Technical Field

The present application concerns a tray for holding a plurality of petri-dishes and a transport packaging, preferably in the form of a blister packaging with the tray or trays. The present application particularly concerns the field of testing in pharmaceutical and food processing and more particularly environmental monitoring of clean or ultra clean processing areas. It is also applicable to other processing situations where cleanness of a processing area or environment is to be determined and monitored, for example in the field of semiconductor, electronics or aircraft manufacturing.

Background

In order to monitor environmental conditions in closed processing areas of the above type it is common practice in passive air sampling to place one or more media plate/plates in an activity zone of the production area and expose them to the surrounding air such that they can capture the maximum amount of particles in the surrounding air. Larger particles tend to settle faster on the plates due to gravitational force. Smaller particles take some time in settling due to factors such as air currents. Media plates work best in still areas. The microorganisms from the air may settle on the media plates alone or in colonies.

In active monitoring of air in production areas a microbial air sampler is used to force air into or onto a collection medium over a specified period of time. The collection medium can be a common petri-dish, for example including a nutrient agar-based test media or other suitable test media depending on the need.

The collection media, for example in the form of the petri-dishes, media plates or settle plates (the terms will be used interchangeably in this specification), have to be transferred repeatedly into the production area and removed therefrom for further handling and evaluation. This is commonly done in a manual process where one or more plates or petri-dishes are conveyed manually through a sterile transfer port into and from the interior of the production area. However, the manual handling of the petri-dishes involves a high risk of contamination when handling the media plate after a lid, cover or seal has been opened, and a non-secured transfer of the media plates during the introduction, installation, removal and further handling, in particular when a plurality of them are handled at once as a set or batch or group, for example in a stack. Maintaining several petri-dishes in a group during a sequence of processing steps is moreover a complex task and requires measures like taping or bundling several petri- dishes together and/or marking them.

Further, the individual petri-dishes as such are not particularly suitable for automated handling in batches or stacks as they typically consist of a media plate holding the nutrient media and a lid or cover releasably covering the plate. It is difficult for automated handling equipment to securely grip, hold and transfer the smooth cylindrical peripheral surfaces of the media plate and/or lid/cover as they require a defined position and orientation for gripping, and there is a high risk that lids are inadvertently opened, displaced or removed from their media plates during handling at the various stages of the process, thereby compromising the detection result.

US 2002/053525 Al discloses a cassette arrangement for accommodating petri-dishes or the like. The arrangement includes a box-shaped cassette housing designed to be stackable and having a slotted opening on one lateral side for inserting or removing the petri-dish from an interior space of the housing. The box-shaped cassette housing is stackable and has finger-operated means arranged on an opposite end side for pushing the petri-dish in the cassette housing out at least partially through the opening. While this cassette arrangement provides for a safe transport of the petri-dish held in the interior space of the cassette housing, it is not useful for automated handling as it is specifically directed to a manual operation by a finger in order to at least release the petri-dish from the housing. Further, the stacking capability is not specifically reliable and likewise not suitable for automated handling of a stack of cassette housings.

What is desired is an at least partly or preferably fully automated process that does not involve human handling steps for introducing, installing and removing the media plates into and from the production areas and further stages of the evaluation processes.

It is furthermore preferable to provide means for such a partly or fully automated process with which it is possible to use standard media plates available on the market, preferably the so-called petri-dishes.

The present application accordingly aims at providing a device for holding a plurality of petri-dishes and a transport packaging, preferably in the form of a blister packaging with a plurality of petri-dishes, which allows secure handling of petri-dishes or settle plates used for microbiological air sampling in a classified or non-classified environment reducing the risk of false positive and final product contamination, which allows a secure handling during the air testing from storage, transportation to sampling area, sampling, counting, waste management for passive or active microbiological air sampling in a fully or partially automated process, i.e. the manual handling should at least not be excluded.

