circuit that can be installed in the fluid processing apparatus of Figure 1 to complete a fluid processing system according to one aspect of the present disclosure.

[0017] Figure 3 is a top plan view of an exemplary cassette of the fluid flow circuit in Figure 2, which can be operated in conjunction with the fluid processing apparatus shown in Figure 1 to perform various different fluid processing procedures.

[0018] Figure 4 is a schematic diagram of a part of the cassette station of the fluid processing apparatus shown in Figure 1 and the cassette shown in Figure 3.

[0019] Figure 5 is a schematic diagram of the fluid flow circuit shown in Figure 2, installed in the fluid processing device shown in Figure 1, illustrating how the system performs the fluid processing procedure. [Modes for carrying out the invention]

[0020] The embodiments disclosed herein are intended to provide an illustrative description of the subject matter. However, these are merely illustrative, and the subject matter can be embodied in various forms. Accordingly, the specific details disclosed herein should not be construed as limiting the subject matter as defined by the appended claims.

[0021] Figures 1 to 5 illustrate the components of a fluid processing system that embodies various aspects of the subject matter. While this specification describes the use of a system for separating blood into two or more components and collecting at least one of them, it should be understood that the system described herein can be used to process a variety of fluids, which may include bodily fluids and non-bodily fluids.

[0022] Generally speaking, this system comprises two main components: a durable and reusable fluid processing device 10 (Figure 1) and a disposable fluid flow circuit 12 (Figure 2). The illustrated fluid processing device 10 includes a rotating membrane separator drive unit 14, a centrifuge or centrifugal separator 16, additional components that control the fluid flow through the disposable fluid flow circuit 12, and a control unit 18 that coordinates the operation of the other components of the fluid processing device 10 to execute the fluid processing procedure. The type of fluid processing device 10 shown in Figure 1 is described in more detail in PCT International Publication WO2018 / 053217A1, which is incorporated herein by reference. While the principles described herein may be applied when using the fluid processing device 10 of Figure 1, it should be understood that the same principles may also be applicable to other fluid processing devices, including those employing a single separation technique or approach.

[0023] I. Durable Fluid Processing Equipment The fluid processing apparatus 10 (Figure 1) is configured as an item with durability for long-term use. It should be understood that the fluid processing apparatus 10 in Figure 1 is merely one example of a possible configuration, and the fluid processing apparatus according to this disclosure may have different configurations.

[0024] In the illustrated embodiment, the fluid processing apparatus 10 is configured to be housed in a single housing or case 20. The illustrated case 20 includes a generally horizontal portion 22 (which may include inclined or angled surfaces or top surfaces to improve visibility and ergonomics) and a generally vertical portion 24. The rotating membrane separator drive unit 14 and the centrifuge 16 are shown to be incorporated into the generally horizontal portion 22 of the case 20, while the control unit 18 is shown to be incorporated into the generally vertical portion 24.

[0025] A Rotating Membrane Separator Drive Unit The fluid treatment apparatus 10 includes a spinner support or a rotary membrane separator drive unit 14 for housing a generally cylindrical rotary membrane separator 26 of a fluid flow circuit 12. U.S. Patent No. 5,194,145, the contents of which are incorporated herein by reference, describes an exemplary rotary membrane separator drive unit suitable for incorporation into the fluid treatment apparatus 10, but it should be understood that the rotary membrane separator drive unit 14 can have a different configuration without departing from the scope of the present disclosure.

[0026] The illustrated rotary membrane separator drive unit 14 includes a base 28 configured to receive the lower portion of the rotary membrane separator 26 and an upper end cap 30 configured to receive the upper portion of the rotary membrane separator 26. Preferably, the upper end cap 30 is disposed directly above the base 28, orienting the rotary membrane separator 26 received by the rotary membrane separator drive unit 14 in a vertical direction and defining a vertical axis about which the rotary membrane separator 26 rotates. While it can be advantageous for the rotary membrane separator drive unit 14 to orient the rotary membrane separator 26 vertically, within the scope of the present disclosure, it is also possible for the rotary membrane separator 26 to be disposed in a different orientation when mounted to the fluid treatment apparatus 10.

[0027] In one embodiment, one of the base 28 and the upper end cap 30 of the rotary membrane separator drive unit 14 is movable relative to the other, thereby enabling the rotary membrane separator drive unit 14 to receive rotary membrane separators 26 of different sizes. For example, the upper end cap 30 can be moved vertically relative to the base 28 and locked in a plurality of different positions, each lock position corresponding to a rotary membrane separator 26 of a different size.

[0028] At least one of the base 28 and the upper end cap 30 is configured to rotate one or more components of the rotary membrane separator 26 about an axis defined by the rotary membrane separator drive unit 14. The mechanism by which the rotating membrane separator drive unit 14 rotates one or more components of the rotating membrane separator 26 can be modified in various ways without departing from the scope of the present disclosure. In one embodiment, the components of the rotating membrane separator 26 to be rotated include at least one element (e.g., a metallic material) configured to be acted upon by a magnet, while the rotating membrane separator drive unit 14 includes a magnet (e.g., a series of magnetic coils or a semicircular magnetic member). By modulating the magnetic field acting on the elements of the rotating membrane separator 26, the components of the rotating membrane separator 26 can be rotated in different directions and at different speeds. In other embodiments, different mechanisms may be used to rotate the components of the rotating membrane separator 26.

[0029] Regardless of the mechanism by which the rotary membrane separator drive unit 14 rotates the components of the rotary membrane separator 26, it is preferable that the components of the rotary membrane separator 26 rotate at a speed sufficient to generate Taylor vortices in the gap between the rotating components and the stationary components (or components rotating at different speeds) of the rotary membrane separator 26. The fluid to be separated in the rotary membrane separator 26 flows through this gap, and the generation of Taylor vortices can dramatically improve filtration performance.

[0030] B Centrifuge The centrifuge 16 includes a centrifugal compartment 32 that receives the centrifugal chamber 36 of the fluid flow circuit 12, as well as other components of the centrifuge 16. Further details regarding the configuration and operation of the exemplary centrifuge are described in PCT International Publication No. WO2018 / 053217A1.

[0031] A fluid (e.g., anticoagulated whole blood) is introduced into the centrifugation chamber 36 by an umbilicus, and as a result of the centrifugal force accompanying the rotation, it is separated into a layer of low-density components (e.g., platelet-rich plasma when separating blood) and a layer of high-density components (e.g., concentrated red blood cells) within the centrifugation chamber 36. Components of the interface monitoring system may be placed in the centrifugation compartment 32 to monitor the separation of the fluid within the centrifugation chamber 36. The interface monitoring system may include a light source 50 and a photodetector 52, the photodetector 52 being positioned and directed to receive at least a portion of the light emitted from the light source 50.

[0032] The orientation of each component of the interface monitoring system depends at least in part on the specific configuration of the centrifuge chamber 36. However, generally, the light source 50 emits a light beam (e.g., a laser beam) through the separated fluid components in the centrifuge chamber 36 (the centrifuge chamber 36 may be made of a material that substantially transmits light, or at least light of a certain wavelength, without absorbing it). Some of the light reaches the photodetector 52, which transmits a signal to the control unit 18 indicating the position of the interface between the separated fluid components. If the control unit 18 determines that the interface is in the wrong position (which may affect the separation efficiency of the centrifuge 16 and / or the quality of the separated fluid components), the control unit 18 can command the appropriate component of the fluid processing apparatus 10 to change its operation to move the interface to the correct position.

[0033] C Other components of the fluid processing apparatus In addition to the rotary membrane separator drive unit 14 and the centrifuge 16, the fluid processing apparatus 10 may include other components compactly arranged to assist in fluid processing.

[0034] A generally horizontal portion 22 of the case 20 of the illustrated fluid processing apparatus 10 includes a cassette station 54 that houses a flow control cassette 48 of the fluid flow circuit 12. An exemplary flow control cassette 48 (described herein) is shown in Figure 3, and Figure 4 shows a portion of the flow control cassette 48 that is received by the cassette station 54. In one embodiment, the cassette station 54 is configured similarly to a pneumatically operated pump and valve station described in U.S. Patent Application Publication 2 006 / 0161092. The illustrated cassette station 54 includes a plurality of clamps or valves V1-V9 (Figure 1) which move to a plurality of positions (e.g., between a retracted or lowered position and an activated or raised position) to selectively contact or otherwise interact with the corresponding valve stations C1-C9 (Figure 3) of the flow control cassette 48 of the fluid flow circuit 12. Depending on the configuration of the fluid flow circuit 12, the cassette 48 may not have valve stations C1 to C9 corresponding to each of the valves V1 to V9 of the cassette station 54. In that case, only some, not all, of the valves V1 to V9 will be used in the fluid processing procedure.

[0035] In the operating position, valves V1-V9 engage with their corresponding valve stations C1-C9, blocking fluid flow through those valve stations (for example, by closing one or more ports associated with valve stations C1-C9, thereby preventing fluid flow through those ports). In the retracted position, valves V1-V9 are detached from their corresponding valve stations C1-C9 (or are in contact with valve stations C1-C9 with less force than in the operating position), allowing fluid flow through those valve stations C1-C9 (for example, by opening one or more ports associated with valve stations C1-C9, thereby allowing fluid flow through those ports). Additional clamps or valves V10 and V11 are located outside the cassette station 54 and interact with portions of the fluid flow circuit 12 corresponding to valve stations C10 and C11 (which may be the length of the tube) to selectively allow or prohibit fluid flow through those portions. The valves V1 to V9 of cassette station 54 and cassette 48, and the corresponding valve stations C1 to C9, may have different configurations and operating methods than valves V10 and V11, which are located away from cassette station 54, and valve stations C10 and C11.

[0036] The cassette station 54 may be equipped with additional components such as pressure sensors A1-A4, which interact with the sensor stations S1-S4 of the cassette 48 to monitor pressure at various locations in the fluid flow circuit 12. For example, if the fluid source is a human donor, one or more of the pressure sensors A1-A4 may be configured to monitor the donor's venous pressure during blood collection and return. Other pressure sensors A1-A4 may monitor the pressure in the rotating membrane separator 26 and the centrifuge chamber 36. The control unit 18 receives signals from the pressure sensors A1-A4 indicating the pressure in the fluid flow circuit 12, and if the signals indicate a low or high pressure state, the control unit 18 may initiate an alarm or error state to inform the operator of the situation and / or attempt to return the pressure to an acceptable range without operator intervention.

[0037] The fluid processing apparatus 10 may include a plurality of pumps P1-P6 (collectively referred to as a pump assembly or pump system) to move fluid through the fluid flow circuit 12. Pumps P1-P6 may have different configurations or similar configurations, and / or may perform similar or different functions. In the illustrated embodiment, pumps P1-P6 are configured as pneumatic pumps, and they may be configured similarly to the configuration described in U.S. Patent Application Publication 2 006 / 0161092. The actuators of each pump P1-P6 are controlled by a control unit 18, which alternately applies positive and negative pressure to the flexible membranes or diaphragms 64 of different pump chambers T1-T6 defined by a flow control cassette 48 (Figure 4), thereby moving fluid through a portion of the fluid flow circuit 12. The configuration and operation of the pump system and control unit 18 will be described in further detail herein.

[0038] The illustrated fluid processing apparatus 10 also includes a spinner inlet sensor M1 for determining one or more characteristics of the fluid flowing into the rotating membrane separator 26, which is mounted in the rotating membrane separator drive unit 14. If the fluid flowing into the rotating membrane separator 26 is whole blood (which may include anticoagulated whole blood), the spinner inlet sensor M1 may be configured to determine the hematocrit of the blood flowing into the rotating membrane separator 26. If the fluid flowing into the rotating membrane separator 26 is platelet-rich plasma, the spinner inlet sensor M1 may be configured to determine the platelet concentration of the platelet-rich plasma flowing into the rotating membrane separator 26. The spinner inlet sensor M1 may detect one or more characteristics of the fluid by optically monitoring the fluid flowing through the tubes of the fluid flow circuit 12, or by other suitable means. The control unit 18 can receive signals from the spinner inlet sensor M1 indicating one or more characteristics of the fluid flowing into the rotating membrane separator 26 and use those signals to optimize the fluid processing procedure based on those characteristics. If the characteristics are outside the acceptable range, the control unit 18 may initiate an alarm or error condition to inform the operator of the situation. Suitable apparatus and methods for monitoring hematocrit and / or platelet concentration are described in U.S. Patent No. 6,419,822 (the contents of which are incorporated herein by reference), but it should be understood that different methods may be used to monitor one or more characteristics of the fluid or fluid components flowing into the rotating membrane separator 26.

[0039] The illustrated fluid processing apparatus 10 further includes a spinner outlet sensor M2 that houses a tube of a fluid flow circuit 12 for discharging fluid components separated from the rotating membrane separator 26. The spinner outlet sensor M2 monitors the separated fluid components and determines one or more of their characteristics, which may be done by optically monitoring the separated fluid components flowing through the tube or by other suitable methods. In one embodiment, separated plasma flows through the tube, in which case the spinner outlet sensor M2 may be configured to determine the amount of cellular blood components in the plasma and / or whether the plasma is hemolytic and / or lipometabolic. This can be done using an optical monitor of the type described in U.S. Patent No. 8,556,793 (the contents of which are incorporated herein by reference), or other suitable apparatus and / or methods, which measure the optical density of the fluid in the relevant tube.

[0040] The illustrated fluid processing apparatus also includes an air detector M3 (e.g., an ultrasonic bubble detector) housing the tube of the fluid flow circuit 12 that carries fluid to the receiving end. Whether the receiving end is a human (e.g., the same person as a blood source) or non-human (e.g., a storage bag or container), it may be advantageous to prevent air from reaching the receiving end, so the air detector M3 may transmit a signal to the control unit 18 indicating whether or not air is present in the tube. If the signal indicates the presence of air in the tube, the control unit 18 may initiate an alarm or error condition to inform the operator of the situation and / or take corrective action to prevent air from reaching the receiving end (e.g., reversing the fluid flow in the tube or diverting the flow to a vent location).

[0041] The generally vertical portion 24 of Case 20 may include a plurality of volume measurement systems W1-W6 (six are shown, but there may be more or fewer). These are configured to be associated with one or more fluid containers F1-F7 (Figures 2 and 5) of the fluid flow circuit 12. Each volume measurement system W1-W6 operates in conjunction with the control unit 18 to measure the current fluid volume in the corresponding fluid container F1-F7 and to calculate the change in that volume between two or more time points. Individual volume measurement systems W1-W6 may take on various configurations without departing from the scope of this disclosure. This includes cases where two or more volume measurement systems W1-W6 have different configurations. As an example, volume measurement systems W1-W6 are configured as weighing scales that support and measure the weight of the fluid in the corresponding fluid containers F1-F7, and the measured weight can be converted to volume by the components of volume measurement systems W1-W6 or by the control unit 18. As another example, a volume measurement system W1-W6 may include one or more sensors configured to detect the volume and / or volume change of fluid in the corresponding fluid containers F1-F7. Volume measurement systems including additional components (both weighers and sensors) and / or other alternative components can also be used without departing from the scope of this disclosure.

[0042] Regardless of its specific configuration, each volume measurement system W1-W6 transmits a signal to the control unit 18 indicating the fluid volume in the corresponding containers F1-F7, allowing it to track volume changes during the process. This enables the control unit 18 to process the incremental volume changes to derive the fluid processing volume and flow rate, and, at least partially, generate signals to control processing events based on the derived processing volume. For example, the control unit 18 can diagnose leaks or blockages in the fluid flow circuit 12 and warn the operator.

