Environmental Cutting Subassembly and Adjustment Assembly - Patent application

Abstract

This application relates to environmental improvements for microbiological testing. Exemplary embodiments provide a uniquely configured tray containing an environmental conditioning material, such as an oxygen scavenger material, for use in a cassette assembly. Additionally, some embodiments provide a cutting mechanism that can reliably break the tray, thereby exposing the material inside to the environment. In some embodiments, specially configured cutter teeth can be used to cut through the material, which can be easily deployed by twisting or pushing the cassette assembly halves.

Description

[Technical Field]

[0001] Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 378,334, filed October 4, 2022, the entire contents of which are incorporated herein by reference. [Background technology]

[0002] Testing for microbial contamination is often performed in a sealed environment, such as a test cassette. The sample may be exposed to a growth medium in the environment, allowing any microbial colonies within the sample to grow for a period of time. After the period has passed, the colonies are identified and quantified.

[0003] Some microbiological tests are performed in anaerobic (low-oxygen or oxygen-free) environments. To perform such tests, it is usually necessary to remove oxygen from the environment. This can be achieved by using oxygen-scavenging materials.

[0004] Unfortunately, successfully deploying capture materials within an environment can be challenging. The capture material needs to be isolated from air before deployment, yet be capable of being exposed to the testing environment once assembled (e.g., after assembling the various components of the cassette). The packaging used to isolate the capture material must be robust enough to prevent the material from accidentally being exposed to air during handling, yet at the same time, must be easily and reliably opened within the sterile environment of the cassette. Furthermore, whatever packaging is used must be filled with the capture material but must prevent the capture material from being exposed to air. Summary of the Invention

[0005] The present application, in some embodiments, relates to improving anaerobic (low-oxygen or oxygen-free) environments for microbiological testing and conditioning the environment with test materials. Exemplary embodiments can provide a uniquely configured tray containing oxygen-scavenging or other environmental conditioning material for use in a cassette assembly. Additionally, some embodiments provide a cutting mechanism that can reliably break the tray, thereby exposing the scavenging material inside to the environment. In some embodiments, specially configured cutter teeth can be used to cut through the material, which can be easily deployed by twisting or pushing the cassette assembly halves.

[0006] In one aspect, a cutter for a cassette assembly includes a tray covered with a sealing lid. The cutter can include an annular planar surface having one or more openings and at least one flexible cutter tooth extending away from an axial top of the planar surface. The flexible cutter tooth can be configured to interact with the lid to bend the flexible cutter tooth. A cutting tip of each of the at least one flexible cutter tooth can be sized such that, upon engagement with the lid, the cutting tip penetrates the seal of the tray.

[0007] The at least one cutter tooth may be further sized such that when not engaged with the lid, the cutting tip is disposed in one of the openings and does not extend beyond the axial bottom of the cutter.

[0008] The at least one cutter tooth may be configured to interact with a ramp on the lid of the cassette assembly to force the cutting tip into the seal.

[0009] The cutter may be a separate ring rather than integral with the lid.

[0010] The sealant may be a foil.

[0011] The one or more flexible cutter teeth may include a plurality of teeth disposed generally around the circumference of the cutter.

[0012] The cutter may be configured to pierce the foil by a relative twisting action between the lid and the remainder of the cassette assembly and / or a relative pushing action between the lid and the remainder of the cassette assembly.

[0013] The cutter may be sized and shaped to surround the internal inspection environment of the cassette assembly.

[0014] The cutter may also include a toothless region configured to receive a tool.

[0015] An exemplary method may include assembling the cutter described above into a cassette assembly and fitting a lid onto the cassette assembly, with the cutting tip penetrating the seal.

[0016] Attaching the lid may include pushing the lid onto the remainder of the cassette assembly.

[0017] The method may also include aligning one or more ramps on the lid with at least one flexible cutter tooth of the cutter.

[0018] The method may also include twisting the lid onto the remainder of the cassette assembly, wherein twisting the lid may rotate one or more ramps on the lid into at least one flexible cutter tooth of the cutter.

[0019] The method may also include placing the tray within a recess in the cassette assembly.

[0020] Assembling the cutter into the cassette assembly may include placing the cutter on top of the tray.

