Multi-layer test packs for sterilization monitoring

Abstract

The disclosed multi-layer test pack includes a channel sheet to form the recessed channel, and then a sealing layer covers the recessed channel to form a buried channel. By providing the recessed channel within the channel sheet of the thin film, the dimensional tolerance of the recessed channel can be better controlled. Furthermore, using a thin film for the channel sheet that can be formed into a roll allows for continuous unwinding and continuous bonding to the sealing layer.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to multi-layer test packs for sterilization monitoring, methods of making multi-layer test packs, and methods of using multi-layer test packs. [Background technology]

[0002] Sterilization uses a sterilizing gas, such as steam, hydrogen peroxide, or ethylene oxide, to sterilize the load. For example, reused clothing, tools, and instruments are placed in a sterilizer before reuse. Sterilization indicators are used to determine whether the sterilizer is functioning properly and killing microorganisms that may be present in the sterilizer.

[0003] Biological indicators are used to measure the effectiveness of sterilization procedures by monitoring the survival of test microorganisms contained therein, which are several times more resistant to sterilization treatment than most organisms. These biological indicators are exposed to a sterilization cycle and then cultured under conditions that promote the growth of any surviving test microorganisms. If the sterilization cycle fails, the biological indicator produces a detectable signature indicating the survival of the biological sample.

[0004] Chemical indicators can be read immediately after the sterilization process is complete, and the results indicate only that certain conditions were present during the sterilization process, such as the presence of a particular chemical or temperature for a certain period of time.

[0005] These sterilization indicators are often contained within test packs, which provide resistance to exposure of the sterilization indicator contained within the test pack to the sterilizing agent. U.S. Patent No. 7,045,343 discloses a sterilization indicator test pack. Summary of the Invention

[0006] The precise formation of the channel in the sterilization test pack provides a consistent amount of resistance for exposing the sterilant to the sterilization indicator contained within the test pack. The recessed channel is formed using a thin film channel slat, and then the sealing layer covers the recessed channel to form a recessed channel. By providing the recessed channel in the thin film channel slat, the dimensional tolerance of the recessed channel can be better controlled. Furthermore, using a thin film that can be formed into a roll for the channel slat allows for continuous unwinding and continuous bonding to the sealing layer. Manufacturing can be continuous, fast, and efficient.

[0007] In one embodiment, the multi-layer test pack comprises a channel sheet including a channel surface and a cover surface opposite the channel surface. The channel surface includes a mating surface and a recessed channel extending from the first mating surface into the channel surface. The test pack further comprises a sealing layer including a sealing surface and an outer surface opposite the sealing surface, the sealing surface being bonded to the mating surface. A buried channel is sandwiched between the recessed channel and the sealing surface. The buried channel extends from an inlet port exposed to the external environment and an outlet port exposed to a sealed cavity. The sealed cavity is separately connected to the channel sheet.

[0008] In one embodiment, the channel lamina is a single, integral structure with the recessed channel extending partially into the channel surface. In one embodiment, the channel lamina includes a first continuous layer including the channel surface and a second continuous layer including the covering surface. In one embodiment, the recessed channel extends completely through the first layer. In one embodiment, the channel lamina is a lamina having a substantially planar covering surface and a substantially planar mating surface. In one embodiment, the channel lamina further includes an edge surrounding the channel surface and the covering surface.

[0009] In one embodiment, the sealing layer further comprises a rim surrounding the sealing surface and the outer surface, hi one embodiment, the sealing layer further comprises a sealed cavity.

[0010] In one embodiment, the inlet port is at the edge of the channel lamina, in the covering surface, or in the sealing layer. In one embodiment, the outlet port is at the channel surface or in the sealing layer.

[0011] In one embodiment, the sealed cavity holds at least one of a biological indicator or a chemical indicator.

[0012] In one embodiment, the sealing surface is bonded to the mating surface by a thermal or adhesive bond.