[0043] The illustrated case 20 is also provided with a number of hooks or supports H1 and H2 that can support various components of the fluid flow circuit 12, or other articles of appropriate size and shape.

[0044] D Control Unit According to one aspect of the present disclosure, the fluid processing apparatus 10 includes a control unit 18 which is appropriately configured and / or programmed to control the operation of the fluid processing apparatus 10. In one embodiment, the control unit 18 comprises a main processing unit (MPU), which may include, for example, an Intel Pentium® type microprocessor, but other types of conventional microprocessors may also be used. In one embodiment, the control unit 18 may be mounted in a generally vertical portion 24 of the case 20, adjacent to or inside an operator interface station (e.g., a touchscreen). In other embodiments, the control unit 18 and the operator interface station may be associated with a generally horizontal portion 22 or incorporated into a separate device connected to the fluid processing apparatus 10 (physically by cable or wirelessly).

[0045] The control unit 18 is configured and / or programmed to perform at least one fluid processing procedure, but more advantageously, it is configured and / or programmed to perform a variety of different fluid processing procedures. For example, the control unit 18 may be configured and / or programmed to perform one or more of the following: a diunit erythrocyte collection procedure, a plasma collection procedure, a plasma / erythrocyte collection procedure, an erythrocyte / platelet / plasma collection procedure, a platelet collection procedure, and a platelet / plasma collection procedure.

[0046] More specifically, in carrying out these fluid processing procedures, the control unit 18 is configured and / or programmed to control one or more of the following tasks: drawing fluid into a fluid flow circuit 12 attached to the fluid processing apparatus 10; transporting the fluid through the fluid flow circuit 12 to a separation location (i.e., a rotating membrane separator 26 or centrifugal separator 36 in the fluid flow circuit 12); separating the fluid into two or more components as desired; and transporting the separated components to a storage container, to a second location for further separation (e.g., to the rotating membrane separator 26 or centrifugal separator 36 not used in the initial separation stage), or to a receiving side (which may be the source from which the fluid was originally drawn).

[0047] This may include instructing the rotary membrane separator drive unit 14 and / or the centrifuge 16 to operate at a specific rotational speed, and instructing the pumps P1-P6 to apply a specific (positive or negative) pressure to the flexible membranes or diaphragms 64 of the corresponding pump chambers T1-T6 of the cassette 48 for a specific period of time, so that fluid passes through a portion of the fluid flow circuit 12 at a specific flow rate. Therefore, even if a specific component of the fluid processing apparatus 10 (e.g., the rotary membrane separator drive unit 14 or the centrifuge 16) is described in this specification as performing a specific function, it should be understood that the component is controlled by the control unit 18 to perform that function.

[0048] Before, during, and after the procedure, the control unit 18 can receive signals from various components of the fluid processing device 10 (e.g., pressure sensors A1-A4) and monitor various aspects of the operation of the fluid processing device 10 and the characteristics of the fluid flowing through the fluid flow circuit 12 and the separated fluid components. If the operation of a component and / or one or more characteristics of the fluid or separated fluid components are outside the acceptable range, the control unit 18 can activate an alarm or error condition to inform the operator of the situation and / or take measures to correct the condition. Appropriate corrective measures depend on the specific error condition and may be performed with or without operator involvement.

[0049] For example, the control unit 18 may include an interface control module, which receives signals from a photodetector 52 of the interface monitoring system. The signals received by the control unit 18 from the photodetector 52 indicate the position of the interface between the separated fluid components in the centrifugal chamber 36. If the control unit 18 determines that the interface is in the wrong position, it can issue commands to the appropriate components of the fluid processing device 10 to change their operation in order to move the interface to the correct position. For example, the control unit 18 can instruct one of the pumps P1 to P6 to introduce fluid into the centrifugal chamber 36 at a different flow rate, and / or to remove the separated fluid components from the centrifugal chamber 36 at a different flow rate, and / or to rotate the centrifugal chamber 36 at a different speed using the centrifuge 16.

[0050] If an operator interface station is provided associated with the control unit 18, the operator can view information about the system's operation (as alphanumeric and / or graphical images) on its screen or display. The operator interface station also allows the operator to select applications executed by the control unit 18, as well as to modify specific functions and performance criteria of the system. If configured as a touchscreen, the screen of the operator interface station can receive input from the operator via touch operation. Otherwise, if the screen is not a touchscreen, the operator interface station can receive input from the operator via a separate input device such as a computer mouse or keyboard. It is also within the scope of this disclosure if the operator interface station is configured to receive input from both a touchscreen and a separate input device such as a keypad.

[0051] II. Disposable Fluid Flow Circuits The fluid flow circuit or flow set 12 (Figure 2) is sterile and intended for single-use disposable items. Before initiating a predetermined fluid handling procedure, the operator attaches the various components of the fluid flow circuit 12 to the case 20 in relation to the fluid processing device 10. The control unit 18 performs the procedure according to a predetermined protocol, taking into account other inputs from the operator. Once the procedure is complete, the operator detaches the fluid flow circuit 12 from its relation to the fluid processing device 10. The portion of the fluid flow circuit 12 holding the collected fluid components (e.g., collection container or bag) is removed from the case 20 and retained for storage, transfusion, or further processing. The remaining portion of the fluid flow circuit 12 is removed from the case 20 and discarded.

[0052] In the illustrated embodiment, the fluid flow circuit 12 includes a cassette 48 (Figure 3), and other components of the fluid flow circuit 12 are connected to this cassette 48 by flexible tubing. Other components may include a plurality of fluid containers F1 to F7. In the context of this disclosure, these containers include an anticoagulant container F1, a saline container F2, a processing container F3, a blood return container F4, a plasma collection container F5, a platelet collection container F6, and (optional) an additive container F7. The illustrated flow path circuit 12 further includes one or more fluid source access devices (e.g., connectors and blood collection needles for accessing blood in the fluid containers), a rotating membrane separator 26, and a centrifuge chamber 36.

[0053] The flow control cassette 48 provides a centralized, programmable, and integrated platform for all the pumping and numerous valve functions required for a given fluid handling procedure. In one embodiment, the cassette 48 is configured similarly to the cassette in U.S. Patent Application Publication 2 006 / 0161092, but is adapted to include various stations and flow paths necessary to perform the fluid handling procedure carried out by the fluid handling system.

[0054] During use, the cassette 48 is attached to the cassette station 54 of the fluid processing apparatus 10, and positioned so that the flexible membrane or diaphragm 64 of the cassette 48 is in contact with the cassette station 54. The flexible diaphragm 64 covers an array of internal cavities formed by the body of the cassette 48. These different internal cavities define sensor stations S1-S4, valve stations C1-C9, pump stations T1-T6, and multiple flow paths. The side of the cassette 48 opposite to the flexible diaphragm 64 may be sealed by another flexible diaphragm or rigid cover. This isolates the fluid flowing inside the cassette 48 from the external environment.

[0055] Each sensor station S1-S4 is aligned with the corresponding pressure sensors A1-A4 of the cassette station 54, and each pressure sensor A1-A4 can monitor the pressure within the corresponding sensor station S1-S4. Each valve station C1-C9 is aligned with the corresponding valves V1-V9, and may define one or more ports that enable fluid communication between the valve stations C1-C9 and other internal cavities (e.g., flow paths) of the cassette 48. As described above, each valve V1-V9 moves to multiple positions (e.g., between a retracted or lowered position and an operating or raised position) at the command of the control unit 18 to selectively contact the valve stations C1-C9 of the cassette 48. In the operating position, the valves V1-V9 engage with the corresponding valve stations C1-C9, closing one or more of their ports to prevent fluid from passing through. In the retracted position, valves V1-V9 are separated from their corresponding valve stations C1-C9 (or are in contact with them with less force than in the operating position), so one or more ports associated with valve stations C1-C9 are opened, allowing fluid to pass through.

[0056] As described above, the cassette 48 defines multiple pump chambers T1 to T6, each pump chamber interacting with a pneumatic pump P1 to P6 located in the cassette station 54 of the fluid processing device 10. Different pumps P1 to P6 may interact with the pump stations T1 to T6 of the cassette 48 to perform different tasks during processing, but in the context of this disclosure, each of the pumps P1 to P6 may be configured to function as an anticoagulant pump P1, a source pump P2, a centrifugal pump P3, an outlet pump P4, a recirculation pump P5, and a plasma pump P6.

[0057] From the side of the cassette 48, tubes of various lengths extend for connecting to other components of the fluid flow circuit 12, such as various fluid containers F1-F7, the rotating membrane separator 26, and the centrifugal chamber 36. The tubes connected to the centrifugal chamber 36 (including one inlet tube and two outlet tubes) can be bundled together as a single umbilicus.

[0058] Various additional components may be incorporated into the tubing extending from the cassette 48, or into one of the cavities of the cassette 48. For example, as shown in Figure 2, a manual clamp 56 may be associated with the line leading to the fluid source. A blood return line filter 58 (e.g., a microaggregate filter) may be associated with the line leading to the fluid receiving side. And / or, an air trap 62 may be positioned on the line upstream of the centrifuge chamber 36.

[0059] III. Exemplary Fluid Processing Procedures An exemplary fluid processing procedure described herein is described below. In this exemplary procedure, blood is separated into packed red blood cells and platelet-rich plasma by centrifugation, a portion of the platelet-rich plasma is recirculated through a centrifuge chamber, and another portion is separated into platelet concentrate and platelet-poor plasma, and processed until a predetermined volume of platelets is collected. The procedure described below is illustrative only, and the principles described herein may be combined with other fluid processing procedures (for example, a procedure for recirculating platelet-poor plasma into a centrifuge chamber during blood separation) without departing from the scope of this disclosure.

[0060] Prior to processing, the operator selects a desired protocol (for example, using an operator interface station, if one is provided). This selection informs the control unit 18 how it should control other components of the fluid processing apparatus 10 during the procedure. This may involve first selecting one of several procedures that the system can perform, then selecting the type of procedure, and finally selecting one or more parameters to be applied during the procedure. For example, this may involve selecting a platelet collection procedure from among various blood separation procedures, and then selecting the total volume of blood to be processed and the target volume of platelets to be collected during the procedure. If the fluid source is a biological source (e.g., a donor or patient), the operator can input various parameters of the fluid source, such as sex, height, and weight. In one embodiment, the operator may also input one or more characteristics of the fluid to be processed, such as a pre-count of platelets.

[0061] If there are fluid containers that are not integrally formed with the fluid flow circuit 12 (e.g., platelet additive containers), they can be connected to the fluid flow circuit 12 (e.g., by puncturing the tubular partitions of the fluid flow circuit 12 or via Luer connectors). The fluid flow circuit 12 is then attached to the fluid processing apparatus 10 (including, as appropriate, as fluid containers F1-F7 are associated with volume measurement systems W1-W6). In one exemplary embodiment, each volume measurement system W1-W6 includes a weight scale associated with a hook for suspending the fluid container. In another exemplary embodiment, at least one of the volume measurement systems W1-W6 includes a weight scale associated with a horizontal platform or surface, on which the container is placed and supported. This weight scale transmits a signal indicating the weight of the container (and its contents) to the control unit 18 throughout the procedure. In other embodiments, fluid containers may be associated with a volume measurement system that omits the weight scale, but still includes other means (e.g., one or more sensors) for measuring the fluid volume in the container.

[0062] To ensure that each component of the fluid flow circuit 12 is properly connected and functioning correctly, the control unit 18 may perform an integrity check of the fluid flow circuit 12. Once the integrity check is successfully completed, a fluid source is connected to the fluid flow circuit 12 (for example, by connecting to a container of fluid that has already been collected, or by drawing blood from a donor). The fluid flow circuit 12 can then be primed (for example, by operating one or more of the pumps P1 to P6 of the fluid processing device 10, using saline solution pumped from the saline solution container F2).

[0063] After the fluid flow circuit 12 is primed, fluid processing can be started. In the first stage of an exemplary platelet collection procedure (Figure 5), blood is drawn from a blood source into the fluid flow circuit 12. If the blood source is a donor, the blood may be drawn into the fluid flow circuit 12 through a single needle connected to a cassette via line L1. Line L1 may include a manual clamp 56, which may initially be in a closed position to prevent fluid flow through line L1. When starting the process, the operator moves the manual clamp 56 from the closed position to the open position to allow fluid flow through line L1.

[0064] Blood is drawn into line L1 by the supply pump P2 of the fluid processing device 10. The anticoagulant from the anticoagulant container F1 is drawn through line L2 by the operation of the anticoagulant pump P1 and can be added to the blood at the junction of lines L1 and L2.

[0065] In the illustrated embodiment, valve V10 is open, allowing anticoagulated blood to pass through line L3 and the sensor station of the cassette associated with pressure sensor A1. Valve V11, on the other hand, is closed, preventing fluid flow through line L4. If the blood source is a living organism (e.g., a donor), pressure sensor A1 can communicate with the control unit 18 to monitor the pressure in the vein of the blood source.

[0066] The cassette has two valve stations downstream of the source pump P2: valve V2 is closed to prevent flow through line L5, and valve V1 is open to allow flow through line L6. A portion of the blood is led to the processing container F3 through line L7 and the cassette's sensor station associated with pressure sensor A3, while the remainder goes to the centrifugal pump P3 through line L8. The centrifugal pump P3 controls the amount of blood sent to the centrifuge chamber 36 instead of the processing container F3. In particular, the flow rate of the source pump P2 is greater than the flow rate of the centrifugal pump P3, and the difference is equal to the flow rate of blood flowing into the processing container F3. The flow rate can be selected so that the processing container F3 is partially or completely filled with blood at the end of the blood collection stage.

[0067] Blood, delivered by the centrifugal pump P3 through line L8, passes through line L9, air trap 62, and a sensor station on a cassette associated with pressure sensor A2, before reaching the centrifugation chamber 36 of the fluid flow circuit 12. Pressure sensor A2 works in conjunction with the control unit 18 of the fluid processing device 10 to monitor the pressure in the centrifugation chamber 36. The centrifuge 16 of the fluid processing device 10 operates the centrifugation chamber 36 to separate the blood in the chamber 36 into platelet-rich plasma and packed red blood cells. In one embodiment, the centrifugation chamber 36 is nominally rotated at 4,500 rpm, but the specific rotation speed may vary depending on the flow rates of inflow and outflow into the centrifugation chamber 36.

[0068] Packed red blood cells are discharged from the centrifuge chamber 36 via line L10 and flow through line L11 to the blood return container F4. Platelet-rich plasma is drawn from the centrifuge chamber 36 via line L12 by the coordinated action of the recirculation pump P5 and outlet pump P4 of the fluid processing device 10. The platelet-rich plasma moves through line L12 and, upon reaching a branching point, splits into lines L13 and L14. The recirculation pump P5 is associated with line L13 and recirculates a portion of the platelet-rich plasma, returning it to a junction where it is mixed with the blood in line L8 being transported to the centrifuge chamber 36 by the centrifugal pump P3. Recirculating a portion of the platelet-rich plasma along with the incoming blood to the centrifuge chamber 36 may lower the hematocrit value of the blood flowing into the centrifuge chamber 36, potentially improving separation efficiency. With this configuration, the flow rate of the fluid flowing into the centrifuge chamber 36 is equal to the sum of the flow rates of the centrifugal pump P3 and the recirculation pump P5. Since the platelet-rich plasma drawn into line L13 by the recirculation pump P5 is immediately returned to the centrifuge chamber 36, the substantial or net outflow rate of platelet-rich plasma from the centrifuge chamber 36 is equal to the flow rate of the outlet pump P4.

