IE20090876U1 - Microbial detection valves and infection control cushioning and bedding devices including said microbial detection valves - Google Patents

Abstract

ABSTRACT The present invention relates to microbial detection valves and particularly, unidirectional valves which include means for detecting the presence of microbes. The present invention also relates to infection control cushioning and bedding devices including said microbial detection valves.

Description

MICROBIAL DETECTION VALVES AND INFECTION CONTROL CUSHIONING AND BEDDING DEVICES INCLUDING SAID IVIICROBIAL DETECTION VALVES The present invention relates to microbial detection valves and particularly, unidirectional valves which include means for detecting the presence of microbes. The present invention also relates to infection control cushioning and bedding devices including said microbial detection valves.

Known hygienic bedding including mattresses, pillows, duvets, seat cushions, and postural supports such as gutter-splints, particularly for use in hospitals, are widely recognised as reservoirs for infection. Typically filled with polymer foam or other porous, spongy materials, such hygienic bedding provides an ideal harbour for breeding microbial organisms. This problem is greatly exacerbated in the presence of moisture.

Cross-infection is known to take place in hospitals by means of microbial (especially bacterial) ingress into the bedding and subsequent incubation in the bedding with subsequent escape of disease-causing microbes into the environment.

For this reason, in recent decades, hospital bedding has been encapsulated in waterproof materials. Many of these materials are permeable to water vapour but not to liquid water.

A typical example of such waterproof material is knitted nylon coated with polyurethane.

PCT Patent Publication No. WO 2009/034193 (Application No. PCTlEP2008/062265) discloses the inclusion of air-permeable waterproof microbial filter media, to allow air to pass in and out of the bedding without carrying air-borne microbes or spores.

In the case of certain forms of hygienic bedding, particularly, mattresses and cushions, it is often deemed desireable to allow inspection of the interior of the bedding. This is typically done in hospitals to check that the interior of a mattress has not become contaminated. Contamination of the mattress interior may have happened in spite of the use of waterproof encapsulation as described above, as a result of puncture, delamination of the waterproof coating to the cover fabric, or by other means. To allow inspection, a zip or other closure is typically provided in the waterproof coating.

[E 090830 in the case of the present invention, use of a conventional zip in the waterproof coating would compromise the functionality of a mattress including microbial filter media for filtering air since unfiltered air could enter the mattress at any time through the closed zip.

One way to overcome this could be by using a waterproof, air-tight zip. However, such a method of closure is prohibitively expensive.

The present invention seeks to alleviate the above disadvantages associated with known hygienic bedding.

An aim of the present invention is to provide a means of determining the contamination status of the interior of infection control cushioning and bedding devices including particularly, but not exclusively, cushioning and bedding devices such as mattresses, pillows, cushions, duvets and other sealed cushioning and bedding devices without compromising the functionality of the cushioning and bedding devices which include microbial filter media for filtering microbes out of the air entering the cushioning and bedding devices.

The present invention accordingly provides a valve including means for detecting presence of microbes in the air flowing through the valve.

The present invention also provides hermetically sealed infection control cushioning and bedding devices such as mattresses, cushions, pillows, duvets, or such like having a sealed cover and having a resiliently deformable filing material comprising a filter medium including a filter membrane for the removal of particles of microbial size whereby the filter medium allows air and water vapour to flow through but is substantial impemieable to liquid while providing a barrier to microbial sized particles and wherein the infection control cushioning and bedding devices also include at least one uni-directional valve which includes microbial detection means.

Thus, the present invention relates to the inclusion of one or more microbial detection means into a uni-directional (one—way) valve for attachment to the cover of an infection control cushioning and bedding device e.g. a pillow and/or mattress cover and such like. lE09087'5 Preferably, the microbial detection means includes at least one of the following means: a pH-sensitive colourant for indicating presence of microbes; metal complexes and solvatochromatic colourants.

United States Patent Specification No. 7,178,555 (Plitek Inc.) discloses a one-way pressure relief valve comprising several die-cut components arranged so as to allow transport of air in one direction only. Such pressure relief valves are typically used for venting gases from bags of coffee.

U.S. 7,178,555 discloses that one embodiment includes a pressure relief valve having a base which may include an adhesive layer and a release liner. The adhesive layer allows the base to be mounted to a package or support surface.

An aperture is included on the base which is often located over an opening on the package. The base may be made of a number of materials known to those of skill in the art including Polyethylene Terephthalate by DuPont Teijin Films.

As is also shown in FIGS. 1-5 of U.S. 7,178,555, inner rails 22 and 24 are provided on base 11. Inner rails 22 and 24 may be an adhesive layer that has been applied to the base or of some other suitable material known to those of skill in the art.

