Technical Field

The present application concerns a transport cage for a petri-dish and a transport packaging with a plurality of petri-dishes. In particular, the present application 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 media plates or settle plates, 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/or in non-secured transfer of the media plates during the introduction, installation and removal, in particularwhen a plurality of them are handled together as a group or batch.

The common petri-dishes are not particularly suitable for automated handling individually or in batches 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 surfaces of the media plate and/or lid/cover, and there is a high risk that lids are inadvertently opened, displaced or removed from their media plates during handling, thereby compromising the detection result.

US 2002/053525 A 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.

US 2013/0095009 Al discloses another approach where a releasable locking connection is provided between the lid of one petri-dish/culture plate and the tray or receptacle of an adjacent petri-dish/culture plate in a stack. According to this solution the lid has, on its peripheral wall, protrusions or nipples which extend radially outwards from the peripheral wall. The receptacle includes the same number of additional radial protrusions which are formed on the lower portion of the wall and are turned towards the inside of the dish. The transverse extension of these protrusions is provided so that, if the receptacle of one dish/plate and a lid of an adjacent dish/plate are superposed, the protrusions interfere when they are brought closer to each other and then pressure is applied on the upper dish to deform a bottom wall of the lid by which, in combination with a rotary movement of the dish relative to the other, it is possible to engage the protrusions into each other. A disadvantage of this solution is that sub-groups of petri-dishes/culture plates are complex to be formed from a stack of plates and inadvertent opening of petri-dishes during the attempt to separate dishes from the stack is a risk. Further, the design requires specific mating lid and receptacles (trays) and is not compatible with standard designs. Lastly, automated handling of the petri-dishes/culture plates is difficult to realize due to the complex kinematics required to separate individual ones from a stack.

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/or sampling sites.

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.

In addition, any solution should preferably facilitate the traceability of samples during the processes.

The present application accordingly aims at providing a transport cage for a petri-dish and a transport packaging with a plurality of petri-dishes, which are in particular suitable for automated handling in environmental monitoring of production areas.

Summary

According to the present application this object is solved by providing a transport cage for a petri-dish with the features of claim 1 and a transport packaging with a plurality of petri-dishes with the features of claim 16. Preferred embodiments of the transport cage are defined in the dependent claims.

The present application in particular provides a transport cage for a Petri-dish, comprising: a main body with a compartment for holding the Petri-dish in a horizontal orientation, and with an opening in a lateral side configured to allow insertion/extraction of the Petri-dish into/from the compartment; and a pair of mating compatible engagement features on vertically upper and lower sides of the main body, respectively, arranged so as to allow a releasable connection, by engagement of the engagement features, of a plurality of the transport cages so as to assemble an aligned vertical stack.

Preferably, the main body has a pair of lateral gripping features arranged to grip and at least frictionally hold the Petri-dish when placed in the compartment.

Preferably, the gripping features include one or more elastic prongs or claws arranged to rest against opposite portions on an outer periphery of the Petri-dish when placed in the compartment.

Preferably, the one or more elastic prongs or claws are located on opposite lateral sides of the compartment.

Preferably, a lateral opening is respectively provided adjacent each elastic prong or claw to allow insertion of a mechanical gripper to grip opposite portions on the outer periphery of the Petri-dish.

Preferably, the pair of mating compatible engagement features comprises a male protrusion and a mating female recess formed on the vertical upper and lower sides of the main body, respectively, so as to allow frictional releasable engagement with each other in a vertical direction and/or a lateral direction when two transport cages are assembled in the vertical stack.

Preferably, the main body has a holding feature arranged to elastically press onto the top of a lid of the Petri-dish when placed in the compartment.

Preferably, the main body has recess portions on opposite lateral outer sides to define gripping zones for a thumb and a finger of a hand to hold the transport cage in the horizontal orientation.

Preferably, the main body has at least one centering feature for centering the Petri- dish upon insertion into the compartment.

Preferably, the main body has at least one window on a side different from the side of the opening for insertion/extraction of the Petri-dish, said at least one window allowing visual inspection of the Petri-dish when placed in the compartment. Preferably, the opening in the lateral side configured to allow insertion/extraction of the Petri-dish into/from the compartment is continuous over at least one lateral side of the main body and extends into one or both adjacent lateral side/sides.

Preferably, the opening in the lateral side configured to allow insertion/extraction of the Petri-dish into/from the compartment is continuous over at least half the lateral circumference in the horizontal orientation of the main body.

Preferably, the main body has an opening on the vertically upper side allowing visual inspection of the Petri-dish when placed in the compartment.

Preferably, the transport cage further comprises a recess formed on the lower side of the main body so as to allow insertion of a tool from outside to induce the release of the connection of the mating engagement features on adjacent transport cages, if assembled in the stack.