Summary

According to the present application this object is solved by providing a tray for holding a plurality of petri-dishes as defined in claim 1 and a transport packaging for a plurality of petri-dishes as defined in claim 7 as well as a blister packaging with a plurality of petri-dishes as defined in claim 11. Preferred embodiments are defined in the dependent claims.

The present application specifically provides a tray for holding a plurality of petri- dishes, comprising a plate-like main body with a plurality of adjacent holding portions each configured to receive and support, in an essentially horizontal orientation that is substantially parallel to a plane of the plate-like main body, a single petri-dish or a stack of essentially vertically aligned petri-dishes, wherein each holding portion includes first centering features for aligning the petri-dish or plural petri-dishes in case of a stack in its/their essentially horizontal orientation in the holding portion.

Preferably, the plate-like main body includes, at a periphery of each holding portion, at least two openings or recesses spaced apart from each other about the periphery of the holding portion and configured to allow insertion of a gripper of a manipulating device or of a finger for grabbing/pinching of a circumferential peripheral wall of a petri-dish at its diameter when the same is placed on the holding portion.

Preferably, the plate-like main body includes one or more flat surface areas on an upper side thereof and configured to allow fluid-tight engagement with a sucking manipulator of a transfer system for holding the tray.

Preferably, the plate-like main body includes second centering features for aligning and separating a plurality of plate-like main bodies in an essentially vertical stack such that contact between petri-dishes accommodated in one tray and an adjacent tray is prevented.

Preferably, the first centering features comprise lower centering features for centering a petri-dish bottom plate and upper centering features for centering a petri-dish lid.

Preferably, each holding portion is provided with a window at a bottom portion of the holding portion to allow a visual inspection of the petri-dish in the holding portion and/or introduction of a lifting device from below for raising the petri-dish or the stack of petri-dishes received in the supporting portion.

The present application also provides a transport packaging for a plurality of petri- dishes, comprising a tray as defined herein or a plurality of trays as defined herein arranged in an essentially vertically aligned stack, and a box-shaped tub configured to removably receive and completely surround the one tray or the stack of trays.

Preferably, the box-shaped tub is formed as a one-piece blister cavity, preferably formed from a formable sheet or web material, and further preferably by thermoforming or cold-forming or a combination thereof.

Preferably, the box-shaped tub and the tray or trays are made from the same material.

Preferably, the transport packaging further comprises a plurality of petri-dishes which are accommodated in the tray or trays.

The present application also provides a blister packaging with a plurality of petri-dishes, comprising a transport packaging as defined herein, wherein the plurality of petri- dishes are accommodated in the tray or trays in the box-shaped tub in a sterile environment, and a gas barrier film, preferably at least partially transparent, sealing the opening of the box-shaped tub.

The present application accordingly provides a tray for holding a plurality of petri- dishes. It is compatible with environmental monitoring in a fully automated process. It in particular allows an accurate positioning and holding together of a set or batch of petri-dishes in a device that can be used during all the steps or stages of the monitoring process, including packaging and shipment, during introduction into the clean production area, setting in the loading and unloading area, grabbing of individual petri- dishes using a gripper or robot arm for transferring the dishes to critical areas for passive or active air monitoring, during removal from the clean production area, during incubation, reading and/or storage.

Brief description of the drawings

Preferred embodiments will be described below by reference to the attached exemplary schematic drawings, in which:

Figure l is a perspective view of the tray for holding a plurality of petri-dishes according to an embodiment.

Figure 2 is a perspective view of a plurality of trays of Figure 1 in a stack and with the petri-dishes supported in the trays, wherein the stack of trays is received in a tub-like transport packaging.

Figure 3 is a perspective view of the stack of trays of Figure 2 removed from the transport packaging and with some petri-dishes removed from the holding portions.

Figure 4 is a partial cut-away perspective view of a detail of one of the trays of Figure 3.

Figure 5 is a partial cut-away perspective view of the stack of trays of Figure 3 from a bottom and a different side.

Figure 6 is a perspective view of the tray for holding a plurality of petri-dishes in stacks according to another embodiment;.

