Splash Guard and Cassette Assembly for Sterility Testing

Abstract

Membrane filtration is a technique for performing sterility testing on products, in which a sample is introduced into a sterile environment (such as a cassette) through an inlet port and passed through one or more filters. The sample may be pumped into the cassette at relatively high pressure, which can cause the sample to spray, mist, or foam. This spraying can lead to inconsistent results, obscure visibility through the cassette lid, and make analyzing the culture medium difficult. Exemplary embodiments provide a uniquely sized and shaped splash guard that transforms the incoming sample fluid from a high-pressure state to a low-pressure flow. This allows the fluid to flow more smoothly into the cassette, resulting in more consistent and accurate results.

Description

[Technical Field]

[0001] Related Applications This application claims priority to and the benefit of U.S. Patent Application No. 18 / 065,247, filed December 13, 2022, the entire contents of which are incorporated herein by reference in their entirety. [Background technology]

[0002] It is sometimes necessary or desirable to test a product for the presence of contaminating microorganisms, especially when developing a product for human consumption. One technique for testing such products is membrane filtration. In membrane filtration, a sterile environment (such as a specially designed cassette) is prepared. A sample is introduced into that environment and filtered through one or more membrane filters. The filters can be selected with an appropriate pore size to ensure that the microorganisms of interest are retained on the filter. An appropriate medium is transferred to the filter, and the microorganisms are cultured on the medium for an appropriate period of time (e.g., 14 days). After this period, the medium is analyzed to determine whether the microorganisms of interest are present. Summary of the Invention

[0003] In one embodiment, the apparatus comprises a cassette assembly having one or more inlets configured to receive one or more fluids at a first pressure, a membrane filter, and an outlet configured to release the one or more fluids from the cassette assembly after the one or more fluids have passed through the membrane filter, and a splash guard configured to block fluid flow between the inlets and the membrane filter.

[0004] The splash guard can be configured to reduce the pressure of one or more fluids from a first pressure to a second pressure that is lower than the first pressure. For example, the splash guard can redirect one or more fluids entering a radial inlet of the cassette to a circumferential direction of the cassette. The splash guard can include a groove configured to redirect the flow of the one or more fluids. The splash guard can include a cover extending between the inlet and the lid.

[0005] A splash guard can be provided between the lid and the mid-body assembly. In some embodiments, a splash guard can be provided on a foil cutter configured to be disposed between the lid and the mid-body assembly.

[0006] The cassette assembly may include a lid, a mid-body assembly having an inlet, and a base assembly having an outlet.

[0007] The splash guard can have through holes configured to receive fasteners for attaching the splash guard to the cassette assembly. The fasteners can be incorporated into the cassette assembly. The splash guard and cassette assembly can have mating alignment elements.

[0008] A method of deploying the cassette assembly and splash guard includes assembling the cassette assembly and splash guard, inserting a fluid supply into the inlet, and supplying fluid to the inlet, where the fluid is diverted by the splash guard.

[0009] For example, the inlet may include a septum, and inserting the fluid delivery device into the inlet may include piercing the rubber septum with a needle. Delivering the fluid to the inlet may include delivering the fluid through the needle.

[0010] Assembling the cassette assembly and splash guard can include inserting one or more fasteners attached to the cassette assembly into one or more through holes in the splash guard.

[0011] Assembling the cassette assembly and splash guard can include aligning the splash guard to the cassette assembly using one or more mating alignment elements on the cassette assembly and the splash guard.

[0012] The method can also include using a splash guard to reduce the pressure of the fluid between the inlet and the membrane.

[0013] The cassette assembly can have a lid, a mid-body assembly having an inlet, and a base assembly having an outlet. Assembling the cassette assembly can include placing the mid-body assembly on the base assembly, attaching a splash guard over the mid-body assembly, and placing the lid over the splash guard and mid-body assembly. Other embodiments can have the inlet and outlet on the mid-body assembly, the inlet and outlet on the base, or separate inlet and outlet on the mid-body assembly and the base.

[0014] Alternatively or additionally, the mid-body assembly may be provided with a foil cutter having a splash guard attached thereto.

[0015] The method may include providing a seal (e.g., an O-ring, ultrasonic welding, heat staking, adhesive, bond, etc.) between the mid-body assembly and the base assembly, and / or providing an O-ring between the mid-body assembly and the lid.

