Ergonomic microbial air sampler

A gas sampler device has a top plate with a concaved outer wall. The concaved outer wall allows users easily to lift the top plate off of the bottom plate without disturbing the bottom plate because the curved surface permits more positive contact between the outer wall and users' fingers. Moreover, the weight of the top plate is reduced by approximately twenty percent compared to conventional top plates, a feature that also makes it easier for users to lift the top plate off of the bottom plate.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a microbiological gas sampler. More particularly, the present invention is for a microbiological gas sampler for use in a controlled environment that includes an ergonomic top plate with concaved sidewalls. The concaved sidewalls allow both more positive contact when attempting to grasp the top plate and a reduction of the weight of the device.

Background of the Related Art

A controlled environment is an area which is designed, maintained, or controlled to prevent particle and microbiological contamination of products. Controlled environments include, for example, clean rooms and clean hoods. There are different levels of cleanliness in clean rooms, generally in the range of a Class100room (i.e., a room having no more than 100 particles of 0.5 micron and larger, per cubic foot of air), to a Class10,000clean room.

Clean rooms are used for a variety of purposes, such as in the manufacture of pharmaceutical products and electronics, such as semiconductors. Often, clean rooms are used to work on extremely expensive and complex products, and it is not unusual that there be millions of dollars worth of product in a clean room at any given time. Clean rooms have to maintain a high level of cleanliness, or risk large financial losses. If a product being developed or manufactured in a clean room becomes contaminated, the entire product in the clean room must often be discarded.

Microbial air samplers are used to monitor the level of cleanliness (in terms of viable contamination) in a controlled environment. One or more samplers are positioned about the clean room to collect airborne particulates and organisms (or microorganisms) such as bacteria and fungi. Samplers that run at high flow rates permit air to enter the sampler at such high flow rates that loss of smaller particulates carrying microorganisms is normality (i.e., smaller particulates are not retained in the medium). At the same time high flow rate air samplers only sample for a short time period and relay on a short snapshot of the condition of the area. Samplers running at 28.3 LPM (liters per minute) must operate for a longer period of time than a unit running at 322 LPM. In doing this, they sample a broader spectrum of the drug fill time and present superior data as the sample time takes a larger snapshot of the operation. Samplers that run at 28.3 LPM also provide the ability to capture more smaller particulates that may be lost due to dynamic drag (or an umbrella affect) in higher flow rate units.

Air sampling systems are generally known, and an air sampling system is offered by Veltek Associates, Inc. known as SMA (Sterilizable Microbiological Atrium) Microbial Air Sampler System. One such system is shown in U.S. Pub. No. 2011/0167931, filed Jan. 12, 2010, and U.S. Pat. No. 7,940,188, filed Jul. 26, 2010, the entire contents of which are hereby incorporated by reference. As noted in those applications, the air sampler system includes a controller connected to a vacuum pump to control the flow of air to air sampler devices located in the clean room.

A prior art air sampler device5is shown inFIGS. 1(a), (b), which is offered by Veltek Associates, Inc. The assembled air sampler device5includes a top plate10with holes11and a bottom plate14. The top plate10has a flat section and an outer side. The flat section forms the top surface of the top plate10and extends substantially horizontally when in use. The openings pass through the flat section. The outer side extends downward to be substantially orthogonal to the flat section. The outer side has a single uniform thickness that extends the entire circumference of the top plate10. The outer surfaces of the top plate10and the bottom plate14are flat and smooth. The bottom plate14is sized and shaped substantially the same as the top plate10. Though the device5is shown as circular, other shapes may be used.

In operation, the top plate10is removed, a Petri dish is placed on the bottom plate14, and the top plate10is replaced on the bottom plate14. A vacuum tube is attached to the air port22. Air is then sucked in through the holes11in the top plate10, so that the air strikes a test medium contained in a Petri dish, which is inside the air sampler device5between the top plate10and the bottom plate14. The air exits through the air port22and vacuum tube. At the end of the testing period, the top plate10is again taken off of the bottom plate14, the Petri dish is removed, and the top plate10is replaced. The Petri dish can then be analyzed to determine the level of cleanliness of the clean room.

The entire device5is metal so that the device5can be sterilized by heat, steam, Vaporized Hydrogen Peroxide (VHP) or Ethylene Oxide (ETO). The Petri dish has a diameter of about 3.5 inches. The top plate10has an outer diameter of 4.5 inches. There are twelve holes11positioned within about a circular area having a 3 inch diameter, and each hole11has a diameter of about 0.5 inches.

However, the sides of the top plate10are smooth and the top plate10is relatively heavy, specifically, 1 pound, 4.2 ounces. Consequently, the top plate10can be difficult to grasp by a person inside the clean room who is wearing gloves.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the invention to provide a device for sampling viable cells in air. It is another object of the invention to provide a microbial air sampler having an improved design that both decreases the weight of the top plate and allows for more positive contact when grasping the top plate.

Accordingly, an air sampler device is provided having a concaved sidewall along the outer circumference of the top plate. The concaved sidewall is particularly useful because users are often required to wear gloves at all times while inside the clean room. The concaved sidewall allows the top plate to be easily lifted off of the bottom plate without disturbing the bottom plate because more positive contact can be made between the fingers of the user and the sidewall of the top plate.

Moreover, the concaved sidewall decreases the weight of the device by approximately twenty percent. The decreased weight of the top plate also makes it easier for users to lift the top plate off of the bottom plate.

These and other objects of the invention, as well as many of the intended advantages thereof, will become more readily apparent when reference is made to the following description, taken in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In describing a preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents that operate in similar manner to accomplish a similar purpose. Preferred embodiments of the invention are described for illustrative purposes, it being understood that the invention may be embodied in other forms not specifically shown in the drawings.