Figure 7 is a partial cut-away perspective view of a detail of the tray of Figure 6.

Figure 8 is a perspective view of the tray of Figure 1 with petri-dishes in some of the holding portions and an exemplary gripper placed in position to engage with a petri- dish.

Figure 9 is a perspective view of the tray of Figure 8 as seen from the bottom to show the engaging state of the gripper with the petri-dish.

Figure 10 is a perspective view of the tray of Figure 6 with stacks of petri-dishes in some of the holding portions and with lifting devices in a position before insertion through a window.

Figure 11 is a perspective view of the tray of Figure 10 with lifting devices in a position after insertion through a window and with the stacks of petri-dishes in a raised position. Detailed description

For the purposes of the present application, terms such as "horizontal", "vertical", "perpendicular", and similar terms are - if not already explicitly indicated - considered to be "essentially horizontal", "essentially vertical", "essentially perpendicular", provided that this does not negatively affect functionality. Preferably, the term "essentially" is to denote a deviation of at most 10°, more preferably of at most 5°, even more preferably of at most 4° or 3°, still even more preferably of at most 2° or 1° from being horizontal, vertical, and perpendicular, respectively.

The tray 30 according to the first embodiment generally comprises a plate-like main body 31 with a plurality of adjacent holding portions or nests 32 each configured to receive and support, in an essentially horizontal orientation that is substantially parallel to a plane of the plate-like main body 31 that is essentially perpendicular to a stacking or thickness direction, a single petri-dish P or a stack S of essentially vertically aligned petri-dishes P in an essentially horizontal orientation (an embodiment for receiving, in each holding portion or nest 32; a stack is described later in connection with Figures 6 and 7, 10 and 11).

Each holding portion or nest 32 is formed as a receptable defining a position for the petri-dish and surrounding the petri-dish to maintain it in its essentially horizontal orientation during handling of the tray 30. In order to align and secure the petri-dish or the plurality of petri-dishes in the stack in their essentially horizontal orientation in the holding portion it includes first centering features 9,9a-9c. The first centering features 9 comprise lower centering features 9a for centering the petri-dish bottom plate or dish D and upper centering features 9b for centering a lid L of the same petri-dish (see Figures 1 and 4). The centering features are, for example, in the form of raised protrusions or rims, preferably of different height and distributed about the circumference of the petri-dish P to achieve a stable support and alignment. Three protrusions in a triangular distribution would be sufficient to achieve this secure centering.

The lower and upper centering features may, however, be integrally formed so as to center the dish D and the lid L of the respective petri-dish.

The holding portions 32 are arranged adjacent to each other in the same plane and the holding portions are preferably regularly arranged in the plate-like main body 31. In the embodiment shown as an example four holding portions are arranged in a quadrangular arrangement, but different arrangements are possible. The outline of the plate-like main body 31 in the embodiments shown as an example is an approximate square, but different outlines are possible depending on the size and arrangement of the holding portions.

The plate-like main body 31 includes, at a periphery of each holding portion 32, at least two spaced-apart openings or recesses 33 which are spaced apart from each other about the periphery of the holding portion 32 and are configured to respectively allow insertion of a part G1 of a mechanical gripper G of a manipulating device or of a finger of a user for grabbing/pinching a circumferential peripheral wall Pc of the petri-dish at its diameter when the same is placed on the holding portion 32.

In the embodiment the openings or recesses 33 are formed as three oval holes distributed regularly about the periphery of the holding portions 32. The holes slightly reach into the bottom portion 36 of the holding portions 32 (and thus under the bottom surface of a petri-dish in the holding portion) and openings 33 of adjacent holding portions may be united to form a common hole as shown in Figure 1. While two such openings or recesses for each holding portion would be sufficient to securely grip the outer perimeter of the petri-dish, three or more openings may be provided as well.