[0016] Other technical features will be readily apparent to those skilled in the art from the following drawings, descriptions, and claims. [Brief explanation of the drawings]

[0017] To easily identify a particular element or operation in the description, the most significant digit(s) of the reference number refers to the figure number in which that element is first introduced. [Figure 1] FIG. 1 illustrates an exemplary cassette assembly according to one embodiment. [Figure 2] FIG. 2 is an enlarged view of a portion of a cross-sectional view of a cassette assembly according to one embodiment. [Figure 3A] FIG. 3A illustrates an exemplary splash guard attached to a cassette assembly according to one embodiment. [Figure 3B] FIG. 3B is a bottom view of an exemplary splash guard according to one embodiment. [Figure 4] FIG. 4 is a top cross-sectional view illustrating fluid delivery through a splash guard according to one embodiment. [Figure 5] FIG. 5 is a flowchart illustrating an exemplary method of deploying a cassette assembly with a splash guard according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] In membrane filtration techniques, the sample may be introduced into the cassette through an inlet port. The inlet port may have a rubber septum that can be penetrated by a needle. The sample may be pumped into the cassette through the needle. This provides relatively high pressure fluid into the cassette, which can cause the sample to spray, mist, or foam. This spraying of the sample can result in inconsistent results and can obstruct the view through the cassette lid, making analysis of the culture medium difficult.

[0019] The exemplary embodiments described herein provide a unique splash guard that is sized and shaped to transition the incoming sample fluid from a high pressure state to a low pressure flow, allowing the fluid to flow more smoothly into the cassette, resulting in more consistent and accurate results.

[0020] An example cassette assembly 100 is shown in FIG. 1, and a cross-sectional side view thereof is shown in FIG. 2. Cassette assembly 100 can provide a sterile environment for testing. Cassette assembly 100 can provide an anaerobic or aerobic environment depending on the application. Note that for ease of explanation, a splash guard, described in more detail below, is omitted from FIGS. 1 and 2, but can be located in a position described in connection with subsequent figures (or in any other suitable position, such as attached to the mid-body assembly or base).

[0021] From top to bottom in FIG. 1, the exemplary cassette assembly 100 includes a lid 102, an O-ring 104, an optional foil cutter 106, a scavenge tray assembly 108, a mid-body assembly 110, a membrane filter 120, a second seal 112, and a base assembly 114.

[0022] Base assembly 114 forms the bottom of cassette assembly 100 and serves as a support structure to which other components can be attached. Base assembly 114 can be sized and shaped to fit within an appropriate testing or analytical device.

[0023] The membrane filter 120 may be provided between the base assembly 114 and the mid-body assembly 110. The membrane filter 120 may be part of a media pad sized and shaped to fit into a corresponding recess in the base assembly 114. The membrane filter 120 may be any suitable filter and may have characteristics (e.g., desired porosity) selected based on the particular application (e.g., the size of the target microorganisms to be captured by the membrane filter 120). In some embodiments, multiple membrane filters 120 are provided, which may include multiple different types of membrane filters 120.

[0024] The target fluid to be analyzed may enter the base assembly 114 through a membrane filter 120. The base assembly 114 may include a drain port 118 for removing fluid from the cassette assembly 100 after filtration. The drain port 118 may have an opening in a portion of the base assembly 114 inside the cassette assembly 100 that connects to a specially molded outlet on the outside of the cassette assembly 100. The outlet may be sized and shaped to mate with a drain manifold that receives the removed fluid and routes it to an appropriate disposal location.

[0025] A seal 112 may be provided between the base assembly 114 and the mid-body assembly 110 to prevent fluid from leaking around and bypassing the membrane filter 120. The mid-body assembly 110 may include a mid-body inlet 116 to allow a target fluid (or fluids) to be analyzed to pass through the cassette assembly 100. The mid-body inlet 116 may be provided in a portion of the mid-body assembly 110 that is inside the cassette assembly 100 and may have an opening that connects to an opening on the outside of the cassette assembly 100. A structure such as a rubber septum that seals the cassette assembly 100 may be included within the mid-body inlet 116. To pass the target fluid through the cassette assembly 100, a needle may be used to pierce the structure of the mid-body inlet 116 and deliver the fluid at a relatively high pressure (although exemplary embodiments also accommodate low-pressure fluid flow).

[0026] In some embodiments, the mid-body assembly 110 may be provided with multiple mid-body inlets 116. For example, the cassette assembly 100 may be provided with one mid-body inlet 116 for passing a first sample (target fluid to be analyzed) and a second mid-body inlet 116 for passing a second, different sample. In other embodiments, a first mid-body inlet 116 may be provided for passing a sample and a second mid-body inlet 116 may be provided for passing a growth medium.