Preferably, the recess is formed in the vicinity of the engagement feature and is configured so that the tool to be inserted can apply a separating force between the adjacent transport cages, if assembled in the stack.

The present application in particular also provides a transport packaging with a plurality of Petri-dishes, comprising: an aligned vertical stack assembled from a plurality of transport cages according to the present application with the Petri-dishes placed in the transport cages; and a bag accommodating the aligned vertical stack of transport cages in a sterilized environment.

Brief description of the drawings

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

Figure 1 shows a transport cage according to an embodiment in a perspective view from the top front.

Figure 2 shows a perspective view of a stack of transport cages according to the embodiment of Fig.l having a petri-dish held in each transport cage.

Figure 3 shows the transport cage according to the embodiment in a perspective view from the bottom with a petri-dish held in the transport cage. Figure 4 shows a detail of an engagement feature of the transport cage of the embodiment with a petri-dish in a partially cut-away view.

Figure 5 shows another detail of the transport cage of the embodiment with the petri- dish in a partially cut-away view.

Figure 6 shows the detail of figure 5 in a partially cut-away view from a slightly different angle of view.

Figure 7 shows a perspective view from above of a stack of transport cages of the embodiment where a lowermost transport cage is spaced apart from the rest of the stack.

Figure 8 shows a perspective view from the bottom of the stack of transport cages of Figure 7.

Figure 9 shows a perspective view from the top of the transport cage of the embodiment with certain elements omitted for clarifying purposes.

Figure 10 shows a perspective view of the transport cage of the embodiment from a rear side.

Figure 11 shows a transport packaging with a stack of a plurality of transport cages with petri-dishes according to the embodiment in a sealed bag.

Figure 12 shows a transport cage according to another embodiment in a perspective view from the top front.

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 transport cage 1 according to the embodiments of the present application is in particular designed so as to be compatible with standard petri-dishes or standard nutrition plates used for environmental monitoring that can be introduced into a environment of the appropriate cleanliness grading (for example, a pharmaceutical class A classified space that satisfies European Medicines Agency (EMA) and PIC/S requirements to meet ISO 5 measured via airborne > 0.5 pm particulate, ISO 4.8* measured via airborne >5.0 pm particulate in the in-operation and at-rest states, airborne viable microorganisms < 1 colony forming unit (CFU) per cubic meter; these spaces are normally unidirectional flow with a suggested air velocity of 0.36-0.54 meters per second) and subsequently re-used for the incubation and evaluation procedures.

The transport cage of the present application is in particular designed to be stackable with other identical transport cages placed one on top of the other so as to form a vertical stack that is sufficiently stable without any external clamps or holding devices to allow the automated and manual handling in selected batches.

The transport cage in particular allows easy and safe insertion and extraction of a petri- dish or nutrition plate (in the following only referred to as "petri-dish" or "plate") by hand and/or by an automated system.

The transport cage 1 of the present application as shown in Figure 1 includes a roughly parallel-epiped or box-like main body 2 defining an internal compartment 10 for accommodating and holding the petri-dish P in a horizontal orientation, and with an opening 3 in a lateral side A of the main body 2 configured to allow insertion/extraction of the petri-dish P into/from the compartment 10 in the horizontal direction.

The main body 2 has, on vertically upper and lower sides in the horizontal orientation, a pair of mating compatible engagement features 4 which are arranged so as to allow a releasable connection, by a mutual engagement of the mating engagement features 4 of a plurality of transport cages, so as to assemble a self-supporting aligned vertical stack S (see figure 2).

The opening 3 in the lateral side configured to allow insertion/extraction of the petri- dish P into/from the compartment 10 can be on one lateral side A only, but can also be continuous over a part of adjacent lateral sides to be continuous over at least half the lateral circumference in the horizontal orientation of the main body 2 as shown in figure 1. The opening 3 can accordingly extend from lateral front side A into both adjacent left and right lateral sides B and C of the box-like main body 2. It may thus be continuous over at least one lateral side of the main body and may extend into one or both adjacent lateral side/sides B, C.

In order to securely hold the petri-dish in the compartment 10 of the main body 2 after insertion, the main body 2 has a pair of lateral gripping features 6 arranged to grip and at least frictionally hold the petri-dish P when placed in the compartment 10. In the embodiment shown in the figures the gripping features 6 include one or more (2 in the embodiment) elastic prongs or claws 6a arranged to rest against opposite portions on an outer periphery Pc of the petri-dish P when the same is placed in the compartment 10 (see figure 6). The elastic prongs or claws 6a are located on opposite lateral sides of the compartment 10 in a cantilevered fashion to pinch the petri-dish from two sides.