[0021] A lid can be placed onto the cassette assembly to create an airtight seal.

[0022] The method may also include placing a tool on the cutter in a toothless area.

[0023] The method may also include aligning a protrusion on the axial bottom of the cutter with a cutout portion of the tray.

[0024] In one aspect, a tray assembly for a cassette assembly may be provided. The assembly may include a tray configured to receive an oxygen scavenging material. The tray may be sized and shaped to fit within a recess in the microbiology test cassette. The assembly may include a seal on one side of the tray configured to create an airtight seal and one or more fill ports configured to receive the oxygen scavenging material.

[0025] The tray assembly may also include a shelf configured to be positioned within the tray. A foam insert may be located on the molded shelf and configured to prevent material from exiting the tray if the seal is pierced.

[0026] The seal may be a foil or a gas permeable membrane. The seal may include an adhesive provided around the edge of the seal. In some embodiments, the seal may be heat welded.

[0027] The tray can be configured to substantially enclose the internal testing environment of the cassette assembly. For example, the tray assembly can be "C" shaped. The one or more fill ports can include at least one fill port provided on each edge of the "C" shape.

[0028] The tray assembly may also include an airtight seal provided over one or more fill ports.

[0029] The tray assembly may also include a ring-shaped foil cutter configured to pierce the seal.

[0030] An exemplary method includes providing a tray assembly as described above, filling the tray with material through one or more fill ports, and applying a seal to seal the tray.

[0031] The method may also include disposing a shelf within the tray.

[0032] The method may also include placing a foam insert on the top of the shelf, the foam insert configured to prevent material from exiting the tray when the seal is pierced.

[0033] The method may also include providing an adhesive around an edge of the seal. The seal may be sealed to the tray with the adhesive. In some embodiments, sealing the seal may include applying heat to activate a heat sensitive adhesive or heat welding a polymer adhesive.

[0034] The tray may include multiple fill ports, and filling the tray may include adding oxygen scavenging material to each fill port. One or more of the fill ports may be sealed.

[0035] The method may also include placing a cutter on top of the tray subassembly, which can be pushed or twisted to pierce the seal.

[0036] Other technical features may be readily apparent to those skilled in the art from the following drawings, descriptions, and claims.

[0037] To easily identify the description of any particular element or act, the most significant digit(s) of a reference number refers to the number of the figure in which that element is first introduced. [Brief explanation of the drawings]

[0038] [Figure 1] 1 illustrates an exemplary cassette assembly, according to one embodiment. [Figure 2] FIG. 10 is an enlarged view of a portion of a cross-sectional view of a cassette assembly, according to one embodiment. [Figure 3] FIG. 10 is an enlarged view of a portion of a cross-sectional view of a cassette assembly, according to one embodiment. [Figure 4]FIG. 1 is a perspective view of a foil cutter 106, according to one embodiment. [Figure 5] 5A is a top view of the foil cutter 106, according to one embodiment. B is a side view of the foil cutter 106 taken along line AA in FIG. 5A, according to one embodiment. C is a side view of the foil cutter 106 taken along line BB in FIG. 5A, according to one embodiment. D is a close-up view of detail C (cutter teeth 402), according to one embodiment. [Figure 6] 1 is a side cross-sectional view illustrating the cutting action of a foil cutter 106 according to an exemplary embodiment. [Figure 7] 7 is an exploded view of an exemplary tray assembly 700, according to one embodiment. [Figure 8] FIG. 7 is a top perspective view of an assembled tray assembly 700, according to one embodiment. [Figure 9] FIG. 7 is a bottom perspective view of an assembled tray assembly 700, according to one embodiment. [Figure 10] FIG. 7 is a bottom view of an assembled tray assembly 700, according to one embodiment. [Figure 11] 10 is a flowchart illustrating an exemplary method for creating an oxygen-limited environment within a cassette assembly, according to one embodiment. [Figure 12] 1 illustrates an exemplary portion of a cutter tooth apparatus having a polymer support arm, according to one embodiment. [Figure 13] FIG. 1 illustrates a front view of an exemplary cutterhead, according to one embodiment. [Figure 14] 1 illustrates an exemplary cutterhead having a flat profile, according to one embodiment. [Figure 15] 1 illustrates an exemplary cutterhead having a curved profile, according to one embodiment. [Figure 16] 1 shows an example of how a metal cutter head can be formed by stamping, punching, or photoetching, according to one embodiment. [Figure 17] 17 shows an exemplary element from the sheet of FIG. 16. [Figure 18] 18 illustrates how the elements of FIG. 17 may fit within a foil cutter, according to one embodiment. [Figure 19] 1 illustrates an example of a foil cutter having a ring structure, according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0039] Microbiological testing can be performed in an environment that can be created within a cassette assembly, for example. In some embodiments, the present application relates to techniques for placing materials within such cassette assemblies in a reliable and easy-to-use manner. Exemplary embodiments can provide a uniquely configured tray containing oxygen scavenging material or other environmental conditioning chemicals for use in the cassette assembly. Additionally, embodiments provide a cutting mechanism that can reliably break the tray, thereby exposing the material within to the environment. In some embodiments, specially configured cutter teeth can be used to cut through the material, which can be easily deployed by twisting or pushing the cassette assembly halves. As a result, the cassette assembly can be closed, and the tray can be broken as part of the action used to close the assembly. If the material is a scavenging material, the scavenging material is exposed to the environment, creating anaerobic conditions within the cassette assembly.