As shown inFIG. 2, a top plate100of an air sampler device50is shown. The top plate100has a top surface112. There are twelve holes116formed in the top surface112. The top plate100has a flat section130and at least one outer side140. The flat section130forms the top surface of the top plate100and extends substantially horizontally when in use. The openings116pass through the flat section130. The outer side or side wall140extends downward to be substantially orthogonal to the flat section130. The side wall140is concaved or curved inward and defines the entire outer circumference of the top plate100. The concaved outer side140makes the top plate100easy to grip, so that a user can easily remove and replace the top plate100with respect to the bottom plate150.

For illustrative purposes, the bottom plate150is also shown inFIG. 3. A vacuum air port160is positioned at the side of the bottom plate and communicates with an air hole162. The air hole162extends through the bottom plate150, from the air port160to the center well158. The vacuum air port160connects to a vacuum tube to draw air through the sampler50.

The operation of the sampler50is best shown inFIG. 3, where the arrows generally show the direction of travel of the air as it flows through the device50. A sterilized air sampler device50is introduced into the clean room, and the top plate100is removed. The Petri dish52is inserted onto the bottom plate150, and the top plate100is replaced. The air flow is then initiated for a predetermined period of time. Air is drawn into the sampler device50by the vacuum tube162through the air port160.

Once the air enters the holes112in the top plate, it strikes the capture material in the Petri dish52, then travels up around the sides of the Petri dish52, through the elongated slots164beneath the Petri dish52, and enters the center well158. The air is then sucked through the air hole162and exits out of the vacuum air port160. Once the predetermined period of time (which can be from 10-60 minutes or longer) has lapsed, the air flow is turned off. The top plate100is then raised, and the Petri dish52is removed for testing. The sampler50can then be sterilized, if desired, and a new Petri dish52introduced.

Accordingly, the air port160is in flow communication with the passageway162, which is in flow communication with the well158. And, the well158is in flow communication with the elongated slots164, which are in flow communication with air entering the holes112in the top plate100. The structure and operation of the device having the bottom plate150shown, is more fully described in Pub. No. 2011/0167931, which is incorporated herein by reference. It should be noted, however, that any suitable bottom plate150can be provided other than the one shown, and the bottom plate150need not have a center well158and air hole162and slots164.

As shown inFIG. 3, the side wall140defines a side wall inner surface170and a side wall outer surface172. The inner surface170defines an inner diameter of the upper plate140. The inner surface170is straight, and does not project inward, so as not to interfere with the Petri dish52. Thus, the inner wall170need not be positioned further away from the Petri dish52. The straight inner wall170also provides a straight air conduit with uniform dimensions (i.e., width) between the Petri dish52and the inner wall170, so that air can flow uniformly around the Petri dish52to the exit port160.

The outer surface172of the side wall140is curved, and therefore the side wall140has a varying thickness. The side wall140is thicker at the top and bottom portions, and thinner in the middle portion where it is curved inward. The outer surface172is curved to be ergonomic and mate with the shape of a user's gloved hand. The top of the curved outer surface172has a curved top lip142that extends around the entire circumference of the top plate100. The top lip142projects outward from the middle portion of the wall140. The top lip142engages the user's fingers when the top plate100is being lifted, thereby making it easier to lift and manipulate the top plate100. The top lip142is rounded or beveled at the end143between the top surface of the flat section130and the side wall140. The rounded end143enhances the safety of the top plate100and increases the comfort of the user, by removing any sharp angles. An additional benefit of the curved outer wall surface172is that the user knows by touch that he is manipulating the top plate100(and not the bottom plate150). Thus, for instance, the user can slide his/her fingers up from the bottom of the device50until the fingers engage the top lip142.

The bottom section of the curved outer wall surface172forms a bottom lip144that is relatively sharp. This provides the side wall140with a flat foot146that forms a seal and mates with the top surface of the bottom plate150. The outer circumference of the foot146of the side wall140where the top plate100meets the bottom plate150is sized and configured substantially the same as the bottom plate150. The foot of the side wall140of the top plate100has an outer diameter of 4.5 inches. There are twelve holes116positioned within about a circular area having a 3 inch diameter, and each hole116has a diameter of about 0.5 inches. The thickness of the top and bottom of the concaved side140is about 0.25 inches.

The concaved outer side140of the top plate100is particularly useful since users are often required to wear gloves (in addition to garments, hoods, and booties) at all times while inside the clean room. In addition, the entire device50is made of metal, so that it can be sterilized by heat, steam, VHP or ETO. Consequently, the top plate100(as well as the bottom plate) is relatively heavy, which makes it difficult to remove with a gloved hand. By providing an inwardly concaved outer side140, the present invention allows the top plate100to be easily lifted off of the bottom plate150without disturbing the bottom plate150.

The curved side wall140also substantially reduces the weight of the top plate100. The weight of the top plate100is 1 pound, 1 ounce, which is about a 20% (18.82%) reduction in weight from the top plate10ofFIG. 1, which weighs 1 pound, 4.2 ounces. The radius of curvature is about 0.337 inches.

The curved outer surface172is preferably uniformly curved completely around the top plate100. However, the outer surface172need not be completely curved and only portions of the outer surface172can be curved. For instance, the side wall140can be curved at two opposite portions of the top plate140. Or, the side wall140can be curved differently at different portions of the side wall140. And, the curve need not have both a top lip142and a bottom lip144. For instance, only a top lip142can be provided.

The foregoing description and drawings should be considered as illustrative only of the principles of the invention. The invention may be configured in a variety of shapes and sizes and is not intended to be limited by the preferred embodiment. Numerous applications of the invention will readily occur to those skilled in the art. Therefore, it is not desired to limit the invention to the specific examples disclosed or the exact construction and operation shown and described. Rather, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.