[0013] In one embodiment, a method for making a multi-layer test pack includes providing a channel sheet including a channel surface and a cover surface opposite the channel surface, the channel surface including a mating surface and a recessed channel extending into the channel surface from the first mating surface, the method further includes providing a sealing layer including a sealing surface and an outer surface opposite the sealing surface, and bonding the sealing surface to the mating surface to form a recessed channel between the recessed channel and the sealing surface.

[0014] In one embodiment of the method, the buried channel extends from an inlet port exposed to the external environment and an outlet port exposed to the sealed cavity. In one embodiment of the method, the sealed cavity is separately connected to the channel thin film. In one embodiment of the method, the bonding is thermal bonding or adhesive bonding. In one embodiment of the method, the channel thin film is a single, integral structure, and the method further includes microreplicating the recessed channel within the channel surface. In one embodiment of the method, the channel thin film includes a first continuous layer including the channel surface and a second continuous layer including the cover surface, and the method further includes bonding the first continuous layer to the second continuous layer. In one embodiment of the method, the channel thin film is provided on a roll, and the sealing layer is provided on the roll, and the method further includes unwinding the channel thin film, unwinding the sealing layer, and continuously bonding the sealing surface to the bonding surface. [Brief explanation of the drawings]

[0015] [Figure 1a]FIG. 1 is an exploded side cross-sectional view of one embodiment of a multi-layer test pack in which the channel lamina is a single layer.

[0016] [Figure 1b] FIG. 1b is a top view of the embodiment of the multi-layer test pack of FIG. 1a.

[0017] [Figure 1c] FIG. 1b is a cross-sectional side assembly view of an embodiment of the multi-layer test pack of FIG. 1a.

[0018] [Figure 2a] FIG. 10 is a cross-sectional side exploded view of a second embodiment of a multi-layer test pack in which the channel lamina includes two layers.

[0019] [Figure 2b] FIG. 2b is a top view of the multi-layer test pack embodiment of FIG. 2a.

[0020] [Figure 2c] FIG. 2b is a cross-sectional side assembly view of the multi-layer test pack embodiment of FIG. 2a.

[0021] [Figure 3a] FIG. 10 is a cross-sectional side exploded view of a third embodiment of a multi-layer test pack in which the channel lamina includes two layers.

[0022] [Figure 3b] FIG. 3b is a top view of the multi-layer test pack embodiment of FIG. 3a.

[0023] [Figure 3c] FIG. 3b is a cross-sectional side assembly view of the multi-layer test pack embodiment of FIG. 3a.

[0024] [Figure 4] FIG. 1 is a side view of one embodiment of a method for making a multi-layer test pack using a high definition process, in which a channel sheet and a sealing layer are bonded together.

[0025] [Figure 5]FIG. 1 is a side view of one embodiment of a method for making a multi-layer test pack, wherein a channel sheet includes a first layer and a second layer, and the first layer, second layer, and seal layer are bonded together.

[0026] While the above-described drawings represent embodiments of the present invention, other embodiments are contemplated, as noted in the description. In all cases, this disclosure presents the invention by way of representation and not limitation. It will be understood that numerous other modifications and embodiments may be devised by those skilled in the art that fall within the scope and spirit of the invention. The figures may not be drawn to scale. DETAILED DESCRIPTION OF THE INVENTION

[0027] The precise formation of the channel within the sterilization test pack provides a consistent amount of resistance for exposing the sterilant to the sterilization indicator contained within the test pack. A thin film channel slat is used to form the recessed channel, and then a sealing layer covers the recessed channel to form a recessed channel. By providing the recessed channel within the thin film channel slat, the dimensional tolerance of the recessed channel is better controlled. As described below, a high-definition process can be used where the manufacturing dimensional tolerances are highly controlled, or in embodiments where the channel slat is a multi-layer structure, the recessed channel can completely traverse the film layer that forms the recessed channel. Furthermore, using a thin film for the channel slat that can be formed into a roll allows for continuous unwinding and continuous bonding to the sealing layer. Therefore, manufacturing can be continuous, fast, and efficient.