[0040] While the embodiments described below employ a specific configuration suitable for use with the illustrated cassette assembly, it will be apparent to those skilled in the art that this specific configuration is provided for illustrative purposes. The described cutter and / or tray may be of different shapes or sizes depending on the environment to be deployed. The cutter and tray may be used separately to obtain the aforementioned benefits or together to obtain additional synergistic effects. Furthermore, the cutter and tray need not be used exclusively in microbiology testing situations, but rather have broad applicability in any situation where materials can be held within the tray and deployed using the cutter. The tray may be used for applications other than creating an anaerobic environment, but more generally for environmental conditioning using desiccants, gases, and / or chemicals that react to create an environment that meets the specific needs of the organisms being detected.

[0041] An example of a cassette assembly 100 is shown in Figure 1, with cross-sectional side views shown in Figures 2 and 3. The cassette assembly 100 can provide a sterile environment for testing. In some embodiments, the cassette assembly 100 can provide an anaerobic or oxygen-limited environment.

[0042] 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 tray assembly 700, a mid-body assembly 108, a membrane filter 118, a second O-ring 110, and a base assembly 112.

[0043] Base assembly 112 forms the bottom of cassette assembly 100 and serves as a support structure to which other components may be attached. Base assembly 112 may be sized and molded to accommodate an appropriate testing or analysis device.

[0044] A membrane filter 118 may be provided on the base assembly between the base assembly 112 and the mid-body assembly 108. The membrane filter 118 may be part of a media pad sized and molded to fit into a corresponding recess in the base assembly 112. The membrane filter 118 may be any suitable filter and may have characteristics (such as a desired porosity) selected based on the particular application (e.g., the size of the target microorganisms intended to be captured by the membrane filter 118). In some embodiments, multiple membrane filters 118 may be provided, which may include multiple different types of membrane filters 118.

[0045] The target fluid for analysis can be passed through a membrane filter 118 into the base assembly 112. The base assembly 112 can include an exhaust port 116 that allows the fluid to be removed from the cassette assembly 100 after filtration. The drain port 116 comprises an opening provided in a portion of the base assembly 112 on the interior of the cassette assembly 100 that connects to a specially shaped outlet on the exterior of the cassette assembly 100. The outlet can be sized and shaped to mate with a drain manifold that receives the removed fluid and routes it to an appropriate disposal location.

[0046] An O-ring 110 can be provided between the base assembly 112 and the mid-body assembly 108 to prevent fluid leakage and bypassing the membrane filter 118. The mid-body assembly 108 includes a mid-body inlet 114 through which the target fluid (or fluids) to be analyzed can be introduced into the cassette assembly 100. The mid-body inlet 114 includes an opening provided in a portion of the mid-body assembly 108 inside the cassette assembly 100 and 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 can be provided within the mid-body inlet 114. To introduce the target fluid into the cassette assembly 100, a needle can be used to pierce the structure of the mid-body inlet 114 and pump the fluid at a relatively high pressure.