U.S. 7,178,555 also discloses that a film or membrane 50 or 150 is also provided which is supported by inner rail 135 or inner rails 22 and 24. The film may be made of Polyethylene Terephthalate by DuPont. in operation, as shown in FIG. 3 of U.S. 7,178,555, the film 50 is in a closed position and extends inwardly to cover aperture 20. In this position, the film 50 acts as a seal which prevents exposure to the outside environment.

According to U.S. 7,18,555, to vent the contents of a container 16, the film 50 moves into an open position through the force created by the pressurized gas located in container 16.

The pressure moves film 50 up off of aperture 20. This, in turn, permits aperture 20 to be in communication with the passageway so as to allow venting to occur. Once the pressure in the package equalizes, the film 50, again, moves inwardly to cover and seal off the aperture. lEo9o330 As is also shown in FIG. 3 of U.S. 7,178,555, in an open position, the passageway and aperture form an opening that is stepped in configuration which permits venting to occur.

By permitting the film 50 to move downwardly and upwardly within space defined by the passageway, contact by extraneous surfaces or objects with film 50 will not interfere with the operation of valve 50.

Although not disclosed in U.S. 7,178,555, it is known that components of the valve of U.S. 7,178,555 may be formed of transparent materials.

It has been found in practice that correct functioning of these valves requires a carefully metred quantitiy of oil being injected between two layers in the valve, on asembly.

Thus, in practice it was found that by adding a drop of oil to the valve assembly in the recess immediately underneath the film 50 assists in forming a seal and atso lubricates and facilitates the movement of the film during pressure release.

Since the oil is inside the film, it only contacts the atmosphere inside the valve when the valve is closed. Since the valve is open only when gas is exhausting through the valve, i.e. there is substantial flow through the valve, the oil on the inside surface of the membrane 50 is never exposed to the atmosphere outside.

In accordance with the present invention, there is provided a uni-directional valve including suitable microbial detection means thereby making it possible to identify the presence of pathogens, or metabolic products of pathogens, contained in the air passing through the valve. Any changes in colour of the microbial detection reagent can be visibly seen, on inspection, through the transparent layers (windows) of the uni-directional valve.

In one embodiment of the present invention, the microbial detection means may be a suitable microbial detection reagent and the microbial detection means may be mixed into the oil included in the uni-directional valve.

According to the present invention, various microbial detection means such as the microbial detection reagents described hereinbelow are miscible with various types of oil, IE0908 or liquids acting as the oil for this purpose. Examples include mineral oil, silicone oil, glycerine, or ther subsrtances miscible with oil—soluble or polar-soluble dyes as necessary.

In an alternative embodiment of the present invention, an additional membrane can be included in the valve assembly, at any layer inside the exhaust menbrane component. The additional membrane may comprise a highly porous membrane, eg a woven or non woven or air blown membrane, impregnated or partially impregnated with a suitable microbial detection means such as a microbial detection reagent.

Various suitable methods and substances are available to detect and disclose the presence of pathogens.

One method of detecting the presence of pathogens is by monitoring changes in pH resulting from bacterial activity. in accordance with the present invention, in one embodiment, the oil within the uni- directional valve may comprise a pH-sensitive colourant capable of changing colour in the presence of one or more microorganisms. That is, the colourant may change from a first colour to a second colour or from colourless to a colour or from a colour to colourless. PH- sensitive indicators exist that are capable of differentiating between certain types of microorganisms. Bacteria, for example, may metabolize the growth medium and generate acidic compounds (e.g., CO2) or alkaline compounds (e.g., ammonia) that lead to a change in pH. Likewise, certain microorganisms (e.g., bacteria) contain highly organised acid moieties on their cell walls. Because the acidic/basic shift may vary for different microorganisms, pH—sensitive colourants can be selected as appropriate for the desired pH transition so as to detect the presence of specific organisms.

Examples of such pH-sensitive colourants include: Phthalein colourants, many of which may be selected to give specific changes at specific pH values.

In an alternative embodiment of the invention, metal complexing can be used to detect and indicate the presence of microbes. For example, many microorganisms (e.g., bacteria and fungi) produce low molecular weight iron—comp|exing compounds in growth media, which are known as "siderophores." Metal complexing indicators may undergo a colour change in the presence of siderophores. Preferred metal complexing indicators include [E 090876 aromatic azo compounds, eg Eriochrome Black T, Eriochrome Biue SE, Eriochrome Blue Black B, Eriochrome Cyanine R, Xylenol Orange and many others. in a further alternative embodiment of the invention, solvatochromatic colourants can be used to detect and indicate the presence of microbes. Solvatochromatic colourants change colour in the presence of a broad range of microorganisms. The colour change occurs as a result of changes in the polar environment. For example, a solvatochromatic colourant may be blue in a polar environment (e.g., water), but yellow or red in a non-polar environment (e.g., lipid-rich solution). Examples of suitable colourants are Merocyanine colourants, zwitterionic colourants (eg N-phenolate betaine colourants), or Reichardt's 4-dicyanmethylenemethyl-6—(p-dimethylaminostyryl)-4H-pyran (DCM); 6- propionyl(dimethylamino)naphthalene (PRODAN); 9-(diethylamino)—5H- benzoia]phenox-azinone (Nile Red); 4-(dicyanovinyl)julolidine (DCVJ); phenol blue; and dye ; many others, or mixtures thereof.

