Sampling Lid Assembly for Particle Monitoring System

Abstract

This application relates to a particle monitoring system, preferably a sampling lid assembly for a microbiological gas (e.g., air) sampler or airborne particle counter. This application also relates to a particle monitoring system including such a sampling lid assembly.

Description

Technical Field

[0001] This application relates to a particle monitoring system, preferably a sampling lid assembly for a microbiological gas (e.g., air) sampler or a particulate counter. This application also relates to a particle monitoring system including such a sampling lid assembly.

Background Art

[0002] Monitoring of a sample fluid that is a liquid or more generally a gas such as air is frequently performed for the purpose of evaluating, classifying, and monitoring contaminants in various cleanroom and manufacturing environments where a low particle level is required, such as cleanroom environments for the manufacture of electronic devices, semiconductor devices, and measuring instruments, and aseptic environments for the manufacture of pharmaceuticals and biological products such as sterile pharmaceuticals.

[0003] For the purpose of monitoring a fluid (e.g., a gas such as air) in such a situation, particle monitoring systems are known, which include a microbiological or active gas (e.g., air) sampler and a particle counter. Microbiological or active gas (such as air) samplers and particulate counters are convenient because they allow a user to sample a quantitative amount of gas (such as air) and determine the risk of contamination (microbiota) of a sterile product in the surrounding environment.

[0004] Examples of methods for sampling, detecting, and / or characterizing particles through the collection, growth, and analysis of viable biological particles such as microorganisms in a microbiological gas (e.g., air) sampler are disclosed in EP0964240A1. This device includes an integrated sampler for collecting biological particles and an impact surface such as the receiving surface of a growth medium in a Petri dish. The collected particles are typically then cultured to grow viable particles, which are then analyzed by various techniques such as visual inspection, microscopy, fluorescence or autofluorescence, and ATP detection.

[0005] A particle counter, which is another type of particle monitoring device, typically feeds the gas to be monitored through a measurement system. A laser beam is directed at the gas flow, and particles crossing the laser beam generate a signal that is detected by a photomultiplier tube. The output of the photomultiplier tube has multiple amplifiers with different gain stages that enable the discrimination of the number of particles and particle size based on the evaluation of the signal, more specifically the amplitude of the signal. SUMMARY OF THE INVENTION

[0006] The present invention relates to a particle monitoring system in which a sampling section for performing a sampling process on a sample fluid, preferably a gas such as air, includes either a particle collector or a particle counter, or the sampling section includes a combination of a particle collector and a particle counter. The monitoring procedures and techniques of the particle monitoring system are not affected by the present invention and are generally known throughout the industry, so they will not be described in detail.

[0007] US2021 / 0214121A1 discloses an air sampler device for a particle monitoring system. This air sampler device includes a lower plate on which a Petri dish is placed, and an upper plate that is placed on the lower plate so as to surround the Petri dish and is an example of a sampling lid assembly. A vacuum tube is attached to the air port of the lower plate. Next, air is sucked into the sampler device through the holes in the upper plate, and the air hits the test medium inside the Petri dish. The Petri dish is housed between the upper plate and the lower plate inside the air sampler device. The air is discharged from the air port. At the end of the test cycle, the upper plate is removed from the lower plate, the Petri dish is removed, and the upper plate is returned. Then, the Petri dish can be analyzed to determine the cleanliness level of the surrounding environment.

[0008] The entire device disclosed in US2021 / 0214121A1 is made of metal and can be sterilized by heat, steam, vaporized hydrogen peroxide (VHP), or ethylene oxide (ETO). Since the diameter of the Petri dish is about 9 cm (3.5 inches), the diameter of the upper plate is slightly larger at 11.5 cm (4.5 inches) and is relatively heavy. Furthermore, since the outer surface of the upper plate is flat and smooth, it is difficult for a gloved person in a cleanroom to grasp. US2021 / 0214121A1 proposes to provide an upper plate with a concave side wall along the outer periphery of the upper plate, making the contact between the user's finger and the side wall of the upper plate more reliable and reducing the weight of the upper plate by about 20%.