[0047] The top of the mid-body assembly 108 is shaped to accommodate the tray assembly 700, which may contain, for example, a scavenger material to absorb oxygen within the cassette assembly 100, or other agents as described herein to create environmental conditions. More generally, the tray assembly may contain desiccants, gases, or chemicals that react to create an environment that meets the specific needs of the organisms being detected. For example, a tray may contain a desiccant to create a dry environment suitable for target microorganisms. Similarly, a tray may contain a material to create a sulfur-rich environment desirable for certain microorganisms. In some embodiments, multiple tray assemblies may be arranged to create the required environmental conditions. For example, one tray may contain a desiccant, and another tray may contain an agent that creates a dry, sulfur-rich environment.

[0048] The top of the mid-body assembly 108 is shaped to accommodate the tray assembly 700, which may contain, for example, a scavenging material that absorbs oxygen within the cassette assembly 100 or other agents as described herein to create environmental conditions. More generally, the tray assembly may contain a desiccant, gas, or chemical that reacts to create an environment that meets the specific needs of the organism being detected. In some embodiments, multiple tray assemblies can be arranged to create the necessary environmental conditions. In some embodiments, the tray assembly 700 may be covered with foil that holds the scavenging material in place and protects it from the outside air until the tray assembly 700 is placed within the cassette assembly 100. In other embodiments, a sock of gas-permeable material can be used instead of the gas-impermeable foil. Such a gas-permeable sock may be used in some embodiments when an environmental conditioning material is used. To release the scavenging material or environmental conditioning material, the cassette assembly 100 may be provided with a foil cutter 106 designed to allow the scavenging material to scavenge the environment within the sealed cassette assembly 100 and the environmental conditioning material to condition the environment through a foil or gas-permeable sock.

[0049] The use of a gas-permeable barrier eliminates the need for heat-activated adhesives and allows for ultrasonic or thermal welding of the tray seal. The gas-permeable barrier also allows for the use of environmental control materials that would otherwise react with metal foil seals. The gas-permeable barrier can be transparent or translucent to allow visibility of items in the tray, including indicators of seal integrity. The gas-permeable barrier is not limited to filling the tray through a fill port as with foil seals. The gas-permeable barrier can be integrated into the shelf on the tray, thus reducing the number of parts required.

[0050] To seal the cassette assembly 100, an O-ring 104 may be placed on top of the mid-body assembly 108, and then a lid 102 may be used to cover the entire assembly. As shown in Figures 2 and 3, the O-ring 104 forms a seal between the mid-body assembly 108 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 to allow materials to regulate the environment).

[0051] 2 and 3, the mid-body assembly 108 may include a mid-body assembly floor 202 that extends radially from an inner circumferential wall 204 of the mid-body assembly 108 toward the interior of the cassette assembly 100. The mid-body assembly floor 202 may be sloped toward the membrane filter 118 to direct fluid flow toward the membrane filter 118.

[0052] Although 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 (with more, fewer, or different configurations of parts) or other sterile environments may be used.

[0053] 4 is a perspective view of foil cutter 106, according to one embodiment. Note that although this element is referred to herein as a foil cutter for ease of explanation, the tray is not limited to being sealed with foil. If another seal is used, a cutter configured to break that type of seal may be constructed according to the principles described below.

[0054] As shown, the foil cutter 106 is substantially in the shape of a ring having a flat surface 404 provided with one or more openings. Attached to and extending axially away from the flat surface 404 are one or more cutter teeth 402. The cutter teeth 402 are non-rigid and can flex under force, thereby extending into the openings. In use, movement of the lid causes the cutter teeth 402 to contact one or more protrusions, which can depress the cutter teeth into the foil seal of the tray assembly (this movement is described in more detail below).

[0055] The foil cutter 106 includes at least one cutter tooth 402, but preferably includes multiple cutter teeth spaced around the circumference of the foil cutter 106. In this manner, the foil cutter 106 can simultaneously break the foil seal of the tray assembly in multiple locations, resulting in uniform exposure of the captured material throughout the environment.

[0056] However, the cutter teeth 402 need not be provided around the entire circumference; for example, Figure 4 shows the foil cutter 106 with a section 406 without cutter teeth 402. This section may serve as an attachment point for a tool or other feature that extends across the inspection area (e.g., the area above the mid-body assembly floor 202).