[0027] The top of the mid-body assembly 110 may be molded to accommodate an environmental conditioning tray 108 that may contain scavenging material (e.g., O 2 scavenger, desiccant, moisture beads, etc.) to absorb oxygen within the cassette assembly 100 (for samples). The scavenge tray assembly 108 may be covered with foil that holds the scavenging material in place and protects it from the atmosphere until the scavenge tray assembly 108 is deployed into the cassette assembly 100. To release the scavenging material, the cassette assembly 100 may be provided with a foil cutter 106 designed to pierce the foil and allow the scavenging material to scavenge the environment within the cassette assembly 100 in which it is sealed.

[0028] To seal the cassette assembly 100, an O-ring 104 can be placed on top of the mid-body assembly 110, and the lid 102 can be used to cover the entire assembly. As shown in FIG. 2, the O-ring 104 forms a seal between the mid-body assembly 110 and the lid 102, preventing fluid from leaking out the top of the cassette assembly 100 (and also sealing the interior of the cassette assembly 100, allowing the scavenging material to scavenge the oxygen-containing environment).

[0029] 2, the mid-body assembly 110 may include a mid-body assembly floor 202 that extends radially from an inner peripheral wall 204 of the mid-body assembly 110 toward the interior of the cassette assembly 100. The mid-body assembly floor 202 may be sloped toward the membrane filter 120 to encourage fluid flow toward the membrane filter 120.

[0030] While the exemplary embodiments are described with reference to the illustrated cassette assembly configuration for purposes of explanation, those skilled in the art will recognize that other types of cassette assemblies (having more, fewer, or different configurations of parts) or other sterile environments may be used. Additionally, while the exemplary embodiments are described with respect to microbial sample testing using membrane filtration (and the structures in FIGS. 1 and 2 are configured accordingly), other applications of the splash guards described below will be readily apparent.

[0031] 3A and 3B show examples of such splash guards 304. The splash guards 304 are attached to the inner periphery of the mid-body assembly 110 and / or foil cutter 106. The splash guards 304 include a cover 322 disposed between the mid-body inlet 116 and the lid 102 to prevent fluid entering the cassette assembly 100 through the inlet from splashing onto the lid 102 and obstructing the view of the membrane filter 120 during analysis.

[0032] The splash guard 304 has a length extending circumferentially around the mid-body assembly 110, a height extending axially around the cassette assembly 100, and a width extending radially around the cassette assembly 100. The length and / or width of the splash guard 304 may depend on the length and configuration of the fluid conduit or groove 310. The fluid conduit or groove 310 is used to redirect fluid from the mid-body inlet 116 into the interior of the cassette assembly 100 (see FIG. 3B ). For example, if fluid is introduced into the cassette assembly 100 at a first high pressure, a first length of the groove 310 is used, calculated to reduce the high pressure to an appropriately low target pressure. On the other hand, if fluid is introduced into the cassette assembly 100 at a second high pressure that is higher than the first high pressure, the groove 310 may need to be longer, wider, or have a different configuration to reduce the fluid to the lower target pressure. This may require a longer and / or wider splash guard 304. Some embodiments may also utilize the internal geometry of the mid-body assembly as part or all of the fluid path.

[0033] 3B, groove 310 begins at the inlet 306 of splash guard 304, which is configured to receive fluid from (and thus be aligned with) midbody inlet 116. Groove 310 redirects the fluid flow around a bend (approximately 90 degrees in this embodiment, although other angles may be used depending on the typical fluid pressure at midbody inlet 116 and the desired target pressure at outlet 308) before continuing to the outlet 308 of splash guard 304.

[0034] Groove 310 may initially be configured to convey fluid radially inward into cassette assembly 100. Groove 310 may then bend at an angle to change the direction of fluid flow. In the illustrated example, groove 310 bends at an angle of approximately 90 degrees to change fluid flow from radial to circumferential (see FIG. 4 ). Thus, the rear portion of groove 310 after bending does not necessarily need to be perfectly straight, but may be slightly curved depending on the curvature of (for example) inner circumferential wall 204 of mid-body assembly 110.

[0035] The grooves 310 may be sized and shaped to reduce the pressure of the fluid received at the midbody inlet 116. The width of the grooves 310 may remain constant from the inlet 306 to the outlet 308. Alternatively, the width may vary (e.g., the grooves 310 become wider as they approach the outlet 308). The outlets 308 may be positioned and shaped to cause the fluid to exit the splash guard 304 in a particular pattern or direction. For example, the outlets 308 may be positioned to direct the fluid toward the midbody assembly floor 202.

[0036] The splash guard 304 may be open or sealed at the bottom.

[0037] The height of the splash guard may be determined by the amount of space (axially) available inside the cassette assembly 100 between the membrane filter 120 (and / or the floor of the mid-body assembly 110) and the lid 102.