Although not shown a single prong or claw may be sufficient if it presses the petri-dish against an opposite support of a wall of the main body.

The elastic prong or claw 6a is formed and arranged such that a lateral free space or opening 11 is respectively provided adjacent to it to allow insertion of a mechanical gripper adjacent to the prong to grip the opposite portions on the outer periphery Pc of the petri-dish P held in the opening. This allows the insertion and removal of the petri-dish P from the transport cage without the need to apply manual handling. In the embodiment the lateral opening 11 is in a form of a gap below the prong or claw 6a and the gap is continuous with the opening in the lateral side B and C and is further continuous with the opening 3 in the lateral front side A.

Although not shown the prong or claw 6a may contain the portion resting against the outer periphery Pc of the petri-dish P with a friction-increasing material or coating as needed. Further, the position and elasticity of the prong or claw can be chosen to determine the holding force needed to securely hold the petri-dish in place in the compartment 10 during handling of the transport cage while still allowing insertion and removal by the available mechanical gripper or other equipment. As shown for example in figure 6 the prong engages with a lateral peripheral portion Pc of the lid or cover of the petri-dish but may also be formed to engage with a portion of the tray or of both, the tray and the lid.

The main body 2 furthermore has an opening 12 on the vertically upper side, when in the horizontal orientation, that is formed to allow visual inspection of the petri-dish P when placed in the compartment 10. The visual inspection through the opening 12 may also include optical inspection by automated equipment including optical cameras, sensors etc.. In the present embodiment the opening 12 on the vertical upper side is slightly smaller than the area of the lid of the petri-dish P, but can have any size, form and arrangement as long as the above mentioned technical effect is achieved. A similar opening can also be provided on the vertical lower side of the main body as shown in the embodiment. It provides the advantage that a visual inspection can be performed through one or more petri dish(es) held in the transport cage or in a stack of transport cages.

In order to allow the assembly into the self-supported aligned vertical stack of the plurality of transport cages 1 the mating compatible engagement features 4 may comprise a male protrusion 4a formed on the vertical upper side of the main body 2 and a mating female recess 4b formed on the vertically lower side of the main body and dimensioned and positioned so as to be able to frictiona lly releasably engage with each other in the vertical direction when two adjacent transport cages 1 are assembled in the vertical stack S.

In the present embodiment two pairs of such compatible engagement features 4a, 4b are provided on the upper and lower sides in the rear part of the main body opposite to the opening 3 into/from which the petri-dish P is inserted into the compartment 10. Further engagement features may be provided on other portions of the upper and lower sides of the main body if needed.

In the present exemplary embodiment the male protrusion 4a is in the form of a protruding pin or cylinder with a rounded upper edge and the corresponding mating female recess 4b is formed as a hexagonal recess with rounded entry edges formed into the lower side of the main body (see figures 3 and 4). Other mating forms of the male and female engagement features are possible as long as a sufficiently fixed releasable connection is possible, i.e. the male protrusion may be, for example, have the form a cylinder or conus with a triangular, square, polygonal or other symmetrical or unsymmetrical cross section and the mating female recess may be formed with a cross section that circumscribes the outer periphery of the male cylinder.

In order to facilitate separation of adjacent transport cages in a stack connected via the mating compatible engagement features the embodiment is provided with a recess 5 formed on the lower side of the main body and accessible from the outer peripheral side of the main body 2 so as to allow insertion of a tool (not shown) from the outside to induce the release of the connection of the mating engagement features 4, 4a, 4b on adjacent transport cages 1, for example in the form of a screw-driver or pin inserted and leveraged to spread apart the adjacent transport cages (see for example figure 8). The recess 5 is formed in the vicinity of the engagement feature or features 4 and is configured so that the tool to be inserted from the outside can apply a separating force between the adjacent transport cages in the stack. It is accordingly also useful in connection with an automated equipment and a manual handling alike.

The recess 5 and any of the elements of the engagement features 4 can be used by the mechanical gripper to fixate and hold the transport cage during handling by engagement with suitable protrusions or recesses on the gripper.

The male and female elements 4a, 4b of the engagement features 4 may be exchanged or alternated between upper and lower sides of the main body 2 in one transport cage (in the current embodiment the male features are both arranged on the upper side whereas the female features are both arranged on the lower side).

The transport cage 1 of the present application can be used, in a primary packaging, to protect petri-dishes and to prevent accidental opening of the lid relative to the dish or plate. In the working area the transport cage 1 protects the petri-dish during handling to and from the working area prior and after the air monitoring testing.