[0057] In some embodiments, the section 406 without cutter teeth may include one or more alignment protrusions 408. As shown in FIG. 7, the tray may not be completely ring-shaped, but may have a cutout section, making the tray "C" shaped. The alignment protrusions 408 may align with the cutout portions of the tray, and the teeth 402 may be configured such that when the foil cutter 106 is aligned via the alignment protrusions 408, the ramps 602 (see FIG. 6) are positioned directly above the teeth 402 (in a push-to-engage configuration) or next to the teeth 402 (when the lid is rotated, the ramps 602 engage the teeth 402).

[0058] Figure 5A is a top view of the foil cutter 106, according to one embodiment. Figures 5B-5D show various details of the foil cutter 106.

[0059] For example, Figure 5B (a side view of the foil cutter 106 taken along line AA in Figure 5A) shows cutter teeth 402. As shown, the teeth 402 extend axially from a major planar surface of the foil cutter 106. For ease of reference and discussion, in Figure 5B, the left side of the drawing is considered to be axially upward, and the plane facing the left side of the image is considered to be the top of the foil cutter 106. The plane on the right side of the image is considered the bottom and faces axially downward.

[0060] As can be seen more clearly in Figures 5C and 5D, the teeth 402 of the foil cutter 106 extend to the planar opening. The axially upper side of the teeth 402 can be configured to mate with a ramped surface on the lid (see Figure 6). This surface can be smooth to provide low resistance in twist-to-actuation embodiments, or the surface can be provided with one or more protrusions or tactile elements that provide feedback to the user when the teeth 402 flex into engagement with the ramp. For example, the teeth 402 can be configured to resist or click when engaging the ramp, thereby notifying the user that the teeth have engaged and penetrated the seal.

[0061] The axial underside of the tooth 402 can terminate in a cutting tip 502 configured to pierce the seal of the tray assembly when the ramp presses down on the top of the tooth 402. This allows the cutting tip 502 to extend downward through the opening and pass through the axial bottom (i.e., bottom side of the plane) of the foil cutter 106 and position the tray seal underneath.

[0062] FIG. 6 is a side cross-sectional view illustrating the cutting action of the foil cutter 106 according to an exemplary embodiment.

[0063] The tray assembly 700 fits into a corresponding recess in the mid-body assembly 108 and is covered with a foil seal 604. The foil cutter 106 is mounted on top of the mid-body assembly 108 and the tray assembly 700. When the teeth 402 are not engaged (as shown in FIG. 6 ), the cutting tip 502 does not extend beyond the bottom surface of the foil cutter 106.

[0064] The lid 102 is placed on top of the mid-body assembly 108 and foil cutter 106. The lid 102 includes one or more ramps 602 configured to engage with the teeth 402. The size and / or shape of the teeth 402 can be selected in combination with the configuration of the ramps 602 so that when the teeth 402 engage the ramps 602, the teeth 402 extend downward from the bottom surface of the foil cutter 106 a sufficient distance to contact and sufficiently penetrate the seal of the tray assembly 700 when the cutting tip 502 is positioned within the mid-body assembly 108.

[0065] The teeth 402 can be made to pierce the foil seal 604 in several ways. For example, in one embodiment, a user can rotate the lid 102 relative to the mid-body assembly 108 and base assembly 112, which are locked together and can move as a unit. The foil cutter 106 can move with the mid-body assembly 108 / base assembly 112. When the lid 102 is twisted, a relative twisting motion 606 occurs, causing the ramps 602 to rotate over the teeth 402 (or vice versa). The shape of the ramps 602 depresses and bends the teeth 402, forcing the cutting tip 502 to press and pierce the foil seal 604 (thus exposing the captured material contained in 700).

[0066] In another embodiment, the lid 102 is aligned with the foil cutter 106 (e.g., by placing the lid 102 on the cassette using the alignment features or by slightly rotating the lid 102 until the alignment features engage indicating the ramps 602 are aligned with the teeth 402) and then pushed to engage the ramps 602 with the teeth 402. In this embodiment, there is a relative pushing action 610 between the lid 102 and the mid-body assembly 108 / base assembly 112, which can move with the foil cutter 106. The pushing action causes the ramps 602, which can be aligned with the teeth 402, to bend the teeth 402 and force the cutting tip 502 into the foil seal 604.