[0038] The splash guard 304 may be integral with the mid-body assembly 110 or the foil cutter 106, or may be attached to either or both of these elements. For example, the foil cutter 106 may have a cutout designed to accommodate the overhang 314 (see FIG. 3B) of the splash guard 304. The overhang 314 may be an extension of the splash guard 304 that extends radially from the point where the splash guard 304 is configured to contact the inner peripheral wall of the mid-body assembly 110.

[0039] The mid-body assembly 110 (or foil cutter 106) can include one or more protrusions that function as fasteners 316, which can pass through corresponding through-holes 312 in the splash guard overhang 314. To facilitate insertion of the fasteners 316 into the through-holes 312, the mid-body assembly 110 can also include one or more alignment protrusions 318 configured to mate with corresponding alignment recesses 320 in the splash guard 304 (or vice versa, the protrusions can be provided on the splash guard 304 and the recesses can be provided on the mid-body assembly 110 and / or foil cutter 106). The alignment protrusions 318 and fasteners 316 can be positioned such that the inlets 306 of the splash guard 304 are aligned with the mid-body inlet 116 of the mid-body assembly 110 when the splash guard 304 is attached to the cassette assembly 100.

[0040] FIG. 5 is a flowchart illustrating an exemplary method for deploying a splash guard on a cassette assembly.

[0041] In block 502, the base assembly, membrane, and mid-body assembly can be deployed. For example, the base assembly can be placed on an appropriate surface in the testing area, and the membrane (and / or media pad) can be placed on the base assembly. A seal (such as an O-ring) can be placed around the appropriate portion of the base assembly. The mid-body assembly can then be lowered onto the base assembly so that the O-ring forms a seal and / or locks the mid-body assembly to the base assembly.

[0042] In some embodiments, the splash guard may be integrally formed with the mid-body assembly or optional foil cutter. If not, the splash guard may be aligned at block 504. For example, the splash guard may be positioned between appropriate alignment protrusions on the mid-body assembly and / or foil cutter. Alternatively or additionally, the splash guard may be provided with a protrusion that mates with a recess on the mid-body assembly and / or foil cutter. The protrusion and recess may be shaped and configured to fit together.

[0043] At block 506, a splash guard can be attached to the mid-body assembly and / or foil cutter. For example, one or more fasteners attached to the cassette assembly (e.g., the mid-body assembly and / or foil cutter) can be inserted into one or more through-holes in the splash guard. Alternatively or additionally, one or more fasteners on the splash guard can be disposed in one or more holes in the cassette assembly (holes that partially or completely pass through the mid-body assembly and / or foil cutter).

[0044] At block 508, a lid can be deployed onto the cassette assembly, which may include providing an O-ring in the appropriate location on the mid-body assembly and securing the lid to the inner or outer periphery of the O-ring.

[0045] At block 510, a fluid delivery device can be inserted into the inlet of the mid-body assembly. For example, the inlet can be provided with a rubber septum. The rubber septum can be pierced with a needle, and fluid can be delivered through the needle to the inlet (block 512). The fluid can be delivered via one or more tubes attached to the needle, or another suitable delivery device.

[0046] In block 514, the fluid can be redirected by the splash guard. For example, the fluid can enter an inlet in the splash guard and then be redirected around a groove in the splash guard. This can reduce the pressure of the fluid between the inlet and the membrane.

[0047] At block 516, a fluid can be passed through the membrane. Thereafter, at block 518, the fluid is released from an outlet in the base assembly. After the fluid is released, a growth medium is supplied near the membrane (e.g., from a midbody inlet or another suitable inlet), and the cassette assembly is maintained for incubation for a predetermined period of time. Growth of the microorganisms on the growth medium is then measured (e.g., by imaging the growth medium through an optically transparent lid).

[0048] 5 illustrates exemplary operations performed in a particular order, although embodiments are not limited to the order shown. For example, another possible order could be to first align the splash guard (block 504), then attach the splash guard to the mid-body assembly (block 506). The membrane and mid-body assembly (with splash guard attached) could then be deployed, and the mid-body assembly / splash guard / membrane could then be deployed to the base assembly (block 502). The lid could then be deployed over the remainder of the assembly.

[0049] Some embodiments may be described using the phrase "in one embodiment" or "embodiment" and their derivatives. These terms mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment. Multiple appearances of the phrase "in one embodiment" in various places in the specification do not necessarily refer to the same embodiment. Furthermore, unless otherwise specified, it is recognized that the features described above can be used in any combination. Thus, features described separately can be used in combination with each other unless they are expressly stated to be incompatible with each other.