[0069] Line L14 terminates at a junction where it merges with lines L15 and L16. Valve V6 is closed, preventing fluid flow through line L16 and guiding the separated platelet-rich plasma through line L15 to the rotating membrane separator 26. Before reaching the rotating membrane separator 26, the portion of platelet-rich plasma transported through line L15 passes through sensor stations on a cassette associated with spinner inlet sensor M1 and pressure sensor A4. Spinner inlet sensor M1 can detect the platelet concentration in the platelet-rich plasma flowing into the rotating membrane separator 26, while pressure sensor A4 can monitor the pressure in the rotating membrane separator 26.

[0070] In Figure 5, valve V6 is shown in a closed state, but it can be selectively opened as needed to divert all or part of the platelet-rich plasma through line L14 to the blood return container F4 via line L16. For example, at the start of the procedure, when the separation has been initialized and platelets have not yet been discharged from the centrifuge chamber 36, the fluid being transported through line L14 by the outlet pump P4 can be diverted to the blood return container F4.

[0071] The rotating membrane separator drive unit 14 of the fluid processing apparatus 10 operates the rotating membrane separator 26 to separate platelet-rich plasma into platelet-poor plasma ("plasma") and platelet concentrate ("platelets"). The plasma is pumped from the rotating membrane separator 26 via line L17 by the plasma pump P6 of the fluid processing apparatus 10. Valves V5, V6, V8, and V9 are closed, and the separated plasma is guided along line L18, through valve V4, to the blood return container F4 (along with the separated red blood cells). On its way to the blood return container F4, the plasma passes through the spinner outlet sensor M2. The spinner outlet sensor M2 works in cooperation with the control unit 18 to determine one or more characteristics of the plasma, such as the amount of cellular blood components in the plasma, whether the plasma is hemolytic or not, and / or whether it is lipemia.

[0072] Platelet concentrate is transported from the rotating membrane separator 26 via line L19. Since line L19 is not associated with a pump, the flow rate of platelets discharged from the rotating membrane separator 26 is equal to the flow rate difference between the outlet pump P4 and the plasma pump P6. Valve V8 is closed, preventing fluid flow through line L20, thereby directing the platelet flow along line L19, through valve V7, and to the platelet collection container F6. If necessary, valve V8 can be selectively opened to allow fluid flow through line L20, which can then be combined at the junction with plasma heading towards the blood return container F4 via line L18.

[0073] Depending on the volume of platelets to be collected, the blood collection step in Figure 5 may be repeated. The blood collection step alternates with a blood return step in which the blood in the processing container F3 is separated in the centrifuge chamber 36, while the already collected blood components in the return container F4 are returned to the blood source. In such a blood return step, the separated red blood cells and platelet-rich plasma can be routed in various ways within the fluid flow circuit 12. Typically, after separation from platelet-poor plasma in the rotating membrane separator 26, an additional volume of platelets is collected in the platelet collection container F6 (similar to the blood collection step in Figure 5). Before the procedure is completed, a platelet additive from the additive container F7 may be added to the collected platelets in the platelet collection container F6.

[0074] IV Pump Control As described above, in the illustrated embodiment, pumps P1 to P6 are configured as pneumatic pumps, and the actuators of each pump P1 to P6 are selectively controlled by the control unit 18 to alternately apply positive and negative pressure to the flexible membranes or diaphragms 64 of different pump chambers T1 to T6 defined by the flow control cassette 48 in order to move the fluid (which may be an unseparated fluid such as whole blood or a separated fluid component such as platelet-poor plasma) flowing through a portion of the fluid flow circuit 12. More specifically, pumps P1 to P6 are operated by the control unit 18 to apply vacuum or negative pressure to the flexible diaphragms 64 superimposed on the corresponding pump chambers T1 to T6, drawing fluid from an adjacent cavity in the cassette 48 (e.g., the upstream fluid flow path) into the pump chambers T1 to T6. Subsequently, they are operated again by the control unit 18 to apply positive pressure to the flexible diaphragms 64, thereby transporting the fluid from the pump chambers T1 to T6 to an adjacent cavity in the cassette 48 (e.g., the downstream fluid flow path).

[0075] When no pressure is applied to the diaphragm 64 by pumps P1 to P6, the diaphragm 64 tends to lie almost flat on the pump chambers T1 to T6 aligned with the pumps P1 to P6, which corresponds to a horizontal arrangement in the orientation of Figure 4. When a vacuum or negative pressure is applied to the diaphragm 64 by any of the pumps P1 to P6, the diaphragm 64 is pulled away from the pump chambers T1 to T6 aligned with the pumps P1 to P6 (the "inflow" state shown by the solid lines in Figure 4). This draws the fluid into the pump chambers T1 to T6.

[0076] When the pump system is operating as intended, applying a vacuum or negative pressure to the region of the diaphragm 64 superimposed on the pump chambers T1-T6 for a predetermined time (referred to herein as “inflow time”) results in the pump chambers T1-T6 being fully filled. As used herein, the term “fully filled” refers to the target volume of fluid drawn into the pump chambers T1-T6 by applying a vacuum or negative pressure for a predetermined time (referred to herein as “inflow time”, which corresponds to the time required to complete one suction stroke). In one embodiment, the target volume drawn into the pump chambers T1-T6 in “fully filled” may correspond to a specific percentage of the volume defined by the pump chambers T1-T6 (for example, “fully filled” is achieved when a volume of fluid equivalent to at least 95% of the volume of the pump chambers T1-T6 has been drawn into the pump chambers T1-T6). The exact target volume depends on several factors, including the configuration of the pump chambers T1-T6 and the magnitude of the vacuum or negative pressure applied to the portion of the diaphragm 64 superimposed on the pump chambers T1-T6.

[0077] Similarly, if the pump system is operating as intended, applying positive pressure to the region of the diaphragm 64 superimposed on the pump chambers T1-T6 for a predetermined time (referred to herein as “flow time,” corresponding to the time required to complete one fluid delivery stroke) will result in the complete discharge of the pump chambers T1-T6. As used herein, the term “complete discharge” refers to the target volume of fluid transported from the pump chambers T1-T6 by applying positive pressure to the region of the diaphragm 64 superimposed on the pump chambers T1-T6 for a predetermined time (referred to herein as “flow time”), or the target volume of fluid remaining in the pump chambers T1-T6 after the application of positive pressure. In one embodiment, the target volume of fluid removed from the pump chambers T1-T6 in “complete discharge” may correspond to the volume of fluid contained in the pump chambers T1-T6 immediately before positive pressure is applied to the diaphragm 64. In this case, “complete discharge” is achieved when all the fluid in the pump chambers T1-T6 has been transported and the pump chambers T1-T6 are completely empty. In other embodiments, after applying positive pressure to the diaphragm 64 during the discharge time, if the volume of fluid remaining in the pump chambers T1 to T6 is less than or equal to a predetermined amount, "complete discharge" may be considered achieved.

[0078] If flow limitations exist, even if a predetermined vacuum or negative pressure is applied to the region of the diaphragm 64 superimposed on specific pump chambers T1 to T6 for the duration of the inflow time, the pump chambers T1 to T6 may not reach complete filling, even though complete filling should be achieved with that vacuum or negative pressure. In such situations, less fluid than expected is drawn into the pump chambers T1 to T6 in relation to the vacuum or negative pressure applied during the inflow time. Similarly, if pump flow limitations exist, even if a predetermined positive pressure is applied to the region of the diaphragm 64 superimposed on specific pump chambers T1 to T6 for the duration of the outflow time, the pump chambers T1 to T6 may not reach complete discharge, even though complete discharge should be achieved with that positive pressure. In such situations, less fluid than expected is transported from the pump chambers T1 to T6 in relation to the positive pressure applied during the outflow time.

[0079] In one aspect of the present disclosure, the control unit 18 is programmed to determine whether complete filling has been achieved by applying vacuum or negative pressure to the region of the diaphragm 64 superimposed on a specific pump chamber T1 to T6 during the inflow time, and whether complete discharge has been achieved by applying positive pressure to the region of the diaphragm 64 superimposed on a specific pump chamber T1 to T6 during the outflow time. While it may be advantageous for the control unit 18 to be programmed to evaluate both complete filling and complete discharge (and to adjust the operation of the pump system in response to incomplete filling and / or incomplete discharge, as described later), within the scope of the present disclosure, the control unit 18 is also programmed to evaluate only one of complete filling or complete discharge (and to adjust the operation of the pump system if the conditions programmed for monitoring by the control unit 18 are not met).

[0080] The control unit 18 operates in conjunction with the electrodes 66 in the pump chambers T1-T6 and the capacitance sensor 68 of the cassette station 54 (as well as the current source 70 of the fluid processing device 10 that supplies current to the electrodes 66) to evaluate the complete filling and / or complete emptying of the pump chambers T1-T6. As shown in Figure 4, at least a portion of the electrodes 66 are located inside the pump chambers T1-T6 so that the electrodes 66 can come into contact with the fluid located inside the pump chambers T1-T6. The electrodes 66 are configured and positioned to be electrically coupled to the corresponding capacitance sensor 68 when the flow control cassette 48 is mounted on the cassette station 54, and the capacitance sensor 68 is operationally coupled to the control unit 18. The specific configurations of the electrodes 66 and the capacitance sensor 68 can be changed without departing from the scope of this disclosure (as long as they are appropriately configured to function in cooperation with each other), and in one embodiment each electrode 66 and each capacitance sensor 68 is in a conventional configuration.

[0081] The electrodes 66 and capacitance sensors 68 operate in a conventional manner (for example, as described in U.S. Patent Publication No. 2006 / 0161092), and the current passing through each electrode 66 creates an electric field in the corresponding pump chambers T1 to T6. The regions of the diaphragm 64 superimposed on the pump chambers T1 to T6 are alternately displaced, drawing fluid into and out of the pump chambers T1 to T6, which changes the electric field and consequently changes the total capacitance of the circuit via the electrodes 66. In particular, the capacitance increases when fluid is drawn into the pump chambers T1 to T6 and decreases when fluid is discharged from the pump chambers T1 to T6.

[0082] The signals transmitted from each capacitance sensor 68 to the control unit 18 reflect the capacitance of the corresponding electrode 66, and therefore the volume of fluid contained in the pump chambers T1 to T6 corresponding to that electrode 66 at the time of signal transmission. During the inflow time, the signals transmitted from the capacitance sensor 68 to the control unit 18 at a timing that reflects the volume of fluid in the corresponding pump chambers T1 to T6 after a vacuum or negative pressure has been applied to the region of the diaphragm 64 superimposed on the pump chambers T1 to T6 are referred to herein as "inflow signals". Similarly, during the outflow time, the signals transmitted from the capacitance sensor 68 to the control unit 18 at a timing that reflects the volume of fluid remaining in the corresponding pump chambers T1 to T6 after a positive pressure has been applied to the region of the diaphragm 64 superimposed on the pump chambers T1 to T6 are referred to herein as "outflow signals".

[0083] When the monitored pump chambers T1 to T6 are filled with fluid (when the diaphragm 64 is in the state or position shown by the solid line in Figure 4), the capacitance signal shows a relatively high signal strength or voltage. When the monitored pump chambers T1 to T6 are empty of fluid (when the diaphragm 64 is in the state or position shown by the dashed line in Figure 4), the capacitance signal shows a relatively low signal strength or voltage. Furthermore, when an intermediate volume of fluid is present in the monitored pump chambers T1 to T6, there is an intermediate range of signal strength or voltage, corresponding to the diaphragm 64 being in a position between the two positions shown in Figure 4. Therefore, an inflow signal with the maximum signal strength or voltage indicates complete filling, and the control unit 18 can determine that complete filling has been achieved. On the other hand, an inflow signal with a lower signal strength or voltage indicates incomplete filling, and the control unit 18 can determine that complete filling has not been achieved. Similarly, an outflow signal with the minimum signal strength or voltage (including cases where the voltage or signal strength is zero) indicates complete discharge, and the control unit 18 can determine that complete discharge has been achieved. On the other hand, an outflow signal with a higher signal intensity or voltage indicates incomplete discharge, and the control unit 18 can determine that complete discharge has not been achieved.

[0084] If the inflow signal indicates that complete filling has not been achieved even after applying a vacuum or negative pressure of a specific strength for the duration of the inflow time, the control unit 18 may calculate the vacuum or negative pressure strength required to achieve complete filling in the same inflow time (this will be a greater value than the vacuum or negative pressure applied immediately before). The control unit 18 may calculate the vacuum or negative pressure strength thus adjusted in any suitable way without departing from the scope of this disclosure. Similarly, if the outflow signal indicates that complete discharge has not been achieved even after applying a positive pressure of a specific strength for the duration of the outflow time, the control unit 18 may calculate the positive pressure strength required to achieve complete discharge in the same outflow time (this will be a greater value than the positive pressure applied immediately before). The control unit 18 may calculate the positive pressure strength thus adjusted in any suitable way without departing from the scope of this disclosure.

[0085] According to one embodiment of the present disclosure, the control unit 18 is programmed to dynamically determine the minimum (or weakest) vacuum or negative pressure that can achieve complete filling of pump chambers T1 to T6 for a given inflow time, and to execute a protocol calculated to apply that vacuum or negative pressure (hereinafter referred to as the “inflow protocol”). According to another embodiment of the present disclosure, the control unit 18 is programmed to dynamically determine the minimum (or weakest) positive pressure that can achieve complete discharge of pump chambers T1 to T6 for a given outflow time, and to execute a protocol calculated to apply that positive pressure (hereinafter referred to as the “outflow protocol”). According to yet another embodiment, the control unit 18 is programmed to execute both the inflow protocol and the outflow protocol.

[0086] Before considering specific inflow and outflow protocols, it is necessary to understand that in a fluid processing procedure, specific pumps P1-P6 and corresponding pump chambers T1-T6 may be used to deliver different fluids at different stages of the procedure. For example, in a typical blood separation procedure, a certain pump / pump chamber set may be used for the flow of saline during the priming stage of the procedure, for the flow of whole blood during the blood separation stage, and for the flow of blood component preservation solution in the post-separation stage. Since different fluids may require different delivery pressures, an inflow and / or outflow protocol performed on a particular pump / pump chamber set while delivering saline may not be applicable later in the same procedure when delivering whole blood using the same pump / pump chamber set. Therefore, the control unit 18 may execute multiple inflow and / or outflow protocols on a particular pump / pump chamber set during a fluid processing procedure. That is, a new inflow and / or outflow protocol is initiated each time a new fluid is delivered using that pump / pump chamber set. Therefore, the term “fluid flow procedure” as used herein should be understood to refer to a specific fluid being delivered using a particular pump / pump chamber set, and a new “fluid flow procedure” (and inflow / outflow protocol) is initiated when a different fluid is delivered using the same pump / pump chamber set. In fact, in a multi-stage fluid handling procedure, multiple inflow and / or outflow protocols may be executed for a particular pump / pump chamber set. Each inflow protocol may have the same or different settings (e.g., different delivery pressure levels), and each outflow protocol may similarly have the same or different settings.

[0087] Moving on to the inflow protocol, in one embodiment, when vacuum or negative pressure is first applied to the region of the diaphragm 64 in the fluid flow procedure, the control unit 18 starts by operating pumps P1-P6 and applying an initial vacuum or negative pressure to the region of the diaphragm 64 superimposed on pump chambers T1-T6 aligned with pumps P1-P6 for the duration of the inflow. The initial vacuum or negative pressure is selected as the minimum or weakest vacuum or negative pressure expected to achieve complete filling of pump chambers T1-T6 when applied to the region of the diaphragm 64 for the duration of the inflow. This value assumes that there are no flow limitations that affect the pump system's ability to achieve complete filling. The strength or magnitude of the initial vacuum or negative pressure can be calculated empirically or theoretically by any suitable method without departing from the scope of this disclosure. Furthermore, this value may differ from system to system, and even from procedure to procedure within the same system.