[0067] In other embodiments, the materials in the trays may be activated in other ways. For example, the materials may be magnetically activated. A magnetic element may apply a magnetic field that causes actuation of the element or act on the material to cause activation of the material. Additionally, the materials may be activated by environmental conditions such as temperature or humidity. For example, a wax motor or other mechanism may be used to convert temperature into mechanical actuation to cause activation. Pressure may also be used to activate the seal or activate the material. Additionally, a push-button activation mechanism may be used to activate the material.

[0068] FIG. 7 is an exploded view of an exemplary tray assembly 700, according to one embodiment.

[0069] The tray assembly 700 may include a tray 704 to which material may be added. The tray 704 may be sized and shaped to fit within a corresponding recess in the mid-body assembly 108. The tray 704 may be circular or substantially circular (e.g., "C" shaped) and may be sized and shaped to at least partially correspond to the size and shape of the foil cutter 106. By providing a circular tray 704, material may be provided around most or all of the area where the sample is to be inspected, so that it is evenly distributed when the foil seal 604 is pierced by the foil cutter 106.

[0070] The axially upper side of the tray assembly 700 is sealed by a foil seal 604 (although other types of sealing materials besides foil can be used). The foil seal 604 can be annular and sized and shaped to fit over the top of the tray 704. The edge(s) of the foil seal 604 may be coated with an adhesive material (such as a heat-activated adhesive material) to allow the foil seal 604 to be affixed to the tray 704 and form an airtight seal on the top surface.

[0071] The bottom axial side of tray 704 includes one or more fill ports (not visible in FIG. 7, see FIG. 9). Materials are added to tray 704 through the fill ports, which are then hermetically sealed.

[0072] If the foil seal 604 is broken during use, it is preferable that the capture material not escape from the tray 704 and contaminate the sample to be tested. Accordingly, the exemplary embodiment provides a shelf 608, which may be a molded shelf (e.g., formed from plastic or other suitable material). The shelf 608 may contain a foam insert 702 located on the shelf 608 and sized and molded to prevent the capture material (contained in the bottom of the tray 704) from escaping through the perforations in the foil seal 604.

[0073] FIG. 8 is a top perspective view of an assembled tray assembly 700, according to one embodiment.

[0074] 9, on the other hand, is a bottom view of the assembled tray assembly 700, according to one embodiment. FIG. 9 shows a fill port 902 provided at the bottom of the anaerobic tray 704, through which material is introduced into the tray 704.

[0075] The fill port 902 is also visible in FIG. 10, which shows a further bottom view of the assembled tray assembly 700 .

[0076] FIG. 11 is a flowchart illustrating an exemplary method for creating an environment within a cassette assembly, according to one embodiment.

[0077] In block 1102, a user may provide a tray assembly including at least an anaerobic tray and a sealing element (such as a foil ring with an adhesive applied to the edge).

[0078] In block 1104, the user can optionally assemble the tray by placing optional molded shelves and foam inserts into the tray. As previously mentioned, these components can be provided to prevent leakage of the oxygen scavenging material into the testing environment when the sealing element is penetrated.

[0079] In block 1106, the top of the tray may be sealed. For example, if the sealing element is a foil ring coated with a heat-sensitive adhesive, the foil ring may be placed on the top of the anaerobic tray and heat may be applied to activate the adhesive. A user may optionally inspect the seal to ensure it is airtight.

[0080] In block 1108, the user can flip the tray over to expose the fill port at the bottom and fill the tray with ingredients through the fill port. Once the tray is filled, the tray can be manipulated (e.g., rotated, tapped, etc.) to ensure the ingredients are distributed throughout the tray.

[0081] After a predetermined amount of capture material has been added to the tray, the fill port may be sealed at block 1110. The fill port may be sealed with foil in a manner similar to the foil seal on the top of the tray, or may be sealed using another type of seal (e.g., a plug). A user may inspect the fill port seal to ensure it is airtight.