[0028] Conventional test packs, such as those shown in U.S. Patent Nos. 7,927,866 and 9,017,944, typically use a thermoforming process to form the structured surface, channel, and sealed cavity all in a single layer. Given the large size difference between the channel and the sealed cavity, a wide range of variability can occur in forming the channel. Furthermore, thermoforming or injection molding can be a slow batch manufacturing process in which parts are made one at a time.

[0029] The disclosed multi-layer test pack comprises a channel sheet and a sealing layer that combine to form an embedded channel, and a sealed cavity for holding a sterilization indicator is separately connected to the channel sheet.

[0030] Figures 1a, 1b, and 1c show an embodiment of a multi-layer test pack 100. Figure 1a is a cross-sectional side exploded view of a multi-layer test pack 100 in which the channel lamina 120 is a single layer. Figure 1b is a top view of the multi-layer test pack 100. Figure 1c is a cross-sectional side assembled view of the multi-layer test pack 100.

[0031] The multi-layer test pack 100 includes a channel slat 120, a sealing layer 130, and a sealed cavity 150. In the assembled configuration shown in Figures 1b and 1c, the channel slat 120 and the sealing layer 130 join to form a buried channel 140.

[0032] The channel sheet 120 is a generally planar sheet including a channel surface 122, a covering surface 128, and an edge 129. The channel sheet 120 generally has a length and width much greater than its thickness. The channel surface 122 includes a joining surface 124 and a recessed channel 126. In this embodiment, the recessed channel 126 extends partially into the channel sheet 120. In this embodiment, the recessed channel 126 does not extend completely through the channel sheet 120. In one embodiment, the recessed channel 126 extends 10% or less, 25% or less, 50% or less, 75% or less, or 90% or less of the thickness of the channel sheet 120. Precise control of the dimensions (length, depth, and diameter) of the recessed channel 126 is important to obtain a reliable test pack. When the channel sheet 120 is a single-layer construction having the channel surface 122, high precision can be achieved using methods such as high-definition machining to manufacture the channel sheet 120 as shown in FIG. 1a.

[0033] The sealing layer 130 has a sealing surface 132, an outer surface 134, and an edge 136. The sealing layer 130 is generally planar and, in this embodiment, further includes a recess 138. The recess 138 is a space that can hold one or more indicators. The indicators include chemical indicators and biological indicators.

[0034] As shown in FIG. 1c, the sealing layer 130 is secured to the mating surface 124 of the channel slat 120. Methods for securing the sealing layer 130 to the channel slat 120 include, but are not limited to, techniques such as ultrasonic welding, solvent welding, adhesives, hot melt bonding, thermal bonding / laminating, and combinations thereof. The recessed channel 126 forms a buried channel 140 when the sealing layer 130 is secured to the channel slat 120. The buried channel 140 has a first end 141 and a second end 143 (illustrated in FIG. 1b). In this embodiment, the first end 141 is at the edge 129 of the channel slat 120 and forms an inlet port 142 open to the environment. The second end 143 includes an outlet port 144 open to the sealed cavity 150. The dimensions of the recessed channel 140 can be any number of sizes, shapes, or lengths that make it sufficiently difficult for outside sterilant to reach the indicator within the sealed cavity 150 .

[0035] The sealed cavity 150 is formed by a recess 138 that is sealed against the channel slat 120. The sealed cavity 150 can receive one or more indicators, such as chemical or biological indicators. As shown in this embodiment, the sealed cavity 150 is integral with the sealing layer 130. The sealed cavity 150 in the assembled configuration as shown in FIG. 1c is sealed from the external environment except through the exit port 144 from the buried channel 140. It can be seen that the size of the sealed cavity 150 is generally much larger than the buried channel 140.