[0088] After the fluid flow procedure is initiated and the pump system is activated to apply an initial vacuum or negative pressure to the diaphragm 64 for the duration of the inflow time, the capacitance sensor 68 transmits an inflow signal to the control unit 18, which evaluates the inflow signal as described above to determine whether full filling has been achieved. If the control unit 18 determines that full filling has not been achieved, it may activate the pump system to apply a second vacuum or negative pressure, stronger than the initial vacuum or negative pressure, to the same region of the diaphragm 64 for the same inflow time. The amount of increase in the vacuum or negative pressure can be set in various ways without departing from the scope of this disclosure. For example, in one embodiment, the control unit 18 may be programmed to increase the strength of the applied vacuum or negative pressure by a predetermined increment. In another embodiment, the control unit 18 may calculate the strength of the vacuum or negative pressure required to achieve full filling (as described above) in the same inflow time, and then be programmed to activate the pump system to apply an increased vacuum or negative pressure of that strength to the same region of the diaphragm 64 for the same inflow time.

[0089] After a second or increased vacuum or negative pressure is applied to the same region of the diaphragm 64 for the same inflow time, the control unit 18 evaluates the inflow signal from the capacitance sensor 68 and determines whether full filling has been achieved by the application of the second or increased vacuum or negative pressure. If full filling has not been achieved, the control unit 18 may repeat the alternating steps of operating the pump system to apply a larger (stronger) vacuum or negative pressure to the same region of the diaphragm 64 for the same inflow time than the vacuum or negative pressure applied immediately before, and analyzing the inflow signal obtained by the application of that vacuum or negative pressure to determine whether full filling has been achieved. These steps are repeated until the control unit 18 receives an inflow signal indicating that full filling has been achieved. In one embodiment, the control unit 18 may be programmed to have a maximum vacuum or negative pressure that the pump system can apply to the region of the diaphragm 64 (this may be the maximum vacuum or negative pressure that the pump system can generate, or a smaller value). In such an embodiment, if the control unit 18 determines, based on the inflow signal, that it is necessary to apply a vacuum or negative pressure exceeding the maximum value, the control unit 18 may generate a warning or alarm and either pause the procedure (instead of performing the pressure change indicated by the inflow signal) or change the applied vacuum or negative pressure to the set maximum value.

[0090] If the control unit 18 determines that full filling has been achieved (whether achieved by the initial vacuum or negative pressure, the second vacuum or negative pressure, or any other increased vacuum or negative pressure), the control unit 18 may continue to control the pump system to apply the same vacuum or negative pressure to the same area of ​​the diaphragm 64 for the same inflow time each time it applies vacuum or negative pressure to the area of ​​the diaphragm 64. With this approach, as long as the inflow signal from the capacitance sensor 68 continues to indicate that full filling has been achieved, the control unit 18 may continue to control the pump system to apply the same vacuum or negative pressure to the same area of ​​the diaphragm 64 for the same inflow time each time it applies vacuum or negative pressure to the area of ​​the diaphragm 64 for the remainder of the fluid flow procedure. If the inflow signal indicates that full filling has not been achieved (for example, if flow restriction occurs), the control unit 18 may proceed with increasing the strength of the applied vacuum or negative pressure according to the approach described above until it receives a signal indicating that full filling has been achieved.

[0091] Alternatively, instead of applying the same vacuum or negative pressure for the remainder of the fluid flow procedure, the control unit 18 may continue to control the pump system to apply the most recently applied vacuum or negative pressure to the same area of ​​the diaphragm 64 for the same inflow time, but only until a predetermined time or volume of fluid has been delivered (provided that the inflow signal from the capacitance sensor 68 continues to indicate that full filling has been achieved). Once the delivery of the predetermined time or volume of fluid is complete, the control unit 18 may operate the pump system to apply a weaker (smaller) vacuum or negative pressure to the area of ​​the diaphragm 64 for the same inflow time. This can be understood as an attempt to verify whether full filling can be achieved with a weaker vacuum or negative pressure, given that any previously existing flow limitations have been removed. If the control unit 18 is programmed to deliver a predetermined time or volume of fluid, this value may remain constant throughout the entire fluid flow procedure or may be changed midway through the procedure. The change may be pre-programmed in the control unit 18, or the control unit 18 may be programmed to determine the change (based on any factor, as long as it does not exceed the scope of this disclosure).

[0092] When a reduced vacuum or negative pressure is applied, the capacitance sensor 68 transmits an inflow signal to the control unit 18, which evaluates the inflow signal to determine whether full filling has been achieved using the reduced vacuum or negative pressure. If the control unit 18 determines that full filling has been achieved, it may continue to operate the pump system to apply the same reduced vacuum or negative pressure for the same inflow time when applying vacuum or negative pressure to the area of ​​the diaphragm 64 for the remainder of the fluid flow procedure (as described above) or for the predetermined period described above. Alternatively, as long as the inflow signal from the capacitance sensor 68 continues to indicate full filling, the control unit 18 may operate the pump system to apply an even weaker vacuum or negative pressure to the same area of ​​the diaphragm 64 for the same inflow time.

[0093] However, if the control unit 18 receives an inflow signal indicating that full filling has not been achieved using the reduced vacuum or negative pressure, the control unit 18 may activate the pump system to apply a stronger increased vacuum or negative pressure to the same area of ​​the diaphragm 64 for the same inflow time than the most recently applied vacuum or negative pressure. The control unit 18 can then continue to increase the strength of the vacuum or negative pressure (according to the approach described above) until it receives an inflow signal indicating full filling. By implementing such a protocol, the control unit 18 can dynamically determine the minimum or weakest vacuum or negative pressure applicable to achieve full filling.

[0094] As an alternative response when full filling is detected, instead of continuing to apply the most recently applied vacuum or negative pressure for the same inflow time when applying vacuum or negative pressure to the same area of ​​the diaphragm 64 thereafter, until a predetermined time or volume of fluid has been delivered, the control unit 18 may be programmed to control the pump system to immediately apply a reduced vacuum or negative pressure for the same inflow time the next time vacuum or negative pressure is applied to the same area of ​​the diaphragm 64. Such an approach can be understood as a more proactive attempt to verify whether full filling is achievable with the application of a reduced vacuum or negative pressure. If fluid flow stability is a priority, it may be desirable to maintain the applied vacuum or negative pressure at the same level for the duration of fluid delivery for a predetermined time or volume before reducing the vacuum or negative pressure. On the other hand, if the priority is to identify the weakest vacuum or negative pressure applicable to achieve full filling, it may be desirable to immediately reduce the applied vacuum or negative pressure.

[0095] If the inflow protocol includes a step of reducing the strength of the vacuum or negative pressure at some point after full filling has been achieved, that step may be continuously performed by the control unit 18 throughout the entire fluid flow procedure. Alternatively, the control unit 18 may be programmed to perform the step a predetermined number of times during the fluid flow procedure (e.g., periodically or in a rolling manner throughout the procedure), including performing it only once. In one embodiment, the control unit 18 may be programmed to perform the step once for each fluid delivered using specific pumps P1-P6 and corresponding pump chambers T1-T6 in a multi-stage fluid processing procedure. For example, it may be performed once for the flow of saline during the priming stage of the procedure, once for the flow of whole blood during the blood separation stage, and once for the flow of blood component preservation solution during the post-separation stage. As described above, the delivery of different fluids by a particular pump / pump chamber can be understood as the execution of different "fluid flow procedures" (each with its own unique inflow protocol), and this approach can be understood as the process being executed once for each fluid flow procedure in a multi-stage fluid processing procedure.

[0096] Regardless of the details of how the inflow protocol is implemented, the overall effect is that the control unit 18 starts by operating the pump system to apply a relatively weak vacuum or negative pressure (calculated to achieve full filling of the pump chambers T1-T6 aligned with the area of ​​the diaphragm 64) to the area of ​​the diaphragm 64, dynamically determines whether full filling has been achieved, and dynamically adjusts the strength of the applied vacuum or negative pressure (without changing the inflow time) until it reaches a strength sufficient to achieve full filling. Even after full filling has been achieved, the control unit 18 may reduce the strength of the applied vacuum or negative pressure (without changing the inflow time) to check whether full filling can be adequately and effectively achieved with a weaker vacuum or negative pressure, for example, if any previously existing flow restrictions have been removed. The advantages of using the weakest applicable vacuum or negative pressure include reduced wear on mechanical parts, reduced need for continuous operation of noisy compressors, minimized wear on the diaphragm 64, improved donor / patient comfort (when the inflow protocol is applied to pumps drawing blood from a donor or patient vein), and the ability to increase speed without increasing the risk of damaging fluid components (e.g., red blood cells or platelets) during the fluid flow procedure.

[0097] Moving on to the discharge protocol, in one embodiment, when positive pressure is first applied to the region of the diaphragm 64 in the fluid flow procedure, the control unit 18 starts by operating pumps P1-P6 and applying an initial positive pressure to the region of the diaphragm 64 superimposed on the pump chambers T1-T6 aligned with the pumps P1-P6 for the duration of the discharge time. The initial positive pressure is selected as the minimum or weakest positive pressure expected to achieve complete discharge of the pump chambers T1-T6 when applied to the region of the diaphragm 64 for the duration of the discharge time. This value assumes that there are no flow constraints that affect the pump system's ability to achieve complete discharge. The strength or magnitude of the initial positive pressure can be calculated empirically or theoretically by any suitable method without departing from the scope of this disclosure. Furthermore, this value may differ from system to system, and even from procedure to procedure within the same system.

[0098] After the fluid flow procedure is initiated and the pump system is activated to apply an initial positive pressure to the diaphragm 64 for the duration of the discharge time, the capacitance sensor 68 transmits a discharge signal to the control unit 18, which evaluates the discharge signal as described above to determine whether complete discharge has been achieved. If the control unit 18 determines that complete discharge has not been achieved, it may activate the pump system to apply a second positive pressure or an increased positive pressure, which is stronger than the initial positive pressure, to the same discharge time when applying positive pressure to the area of ​​the diaphragm 64 next. The amount of increase in the strength of the positive pressure can be set in various ways without departing from the scope of this disclosure. For example, in one embodiment, the control unit 18 may be programmed to increase the strength of the applied positive pressure by a predetermined increment. In another embodiment, the control unit 18 may calculate the strength of the positive pressure required to achieve complete discharge in the same discharge time (as described above) and then activate the pump system to apply an increased positive pressure of that strength to the same discharge time when applying positive pressure to the same area of ​​the diaphragm 64 next.

[0099] After a second or increased positive pressure is applied to the same area of ​​the diaphragm 64 for the same discharge time, the control unit 18 evaluates the discharge signal from the capacitance sensor 68 and determines whether complete discharge has been achieved by the application of the second or increased positive pressure. If complete discharge has not been achieved, the control unit 18 may repeat the alternating steps of operating the pump system to apply a greater (stronger) positive pressure to the same area of ​​the diaphragm 64 for the same discharge time than the previously applied positive pressure, and analyzing the discharge signal obtained by the application of that positive pressure to determine whether complete discharge has been achieved. These steps are repeated until the control unit 18 receives a discharge signal indicating that complete discharge has been achieved. In one embodiment, the control unit 18 may be programmed to have a maximum positive pressure that the pump system can apply to the area of ​​the diaphragm 64 (this may be the maximum value that the pump system can generate, or a smaller value). In such an embodiment, if the control unit 18 determines, based on the outflow signal, that it is necessary to apply a positive pressure exceeding the maximum value, the control unit 18 may generate a warning or alarm, pause the procedure (instead of performing the pressure change indicated by the outflow signal), or change the applied positive pressure to the set maximum value.

[0100] If the control unit 18 determines that complete evacuation has been achieved (whether achieved by the initial positive pressure, the second positive pressure, or any other increased positive pressure), the control unit 18 may continue to control the pump system to apply the same positive pressure to the same area of ​​the diaphragm 64 for the same evacuation time each time positive pressure is applied to the area of ​​the diaphragm 64. With this approach, as long as the evacuation signal from the capacitance sensor 68 continues to indicate that complete evacuation has been achieved, the control unit 18 may continue to control the pump system to apply the same positive pressure to the same area of ​​the diaphragm 64 for the remainder of the fluid flow procedure each time positive pressure is applied to the area of ​​the diaphragm 64 for the same evacuation time. If the evacuation signal indicates that complete evacuation has not been achieved (for example, if flow restriction occurs), the control unit 18 may proceed with increasing the strength of the applied positive pressure according to the approach described above until it receives a signal indicating that complete evacuation has been achieved.

[0101] Alternatively, instead of applying the same positive pressure for the remainder of the fluid flow procedure, the control unit 18 may continue to control the pump system to apply the most recently applied positive pressure to the same area of ​​the diaphragm 64 for the same discharge time, but only until a predetermined time or amount of fluid has been delivered (provided that the discharge signal from the capacitance sensor 68 continues to indicate that complete discharge has been achieved). Once the delivery of the predetermined time or amount of fluid is complete, the control unit 18 may operate the pump system to apply a weaker (smaller) positive pressure to the area of ​​the diaphragm 64 for the same discharge time. This can be understood as an attempt to verify whether complete discharge can be achieved with a weaker positive pressure, given that any previously existing flow limitations have been removed. If the control unit 18 is programmed to deliver a predetermined time or amount of fluid, this value may remain constant throughout the entire fluid flow procedure or may be changed midway through the procedure. The change may be pre-programmed in the control unit 18, or the control unit 18 may be programmed to determine the change (based on any factor, as long as it does not exceed the scope of this disclosure).

[0102] When the reduced positive pressure is applied, the capacitance sensor 68 transmits an outflow signal to the control unit 18, which evaluates the outflow signal to determine whether complete discharge has been achieved using the reduced positive pressure. If the control unit 18 determines that complete discharge has been achieved, it may continue to operate the pump system to apply the same reduced positive pressure for the same discharge time when applying positive pressure to the area of ​​the diaphragm 64 next for the remainder of the fluid flow procedure or for the predetermined period described above. Alternatively, as long as the outflow signal from the capacitance sensor 68 continues to indicate complete discharge, the control unit 18 may operate the pump system to apply an even weaker positive pressure to the same area of ​​the diaphragm 64 for the same discharge time.

[0103] However, if the control unit 18 receives an outflow signal indicating that complete discharge has not been achieved using the reduced positive pressure, the control unit 18 may activate the pump system to apply an increased positive pressure to the same area of ​​the diaphragm 64 that is stronger than the most recently applied positive pressure for the same discharge time. The control unit 18 can then continue to increase the strength of the positive pressure (according to the approach described above) until it receives an outflow signal indicating complete discharge. By implementing such a protocol, the control unit 18 can dynamically determine the minimum or weakest positive pressure applicable to achieve complete discharge.

[0104] As an alternative response when complete discharge is detected, instead of continuing to apply the most recently applied positive pressure for the same discharge time when applying positive pressure to the same area of ​​the diaphragm 64 for a predetermined time or until a predetermined amount of fluid has been delivered, the control unit 18 may be programmed to control the pump system to immediately apply a reduced positive pressure for the same discharge time when applying positive pressure to the same area of ​​the diaphragm 64 next. Such an approach can be understood as an attempt to more actively verify whether complete discharge is achievable with the application of reduced positive pressure. If fluid flow stability is a priority, it may be desirable to maintain the applied positive pressure at the same level for a predetermined time or for the delivery of a predetermined amount of fluid before reducing the positive pressure. On the other hand, if the priority is to identify the weakest positive pressure applicable to achieve complete discharge, it may be desirable to immediately reduce the applied positive pressure.