[0082] In block 1112, the base assembly, membrane, and mid-body assembly may be positioned. For example, the base assembly may be placed on a suitable surface within the testing area, and the membrane (and / or media pad) may be placed on the base assembly. O-rings may be placed in position around the circumference of the appropriate portion of the base assembly. The mid-body assembly may then be lowered onto the base assembly, with the O-rings creating a seal and / or securing the mid-body assembly to the base assembly.

[0083] At block 1114, the user may place the filled tray assembly into the corresponding recess in the mid-body assembly. The foil cutter 106 may be placed on top of the tray.

[0084] At block 1116, the lid may be placed on the cassette assembly, which may include providing an O-ring in the appropriate location on the mid-body assembly and then securing the lid to the inner or outer periphery of the O-ring.

[0085] The lid may initially be partially secured, preventing the foil cutter 106 from engaging the ramp 602 and penetrating the foil seal 604. The cassette assembly is moved to the location where filling or inspection will occur, after which the lid is fully secured. Depending on the operating mechanism of the foil cutter 106, the lid may be pushed or twisted closed. In either case, closing the lid may cause the ramp 602 to engage with the teeth 402, forcing the cutting tip 502 into the foil seal 604. The cutting tip 502 pierces the foil seal 604, exposing material to the sealed internal environment of the cassette.

[0086] At block 1118, a fluid delivery device may be inserted into the inlet of the mid-body assembly. For example, the inlet may include a rubber septum. The rubber septum may be pierced with a needle, and fluid may be delivered to the inlet through the needle. The fluid may be delivered via one or more tubes attached to the needle, or via another suitable delivery device.

[0087] The fluid can be allowed to pass through the membrane. The fluid can then be released from the outlet of the base assembly. After the fluid is released, growth medium can be provided near the membrane (e.g., via an inlet in the center of the body or another suitable inlet), and the cassette assembly can be left to incubate for a predetermined period of time. The growth of any microorganisms on the growth medium can then be measured (e.g., by imaging the growth medium through the optically transparent lid).

[0088] In some embodiments, a hybrid design may be used in which polymer is used for the support arms of the cutter teeth. One advantage of using polymer support arms is that they allow the cutter head to return to its original position after cutting. This simplifies the design of the foil cutter 106 and prevents accidental cuts.

[0089] FIG. 12 shows an exemplary portion of a cutter tooth arrangement 1200 with a polymer support arm. The cutter head 1204 is formed of a suitable metal, while the support arm 1202 is formed of a polymer, such as plastic. Using a metal cutter head 1204 has the advantage that the metal cutting head can be formed to create a larger hole than if the entire cutter tooth assembly were formed of a polymer. The resulting larger hole allows for more efficient capture. While fully plastic cutters typically cannot pierce or cut through gas-permeable membranes, metal cutter heads can cut through gas-permeable membranes. As can be seen, the cutter head 1204 is shaped like an arrow. The combination of the support arm 1202 and metal cutter head 1204 is more cost-effective to manufacture than an all-metal cutter tooth arrangement.

[0090] Figure 13 shows a front view of a cutterhead 1300. The cutterhead includes a portion 1304 connected to the support arm, a neck portion 1306, and an arrow portion 1302 for tearing foil or other sealing layers within the cassette assembly. Figure 14 shows a cutterhead 1400 with a flat profile. This view includes the arrow portion 1402 and the neck portion 1404. Figure 15 shows an alternative arrangement of a cutterhead 1500 in which the tip 1502 has a curved profile rather than a flat profile. The neck portion 1504 is also shown.

[0091] Figure 16 shows an example of how a metal cutter head can be formed by stamping, punching, or photoetching. As shown, a metal sheet 1600 has been processed to create a plurality of elements 1606 connected to a top 1602 and metal portions 1604 (only some of which are shown). As shown in Figure 17, elements 1700 include protrusions 1702.

[0092] FIG. 18 shows how such an element is fitted to the foil cutter 106, as described above. The cutting edge 1802 is inserted into and attached to a recess 1806 in the ramp 1804. The cutting edge 1802 may be configured to friction fit with the recess 1806, or alternative retention means may be provided to securely connect the cutting edge 1802 within the recess 1806. FIG. 19 shows an example of a foil cutter 1900 with a ring structure 1902. The element 1904 is attached. The protrusion 1906 is still in place, and the cutting edge 1908 is placed within the recess in the ramp. Once the cutting edge 1908 is securely attached, the protrusion 1906 can be removed, such as by cutting off any excess.