[0036] The channel slats 120 and sealing layer 130 can be formed from materials that can be bonded together and can withstand sterilization processes, for example, the materials can be thermoplastic materials, including, but not limited to, propylene, polyethylene, polystyrene, and polyvinyl chloride.

[0037] Figures 2a, 2b, and 2c show another embodiment of a multi-layer test pack 200. Figure 2a is a cross-sectional side exploded view of multi-layer test pack 200 in which channel lamina 220 includes two layers. Figure 2b is a top view of multi-layer test pack 200. Figure 2c is a cross-sectional side assembled view of multi-layer test pack 200.

[0038] Multi-layer test pack 200 includes a channel sheet 220, which includes a channel layer 221 and a surface layer 225, a sealing layer 230, and a sealed cavity 250. In an assembled configuration, channel sheet 220 and sealing layer 230 join together to form a sealed channel 240.

[0039] Channel lamella 220 includes a channel layer 221, a surface layer 225, surrounded by an edge 229. Channel layer 221 includes a top surface 223 and a channel surface 222. Channel surface 222 includes a joining surface 224 and a recessed channel 226. Recessed channel 226 extends through the entire thickness of channel layer 221. Top surface 223 of channel layer 221 is fixed to surface layer 225. Because control of the thickness of channel layer 221 defines the thickness of recessed channel 226, precise control of the depth of recessed channel 226 can be achieved.

[0040] Sealing layer 230 has a sealing surface 232, an outer surface 234, and an edge 236. Sealing layer 230 is generally planar and further includes a recess 238. Recess 238 is a space that can hold one or more indicators, such as chemical and biological indicators.

[0041] FIG. 2c is shown as an assembled view. The sealing layer 230 is secured to the channel slat 220 at the interface between the joining surface 224 and the sealing surface 232. Methods for securing the sealing layer 230 to the channel slat 220 include, but are not limited to, ultrasonic welding, solvent welding, adhesives, hot melt bonding, thermal bonding / laminating, and combinations thereof. The recessed channel 226 forms a buried channel 240 when the sealing layer 230 is secured to the channel slat 220; in this embodiment, the surface layer 225 is disposed on the channel layer 221. The buried channel 240 has a first end 241 and a second end 243. The first end 241 includes an inlet port 242 open to the environment, and the second end 243 includes an outlet port 244 open to the sealed cavity 250. In this embodiment, the inlet port 244 is within the channel layer 221 of the channel slat 220. The dimensions of the recessed channel 240 can be any number of sizes, shapes, or lengths that make it sufficiently difficult for outside sterilant to reach the indicator within the sealed cavity 250 .

[0042] The sealed cavity 250 is formed by a recess 238 that is sealed against the channel slat 220. The sealed cavity 250 can receive one or more indicators, such as chemical or biological indicators. As shown, the sealed cavity 250 is integral with the sealing layer 230. The sealed cavity 250 in the assembled configuration shown in FIG. 2c is sealed from the external environment except through the exit port 244 from the buried channel 240. It can be seen that the size of the sealed cavity 250 is generally much larger than the buried channel 240.

[0043] The channel slats 220 and sealing layer 230 can be formed from materials that can be bonded together and can withstand sterilization, for example, the materials can be thermoplastic materials, including, but not limited to, propylene, polyethylene, polystyrene, and polyvinyl chloride.

[0044] Figures 3a, 3b, and 3c show another embodiment of a multi-layer test pack 300. Figure 3a is a cross-sectional side exploded view of a multi-layer test pack 300 in which the channel lamina 320 includes two layers. Figure 3b is a top view of the multi-layer test pack 300. Figure 3c is a cross-sectional side assembled view of the multi-layer test pack 300.

[0045] Multi-layer test pack 300 includes a channel sheet 320, which includes a channel layer 321 and a surface layer 325, a sealing layer 330, and a sealed cavity 350. When assembled, channel sheet 320 and sealing layer 330 join to form a sealed channel 340. In this embodiment, sealed cavity 350 is not integrally formed with sealing layer 330, but instead is separately connected to sealing layer 330.