[0105] If the discharge protocol includes a step of reducing the strength of the positive pressure at some point after complete discharge has been achieved, that step may be continuously performed by the control unit 18 throughout the entire fluid flow procedure. Alternatively, the control unit 18 may be programmed to perform the step a predetermined number of times during the fluid flow procedure (e.g., periodically or in a rolling manner throughout the procedure), including performing it only once. In one embodiment, the control unit 18 may be programmed to perform the step once for each fluid delivered using specific pumps P1-P6 and corresponding pump chambers T1-T6 in a multi-stage fluid processing procedure. For example, it may be performed once for the flow of saline in the priming stage of the procedure, once for the flow of whole blood in the blood separation stage, and once for the flow of blood component preservation solution in the post-separation stage. As described above, the delivery of different fluids by specific pump / pump chamber pairs can be understood as the execution of different “fluid flow procedures” (each with its own unique discharge protocol), so this approach can be understood as the step being performed once for each fluid flow procedure in a multi-stage fluid processing procedure.

[0106] Regardless of the details of how the discharge protocol is implemented, the overall effect is that the control unit 18 starts by operating the pump system to apply a relatively weak positive pressure (calculated to achieve complete discharge of pump chambers T1-T6 aligned with the area of ​​the diaphragm 64) to the area of ​​the diaphragm 64, dynamically determines whether complete discharge has been achieved, and dynamically adjusts the strength of the applied positive pressure (without changing the discharge time) until it reaches a strength sufficient to achieve complete discharge. Even after complete discharge has been achieved, the control unit 18 may reduce the strength of the applied positive pressure (without changing the discharge time) to check whether complete discharge can be adequately and effectively achieved with a weaker positive pressure, for example, if any previously existing flow restrictions have been removed. Similar to the description of the inflow protocol mentioned above, the advantages of using the weakest applicable positive pressure include reduced wear on mechanical parts, reduced need for continuous operation of noisy compressors, minimized wear on the diaphragm 64, improved donor / patient comfort (when the outflow protocol is applied to a pump delivering fluid to a donor or patient), and the ability to increase speed without increasing the risk of damaging fluid components (e.g., red blood cells or platelets) during the fluid flow procedure.

[0107] V. Mode Appearance 1 A fluid processing apparatus used in combination with a fluid flow circuit comprising a pump chamber including a flexible diaphragm and electrodes, comprising: a control unit programmed to perform a fluid flow procedure; and a pneumatic pump operationally coupled to the control unit and configured to be operated by the control unit to alternately perform, during the fluid flow procedure, negative pressure applied to the flexible diaphragm of the pump chamber during the inflow time to draw fluid into the pump chamber, and positive pressure applied to the flexible diaphragm of the pump chamber during the outflow time to transport fluid out of the pump chamber. The system includes a capacitive sensor configured to be operationally coupled to the control unit and electrically coupled to the electrodes of the pump chamber, and to transmit an inflow signal to the control unit indicating the inflow volume of fluid drawn into the pump chamber while the pneumatic pump is applying negative pressure to the flexible diaphragm of the pump chamber during the inflow time, wherein the control unit operates the pneumatic pump to apply an initial negative pressure to the flexible diaphragm of the pump chamber with respect to the inflow time when negative pressure is first applied to the flexible diaphragm of the pump chamber during the fluid flow procedure, and the initial negative pressure is achieved when the pump chamber is fully filled while negative pressure is applied to the flexible diaphragm of the pump chamber during the inflow time. A fluid processing apparatus selected as the minimum expected negative pressure, which determines, at least partially, based on the inflow signal, whether the pump chamber is fully filled while the initial negative pressure is applied to the flexible diaphragm of the pump chamber during the inflow time, and if it is determined that the pump chamber is not fully filled while the initial negative pressure is applied to the flexible diaphragm of the pump chamber during the inflow time, the apparatus is programmed to operate the pneumatic pump to apply a second negative pressure to the flexible diaphragm of the pump chamber, which is greater than the initial negative pressure relative to the inflow time, when the next negative pressure is applied to the flexible diaphragm of the pump chamber in the fluid flow procedure.

[0108] Appearance 2 The fluid apparatus according to embodiment 1, wherein the second negative pressure is greater than the initial negative pressure by a predetermined increment.

[0109] Appearance 3 The fluid apparatus according to Embodiment 1, wherein the control unit is further programmed to determine the negative pressure required to achieve full filling of the pump chamber, which should be applied to the flexible diaphragm of the pump chamber during the inflow time, if it determines that full filling of the pump chamber has not been achieved while an initial negative pressure is being applied to the flexible diaphragm of the pump chamber during the inflow time, and the second negative pressure is selected to be equal to the negative pressure required to achieve full filling of the flexible diaphragm of the pump chamber during the inflow time.

[0110] Pattern 4 The fluid processing apparatus according to any one of Embodiments 1 to 3, wherein the control unit is programmed to (a) determine whether the negative pressure most recently applied to the flexible diaphragm of the pump chamber during the inflow time has achieved complete filling of the pump chamber, and (b) if it is determined that the negative pressure most recently applied to the flexible diaphragm of the pump chamber during the inflow time has not achieved complete filling of the pump chamber, then operate the pneumatic pump to apply an increased negative pressure greater than the negative pressure most recently applied relative to the inflow time to the flexible diaphragm of the pump chamber when applying negative pressure to the flexible diaphragm of the pump chamber in the next fluid flow procedure, and (c) repeat (a) and (b) until it is determined that the negative pressure most recently applied to the flexible diaphragm of the pump chamber during the inflow time has achieved complete filling of the pump chamber.

[0111] Appearance 5 The fluid processing apparatus according to any one of embodiments 1 to 4, wherein the control unit is further programmed to operate the pneumatic pump to continue applying the negative pressure most recently applied to the flexible diaphragm of the pump chamber to the flexible diaphragm of the pump chamber when applying negative pressure to the flexible diaphragm of the pump chamber in the next fluid flow procedure, if it determines that the pump chamber has been fully filled by the application of negative pressure most recently applied to the flexible diaphragm of the pump chamber during the inflow time.

[0112] Appearance 6 The fluid processing apparatus according to any one of embodiments 1 to 5, wherein the control unit is further programmed to operate the pneumatic pump so that, when it determines that the pump chamber has been fully filled by the application of the most recently applied negative pressure to the flexible diaphragm of the pump chamber during the inflow time, it continues to apply the most recently applied negative pressure to the flexible diaphragm of the pump chamber to the flexible diaphragm of the pump chamber until the fluid flow procedure is completed.

[0113] Appearance 7 The fluid processing apparatus according to any one of embodiments 1 to 5, wherein the control unit is further programmed to operate the pneumatic pump to continue applying the most recently applied negative pressure to the flexible diaphragm of the pump chamber to the flexible diaphragm of the pump chamber when applying negative pressure to the flexible diaphragm of the pump chamber thereafter, until a predetermined amount of fluid has been delivered for a predetermined time in the fluid flow procedure.

[0114] Appearance 8 The fluid processing apparatus according to embodiment 7, wherein the control unit is further programmed to (d) determine whether the delivery of a predetermined time or volume of fluid has been completed, and if it is determined that the delivery of a predetermined time or volume of fluid has been completed, (e) when the next time negative pressure is applied to the flexible diaphragm of the pump chamber in the fluid flow procedure, the pneumatic pump is to apply a reduced negative pressure to the flexible diaphragm of the pump chamber that is lower than the negative pressure most recently applied relative to the inflow time.

[0115] Appearance 9 The fluid processing apparatus according to embodiment 8, wherein the control unit is further programmed to (f) determine whether the most recently applied reduced negative pressure to the flexible diaphragm of the pump chamber during the inflow time has achieved complete filling of the pump chamber, and (g) repeat (e) and (f) until it determines that the most recently applied reduced negative pressure to the flexible diaphragm of the pump chamber during the inflow time has not achieved complete filling of the pump chamber, and if it determines that the most recently applied reduced negative pressure to the flexible diaphragm of the pump chamber during the inflow time has not achieved complete filling of the pump chamber, it operates the pneumatic pump to apply an increased negative pressure to the flexible diaphragm of the pump chamber that is greater than the most recently applied reduced negative pressure relative to the inflow time when the next time negative pressure is applied to the flexible diaphragm of the pump chamber in the fluid flow procedure.

[0116] Appearance 10 The control unit (d) determines whether the negative pressure most recently applied to the flexible diaphragm of the pump chamber during the inflow time has achieved complete filling of the pump chamber, and if it determines that the negative pressure most recently applied to the flexible diaphragm of the pump chamber during the inflow time has achieved complete filling of the pump chamber, (e) when applying negative pressure to the flexible diaphragm of the pump chamber next in the fluid flow procedure, it operates the pneumatic pump to apply a reduced negative pressure to the flexible diaphragm of the pump chamber that is lower than the negative pressure most recently applied relative to the inflow time, (f) determines whether the reduced negative pressure most recently applied to the flexible diaphragm of the pump chamber has achieved complete filling of the pump chamber, and (g) The fluid processing apparatus according to any one of embodiments 1 to 4, wherein (e) and (f) are repeated until it is determined that the most recently applied reduced negative pressure to the flexible diaphragm of the pump chamber during the inflow time has not achieved full filling of the pump chamber, and if it is determined that the most recently applied reduced negative pressure to the flexible diaphragm of the pump chamber during the inflow time has not achieved full filling of the pump chamber, the apparatus is further programmed to operate the pneumatic pump to apply an increased negative pressure to the flexible diaphragm of the pump chamber that is greater than the most recently applied reduced negative pressure relative to the inflow time when the next time negative pressure is applied to the flexible diaphragm of the pump chamber in the fluid flow procedure.

[0117] Appearance 11 The control unit is A multi-stage fluid processing procedure is performed in which different fluids are pumped through a pump chamber by a pneumatic pump in at least two stages of the fluid processing procedure. A fluid apparatus according to any one of embodiments 1 to 10, further programmed to perform separate fluid flow procedures for at least two different fluids.

[0118] Appearance 12 A method for performing a fluid flow procedure using a fluid flow circuit comprising a pump chamber including a flexible diaphragm and electrodes, which is executed by a control unit, comprising the step of operating a pneumatic pump to alternately apply negative pressure to the flexible diaphragm of the pump chamber during the inflow time to draw fluid into the pump chamber, and apply positive pressure to the flexible diaphragm of the pump chamber during the outflow time to transport fluid out of the pump chamber, wherein when negative pressure is first applied to the flexible diaphragm of the pump chamber in the fluid flow procedure, the pneumatic pump is operated to apply an initial negative pressure to the flexible diaphragm of the pump chamber with respect to the inflow time, and the initial negative pressure is selected as the minimum negative pressure at which complete filling of the pump chamber is expected to be achieved when negative pressure is applied to the flexible diaphragm of the pump chamber during the inflow time. The method includes the steps of: receiving an inflow signal from a capacitance sensor electrically coupled to an electrode in the pump chamber, indicating the volume of fluid drawn into the pump chamber while the pneumatic pump is applying negative pressure to the flexible diaphragm of the pump chamber during the inflow time; determining, at least partially based on the inflow signal, whether the pump chamber is fully filled while an initial negative pressure is applied to the flexible diaphragm of the pump chamber during the inflow time; and, if it is determined that the pump chamber is not fully filled while an initial negative pressure is applied to the flexible diaphragm of the pump chamber during the inflow time, operating the pneumatic pump to apply a second negative pressure to the flexible diaphragm of the pump chamber, which is greater than the initial negative pressure relative to the inflow time, when applying negative pressure to the flexible diaphragm of the pump chamber next in the fluid flow procedure.

[0119] Appearance 13 The method according to embodiment 12, wherein the second negative pressure is greater than the initial negative pressure by a predetermined increment.

[0120] Appearance 14 The method according to embodiment 12, further comprising the step of determining the negative pressure required to achieve full filling of the pump chamber to be applied to the flexible diaphragm of the pump chamber during the inflow time, if it is determined that full filling of the pump chamber has not been achieved while an initial negative pressure is applied to the flexible diaphragm of the pump chamber during the inflow time, wherein the second negative pressure is equal to the negative pressure required to achieve full filling to be applied to the flexible diaphragm of the pump chamber during the inflow time.

[0121] Appearance 15 (a) Determine whether the negative pressure most recently applied to the flexible diaphragm of the pump chamber during the inflow time has achieved complete filling of the pump chamber; (b) If it is determined that the negative pressure most recently applied to the flexible diaphragm of the pump chamber during the inflow time has not achieved complete filling of the pump chamber, operate the pneumatic pump to apply an increased negative pressure to the flexible diaphragm of the pump chamber that is greater than the negative pressure most recently applied during the inflow time when the next negative pressure is applied to the flexible diaphragm of the pump chamber in the fluid flow procedure. (c) The method according to any one of embodiments 12 to 14, wherein (a) and (b) are repeated until it is determined that the negative pressure most recently applied to the flexible diaphragm of the pump chamber during the inflow time has achieved complete filling of the pump chamber.

[0122] Appearance 16 The method according to any one of embodiments 12 to 15, further comprising the step of operating a pneumatic pump to continue applying the most recently applied negative pressure to the flexible diaphragm of the pump chamber to the flexible diaphragm of the pump chamber when applying negative pressure to the flexible diaphragm of the pump chamber in the fluid flow procedure, if it is determined that the pump chamber has been fully filled by the application of the most recently applied negative pressure to the flexible diaphragm of the pump chamber during the inflow time.

[0123] Appearance 17 The method according to any one of embodiments 12 to 16, further comprising the step of operating the pneumatic pump to continue applying the most recently applied negative pressure to the flexible diaphragm of the pump chamber to the flexible diaphragm of the pump chamber when applying negative pressure thereafter, until the fluid flow procedure is completed.

[0124] Appearance 18 The method according to any one of embodiments 12 to 16, further comprising the step of operating the pneumatic pump to continue applying the most recently applied negative pressure to the flexible diaphragm of the pump chamber to the flexible diaphragm of the pump chamber when applying negative pressure to the flexible diaphragm of the pump chamber thereafter, until a predetermined amount of fluid has been delivered for a predetermined time in the fluid flow procedure, until a predetermined amount of fluid has been delivered.

[0125] Appearance 19 (d) Determining whether the delivery of a predetermined time or volume of fluid has been completed, and if it is determined that the delivery of a predetermined time or volume of fluid has been completed, (e) The method according to embodiment 18, further comprising the step of operating the pneumatic pump to apply a reduced negative pressure to the flexible diaphragm of the pump chamber, which is lower than the negative pressure most recently applied with respect to the inflow time, when the next negative pressure is applied to the flexible diaphragm of the pump chamber in the fluid flow procedure.

[0126] Appearance 20 The method according to embodiment 19, further comprising: (f) determining whether the most recent reduced negative pressure applied to the flexible diaphragm of the pump chamber during the inflow time has achieved full filling of the pump chamber; and (g) repeating (e) and (f) until it is determined that the most recent reduced negative pressure applied to the flexible diaphragm of the pump chamber during the inflow time has not achieved full filling of the pump chamber, and if it is determined that the most recent reduced negative pressure applied to the flexible diaphragm of the pump chamber during the inflow time has not achieved full filling of the pump chamber, operating the pneumatic pump to apply an increased negative pressure to the flexible diaphragm of the pump chamber that is greater than the most recent reduced negative pressure applied relative to the inflow time when the next negative pressure is applied to the flexible diaphragm of the pump chamber in the fluid flow procedure.