[0093] Some embodiments may be described using the phrase "in one embodiment" or "one embodiment," and derivatives thereof. These terms mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment. The appearances of the phrase "in one embodiment" in various places in this specification do not necessarily all refer to the same embodiment. Furthermore, unless otherwise stated, it is contemplated that the above-described features can be used in any combination. Thus, any features described individually can be used in combination with each other, unless it is expressly stated that the features are incompatible with each other.

[0094] To generally refer to the notation and nomenclature used herein, the detailed descriptions herein may be presented in terms of program procedures executed on a computer or network of computers. These procedural descriptions and representations are used by those skilled in the art to most effectively convey the substance of their work to others skilled in the art.

[0095] Some embodiments may be described using the terms "coupled" and "connected," along with their derivatives. These terms are not necessarily intended as synonyms. 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" can also mean that two or more elements are not in direct contact with each other, but yet still cooperate or interact with each other.

[0096] It is emphasized that the Abstract of the Disclosure is provided to enable the reader to quickly ascertain 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. It should be noted that in the foregoing Detailed Description, various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in fewer than 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 separate embodiment. In the appended claims, the terms "including" and "in which" are used as plain-English equivalents of the terms "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.

[0097] The above includes examples of the disclosed architecture. Of course, it is not possible to describe every conceivable combination of components and / or techniques, and one of ordinary skill in the art will recognize that many more combinations and permutations are possible. Accordingly, this novel architecture is intended to embrace all such alterations, modifications, and variations that fall within the spirit and scope of the appended claims.

Claims

1. 1. A tray assembly for a cassette assembly, comprising: a tray configured to receive the oxygen scavenging material, said tray being sized and shaped to fit within a recess in the microbiology test cassette; a seal configured to create an airtight seal on one side of the tray; one or more fill ports configured to receive an oxygen scavenging material; A tray assembly comprising:

2. The tray assembly of claim 1 , further comprising a shelf disposed within the tray.

3. 3. The tray assembly of claim 2, further comprising a foam insert disposed on a molded shelf and configured to prevent the oxygen scavenging material from exiting the tray when the seal is pierced.

4. The tray assembly of claim 1 , wherein the seal is a foil.

5. The tray assembly of claim 1 , wherein the seal includes an adhesive provided around an edge of the seal.

6. The tray assembly of claim 1 , wherein the tray is "C" shaped.

7. The tray assembly of claim 6 , wherein the one or more fill ports comprise at least one fill port provided on each edge of the “C” shape.

8. The tray assembly of claim 1 , wherein the tray is configured to substantially enclose an internal testing environment of the cassette assembly.

9. The tray assembly of claim 1 , further comprising an airtight seal provided over the one or more fill ports.

10. The tray assembly of claim 1 , further comprising a ring-shaped foil cutter configured to pierce the seal.

11. 1. A method comprising: Providing a tray assembly according to claim 1; filling the tray with oxygen scavenging material through the one or more fill ports; applying the seal to seal the tray; A method comprising:

12. The method of claim 11 further comprising disposing a shelf within the tray.

13. 13. The method of claim 12, further comprising placing a foam insert on the top of the shelf, the foam insert configured to prevent the oxygen scavenging material from exiting the tray when the seal is pierced.

14. The method of claim 11 further comprising providing adhesive around an edge of the seal.

15. The method of claim 14 further comprising sealing the seal to the tray with the adhesive.

16. 16. The method of claim 15, wherein sealing the seal comprises applying heat to activate a heat sensitive adhesive or applying heat to thermally weld the seal.

17. 12. The method of claim 11, wherein the tray includes a plurality of fill ports, and filling the tray includes adding the oxygen scavenging material to each of the fill ports.

18. The method of claim 11 , further comprising sealing the one or more fill ports.

19. The method of claim 11 further comprising disposing a cutter on top of the tray subassembly.

20. 20. The method of claim 19, wherein the cutter is forced to penetrate the seal by twisting or pushing the cutter.

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