[0009] This solution still requires relatively bulky, heavy, and difficult-to-clean high-energy-consuming sterilization equipment such as autoclaves that may not be available at each site. Outsourcing the autoclave process is costly, and to maintain continuous operation, a large inventory of sterilized and used materials is required.

[0010] There are also solutions where the entire upper plate or air sampler device for a particle monitoring system is made of plastic material and designed for single-use applications. These solutions generate a large amount of waste and are still bulky, so they cannot be easily stacked and require a large storage space for storing the materials.

[0011] Finally, the current sampling lid or upper plate of the air sampler device for a particle monitoring system for environmental monitoring is not optimized for robotics and automation applications, which is a trend in the industry to reduce labor and improve safety and quality standards.

Problems to be Solved by the Invention

[0012] Accordingly, the present invention aims to provide a sampling lid assembly for a particle monitoring system, preferably for a microbiological gas (e.g., air) sampler or a suspended particle counter, which solves at least some of the problems associated with existing solutions.

Means for Solving the Problems

[0013] Overview To solve the above problems, the present invention provides a sampling lid assembly for a particle monitoring system as defined in claim 1 and a particle monitoring system as defined in claim 15. Preferred embodiments of the sampling lid assembly for the particle monitoring system are defined in the dependent claims.

[0014] The present invention relates to a sampling lid assembly for a particle monitoring system, comprising: a support frame configured to be removably attached to a sampling section of the particle monitoring system and to define a collision and collection surface disposed on the sampling section, preferably a space surrounding a Petri dish; a sieve removably attached to the support frame and configured to close an open side of a space above the collision and collection surface, preferably the Petri dish, the sieve being provided with a fluid opening arranged to direct fluid towards the collision and collection surface disposed on the sampling section, preferably the Petri dish, during operation of the particle monitoring system.

[0015] The sampling lid assembly of the present invention is composed of a disposable sieve (preferably made of a plastic material) and a reusable support frame that is compatible with each environmental particle monitoring system. By reducing the size of the disposable part, i.e., the sieve, and by avoiding the need for cleaning and autoclaving of the disposable part, and by reducing the geometric complexity, the cleaning requirements of the reusable support frame are reduced, thereby reducing the waste level (thus enabling sufficient cleaning with less complex cleaning equipment and procedures).

[0016] Also, since the support frame and the sieve can be handled separately, the weight of the parts to be handled is reduced, and the inventory of materials for continuous operation is also reduced. Since the sieve is provided without the support frame, it can be flattened overall, reducing the volume and the amount of packaging, contributing to making environmental monitoring more sustainable.

[0017] The sampling lid assembly of the present invention also provides a solution for an air sampling lid that is suitable for both manual and automatic use. Preferably, the support frame and the sieve are made of different materials. Preferably, the support frame is made of a material that can withstand autoclaving for sterilization, preferably a metal material, preferably stainless steel, or a disposable material, preferably a plastic material.

[0018] Preferably, the support frame and the sieve are configured to be releasably engaged with each other, preferably engaged by a shape-lock engagement. Preferably, the support frame and the sieve are configured to be engaged by movement along the axial direction of the support frame and / or by lateral movement along the radial direction of the support frame. Preferably, the support frame and the sieve are provided with fitting centering features, preferably fitting conical surfaces and / or one or more fitting protrusions and recesses, for defining the attachment position.

[0019] Preferably, the support frame is configured to move between a position defining a space around a collision and collection surface, preferably a Petri dish, placed on the sampling section along the body of the sampling section of the particle monitoring system, and a position providing access to the sampling section. Preferably, the sieve is provided with one or more lateral protrusions, preferably in the form of one or more protrusions, and can be grasped for the purpose of placing the sieve on the support frame.

[0020] Preferably, the sieve is provided with a plurality of radial ribs distributed around it to enhance its rigidity against deformation. Preferably, the support frame is a ring-shaped body preferably having one or more lateral protrusions and / or recesses, preferably in the shape of a peripheral shoulder or groove.

[0021] Preferably, the sieve is configured to engage with other sieves to form a self-standing stack. Preferably, the sieve and / or the support frame is provided with a data tag preferably containing an electronically readable type identifier.