The stacking capability provides the effect that plural petri-dishes can be grouped and fixedly maintained in the group in the form of the self-supporting stack without external fixation or means like clamps, wrapping etc., to group petri-dishes for example relating to the same air monitoring time slot or working area or working room in order to avoid mixing of plates between batches during the processing sequence. For example, a group of plates can be maintained in an incubator in the form of the stack, that need to be incubated in the same conditions (like time, temperature, gas etc.).

The transport cages allow automated gripping and access to the petri-dishes in the respective cages by mechanical grippers, thereby facilitating a fully automated handling of petri-dishes in an air monitoring system.

In addition, as shown in figures 1, 5 and 6 the main body 2 may have a holding feature 7 arranged to elastically press onto the top of a lid Pl of the petri-dish P when placed in the compartment 10. Thereby, accidental opening of the lid can be surely prevented while not hindering the insertion and removal of the petri-dish P with the lid Pl from the compartment 10 in the insertion direction through the opening 3. As shown in figures 1, 5 and 6 the holding feature 7 may be in the form of one or several elastic bar/bars formed in the top side of the main body 2 and aligned with the position of the outer raised upper rim of the lid Pl to press the rim downward.

As shown in figures 5, 6 and 2 in particular the main body 2 may have one or more centering features 9 for centering the petri-dish P during and after insertion into the compartment 10. The centering features 9 may be universal or may be specifically adapted to a specific type of petri-dish to be held in the cage. It may comprise, as shown in figure 9, a series of protrusions or raised rims or steps arranged so as to engage with edges of the dish or plate and the lid in the vertical (upward) direction and/or in the circumferential direction.

As shown in figure 10 the main body 2 may have one or more further windows 16, in addition to the opening 12 on the vertically upper and/or lower sides, which window 16 may be provided on a lateral peripheral side different from the side of the opening 3 in order to allow a visual inspection of the petri-dish P when placed in the compartment 10 from another side than the opening 3. The opening 12, for example, may be larger than the windows 16 in order to provide full visibility of the media surface in the dish or plate through the lid or from the bottom of the dish.

The window 16 does allow reading of data and/or a label on the petri-dish-periphery. A side surface of the main body 2 may also provide space for accommodating an RFID label 15 for the cage as shown in figure 10. Integration or attachment of an RFID label 15 on the main body 2 allows defining an association between an individual transport cage and a specific petri-dish accommodated in the transport cage to define its storing position and membership of plural petri-dishes in a group or batch. Further, the transport cage may have a colour coding label 14 indicated by the round dot in figure 10 in order to allow easy distinction of dishes associated in a group or batch via their cages.

Further, a dedicated zone or section (not shown) may be provided on the main body in order to allow handwriting or other markings on the cage.

As shown in figure 11 a useful entity for the above stated purposes of automated handling in environmental monitoring of production areas is a transport packaging 20 with a plurality of petri-dishes P in a form which includes an aligned vertical stack S assembled from a plurality of transport cages 1 according to the present application and a bag 13 accommodating the aligned vertical stack S in a sterilized environment while the petri-dishes are respectively placed in the transport cages 1.

In combination with the colour coding label 14 and/or RFID label 15 and/or windows 16 an easy inspection and confirmation that the petri-dishes in the stack belong to the same group or batch is possible, in particular where the bag is transparent or semitransparent.

Figure 12 shows another embodiment of a transport cage 1 which is based on the embodiment shown in figures 1 to 11 and which is modified for improving the manual handling. In this embodiment the main body 2 has one or more additional recess portions 8 on opposite lateral outer peripheral sides to define dedicated gripping zones for a thumb and a finger of a hand to hold the transport cage 1 in the horizontal orientation during manual handling at any step in the processes. The recess portions 8 are, for example, formed as rounded concave segments in the vicinity of the rear corners of the lateral sides B and C which are not occupied with the petri-dish inside the compartment 10. The recess portions 8 may be provided with additional (not shown) smaller grooves or other surface protrusions or features that reduce the smoothness in order to increase the friction with respect to the fingers.

The material for the main body is preferably plastic, preferably injection-moulded plastic. The main body may also be formed from a stamped piece of metal sheet or by additive manufacturing technologies. The material may be selected to allow sterilization by radiation and/or steam. The main body 2 may be an integral piece, but may be assembled from different parts. The material of the main body, in particular where it is plastic, can be coloured throughout the material in orderto allow immediate distinction between transport cages, for example according to batches, groups or according to the respective types of dishes or plates for which they are specifically designed.

The transport cages of the present application are described with a primary horizontal orientation but, due to the holding features and the fixation of the petri-dish in the compartment they may also be oriented in a vertical orientation without the risk of the petri-dish falling out from the compartment.

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 transport cages 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. transport cage) using data matrix or RFID;

- allowing read and write information in the RFID tag of the transport cage(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.