It should be understood that the present invention is not limited to any particular mechanism for the colour change. Even when a pH-sensitive colourant is employed, for instance, other mechanisms may actually be wholly or partially responsible for the colour change of the colourant. For example, redox reactions between the colourant and microorganism may contribute to the colour change.

In one embodiment of the present invention, the microbial detection means such as one of the colourants described above, is impregnated into the vaive by mixing the microbial detection means with the oil referred to above, inside the valve. The valve can be in the form of a single self-adhesive valve for attachment to a mattress cover. In use, air is periodically expelled from the mattress, and all or some of this air must pass through the valve. The air, having been static within the mattress for some time, will be rich in any microbial metabolites, if any are present. If these are present in sufficiently large quantities, the colourant contained within the valve will change colour.

This colour change may be visible to the naked eye, or visible when illuminated by fluoroscopic or other methods.

The dye may be chosen to be sensitive to microbial activity in general, or specific categories of organism such as gram positive or gram negative bacteria.

E 0908 In a further embodiment. two or more valves may be provided, each valve adapted to be sensitive to a different category of organism. in this way, a profile of the colonisation in the bedding may be visible. With a greater number of valves in the array. a more detailed profile can be generated.

It is to be understood that the invention is not limited to the specific details described herein which are given by way of example only and that various modifications and alterations are possible without departing from the scope of the invention.

MACLACHLAN & DONALDSON Applicants’ Agents Merrion Square Dublin 2 The following amended page 7 of the Specification was filed on 17"‘ November 2010 in a further embodiment, two or more valves may be provided, each valve adapted to be sensitive to a different category of organism. In this way, a profile of the colonisation in the bedding may be visible. With a greater number of valves in the array, a more detailed profile can be generated. it is to be understood that the invention is not limited to the specific details described herein which are given by way of example only and that various modifications and alterations are possible without departing from the scope of the invention as claimed in the appended claims.

Claims (5)

CLAIMS:

1. A bedding device e.g. a pillow andfor mattress cover and such like, the valve including valve for attachment to the cover of an infection control cushioning and means for detecting presence of microbes in the air flowing through the valve; Optionally wherein the valve is uni-directional and Optionally wherein the microbial detection means is a suitable microbial detection reagent and the microbial detection means may be mixed into the oil included in the uni- directional valve; and Optionally wherein the microbial detection means includes at least one of the following means: a pH-sensitive colourant for indicating presence of microbes; metal complexes and solvatochromatic colourants.

2. A hermetically sealed infection control cushioning and bedding device such as a mattress, cushion, pillow, duvet, or such like, having a sealed cover and having a resiliently deformable filing material comprising a filter medium including a filter membrane for the removal of particles of microbial size whereby the filter medium allows air and water vapour to flow through but is substantial impermeable to liquid while providing a barrier to microbial sized particles and wherein the infection control cushioning and bedding devices also include at least one valve which includes microbial detection means; Optionally wherein the valve is uni-directional; and Optionally wherein the microbial detection means is a suitable microbial detection reagent and the microbial detection means may be mixed into the oil included in the uni- directional valve; and Optionally wherein the microbial detection means includes at least one of the following means: a pH-sensitive colourant for indicating presence of microbes; metal complexes and solvatochromatic colourants.

3. A hermetically sealed infection control cushioning and bedding device such as A mattress, cushion, pillow, duvet, or such like, having a sealed cover and having a resiliently deformable filing material comprising a filter medium including a filter membrane for the removal of particles of microbial size whereby the filter medium allows air and water vapour to flow through but is substantial impermeable to liquid while providing a barrier to microbial sized particles and wherein the infection control cushioning and bedding devices also include at least one uni-directional valve adapted to allow air to be IEo9oe76 9 vented from the pillow whereby any air entering the pillow is forced to pass through the filter medium.

4. A valve substantially in accordance with any of the embodiments herein described. 5

5. A hermetically sealed infection control cushioning and bedding device, substantially in accordance with any of the embodiments herein described. 10 MACLACHLAN & DONALDSON Applicants’ Agents 47 Merrion Square Dublin 2 15