[0022] Preferably, when the sampling lid assembly is attached to the sampling section and the sieve is in its mounting position on the support frame, the surface of the support frame facing the space is formed to be protected from contact with fluid passing through the fluid opening towards the collision and collection surface, preferably a Petri dish placed on the sampling section, during operation of the particle monitoring system.

[0023] Preferably, the sampling lid assembly includes a collision and collection surface, preferably a Petri dish. This application also relates to a particle monitoring system including a sampling lid assembly as defined herein.

Brief Description of the Drawings

[0024] The present invention will be described in detail below based on preferred but non-limiting embodiments with reference to the accompanying exemplary schematic drawings.

Fig. 1a-b

Fig. 1c

Fig. 2a-b

Fig. 2c

Fig. 2d-e

Fig. 2f

Fig. 2g-h

[0025]

Fig. 3a-b

Fig. 4a-b

Fig. 4c

[0026] The particle monitoring system and sampling lid assembly of the present invention are described in connection with various embodiments, and it is understood that the features of the embodiments can be combined with each other.

[0027] Figures 1a to 1c illustrate and schematically represent a first embodiment of a sampling lid assembly 1 according to the present invention in combination with a sampling section 3 of a particle monitoring system (not shown). It should be noted that the sampling section 3 is not part of the present invention but is a component of a particle monitoring system known per se. The sampling lid assembly 1 is designed to be compatible with each sampling section 3 in order to provide the functions described below in any case.

[0028] A sampling lid assembly 1 for a particle monitoring system is removably attached and fixed to a sampling section 3 of the particle monitoring system, and includes a support frame 2 configured to define a space 5 surrounding a collision and collection surface such as a Petri dish 4 placed on a base 3a of the sampling section 3 (as described above in combination with the prior art). In the following, the sampling lid assembly of the present invention will be described using a Petri dish as the collision and collection surface, but it should be understood that any collision and collection surface may be used instead of the Petri dish.

[0029] The sampling lid assembly 1 also includes a sieve 6 formed as a component separate from the support frame 2 and configured to be removably attached to the support frame 2 to close (or "cover") the open side of the space 5 above the Petri dish 4. The sieve 6 is provided with an array of fluid openings 7 arranged to direct a fluid that may support bacterial contaminants and / or other particles during operation of the particle monitoring system towards a growth medium or test medium contained in the Petri dish 4 disposed in the sampling section 3. After the fluid collides with the medium in the Petri dish 4, it is directed towards the periphery of the sieve 6 and then through a gap 16 between the support frame and the Petri dish to the outlet port 3b of the sampling section (the flow of the fluid is forced by a reduced pressure generated by a vacuum pump downstream of the outlet port 3b).

[0030] In the prior art, the support frame and the sieve are integrally formed. By separating the support frame 2 and the sieve 6 according to the present invention, the support frame 2 and the sieve 6 are made of different materials. In particular, the support frame 2 is a reusable part and is made of a material that can withstand an autoclave for sterilization, preferably a metal material, preferably stainless steel. The sieve 6 is preferably a disposable part made of a disposable material, preferably a plastic material. The plastic material is not particularly limited, and suitable plastic materials can be selected from a list consisting of, for example, acrylonitrile butadiene styrene (ABS), polypropylene (PP), such as propylene homopolymer, propylene random copolymer, or heterophasic propylene block copolymer, polycarbonate (PC), polystyrene (PS), such as high impact polystyrene (HIPS), polyamide (PA), and polyester.

[0031] However, the concept of separating the support frame 3 and the sieve 6 is also applicable to the concept that the sieve can be reused. In any case, separating these two components reduces the volume of the disposable part (i.e., the sieve) of the sampling lid assembly 1, and the important part (i.e., the support frame) can be reused.

[0032] The support frame 2 and the sieve 6 are preferably configured to be releasably engaged with each other, although they do not necessarily have to be in a form-lock engagement. The support frame 2 and the sieve 6 are configured to engage by movement along the axial direction of the support frame 2 and / or by lateral movement along the radial direction of the support frame 2. In this embodiment, the sieve 6 is provided with an annular ridge 8 formed to project downward from the downward side surface and engage with a fitting circular groove 9 recessed in the upper surface of the support frame 2.