[0050] The detailed descriptions herein may be presented in terms of program procedures executed on a computer or network of computers, with general reference to symbols and terms used herein. These procedural descriptions and representations are the means used by those skilled in the art to most effectively convey the substance of their work to others skilled in the art.

[0051] Some embodiments may be described using the terms "coupled" and "connected," along with their derivatives. These terms are not necessarily intended as synonyms for each other. For example, some embodiments may be described using the terms "connected" and / or "coupled" to indicate that two or more elements are in direct physical or electrical contact with each other. However, the term "coupled" may also mean that two or more elements are not in direct contact with each other, but yet still cooperate or interact with each other.

[0052] It is emphasized that the Abstract of the Disclosure is provided to allow the reader to quickly grasp the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Moreover, in the foregoing Detailed Description, various features are grouped together in a single embodiment to streamline the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the claimed embodiment requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in some, but not all, features of a single disclosed embodiment. Accordingly, the following claims are incorporated into the Detailed Description, with each claim standing on its own as a standalone embodiment. In the appended claims, the terms "including" and "in which" are used as plain English versions of "comprising" and "wherein," respectively. Furthermore, the terms "first," "second," "third," etc. are used merely as labels and are not intended to impose numerical requirements on their objects.

[0053] The above description includes examples of the disclosed architecture. Of course, it is not possible to describe every conceivable combination of components and / or techniques, but one of ordinary skill in the art will recognize that many further combinations and permutations are possible. Accordingly, the novel architecture is intended to encompass all such changes, modifications, and variations that fall within the spirit and scope of the appended claims.

Claims

1. a cassette assembly having an inlet configured to receive one or more fluids at a first pressure, a membrane filter, and an outlet configured to discharge the one or more fluids from the cassette assembly after the one or more fluids have passed through the membrane filter; a splash guard configured to block fluid flow between the inlet and the membrane filter.

2. The apparatus of claim 1 , wherein the splash guard is configured to reduce the pressure of the one or more fluids from the first pressure to a second pressure that is lower than the first pressure.

3. The apparatus of claim 1 , wherein the cassette assembly includes a lid, a mid-body assembly having the inlet, and a base assembly having the outlet.

4. The device of claim 3 , wherein the splash guard is disposed between the lid and the mid-body assembly.

5. The apparatus of claim 2 , wherein the splash guard includes a cover extending between the inlet and the lid.

6. The device of claim 3 , wherein the splash guard is provided on the mid-body assembly or on a foil cutter configured to be disposed between the lid and the mid-body assembly.

7. The apparatus of claim 1 , wherein the splash guard has through holes configured to receive fasteners for attaching the splash guard to the cassette assembly.

8. The apparatus of claim 1 , wherein the fastener is integrated into the cassette assembly.

9. The apparatus of claim 1 , wherein the splash guard redirects the one or more fluids entering the inlet radially about the cassette in a circumferential direction about the cassette.

10. The apparatus of claim 1 , wherein the splash guard includes a groove configured to redirect the flow of the one or more fluids.

11. The apparatus of claim 1 , wherein the splash guard and the cassette assembly have mating alignment elements.

12. Assembling the cassette assembly and the splash guard of claim 1; inserting a fluid supply into the inlet; providing a fluid to the inlet and redirecting the fluid by the splash guard.

13. the inlet includes a rubber septum; inserting the fluid supply into the inlet includes piercing the rubber septum with a needle; The method of claim 12 , wherein supplying the fluid to the inlet comprises supplying the fluid through the needle.

14. The method of claim 12 , wherein assembling the cassette assembly and the splash guard comprises inserting one or more fasteners attached to the cassette assembly into one or more through holes in the splash guard.

15. 13. The method of claim 12, wherein assembling the cassette assembly and the splash guard includes aligning the splash guard to the cassette assembly using one or more mating alignment elements on the cassette assembly and the splash guard.

16. The method of claim 12 further comprising using the splash guard to reduce the pressure of the fluid between the inlet and the membrane.

17. The cassette assembly includes a lid, a mid-body assembly having the inlet, and a base assembly having the outlet, and assembling the cassette assembly includes: attaching the splash guard above the mid-body assembly; placing the mid-body assembly on the base assembly; and placing the lid over the splash guard and the mid-body assembly.

18. The method of claim 17 further comprising providing the mid-body assembly with a foil cutter to which the splash guard is attached.

19. The method of claim 17 , further comprising providing a seal between the mid-body assembly and the base assembly.

20. The method of claim 17 , further comprising providing a seal between the mid-body assembly and the lid.

Images