[0046] Channel slab 320 includes a channel layer 321 and a surface layer 325, surrounded by an edge 329. Similar to the configuration depicted in Figure 2a, channel layer 321 includes a top surface 323 and a channel surface 322. Channel surface 322 includes a joining surface 324 and a recessed channel 326. Recessed channel 326 penetrates the entire thickness of channel layer 321. Surface layer 325 is a solid, continuous, extended surface with no through holes.

[0047] The sealing layer 330 has a sealing surface 332, an outer surface 334, and an edge 336. The sealing layer 330 is generally planar. When assembled, the sealing layer 330 is secured to the channel sheet 320 at the interface between the joining surface 324 and the sealing surface 332 using techniques such as ultrasonic welding, solvent welding, adhesives, hot melt bonding, thermal bonding / laminating, and combinations thereof. The recessed channel 326 forms a buried channel 340 when the sealing layer 330 is secured to the channel sheet 320 and the channel sheet 320 has the surface layer 325 secured thereto. The buried channel 340 has a first end 341 and a second end 343 (illustrated in FIG. 3b). The first end 341 is within the sealing layer 330 and forms an inlet port 342 open to the environment. A second end 343 is also within the sealing layer 330 and forms an exit port 344 that is open to the sealed cavity 350. The dimensions of the recessed channel can be any number of sizes, shapes, or lengths that make it sufficiently difficult for outside sterilant to reach the indicator within the sealed cavity 350.

[0048] The sealed cavity 350 is formed by a recess 338 sealed against the sealing layer 330. The sealed cavity 350 receives one or more indicators, such as chemical and biological indicators. As shown, the sealed cavity 350 is separately connected to the sealing layer 330. In this embodiment, the sealed cavity 350 can be bonded or secured to the sealing layer 330 by techniques such as ultrasonic welding, solvent welding, adhesives, hot melt bonding, thermal bonding / laminating, or combinations thereof. The sealed cavity 350 in the assembled configuration shown in FIG. 3c is sealed from the external environment except through the exit port 344 from the embedded channel 340. It can be seen that the size of the sealed cavity 350 is generally much larger than the embedded channel 340.

[0049] The channel slats 320, sealing layer 330, and sealed cavity 350 can be formed from materials that can be bonded together and can withstand sterilization. For example, the materials can be thermoplastic materials, including, but not limited to, propylene, polyethylene, polystyrene, and polyvinyl chloride. Any one of these layers can be of various thicknesses, flexibility, or rigidity.

[0050] Inserted into the sealed cavity 350 is at least one biological or chemical indicator. The indicator must be read after a sterilization cycle, when the sterilant migrates through the recessed channels and reaches the sealed cavity. If the sealed cavity is constructed of a transparent material, the visual display of the indicator can be perceived. However, typically, the biological indicator must be removed from the sealed cavity and incubated. After incubation, the biological indicator is read. Therefore, the various layers of the disclosed test package should be configured to allow access into the sealed cavity after sterilization. In one example, the adhesive or laminate of the sealed cavity is removable to allow access to the indicator contained within the sealed cavity.

[0051] Although the embodiments describe a single buried channel, it is understood that more than one buried channel can be formed to provide access to the sealed cavity from the external environment.

[0052] It is understood that for any embodiment, the location of the inlet port can be interchangeably located at the edge of the channel plate as shown in Figures 1a-1c, or internally as shown in Figures 2a-2c and 3a-3c.

[0053] It is understood that for any embodiment, the channel lamina may be a single layer, as shown in Figure 1a, or a multi-layer configuration, as shown in Figures 2a and 3a. Additionally, additional layers may be included, such as channel lamina having three or more layers.