[0033] The support frame 2 and the sieve 6 may be provided with a fitting centering function for defining the attachment position, preferably a fitting conical surface and / or one or more fitting protrusions and recesses. During use, since the sieve is pulled or pushed towards the support frame by the flow of gas (e.g., air), a particularly tight connection or engagement is not necessary, but can be implemented depending on the situation.

[0034] The sieve 6 may also be provided with an extension of the inner wall 10 that extends downward so as to shield substantially the entire inner peripheral wall of the support frame 2 facing the space 5. Such an extension (not shown) is formed of a relatively thin sheet-like strip of material integrally formed with the sieve, reducing or avoiding the exposure of the inner peripheral wall of the support frame to contaminants in the fluid, enabling the support frame to be washed and reused before being sterilized again if necessary.

[0035] The shape, number, and arrangement of the openings 7 at the top of the sieve 6 are not particularly limited as long as they function to direct the desired fluid flow towards the medium in the Petri dish 4. In an embodiment, the openings 7 are in the shape of elongated narrow slits radially towards the center of the sieve. The surface on which the openings are formed is in the shape of a recessed trough-like portion 11 surrounded by a raised peripheral rim 12. Below the peripheral rim 12, an annular channel 13 is accommodated and formed for guiding the fluid through the gap between the support frame 2 and the Petri dish 4 to the outlet port 3b.

[0036] As shown in FIGS. 1a and 1b, the raised peripheral rim 12 of the sieve 6 is provided with a number of radial ribs 14 distributed along the circumference on its upper side. In addition to the effect of the raised peripheral rim 12, the rigidity of the sieve against bending deformation can be increased while reducing the thickness of the material of the wall itself. This enables the sieve to be grasped and handled by the gripper device of the robot.

[0037] The support frame 2 is mainly flat and is specially designed to have a relatively simple geometric shape with a preferably continuous and smooth surface without interruption and only minimal recesses or sharp edges. Thus, it can be easily cleaned to remove any potential contaminants adhering to it without special autoclave equipment, whereas with the more complex structure of the sieve 6 with slits, openings, ribs, etc., such simple cleaning with such equipment is impossible and autoclaving or similar treatment is required if reuse is necessary.

[0038] In this embodiment, the support frame 2 is a ring-shaped body, preferably with one or more small lateral protrusions and / or recesses, preferably in the form of a peripheral shoulder or a shallow groove 15, to prevent the support frame from slipping through the gripper or glove of a robot when handled manually. To facilitate mounting, the support frame 2 preferably has a substantially vertical surface that is wide enough along the outer periphery to be easily and securely gripped. The support frame 2 is designed to be fixed to the base 3a of the sampling section 3. This can be achieved by providing the support frame 2 and the base 3a with mating centering and engagement functions to define a removable mounting position. Compared to the releasable connection between the sieve and the support frame, the reusable support ring 2 does not need to be cleaned between each sampling cycle, so if the support frame 2 needs to be maintained in a predetermined position over multiple cycles of sieve 6 replacement, the releasable connection between the base 3a and the support frame 2 needs to be more robust.

[0039] Separating the support frame 2 from the sieve 6 according to the present invention also reduces the packaging volume of the material inventory in several respects. First, the disposable sieve 6 can be made relatively flat (since the support frame is no longer part of the sieve during storage and handling), and the sieve 6 can be configured to engage with other sieves 6 to form a self-standing stack.

[0040] Furthermore, the relatively flat sieve 6 can be provided with a relatively simple rigid primary packaging for disposable sieves in order to enable automated and robotic use. A synergistic effect of functions occurs between the packaging and the disposable sieve for robotic and automated use. The rigid packaging can keep the sieve sterile until immediately before use.

[0041] Second, reusable support frames can be provided in fewer numbers depending on the cleaning cycle or processing time. Since the cleaning procedure for this component is not very demanding, the components can be cleaned on-site at most locations without dedicated autoclave equipment. Therefore, especially when the cleaning procedure is outsourced, that is, sent to an external service provider for cleaning, there is no need to consider the associated time and processing procedures for the cleaning cycle time.