[0127] Appearance 21 (d) Determine whether the negative pressure most recently applied to the flexible diaphragm of the pump chamber during the inflow time has achieved complete filling of the pump chamber, and if it is determined that the negative pressure most recently applied to the flexible diaphragm of the pump chamber during the inflow time has achieved complete filling of the pump chamber, (e) In the fluid flow procedure, when applying negative pressure to the flexible diaphragm of the pump chamber next, operate the pneumatic pump to apply a reduced negative pressure to the flexible diaphragm of the pump chamber that is lower than the negative pressure most recently applied relative to the inflow time, (f) Determine whether the reduced negative pressure most recently applied to the flexible diaphragm of the pump chamber has achieved complete filling of the pump chamber, (g) Repeating (e) and (f) until it is determined that the most recent reduced negative pressure applied to the flexible diaphragm of the pump chamber during the inflow time has not achieved full filling of the pump chamber, and if it is determined that the most recent reduced negative pressure applied to the flexible diaphragm of the pump chamber during the inflow time has not achieved full filling of the pump chamber, the method according to any one of embodiments 12 to 15, further comprising the step of operating the pneumatic pump to apply an increased negative pressure to the flexible diaphragm of the pump chamber that is greater than the most recent reduced negative pressure applied relative to the inflow time when the next negative pressure is applied to the flexible diaphragm of the pump chamber in the fluid flow procedure.

[0128] Appearance 22 The method according to any one of embodiments 12 to 21, comprising the step of performing a multi-stage fluid processing procedure in which different fluids are delivered through a pump chamber by a pneumatic pump in at least two stages of the fluid processing procedure, wherein separate fluid flow procedures are performed for at least two of the different fluids.

[0129] Appearance 23 A fluid processing apparatus for use in combination with a fluid flow circuit comprising a pump chamber including a flexible diaphragm and electrodes, comprising: a control unit programmed to perform a fluid flow procedure; a pneumatic pump operationally coupled to the control unit and configured to be operated by the control unit to alternately apply negative pressure to the flexible diaphragm of the pump chamber during the inflow time to draw fluid into the pump chamber and apply positive pressure to the flexible diaphragm of the pump chamber during the outflow time to transport fluid out of the pump chamber; and a capacitive sensor operationally coupled to the control unit and configured to be electrically coupled to the electrodes of the pump chamber, and configured to transmit an outflow signal to the control unit indicating the outflow volume of fluid transported from the pump chamber while the pneumatic pump is applying positive pressure to the flexible diaphragm of the pump chamber during the outflow time, wherein the control unit applies positive pressure to the flexible diaphragm of the pump chamber during the fluid flow procedure. A fluid processing apparatus is programmed to operate a pneumatic pump to apply an initial positive pressure to the flexible diaphragm of the pump chamber relative to the flow time when a fluid is first applied, the initial positive pressure being selected as the minimum positive pressure at which complete discharge of the pump chamber is expected to be achieved when positive pressure is applied to the flexible diaphragm of the pump chamber during the flow time, and to determine, at least partially based on the flow signal, whether complete discharge of the pump chamber has been achieved while the initial positive pressure is applied to the flexible diaphragm of the pump chamber during the flow time, and if it is determined that complete discharge of the pump chamber has not been achieved while the initial positive pressure is applied to the flexible diaphragm of the pump chamber during the flow time, to operate the pneumatic pump to apply a second positive pressure at which positive pressure is greater than the initial positive pressure relative to the flow time when positive pressure is next applied to the flexible diaphragm of the pump chamber in the fluid flow procedure.

[0130] Pattern 24 The fluid apparatus according to embodiment 23, wherein the second positive pressure is greater than the initial positive pressure by a predetermined increment.

[0131] Appearance 25 The fluid apparatus according to embodiment 23, wherein the control unit is further programmed to determine the positive pressure required to be applied to the flexible diaphragm of the pump chamber for complete discharge during the discharge time if it determines that complete discharge of the pump chamber has not been achieved while an initial positive pressure is applied to the flexible diaphragm of the pump chamber, and the second positive pressure is selected to be equal to the positive pressure required to be applied to the flexible diaphragm of the pump chamber for complete discharge during the discharge time.

[0132] Appearance 26 The fluid processing apparatus according to any one of embodiments 23 to 25, wherein the control unit (a) determines whether the positive pressure most recently applied to the flexible diaphragm of the pump chamber during the outflow time has achieved complete discharge of the pump chamber; (b) if it determines that the positive pressure most recently applied to the flexible diaphragm of the pump chamber during the outflow time has not achieved complete discharge of the pump chamber, it operates the pneumatic pump to apply an increased positive pressure to the flexible diaphragm of the pump chamber that is greater than the positive pressure most recently applied relative to the outflow time when applying positive pressure to the flexible diaphragm of the pump chamber in the next fluid flow procedure; and (c) repeats (a) and (b) until it determines that the positive pressure most recently applied to the flexible diaphragm of the pump chamber during the outflow time has achieved complete discharge of the pump chamber.

[0133] Appearance 27 The fluid processing apparatus according to any one of embodiments 23 to 26, wherein the control unit is further programmed to operate the pneumatic pump so that when it determines that complete discharge of the pump chamber has been achieved by applying the most recently applied positive pressure to the flexible diaphragm of the pump chamber during the discharge time, it continues to apply the most recently applied positive pressure to the flexible diaphragm of the pump chamber during the fluid flow procedure.

[0134] Appearance 28 The fluid processing apparatus according to any one of embodiments 23 to 27, wherein the control unit is further programmed to operate the pneumatic pump so that, when applying positive pressure to the flexible diaphragm of the pump chamber in the subsequent instances until the fluid flow procedure is completed, the positive pressure applied to the flexible diaphragm of the pump chamber in the most recent instance is applied to the flexible diaphragm of the pump chamber.

[0135] Appearance 29 The fluid processing apparatus according to any one of embodiments 23 to 27, wherein the control unit is further programmed to operate the pneumatic pump to continue applying the most recently applied positive pressure relative to the flow time to the flexible diaphragm of the pump chamber when applying positive pressure to the flexible diaphragm of the pump chamber thereafter, until a predetermined amount of fluid has been delivered for a predetermined time in the fluid flow procedure.

[0136] Appearance 30 The control unit is (d) Determining whether the delivery of a predetermined time or volume of fluid has been completed, and if it is determined that the delivery of a predetermined time or volume of fluid has been completed, (e) The fluid processing apparatus according to embodiment 29 is further programmed to operate the pneumatic pump to apply a reduced positive pressure to the flexible diaphragm of the pump chamber, which is lower than the most recently applied positive pressure relative to the outflow time, when applying positive pressure to the flexible diaphragm of the pump chamber in the next fluid flow procedure.

[0137] Appearance 31 The fluid processing apparatus according to embodiment 30, wherein the control unit is further programmed to (f) determine whether the most recently applied reduced positive pressure to the flexible diaphragm of the pump chamber during the outflow time has achieved complete discharge of the pump chamber, and (g) repeat (e) and (f) until it determines that the most recently applied reduced positive pressure to the flexible diaphragm of the pump chamber during the outflow time has not achieved complete discharge of the pump chamber, and if it determines that the most recently applied reduced positive pressure to the flexible diaphragm of the pump chamber during the outflow time has not achieved complete discharge of the pump chamber, the control unit is further programmed to operate the pneumatic pump to apply an increased positive pressure to the flexible diaphragm of the pump chamber that is greater than the most recently applied reduced positive pressure relative to the outflow time when applying positive pressure to the flexible diaphragm of the pump chamber in the next fluid flow procedure.

[0138] Appearance 32 The control unit (d) determines whether the positive pressure most recently applied to the flexible diaphragm of the pump chamber during the outflow time has achieved complete discharge of the pump chamber, and if it determines that the positive pressure most recently applied to the flexible diaphragm of the pump chamber during the outflow time has achieved complete discharge of the pump chamber, (e) when applying positive pressure to the flexible diaphragm of the pump chamber next in the fluid flow procedure, it operates the pneumatic pump to apply a reduced positive pressure to the flexible diaphragm of the pump chamber that is lower than the positive pressure most recently applied relative to the outflow time, (f) determines whether the reduced positive pressure most recently applied to the flexible diaphragm of the pump chamber has achieved complete discharge of the pump chamber, and (g) The fluid processing apparatus according to any one of embodiments 23 to 26, wherein (e) and (f) are repeated until it is determined that the most recently applied reduced positive pressure to the flexible diaphragm of the pump chamber has not achieved complete discharge of the pump chamber during the discharge time, and if it is determined that the most recently applied reduced positive pressure to the flexible diaphragm of the pump chamber has not achieved complete discharge of the pump chamber, the apparatus is further programmed to operate the pneumatic pump to apply an increased positive pressure to the flexible diaphragm of the pump chamber that is greater than the most recently applied reduced positive pressure for the discharge time when applying positive pressure to the flexible diaphragm of the pump chamber in the next fluid flow procedure.

[0139] Appearance 33 The fluid processing apparatus according to any one of embodiments 23 to 32, wherein the control unit is further programmed to perform a multi-stage fluid processing procedure in which different fluids are delivered through a pump chamber by a pneumatic pump in at least two stages of the fluid processing procedure, and to perform separate fluid flow procedures for at least two of the different fluids.

[0140] Appearance 34 A method for performing a fluid flow procedure using a fluid flow circuit comprising a pump chamber including a flexible diaphragm and electrodes, which is executed by a control unit, comprising the steps of operating a pneumatic pump to alternately apply negative pressure to the flexible diaphragm of the pump chamber during the inflow time to draw fluid into the pump chamber, and apply positive pressure to the flexible diaphragm of the pump chamber during the outflow time to transport the fluid out of the pump chamber, wherein when positive pressure is first applied to the flexible diaphragm of the pump chamber in the fluid flow procedure, the pneumatic pump is operated to apply an initial positive pressure to the flexible diaphragm of the pump chamber during the outflow time, and the initial positive pressure is selected as the minimum positive pressure at which complete discharge of the pump chamber is expected to be achieved when positive pressure is applied to the flexible diaphragm of the pump chamber during the outflow time. A method comprising: receiving an outflow signal from a capacitance sensor electrically coupled to an electrode in the pump chamber, indicating the outflow volume of fluid transported from the pump chamber while the pneumatic pump is applying positive pressure to the flexible diaphragm of the pump chamber during the outflow time; determining, at least partially, based on the outflow signal, whether complete discharge of the pump chamber has been achieved while an initial positive pressure is being applied to the flexible diaphragm of the pump chamber during the outflow time; and, if it is determined that complete discharge of the pump chamber has not been achieved while an initial positive pressure is being applied to the flexible diaphragm of the pump chamber during the outflow time, operating the pneumatic pump to apply a second positive pressure to the flexible diaphragm of the pump chamber, which is greater than the initial positive pressure with respect to the outflow time, when applying positive pressure to the flexible diaphragm of the pump chamber next in the fluid flow procedure.

[0141] Appearance 35 The method according to embodiment 34, wherein the second positive pressure is greater than the initial positive pressure by a predetermined increment.

[0142] Appearance 36 The method according to embodiment 34, further comprising the step of determining the positive pressure required to achieve complete discharge to be applied to the flexible diaphragm of the pump chamber during the discharge time, if it is determined that complete discharge of the pump chamber has not been achieved while an initial positive pressure is applied to the flexible diaphragm of the pump chamber during the discharge time, wherein the second positive pressure is equal to the positive pressure required to achieve complete discharge to be applied to the flexible diaphragm of the pump chamber during the discharge time.

[0143] Appearance 37 The method according to any one of embodiments 34 to 36, wherein (a) it is determined whether the positive pressure most recently applied to the flexible diaphragm of the pump chamber during the outflow time has achieved complete discharge of the pump chamber; (b) if it is determined that the positive pressure most recently applied to the flexible diaphragm of the pump chamber during the outflow time has not achieved complete discharge of the pump chamber, the pneumatic pump is operated to apply an increased positive pressure to the flexible diaphragm of the pump chamber that is greater than the positive pressure most recently applied relative to the outflow time when applying positive pressure to the flexible diaphragm of the pump chamber in the fluid flow procedure; and (c) steps (a) and (b) are repeated until it is determined that the positive pressure most recently applied to the flexible diaphragm of the pump chamber during the outflow time has achieved complete discharge of the pump chamber.

[0144] Appearance 38 The method according to any one of embodiments 34 to 37, further comprising, if it is determined that complete discharge of the pump chamber has been achieved by the application of the most recently applied positive pressure to the flexible diaphragm of the pump chamber during the discharge time, operating the pneumatic pump to continue applying the most recently applied positive pressure to the flexible diaphragm of the pump chamber during the next application of positive pressure to the flexible diaphragm of the pump chamber in the fluid flow procedure.

[0145] Appearance 39 The method according to any one of embodiments 34 to 38, further comprising, if it is determined that complete discharge of the pump chamber has been achieved by applying the most recently applied positive pressure to the flexible diaphragm of the pump chamber during the discharge time, operating the pneumatic pump to continue applying the most recently applied positive pressure to the flexible diaphragm of the pump chamber to the flexible diaphragm of the pump chamber until the fluid flow procedure is completed.

[0146] Pattern 40 The method according to any one of embodiments 34 to 38, further comprising: if it is determined that complete discharge of the pump chamber has been achieved by the application of the most recently applied positive pressure to the flexible diaphragm of the pump chamber during the discharge time, then operating the pneumatic pump to continue applying the most recently applied positive pressure to the flexible diaphragm of the pump chamber to the flexible diaphragm of the pump chamber whenever positive pressure is applied to the flexible diaphragm of the pump chamber thereafter, until a predetermined amount of fluid has been delivered for a predetermined time in the fluid flow procedure;

[0147] Appearance 41 (d) Determining whether the delivery of a predetermined time or a predetermined amount of fluid has been completed, and if it is determined that the delivery of a predetermined time or a predetermined amount of fluid has been completed, (e) The method according to embodiment 40, further comprising: operating the pneumatic pump to apply a reduced positive pressure to the flexible diaphragm of the pump chamber, which is lower than the most recently applied positive pressure relative to the outflow time, when applying positive pressure to the flexible diaphragm of the pump chamber next in the fluid flow procedure.

[0148] Pattern 42 The method according to embodiment 41, further comprising: (f) determining whether the most recently applied reduced positive pressure to the flexible diaphragm of the pump chamber during the outflow time has achieved complete discharge of the pump chamber; and (g) repeating (e) and (f) until it is determined that the most recently applied reduced positive pressure to the flexible diaphragm of the pump chamber during the outflow time has not achieved complete discharge of the pump chamber, and if it is determined that the most recently applied reduced positive pressure to the flexible diaphragm of the pump chamber during the outflow time has not achieved complete discharge of the pump chamber, operating the pneumatic pump to apply an increased positive pressure to the flexible diaphragm of the pump chamber that is greater than the most recently applied reduced positive pressure for the outflow time when applying positive pressure to the flexible diaphragm of the pump chamber in the fluid flow procedure.