[0054] It will be appreciated that for any embodiment, the cavity may be integrally formed as part of the sealing layer, as shown in Figures 1a and 2a, or may itself be a separate element applied to the multi-layer test pack, as shown in Figure 3a.

[0055] An advantage of the test packs described herein is that the buried channel can span the area of ​​the sealed cavity, thereby minimizing the overall area of ​​the test pack. Alternative designs, in which the channel and cavity are integrally formed in the same material, have the channel adjacent to the cavity, thus increasing the size of the test pack. In some embodiments, the cavity can be located directly below the buried channel.

[0056] FIG. 4 illustrates an embodiment of a method for making a test pack, such as test pack 100 shown in FIGS. 1a-1c. The method for making test pack 100 includes an extrusion die 410, a definition roll 420, a nip 430, and a sealing layer roll 440. The extrusion die 410 extrudes a material, such as a thermoplastic material, onto the definition roll 420, which has a structured surface that creates the structure of a channel slat 425. The channel slat 425 is then fed into the nip 430, where it is secured to a sealing layer 445 from the sealing layer roll 440. Depending on the technique used to connect the channel slat 425 to the sealing layer 445, additional elements may be included. For example, an adhesive applicator or sprayer may be included.

[0057] FIG. 5 illustrates an embodiment of a method for making a test pack, such as test pack 200, 300 shown in FIGS. 2a-2c or 3a-3c. The method includes a seal layer roll 440, a channel layer roll 450, and a surface layer roll 460. These layers are fed from their respective rolls into a nip 430, which secures the layers together. Depending on the technique used to connect the channel laminate 425 to the seal layer 445, additional elements may be included. For example, an adhesive applicator or sprayer may be included.

[0058] A method of using the test pack can include subjecting the test pack, including one or more indicators, to a decontamination process, such as autoclaving, along with the material to be decontaminated. A sterilant, such as steam, ethylene oxide, or hydrogen peroxide, travels from the external environment through the recessed channels into the sealed cavity containing the indicator. The chemical indicator indicates exposure to the sterilant. The sterilant kills any biological material within the biological indicator. After sterilization, the indicator can be removed. If used, the biological indicator may be cultured to determine whether any remaining biological material grows, indicating a "failure" of the sterilization cycle.

[0059] While specific embodiments have been shown and described herein, it will be understood that these embodiments are merely illustrative of the many specific configurations that may be devised in application of the principles of the present invention. Those skilled in the art will be able to devise numerous and varied other configurations in accordance with these principles without departing from the spirit and scope of the present invention. The scope of the present invention should not be limited to the structures described in this application, but rather only by the structures set forth by the language of the claims and the equivalents of such structures.

Claims

1. A channel thin plate including a channel surface and a coating surface opposite the channel surface, the channel surface comprising: The joint surface and a channel sheet including a recessed channel extending from the joining surface into the channel surface; a sealing layer including a sealing surface and an outer surface opposite the sealing surface, the sealing surface being joined to the joining surface; a recessed channel received between the recessed channel and the sealing surface; Equipped with the buried channel extends from an inlet port exposed to the external environment and an outlet port exposed to the sealed cavity; the sealed cavity is formed in a layer of a multi-layer test pack separate from the channel thin plate; The channel sheet includes a first continuous layer including the channel surface and a second continuous layer including the cover surface.

2. 1. A method for manufacturing a multi-layer test pack, comprising: A channel sheet including a channel surface and a covering surface opposite the channel surface, the channel surface comprising: The joint surface and a recessed channel extending from the mating surface into the channel surface; providing a sealing layer including a sealing surface and an outer surface opposite the sealing surface; bonding the sealing surface to the mating surface to form a recessed channel between the recessed channel and the sealing surface; Including, The method wherein the channel sheet comprises a first continuous layer including the channel surface and a second continuous layer including the cover surface.

3. 10. The multi-layer test pack of claim 1, further comprising a biological indicator disposed within the sealed cavity.

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