[0042] Figures 2a - 2h show an exemplary and schematic representation of a sequence of characteristic stages of an air monitoring process using a sampling lid assembly according to the first embodiment, together with the sampling section of a particle monitoring system, in perspective views (Figures 2a, 2c, 2d, 2f, 2g) and perspective cross-sectional views (Figures 2b, 2e, 2h).

[0043] To start the air monitoring process, a Petri dish 4 (containing a growth medium or test medium, such as an agar medium) is placed on the base 3a of the sampling section 3 of a particle monitoring system (such as an air sampling system). This step is shown in Figures 2a and 2b and is known per se in the art. The Petri dish 4 can be placed either manually or automatically by a robot without discrimination.

[0044] Next, the reusable support frame 2 is also placed on the base 3a of the sampling section 3 so as to surround the Petri dish 4 with a gap 16 (see Figures 2c - 2e). The support frame 2 can be placed either manually or automatically by a robot without discrimination.

[0045] In the next step, the disposable sieve 6 is placed on the reusable support frame 2 (see FIGS. 2f - 2h). The disposable sieve 6 can be placed manually or automatically using a robot. FIG. 2f shows an example where the sieve 6 is grasped by the gripper device 17 of such a handling robot (not shown). The rigidity of the disposable sieve 6 and, if necessary, the use of a rigid packaging (not shown) as the primary packaging of the disposable sieve 6 enable the automation and robotic use of the proposed solution using the gripper 17. The primary packaging can be a unit packaging or a packaging of multiple sieves 6. In the latter case, it is preferable that, due to the design of the sieve, the sieves can be easily stacked and taken out one by one by the gripper device 17.

[0046] Once the sieve 6 is placed on the support frame 2, the fluid sampling system is ready to start, and a vacuum pump (not shown) is started to suck in fluid (air) through the holes 7 of the sieve 6. Contaminated particles entrained in the fluid flow are released by kinetic energy onto the surface of the medium in the Petri dish 4 and remain on the surface of the medium. The sucked-in fluid is pushed outwards and upwards by the peripheral wall of the Petri dish 4, and further guided downwards by the annular channel 13 of the sieve 6, and is led to the outlet port 3b through the gap 16 between the inner peripheral wall of the support frame 3 and the Petri dish 4, and finally discharged from the port 3b of the air sampling system (see also FIG. 1c).

[0047] In a preferred variant, the sieve 6 and / or the support frame 2, and optionally the gas (e.g., air) sampling system, are provided with a data tag containing an identifier, preferably of an electronically readable type attached to the accessible outer surface of each component. This data tag can have a unique data matrix to ensure clear traceability of the tests performed. Such traceability reading needs to be usable both manually and automatically.

[0048] In the second embodiment shown in FIGS. 3a and 3b, the support frame 2 and the sieve 6 are provided with a fitting centering function for defining the attachment position, in this case a fitting conical surface 18. In the embodiment of FIG. 3b, the reusable support frame 2 and the disposable sieve 6 are each designed such that the fitting contact surfaces are conical in order to facilitate the placement of the disposable sieve on the support frame 2 even in the case of automated handling.

[0049] In this second embodiment, the sieve 6 is preferably provided with one or more lateral protrusions 9, preferably in the form of one or more projections (only one shown), which enable the sieve 6 to be grasped (e.g., by the gripper of a robotic arm) for the purpose of placing the sieve 6 on the support frame 2 without touching the recessed portion provided with the opening 7 and without introducing bending forces into the sieve itself.

[0050] In the third embodiment shown in FIGS. 4a to 4c, the support frame 2 and the sieve 6 are provided with a fitting centering function for defining the attachment position. In this case, one or more fitting protrusions 19 in the form of a plurality of ribs arranged below the sieve 6 are arranged annularly around the recessed portion provided with the opening 7 and engage with the inner peripheral wall of the support frame 2 when turned upside down. In a further variant (not shown), fitting recesses may be provided in cooperation with the protrusions in order to define and fix a specific attachment position.