[0149] Appearance 43 (d) Determine whether the positive pressure most recently applied to the flexible diaphragm of the pump chamber during the outflow time has achieved complete discharge of the pump chamber, and if it is determined that the positive pressure most recently applied during the outflow time has achieved complete discharge of the pump chamber, (e) when applying negative pressure to the flexible diaphragm of the pump chamber next in the fluid flow procedure, operate the pneumatic pump to apply a reduced positive pressure to the flexible diaphragm of the pump chamber that is lower than the positive pressure most recently applied during the outflow time, (f) Determine whether the reduced positive pressure most recently applied to the flexible diaphragm of the pump chamber has achieved complete discharge of the pump chamber, (g) Repeating (e) and (f) until it is determined that the most recent reduced positive pressure applied to the flexible diaphragm of the pump chamber during the outflow time has not achieved complete discharge of the pump chamber, and if it is determined that the most recent reduced positive pressure applied to the flexible diaphragm of the pump chamber has not achieved complete discharge of the pump chamber, the method according to any one of embodiments 34 to 37, further comprising: (g) Repeating (e) and (f) until it is determined that the most recent reduced positive pressure applied to the flexible diaphragm of the pump chamber during the outflow time has not achieved complete discharge of the pump chamber, and if it is determined that the most recent reduced positive pressure applied to the flexible diaphragm of the pump chamber during the outflow time has not achieved complete discharge of the pump chamber, the next time positive pressure is applied to the flexible diaphragm of the pump chamber during the fluid flow procedure, an increased positive pressure greater than the most recent reduced positive pressure applied to the flexible diaphragm of the pump chamber during the outflow time.

[0150] 44 The method according to any one of embodiments 34 to 43, further comprising performing a multi-stage fluid processing procedure in which different fluids are delivered through a pump chamber by a pneumatic pump in at least two stages of the fluid processing procedure, and performing separate fluid flow procedures for at least two of the different fluids.

[0151] As examples of the application of the principles of the subject matter, it will be understood that the embodiments described above are illustrative. Those skilled in the art can make numerous modifications, including combinations of features individually disclosed or claimed herein, without departing from the spirit and scope of the claimed subject matter. For these reasons, it will be understood that the scope of this project is not limited to the above description but is defined by the following claims, which may be directed to the features of this project and to combinations of features individually disclosed or claimed herein.

Claims

1. A fluid processing apparatus used in combination with a fluid flow circuit comprising a pump chamber including a flexible diaphragm and electrodes, A control unit programmed to execute a fluid flow procedure, A pneumatic pump is configured to be operated by the control unit so as to alternately perform the following actions during the fluid flow procedure: applying negative pressure to the flexible diaphragm of the pump chamber during the inflow time to draw fluid into the pump chamber, and applying positive pressure to the flexible diaphragm of the pump chamber during the outflow time to transport the fluid out of the pump chamber. The system includes a capacitive sensor configured to be operationally coupled to the control unit and electrically coupled to the electrodes of the pump chamber, and to transmit an inflow signal to the control unit indicating the inflow volume of fluid drawn into the pump chamber while the pneumatic pump is applying negative pressure to the flexible diaphragm of the pump chamber during the inflow time, The control unit, In the fluid flow procedure, when negative pressure is first applied to the flexible diaphragm of the pump chamber, the pneumatic pump is operated to apply an initial negative pressure to the flexible diaphragm of the pump chamber with respect to the inflow time, and the initial negative pressure is selected as the minimum negative pressure at which complete filling of the pump chamber is expected to be achieved when negative pressure is applied to the flexible diaphragm of the pump chamber during the inflow time. Whether the pump chamber is fully filled during the inflow time while the initial negative pressure is applied to the flexible diaphragm of the pump chamber is determined, at least partially, based on the inflow signal. A fluid processing apparatus, which is programmed to operate the pneumatic pump to apply a second negative pressure to the flexible diaphragm of the pump chamber, which is greater than the initial negative pressure relative to the inflow time, when it is determined that the pump chamber has not been fully filled during the inflow time while the initial negative pressure is applied to the flexible diaphragm of the pump chamber during the fluid flow procedure.

2. The fluid apparatus according to claim 1, wherein the second negative pressure is greater than the initial negative pressure by a predetermined increment.

3. The control unit is further programmed to determine the negative pressure necessary to achieve complete filling of the pump chamber if it determines that the pump chamber is not fully filled while the initial negative pressure is being applied to the flexible diaphragm of the pump chamber during the inflow time, The fluid apparatus according to claim 1, wherein the second negative pressure is selected to be equal to the negative pressure necessary to achieve the complete filling to be applied to the flexible diaphragm of the pump chamber during the inflow time.

4. The control unit, (a) Determine whether the negative pressure applied most recently to the flexible diaphragm of the pump chamber during the inflow time has achieved complete filling of the pump chamber. (b) If it is determined that the negative pressure most recently applied to the flexible diaphragm of the pump chamber during the inflow time has not achieved complete filling of the pump chamber, the pneumatic pump is operated to apply an increased negative pressure to the flexible diaphragm of the pump chamber during the next fluid flow procedure, which is greater than the negative pressure most recently applied during the inflow time. (c) The fluid apparatus according to any one of claims 1 to 3, programmed to repeat (a) and (b) until it is determined that the negative pressure most recently applied to the flexible diaphragm of the pump chamber has achieved complete filling of the pump chamber during the inflow time.

5. The fluid processing apparatus according to any one of claims 1 to 4, wherein the control unit is further programmed to operate the pneumatic pump so as to continue applying the negative pressure most recently applied to the flexible diaphragm of the pump chamber to the flexible diaphragm of the pump chamber when applying negative pressure to the flexible diaphragm of the pump chamber in the next fluid flow procedure, in relation to the inflow time, if it determines that the pump chamber has been fully filled by the application of negative pressure most recently applied to the flexible diaphragm of the pump chamber during the inflow time.

6. The fluid processing apparatus according to any one of claims 1 to 5, wherein the control unit is further programmed to operate the pneumatic pump so as to continue applying the most recently applied negative pressure to the flexible diaphragm of the pump chamber to the flexible diaphragm of the pump chamber when applying negative pressure to the flexible diaphragm of the pump chamber thereafter, until the fluid flow procedure is completed.

7. The fluid processing apparatus according to any one of claims 1 to 5, wherein the control unit is further programmed to operate the pneumatic pump so as to continue applying the negative pressure most recently applied to the flexible diaphragm of the pump chamber to the flexible diaphragm of the pump chamber when applying negative pressure to the flexible diaphragm of the pump chamber thereafter, until a predetermined amount of fluid has been delivered for a predetermined time in the fluid flow procedure.

8. The control unit, (d) Determine whether the delivery of the predetermined time or predetermined volume of fluid has been completed, and if it is determined that the delivery of the predetermined time or predetermined volume of fluid has been completed, (e) The fluid apparatus according to claim 7, further programmed to operate the pneumatic pump to apply a reduced negative pressure to the flexible diaphragm of the pump chamber, which is lower than the most recently applied negative pressure relative to the inflow time, when applying a negative pressure to the flexible diaphragm of the pump chamber in the fluid flow procedure.

9. The control unit, (f) Determine whether the reduced negative pressure applied most recently to the flexible diaphragm of the pump chamber during the inflow time has achieved complete filling of the pump chamber. (g) Repeating (e) and (f) until it is determined that the reduced negative pressure most recently applied to the flexible diaphragm of the pump chamber during the inflow time has not achieved complete filling of the pump chamber, and if it is determined that the reduced negative pressure most recently applied to the flexible diaphragm of the pump chamber during the inflow time has not achieved complete filling of the pump chamber, the pneumatic pump is further programmed to operate to apply an increased negative pressure greater than the reduced negative pressure most recently applied to the flexible diaphragm of the pump chamber when applying negative pressure to the flexible diaphragm of the pump chamber in the next fluid flow procedure, relative to the inflow time.

10. The control unit, (d) Determine whether the negative pressure applied most recently to the flexible diaphragm of the pump chamber during the inflow time has achieved complete filling of the pump chamber, and if it is determined that the negative pressure applied most recently to the flexible diaphragm of the pump chamber during the inflow time has achieved complete filling of the pump chamber, (e) When applying negative pressure to the flexible diaphragm of the pump chamber in the fluid flow procedure, the pneumatic pump is operated to apply a reduced negative pressure to the flexible diaphragm of the pump chamber that is lower than the most recently applied negative pressure relative to the inflow time, (f) Determine whether the reduced negative pressure applied most recently to the flexible diaphragm of the pump chamber during the inflow time has achieved complete filling of the pump chamber. (g) Repeating (e) and (f) until it is determined that the reduced negative pressure most recently applied to the flexible diaphragm of the pump chamber during the inflow time has not achieved complete filling of the pump chamber, and if it is determined that the reduced negative pressure most recently applied to the flexible diaphragm of the pump chamber during the inflow time has not achieved complete filling of the pump chamber, the pneumatic pump is further programmed to operate to apply an increased negative pressure greater than the reduced negative pressure most recently applied to the flexible diaphragm of the pump chamber relative to the inflow time when applying negative pressure to the flexible diaphragm of the pump chamber in the next fluid flow procedure.

11. The control unit, A multi-stage fluid processing procedure is performed in which different fluids are delivered through the pump chamber by the pneumatic pump in at least two stages of the fluid processing procedure. The fluid apparatus according to any one of claims 1 to 10, further programmed to perform separate fluid flow procedures for at least two of the different fluids.

12. A method for performing a fluid flow procedure using a fluid flow circuit comprising a pump chamber including a flexible diaphragm and electrodes, which is executed by a control unit, A step of operating a pneumatic pump to alternately perform the following actions: applying negative pressure to the flexible diaphragm of the pump chamber during the inflow time to draw fluid into the pump chamber, and applying positive pressure to the flexible diaphragm of the pump chamber during the outflow time to transport the fluid out of the pump chamber, wherein, when negative pressure is first applied to the flexible diaphragm of the pump chamber in the fluid flow procedure, the pneumatic pump is operated to apply an initial negative pressure to the flexible diaphragm of the pump chamber relative to the inflow time, and the initial negative pressure is selected as the minimum negative pressure at which complete filling of the pump chamber is expected to be achieved when negative pressure is applied to the flexible diaphragm of the pump chamber during the inflow time. The process of receiving an inflow signal from a capacitance sensor electrically coupled to the electrode of the pump chamber, indicating the volume of fluid drawn into the pump chamber while the pneumatic pump is applying negative pressure to the flexible diaphragm of the pump chamber during the aforementioned inflow time, A step of determining, at least partially based on the inflow signal, whether complete filling of the pump chamber was achieved while the initial negative pressure was applied to the flexible diaphragm of the pump chamber during the inflow time, A method comprising the step of, if it is determined that the pump chamber is not fully filled during the inflow time while the initial negative pressure is applied to the flexible diaphragm of the pump chamber, operating the pneumatic pump to apply a second negative pressure to the flexible diaphragm of the pump chamber, which is greater than the initial negative pressure relative to the inflow time, when applying negative pressure to the flexible diaphragm of the pump chamber in the next step of the fluid flow procedure.

13. The method according to claim 12, wherein the second negative pressure is greater than the initial negative pressure by a predetermined increment.

14. The method according to claim 12, further comprising the step of determining the negative pressure required to achieve complete filling of the pump chamber to be applied to the flexible diaphragm of the pump chamber during the inflow time, if it is determined that complete filling of the pump chamber has not been achieved while the initial negative pressure is applied to the flexible diaphragm of the pump chamber during the inflow time, wherein the second negative pressure is equal to the negative pressure required to achieve complete filling to be applied to the flexible diaphragm of the pump chamber during the inflow time.

15. (a) Determine whether the negative pressure applied most recently to the flexible diaphragm of the pump chamber during the inflow time has achieved complete filling of the pump chamber. (b) If it is determined that the negative pressure most recently applied to the flexible diaphragm of the pump chamber during the inflow time has not achieved complete filling of the pump chamber, the pneumatic pump is operated to apply an increased negative pressure to the flexible diaphragm of the pump chamber during the next fluid flow procedure, which is greater than the negative pressure most recently applied during the inflow time. (c) The method according to any one of claims 12 to 14, wherein the steps (a) and (b) are repeated until it is determined that the negative pressure most recently applied to the flexible diaphragm of the pump chamber during the inflow time has achieved complete filling of the pump chamber.

16. The method according to any one of claims 12 to 15, further comprising the step of operating the pneumatic pump to continue applying the negative pressure most recently applied to the flexible diaphragm of the pump chamber to the flexible diaphragm of the pump chamber when applying negative pressure to the flexible diaphragm of the pump chamber in the next step of the fluid flow procedure, in which it is determined that the pump chamber has been completely filled by the application of negative pressure most recently applied to the flexible diaphragm of the pump chamber during the inflow time.

17. The method according to any one of claims 12 to 16, further comprising the step of operating the pneumatic pump so as to continue applying the most recently applied negative pressure to the flexible diaphragm of the pump chamber to the flexible diaphragm of the pump chamber when applying negative pressure to the flexible diaphragm of the pump chamber thereafter, until the fluid flow procedure is completed.

18. The method according to any one of claims 12 to 16, further comprising the step of operating the pneumatic pump so as to continue applying the most recently applied negative pressure to the flexible diaphragm of the pump chamber to the flexible diaphragm of the pump chamber when applying negative pressure to the flexible diaphragm of the pump chamber thereafter, until a predetermined amount of fluid has been delivered for a predetermined time in the fluid flow procedure, with respect to the inflow time.

19. (d) Determine whether the delivery of the predetermined time or predetermined volume of fluid has been completed, and if it is determined that the delivery of the predetermined time or predetermined volume of fluid has been completed, (e) The method of claim 18, further comprising the step of operating the pneumatic pump to apply a reduced negative pressure to the flexible diaphragm of the pump chamber, which is lower than the most recently applied negative pressure with respect to the inflow time, when the next negative pressure is applied to the flexible diaphragm of the pump chamber in the fluid flow procedure.

20. (f) Determine whether the reduced negative pressure applied most recently to the flexible diaphragm of the pump chamber during the inflow time has achieved complete filling of the pump chamber. (g) Repeating (e) and (f) until it is determined that the most recent reduced negative pressure applied to the flexible diaphragm of the pump chamber during the inflow time has not achieved full filling of the pump chamber, and if it is determined that the most recent reduced negative pressure applied to the flexible diaphragm of the pump chamber during the inflow time has not achieved full filling of the pump chamber, the step of operating the pneumatic pump to apply an increased negative pressure to the flexible diaphragm of the pump chamber that is greater than the most recent reduced negative pressure applied for the inflow time when the next negative pressure is applied to the flexible diaphragm of the pump chamber in the fluid flow procedure, further comprising the step of (g) repeating (e) and (f) until it is determined that the most recent reduced negative pressure applied to the flexible diaphragm of the pump chamber during the inflow time has not achieved full filling of the pump chamber, and if it is determined that the most recent reduced negative pressure applied to the flexible diaphragm of the pump chamber during the inflow time has not achieved full filling of the pump chamber, the method according to claim 19.

21. (d) Determine whether the negative pressure applied most recently to the flexible diaphragm of the pump chamber during the inflow time has achieved complete filling of the pump chamber, and if it is determined that the negative pressure applied most recently to the flexible diaphragm of the pump chamber during the inflow time has achieved complete filling of the pump chamber, (e) When applying negative pressure to the flexible diaphragm of the pump chamber in the fluid flow procedure, the pneumatic pump is operated to apply a reduced negative pressure to the flexible diaphragm of the pump chamber that is lower than the most recently applied negative pressure relative to the inflow time, (f) Determine whether the reduced negative pressure applied most recently to the flexible diaphragm of the pump chamber during the inflow time has achieved complete filling of the pump chamber. (g) Repeating (e) and (f) until it is determined that the most recent reduced negative pressure applied to the flexible diaphragm of the pump chamber during the inflow time has not achieved full filling of the pump chamber, and if it is determined that the most recent reduced negative pressure applied to the flexible diaphragm of the pump chamber during the inflow time has not achieved full filling of the pump chamber, the method according to any one of claims 12 to 15, further comprising the step of operating the pneumatic pump to apply an increased negative pressure to the flexible diaphragm of the pump chamber that is greater than the most recent reduced negative pressure applied for the inflow time when the next negative pressure is applied to the flexible diaphragm of the pump chamber in the fluid flow procedure.