The plate-like main body 31 includes one or more flat surface areas 34, preferably on an upper side, which are arranged and configured to allow a fluid-tight engagement with a sucking manipulator of a transfer system for holding the tray 30 (see Figure 4). Such dedicated flat surface areas for sucking engagement are regularly distributed about the periphery of the plate-like main body at the corner portions as shown but may also be provided at different positions, for example in a center of gravity, in particular if only a single surface area is provided for the tray.

The plate-like main body 31 further preferably includes second centering features 10, 35 for aligning and separating a plurality of the plate-like main bodes 31 in an essentially vertical stack such that contact between petri-dishes P accommodated in one tray 30 and in an adjacent tray 30 is prevented. Such second centering features are shown as an example in Figures 1, 2 and 5 in the form of semi-circular raised wall sections 35 at the centres of opposed lateral sides of the plate-like main body. These raised-circular wall sections 35 are formed so as to be able to engage with corresponding wall sections 35 of the adjacent main body to form a continuous and aligned stack as shown in particular in Figure 5. The semi-circle shape being recessed towards the inside of the main body and being open laterally to the outside circumference provides a further advantage that the aligned semi-circular wall sections 35 form, together, a continuous hollow cylinder that is open to an outside and allows insertion of a rod or other gripper for connecting a plurality of plate-like main bodies in a stack even more securely if needed. The second centering features may be provided in the centres of each of the lateral sides or may be located at different positions about the periphery or towards the center of the plate-like main bodies provided they are aligned to be able to engage with mating centering features of other trays to releasably connect them together to form the stack.

While the plate-like main body has the basic overall form of a sheet or plate with the functional features described above raised or lowered from the plane of the plate-like main body it may have a different shape reduced from a sheet to rather resemble a grid and/or may include further protrusions or grooves to secure the bending or torsional stiffness required to handle the plate-like main body in the process even when the plural petri-dishes are arranged in the holding portions. The plate-like main body 31 can, however, be relatively thin as the petri-dishes provide additional stiffness when received and engaged or locked in the holding portions 32.

The upper side of the petri-dishes supported in the holding portions 32 is essentially freely accessible so as to allow gripping of the petri-dish by means of a gripper connecting to the top side of the petri-dish. The openings or recesses 33 distributed about the periphery of the holding portion allow insertion of the part G1 of the gripper G at positions distributed about the periphery in order to securely hold the petri-dish against the holder on the top side to lift it up from the holding portion 32 (see Figures 8 and 9). The gripper may include parts like arms or fingers G1 reaching partly around the lower edge of the dish to the bottom side.

The embodiment shown in Figures 6, 7, 10 and 11 is similar to the first embodiment but has the holding portions 32 adapted to receive an essentially vertically aligned stack S of petri-dishes. Consequently, the first centering features 9c are enlarged in the protruding dimension from the plate-like main body to engage with the peripheral wall Pc of all the petri-dishes in the stack. The centering features of the holding portions may be raised above a main portion of the plate-like main body 31 which thus forms the lowest part of the tray but may extend to both sides, i.e. upper and lower sides of the plate-like main body from an intermedia main portion or may be formed so as to be recessed from the main portion of the plate-like main body which essentially forms the upper end of the tray as shown in Figure 10, for example.

In both embodiments (but shown only in connection with the embodiment for holding the stack of petri-dishes as an example) each holding portion 32 may be provided with a cut-out or window 12 at the bottom portion 36 to allow a visual inspection of the petri-dish P or of the stack of petri-dishes in the holding portion 32 and/or introduction of a lifting device 40 from below for raising the petri-dish or the stack of petri-dishes P received in the respective supporting portion 32 as shown in Figures 10 and 11. Such lifting device 40 may include a rod 42 and a plate 41 movable in an essentially vertical direction back and forth (or more precisely up-and-down) to engage with the bottom side of the lowermost petri-dish in the holding portion. In this way the plural petri- dishes in a holding portion can be raised above the main portion of the plate-like main body as shown in Figure 11 to allow gripping of the full stack and transfer of the entire stack or of individual petri-dishes by hand or by a suitable gripper of an automated handling device.