[0051] In the third embodiment, the reusable support frame 2 has a substantially linear cylindrical shape. This form is a preferred way to further facilitate the cleaning process without using special equipment. The inner diameter of the support frame or ring can be dimensioned to fit snugly around the outer perimeter of the base 3a of the sampling section 3, and the support frame 2 is configured to move between a raised position that defines a space 5 surrounding the Petri dish 4 placed on the sampling section 3 along the body of the base 3a of the sampling section 3, and a lowered position that provides access to the sampling section 3. This arrangement allows the Petri dish 4 to be smoothly loaded when the support frame 2 is moved to the lowered position while holding the support frame 2 on the sampling section 3. In the raised position, a sieve can be placed on top of the support frame to cover the Petri dish for sampling operations.

Claims

1. A sampling lid assembly (1) for a particle monitoring system, comprising: A support frame (2) configured to be removably attached to a sampling section (3) of the particle monitoring system and to define a space (5) that surrounds a collision and collection surface, preferably a Petri dish (4), disposed on the sampling section (3); and A sieve (6) removably attached to the support frame (2) and configured to close an open side of a space (5) above a collision and collection surface, preferably a Petri dish (4), wherein the sieve (6) is provided with a fluid opening (7) arranged to direct fluid towards a collision and collection surface, preferably a Petri dish (4), disposed on the sampling section (3) during operation of the particle monitoring system The sampling lid assembly (1) comprising the same.

2. The sampling lid assembly (1) according to claim 1, wherein the support frame (2) and the sieve (6) are made of different materials.

3. The sampling lid assembly (1) according to claim 1 or 2, wherein the support frame (2) is made of a material capable of withstanding an autoclave for sterilization, preferably a metallic material, preferably stainless steel, and the sieve (6) is made of a disposable material, preferably a plastic material.

4. The sampling lid assembly (1) according to any one of claims 1 to 3, wherein the support frame (2) and the sieve (6) are configured to be releasably engaged with each other, preferably by a form-fit engagement.

5. The sampling lid assembly (1) according to claim 4, wherein the support frame (2) and the sieve (6) are configured to engage by movement along an axial direction of the support frame (2) and / or lateral movement along a radial direction of the support frame (2).

6. The sampling lid assembly (1) according to any one of claims 1 to 5, wherein the support frame (2) and the sieve (6) are provided with mating centering features, preferably mating conical surfaces and / or one or more mating protrusions and recesses, for defining an attachment position.

7. The support frame (2) is configured to move between a position that defines a space (5) surrounding a collision and collection surface, preferably a Petri dish (4), disposed on the sampling section (3) along the body of the sampling section (3) of the particle monitoring system, and a position that provides access to the sampling section (3). The sampling lid assembly (1) according to any one of claims 1 to 6.

8. The sieve (6) is preferably provided with one or more lateral convex portions (9) in the shape of one or more protrusions, and can be grasped and placed on the support frame (2). The sampling lid assembly (1) according to any one of claims 1 to 7.

9. The sieve (6) is provided with a plurality of radial ribs (14) distributed around it to enhance its rigidity against deformation. The sampling lid assembly (1) according to any one of claims 1 to 8.

10. The support frame (2) is a ring-shaped body, preferably in the shape of a peripheral shoulder or groove, and preferably includes one or more lateral convex portions and / or recesses. The sampling lid assembly (1) according to any one of claims 1 to 9.

11. The sieve (6) is configured to engage with another sieve (6) to form a self-standing stack. The sampling lid assembly (1) according to any one of claims 1 to 10.

12. The sieve (6) and / or the support frame (2) is preferably provided with a data tag including an identifier of an electronically readable type. The sampling lid assembly (1) according to any one of claims 1 to 11.

13. When the sieve (6) is in the mounting position on the support frame (2) with the sampling lid assembly (1) attached to the sampling section (3), the surface of the support frame (2) facing the space (5) is formed to be protected from contact with the fluid directed through the fluid opening (7) towards the collision and collection surface, preferably the Petri dish (4) placed on the sampling section (3) during the operation of the particle monitoring system. The sampling lid assembly (1) according to any one of claims 1 to 12.

14. The sampling lid assembly (1) according to any one of claims 1 to 13, comprising a collision and collection surface, preferably a Petri dish (4).

15. A particle monitoring system comprising the sampling lid assembly according to any one of claims 1 to 14.

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