22. The method according to any one of claims 12 to 21, comprising the step of performing a multi-stage fluid processing procedure in which different fluids are delivered through the pump chamber by the pneumatic pump in at least two stages of the fluid processing procedure, wherein separate fluid flow procedures are performed for at least two of the different fluids.

23. A fluid processing apparatus used in combination with a fluid flow circuit comprising a pump chamber including a flexible diaphragm and electrodes, A control unit programmed to execute a fluid flow procedure, A pneumatic pump is operatively coupled to the control unit and is operated by the control unit to alternately perform the following actions during the fluid flow procedure: applying negative pressure to the flexible diaphragm of the pump chamber during the inflow time to draw fluid into the pump chamber, and applying positive pressure to the flexible diaphragm of the pump chamber during the outflow time to transport the fluid out of the pump chamber. The system includes a capacitive sensor configured to be operationally coupled to the control unit and electrically coupled to the electrodes of the pump chamber, and to transmit an outflow signal to the control unit indicating the outflow volume of fluid transported from the pump chamber while the pneumatic pump is applying positive pressure to the flexible diaphragm of the pump chamber during the outflow time, The control unit, In the fluid flow procedure, when positive pressure is first applied to the flexible diaphragm of the pump chamber, the pneumatic pump is operated to apply an initial positive pressure to the flexible diaphragm of the pump chamber with respect to the discharge time, and the initial positive pressure is selected as the minimum positive pressure at which complete discharge of the pump chamber is expected to be achieved when positive pressure is applied to the flexible diaphragm of the pump chamber during the discharge time. Whether complete discharge of the pump chamber was achieved during the discharge time while the initial positive pressure was applied to the flexible diaphragm of the pump chamber is determined, at least partially, based on the discharge signal. A fluid processing apparatus, which is programmed to operate the pneumatic pump to apply a second positive pressure greater than the initial positive pressure relative to the flow time to the flexible diaphragm of the pump chamber when it is determined that complete discharge of the pump chamber has not been achieved while the initial positive pressure is applied to the flexible diaphragm of the pump chamber during the discharge time, in the next time positive pressure is applied to the flexible diaphragm of the pump chamber during the fluid flow procedure.

24. The fluid apparatus according to claim 23, wherein the second positive pressure is greater than the initial positive pressure by a predetermined increment.

25. The control unit is further programmed to determine the positive pressure necessary to achieve complete discharge of the pump chamber if it determines that complete discharge of the pump chamber has not been achieved while the initial positive pressure is being applied to the flexible diaphragm of the pump chamber during the discharge time. The fluid apparatus according to claim 23, wherein the second positive pressure is selected to be equal to the positive pressure required to achieve complete discharge to be applied to the flexible diaphragm of the pump chamber during the discharge time.

26. The control unit, (a) Determine whether the positive pressure applied most recently to the flexible diaphragm in the pump chamber during the discharge time has achieved complete discharge of the pump chamber. (b) If it is determined that the positive pressure most recently applied to the flexible diaphragm of the pump chamber during the discharge time has not achieved complete discharge of the pump chamber, the pneumatic pump is operated to apply an increased positive pressure to the flexible diaphragm of the pump chamber during the next fluid flow procedure, which is greater than the positive pressure most recently applied during the discharge time. (c) The fluid processing apparatus according to any one of claims 23 to 25, wherein the steps (a) and (b) are repeated until it is determined that the positive pressure applied most recently to the flexible diaphragm of the pump chamber during the discharge time has achieved complete discharge of the pump chamber.

27. The fluid processing apparatus according to any one of claims 23 to 26, wherein the control unit is further programmed to operate the pneumatic pump so as to continue applying the most recently applied positive pressure to the flexible diaphragm of the pump chamber when applying positive pressure to the flexible diaphragm of the pump chamber in the next step in the fluid flow procedure, in the case where the control unit determines that complete discharge of the pump chamber has been achieved by the application of the most recently applied positive pressure to the flexible diaphragm of the pump chamber during the discharge time.

28. The fluid processing apparatus according to any one of claims 23 to 27, wherein the control unit is further programmed to operate the pneumatic pump so as to continue applying the most recently applied positive pressure to the flexible diaphragm of the pump chamber to the flexible diaphragm of the pump chamber when applying positive pressure to the flexible diaphragm of the pump chamber thereafter, until the fluid flow procedure is completed.

29. The fluid processing apparatus according to any one of claims 23 to 27, wherein the control unit is further programmed to operate the pneumatic pump to continue applying the most recently applied positive pressure to the flexible diaphragm of the pump chamber when applying positive pressure to the flexible diaphragm of the pump chamber thereafter, until a predetermined amount of fluid has been delivered for a predetermined time in the fluid flow procedure, with respect to the most recently applied positive pressure.

30. The control unit, (d) Determine whether the delivery of the predetermined time or predetermined volume of fluid has been completed, and if it is determined that the delivery of the predetermined time or predetermined volume of fluid has been completed, (e) The fluid apparatus according to claim 29, further programmed to operate the pneumatic pump to apply a reduced positive pressure to the flexible diaphragm of the pump chamber, which is lower than the most recently applied positive pressure with respect to the outflow time, when applying a positive pressure to the flexible diaphragm of the pump chamber in the fluid flow procedure.

31. The control unit, (f) Determine whether the reduced positive pressure applied most recently to the flexible diaphragm of the pump chamber during the discharge time has achieved complete discharge of the pump chamber. (g) Repeating (e) and (f) until it is determined that the reduced positive pressure most recently applied to the flexible diaphragm of the pump chamber during the outflow time has not achieved complete discharge of the pump chamber, and if it is determined that the reduced positive pressure most recently applied to the flexible diaphragm of the pump chamber during the outflow time has not achieved complete discharge of the pump chamber, the pneumatic pump is further programmed to operate to apply an increased positive pressure greater than the reduced positive pressure most recently applied to the flexible diaphragm of the pump chamber with respect to the outflow time when applying positive pressure to the flexible diaphragm of the pump chamber in the next fluid flow procedure.

32. The control unit, (d) Determine whether the positive pressure applied most recently to the flexible diaphragm of the pump chamber during the discharge time has achieved complete discharge of the pump chamber, and if it is determined that the positive pressure applied most recently to the flexible diaphragm of the pump chamber during the discharge time has achieved complete discharge of the pump chamber, (e) When applying positive pressure to the flexible diaphragm of the pump chamber in the fluid flow procedure, the pneumatic pump is operated to apply a reduced positive pressure to the flexible diaphragm of the pump chamber that is lower than the most recently applied positive pressure relative to the outflow time, (f) Determine whether the reduced positive pressure applied most recently to the flexible diaphragm of the pump chamber during the discharge time has achieved complete discharge of the pump chamber. (g) Repeating (e) and (f) until it is determined that the reduced positive pressure most recently applied to the flexible diaphragm of the pump chamber during the outflow time has not achieved complete discharge of the pump chamber, and if it is determined that the reduced positive pressure most recently applied to the flexible diaphragm of the pump chamber during the outflow time has not achieved complete discharge of the pump chamber, the fluid flow procedure is further programmed to operate the pneumatic pump to apply an increased positive pressure greater than the reduced positive pressure most recently applied to the flexible diaphragm of the pump chamber for the next time positive pressure is applied to the flexible diaphragm of the pump chamber for the outflow time, the fluid flow procedure.

33. The control unit, A multi-stage fluid processing procedure is performed in which different fluids are delivered through the pump chamber by the pneumatic pump in at least two stages of the fluid processing procedure. The fluid apparatus according to any one of claims 23 to 32, further programmed to perform separate fluid flow procedures for at least two of the different fluids.

34. A method for performing a fluid flow procedure using a fluid flow circuit comprising a pump chamber including a flexible diaphragm and electrodes, which is executed by a control unit, A step of operating a pneumatic pump to alternately perform the following actions: applying negative pressure to the flexible diaphragm of the pump chamber during the inflow time to draw fluid into the pump chamber, and applying positive pressure to the flexible diaphragm of the pump chamber during the outflow time to transport the fluid out of the pump chamber, wherein when positive pressure is first applied to the flexible diaphragm of the pump chamber in the fluid flow procedure, the pneumatic pump is operated to apply an initial positive pressure to the flexible diaphragm of the pump chamber with respect to the outflow time, and the initial positive pressure is selected as the minimum positive pressure at which complete discharge of the pump chamber is expected to be achieved when positive pressure is applied to the flexible diaphragm of the pump chamber during the outflow time. The process includes receiving an outflow signal indicating the outflow volume of fluid transported from the pump chamber while the pneumatic pump is applying positive pressure to the flexible diaphragm of the pump chamber during the aforementioned outflow time, from a capacitive sensor electrically coupled to the electrode of the pump chamber, A step of determining, at least partially, based on the discharge signal, whether complete discharge of the pump chamber was achieved during the discharge time while the initial positive pressure was applied to the flexible diaphragm of the pump chamber, A method comprising the step of, if it is determined that complete discharge of the pump chamber has not been achieved while the initial positive pressure is applied to the flexible diaphragm of the pump chamber during the discharge time, operating the pneumatic pump to apply a second positive pressure greater than the initial positive pressure relative to the discharge time to the flexible diaphragm of the pump chamber when applying positive pressure to the flexible diaphragm of the pump chamber in the next fluid flow procedure.

35. The method according to claim 34, wherein the second positive pressure is greater than the initial positive pressure by a predetermined increment.

36. The method according to claim 34, further comprising the step of determining the positive pressure required to achieve complete discharge to be applied to the flexible diaphragm of the pump chamber during the discharge time if it is determined that complete discharge of the pump chamber has not been achieved while the initial positive pressure is applied to the flexible diaphragm of the pump chamber during the discharge time, wherein the second positive pressure is equal to the positive pressure required to achieve complete discharge to be applied to the flexible diaphragm of the pump chamber during the discharge time.

37. (a) Determine whether the positive pressure applied most recently to the flexible diaphragm in the pump chamber during the discharge time has achieved complete discharge of the pump chamber. (b) If it is determined that the positive pressure most recently applied to the flexible diaphragm of the pump chamber during the discharge time has not achieved complete discharge of the pump chamber, the pneumatic pump is operated to apply an increased positive pressure to the flexible diaphragm of the pump chamber during the next fluid flow procedure, which is greater than the positive pressure most recently applied during the discharge time. (c) The method according to any one of claims 34 to 36, wherein the steps (a) and (b) are repeated until it is determined that the positive pressure applied most recently to the flexible diaphragm of the pump chamber during the discharge time has achieved complete discharge of the pump chamber.

38. The method according to any one of claims 34 to 37, further comprising: if it is determined that complete discharge of the pump chamber has been achieved by the application of the most recent positive pressure applied to the flexible diaphragm of the pump chamber during the discharge time, operating the pneumatic pump to continue applying the most recent positive pressure applied to the flexible diaphragm of the pump chamber during the next application of positive pressure to the flexible diaphragm of the pump chamber in the fluid flow procedure.

39. The method according to any one of claims 34 to 38, further comprising: if it is determined that complete discharge of the pump chamber has been achieved by applying the most recent positive pressure applied to the flexible diaphragm of the pump chamber during the discharge time, operating the pneumatic pump so as to continue applying the most recent positive pressure applied to the flexible diaphragm of the pump chamber to the flexible diaphragm of the pump chamber when applying positive pressure thereafter until the fluid flow procedure is completed.

40. The method according to any one of claims 34 to 38, further comprising: if it is determined that complete discharge of the pump chamber has been achieved by the application of the most recent positive pressure applied to the flexible diaphragm of the pump chamber during the discharge time, then in the fluid flow procedure until a predetermined time or a predetermined volume of fluid has been delivered, operating the pneumatic pump to continue applying the most recent positive pressure applied to the flexible diaphragm of the pump chamber to the flexible diaphragm of the pump chamber for the duration of the discharge time.

41. (d) Determine whether the delivery of the predetermined time or predetermined amount of fluid has been completed, and if it is determined that the delivery of the predetermined time or predetermined amount of fluid has been completed, (e) The method of claim 40, further comprising operating the pneumatic pump to apply a reduced positive pressure to the flexible diaphragm of the pump chamber, which is lower than the most recently applied positive pressure with respect to the outflow time, when applying a positive pressure to the flexible diaphragm of the pump chamber in the fluid flow procedure.

42. (f) Determine whether the reduced positive pressure applied most recently to the flexible diaphragm of the pump chamber during the discharge time has achieved complete discharge of the pump chamber. (g) Repeating (e) and (f) until it is determined that the most recent reduced positive pressure applied to the flexible diaphragm of the pump chamber during the outflow time has not achieved complete discharge of the pump chamber, and if it is determined that the most recent reduced positive pressure applied to the flexible diaphragm of the pump chamber during the outflow time has not achieved complete discharge of the pump chamber, the method of claim 41, further comprising: (g) Repeating (e) and (f) until it is determined that the most recent reduced positive pressure applied to the flexible diaphragm of the pump chamber during the outflow time has not achieved complete discharge of the pump chamber, and if it is determined that the most recent reduced positive pressure applied to the flexible diaphragm of the pump chamber during the outflow time has not achieved complete discharge of the pump chamber, the pneumatic pump is operated to apply an increased positive pressure to the flexible diaphragm of the pump chamber that is greater than the most recent reduced positive pressure applied for the outflow time when the next positive pressure is applied to the flexible diaphragm of the pump chamber in the fluid flow procedure.

43. (d) Determine whether the positive pressure applied most recently to the flexible diaphragm of the pump chamber during the discharge time has achieved complete discharge of the pump chamber, and if it is determined that the positive pressure applied most recently during the discharge time has achieved complete discharge of the pump chamber, (e) When applying negative pressure to the flexible diaphragm of the pump chamber in the fluid flow procedure, the pneumatic pump is operated to apply a reduced positive pressure to the flexible diaphragm of the pump chamber that is lower than the most recently applied positive pressure relative to the outflow time, (f) Determine whether the reduced positive pressure applied most recently to the flexible diaphragm of the pump chamber during the discharge time has achieved complete discharge of the pump chamber. (g) Repeating (e) and (f) until it is determined that the most recent reduced positive pressure applied to the flexible diaphragm of the pump chamber during the outflow time has not achieved complete discharge of the pump chamber, and if it is determined that the most recent reduced positive pressure applied during the outflow time has not achieved complete discharge of the pump chamber, the method according to any one of claims 34 to 37, further comprising: (g) Repeating (e) and (f) until it is determined that the most recent reduced positive pressure applied to the flexible diaphragm of the pump chamber has not achieved complete discharge of the pump chamber; and if it is determined that the most recent reduced positive pressure applied during the outflow time has not achieved complete discharge of the pump chamber, operating the pneumatic pump to apply an increased positive pressure to the flexible diaphragm of the pump chamber that is greater than the most recent reduced positive pressure applied during the outflow time when applying positive pressure to the flexible diaphragm of the pump chamber in the next fluid flow procedure.

44. The method according to any one of claims 34 to 43, further comprising performing a multi-stage fluid processing procedure in which different fluids are delivered through the pump chamber by the pneumatic pump in at least two stages of the fluid processing procedure, and performing separate fluid flow procedures for at least two of the different fluids.

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