The possibility of a visual inspection of the petri-dish and the holding portion includes the possibility of reading and writing electronic tags (for example with RFID technology) to store information related to each petri-dish. Such information may include a batch number, a location site number, a set number, an ID of the plate, position of the plate inside a transport packaging or blister, a time when the plate was placed and removed from an isolator, an hour of sampling, conformity information of air monitoring parameters, an operator or other events during the processing. Such electronic tags may be provided on each petri-dish and/or may be provided so as to be associated to each holding portion and/or the tray as such. Colour coding of the material of the tray or in the form of stickers or labels is available as well.

The tray of the present application, in particular the plate-like main body 31 may be formed from a material that is sufficiently stiff to carry the desired number of petri- dishes in the holding portions. It may be formed from paper of cardboard or plastic or metal or laminates or composites of such materials depending on the need. In a preferred structure it is formed from injection moulded plastic as this facilitates forming of the various functional features integral with the main portion of the plate including any cut-outs or recesses and protrusions. It is, however, possible to form the plate-like main body from a deformed metal sheet or from a cast metal which may be useful if multiple uses and sterilization is desired.

The tray 30 or plural stacked trays 30 each with plural petri-dishes, for example in the form of plural stacks S which respectively define a group of petri-dishes and which are received in a respective holding portion 32 can be packaged and sealed in a bag (not shown) or in a cavity 38 of a more rigid box-shaped tub 36 as shown in Figure 2 that respectively removably receives and surrounds the tray or trays with the petri-dishes except for an upper opening 37. Accordingly, the tray/trays with the box-shaped tub or bag forms a transport packaging 20 for a plurality of petri-dishes P.

The box-shaped tub 36 is preferably formed as a one-piece blister cavity, preferably is formed from a formable sheet of a plastic material, further preferably by thermal forming or cold-forming or a combination of the two. The tub 36 may be designed for one-time use or may be reusable.

The opening 37 of the box-shaped tub 36 is configured to be sealed by a gas-barrier film (not shown), preferably at least partially transparent, to form a blister-like packaging. In conjunction with a sterilized set of petri-dishes held in the tray/trays such sealed transport packaging provides a useful unit for use in connection with the environmental monitoring as described in the introductory portion of this specification. In a preferred embodiment the box-shaped tub 36 and the tray/trays 30 are made from the same material, thus facilitating the waste-processing of the material after use.

Traceability elements in the form of a bar code, a data matrix or a RFID may be accommodated and provided on the bag for the packaging or on the present trays for accommodating the individual petri-dishes and/or directly on the petri-dishes.

Based on the traceability elements all critical process data may be recorded and linked through an integrated RFID-type system or via an external system, for example cloudbased. Such a process may include a number of typical stations or stages of the process where specific data is collected and recorded like the storage stage SI (time/date of entrance, storage temperature, moisture level, expiry date management, fifo management), transportation stage S2 (duration and temperature), grouping stage S3 (position or group to which the individual petri-dishes belong), transfer stage S4 (location and time), air sampling stage S5 (duration, location, time/date, link of the ID of the plate with the ID of the rack ID), incubation stage S6 (time/date of entrance, real temperature, moisture level, 02 level), counting stage S7 (time/date and counting results) where counting takes place in order to determine the number of contaminants. At stage S8 all the data are exported and transferred to a storage from where they can be accessed and further processed.

The traceability can be realized externally with dedicated RFID reader systems connected to a central system, but the RFID (or data matrix) reader can also be driven directly from an air monitoring system which allows full traceability of the process plate including:

- positive detection of the processed plate using data matrix reader;

- positive detection of the plate storage location (e.g. tray) using data matrix or RFID;

- allowing read and write information in the RFID tag of the tray(s) containing the plate(s);

- each tag may contain the following information: batch number, location site number, set number, ID of the plate, position of the plate in a stack or inside a blister pack;

- time when the plate was placed and removed from the isolator;

- hour of the sampling, conformity of the air monitoring parameters, operator, events during the presence of the blister in the sampling environment.