WO2012119617A1

WO2012119617A1 - Disinfection appliance and disinfection method

Info

Publication number: WO2012119617A1
Application number: PCT/EP2011/001175
Authority: WO
Inventors: Gregor Morfill; Tetsuji SCHMIZU; Julia Zimmermann; Yang-fang LI
Original assignee: Max-Planck-Gesellschaft Zur Foerderung Der Wissenschaften E.V.
Priority date: 2011-03-10
Filing date: 2011-03-10
Publication date: 2012-09-13
Also published as: WO2012119617A8

Abstract

The invention is related to a disinfection appliance comprising a storage element with cavities containing a plasma activatable fluid, and to a disinfection method comprising the following steps: - plasma activating fluid comprised in cavities of a storage element according to said disinfection appliance - applying an object to be disinfected onto the storage element, or - applying the storage element onto an object to be disinfected, or - wiping an object to be disinfected with the storage element, or - wrapping an object to be disinfected in the storage element.

Description

Disinfection Appliance and Disinfection Method

Description

The invention is related to a disinfection appliance according to Claim 1 and to a disinfection method according to Claim 9.

The use of non-equilibrium plasmas often referred to as non-thermal plasmas or low-temperature plasmas for a treatment of wounds and for disinfection purposes is known and disclosed, for example, in the US-patent US 7,683,342 B2, in WO 2008/138504 A1 , WO 2007/031250 A1 , WO 2001/094307 A1 and in EP 10013940.1. Disinfection appliances of this kind tend to be complex and expensive.

Therefore it is a general object of the invention to provide an approved disinfection appliance.

This object is achieved by a disinfection appliance with the features of Claim 1. It comprises a storage element having cavities containing a plasma activatable fluid. The appliance itself is independent of plasma sources and may be used separately from said sources.

In a preferred embodiment of the invention the disinfection device comprises natural fibres or is made of such fibres. Generally, the storage element of the disinfection appliance comprises or is made of natural fibres, but it is possible that the disinfection appliance itself realizes the storage element. In this case the appliance, as mentioned above, comprises or is made of natural fibres. Fibres of this kind may comprise cotton, linen or other materials. Natural fibres generally tend to be reasonably priced and easy to process. Additionally, these fibres are easy to clean. An additional advantage of natural fibres is, that they themselves comprise cavities which can take up plasma activatable fluid. In another embodiment of the invention, the storage element of the disinfection appliance, or the disinfection appliance itself, comprises or is made of artificial fibres. The advantage of the use of such fibres is that they may be chosen in a way to be wear resistant or resistant against chemical substances and easy to be cleaned. Additionally, it is possible to use artificial fibres comprising fibrels or microfibrels and are enclosing quite a large number of cavities to take up plasma activatable fluid. When using natural or artificial fibres for producing a storage element or a disinfection appliance, it is possible to realize cavities between the fibres taking up plasma activatable fluid. In another embodiment of the invention, the disinfection appliance comprises fibres, which are inactive with respect to plasma activatable fluid. This enhances the durability of the disinfection appliance.

In another embodiment of the invention, the disinfection appliance is realized by a folded cloth. In this case the cloth is used as storage element, as it comprises cavities containing a plasma activatable fluid. However, not only the cloth comprises said cavities but folding said cloth means that between the single layers of the cloth cavities are included enlarging the volume to store plasma activatable fluid within the disinfection appliance of this kind. This enhances the disin- fection ability of the appliance.

In another preferred embodiment of the invention, the storage element comprises or is made of sponge or a sponge-like substance, especially of a foamed substance. Said substances comprise a large number of cavities which may take up plasma activatable fluid, enhancing the storage abilities of the disinfection appliance and the disinfection abilities of said appliance. The cavities in the substances mentioned above should not be totally sealed against the environment as the plasma in the cavities of the substance should be able to emanate from the storage element and from the disinfection appliance to disinfect an object.

In another embodiment of the invention, the storage element of the disinfection appliance comprises or is made of porous ceramics. Also in this case the whole disinfection appliance may be made of porous ceramics. Ceramics are very wear resistant and can be used many times. In case the disinfection appliance should be able to adapt to the surface of an object to be disinfected, the storage element pref- erably comprises a number of elements made of porous ceramics which are connected or linked together in a bendable way, preferably by a bendable element which is fixed to adjoining elements. For example, the elements may be placed between two or more layers of a net or fabric. It is also possible to connect the elements to each other without using such layers.

In another embodiment of the invention, the disinfection appliance comprises an energy harvesting device and a plasma source connected to it to produce plasma for activating the fluid comprised in the cavities of the storage element of the appliance. This disinfection appliance may be used independently from separate plasma sources which are used to activate the fluid contained in cavities of the storage element and/or the disinfection appliance. It is also a general object of the invention to provide an economic and simple disinfection method.

This object is achieved by the disinfection method having the features of Claim 9. In a preferred embodiment of the invention, the disinfection appliance is placed in a plasma chamber comprising a plasma source producing plasma to activate the fluid within the cavities of the storage element. The disinfection appliance itself is light and cost effective, as it does not comprise any elements for generating plasma to activate the fluid within the cavities of the appliance.

In another embodiment of the invention the output of the plasma source of the plasma chamber is chosen in a range between 0,1 W/cm² to 2 W/cm² and preferably is about 0,5 W/cm². Because of the simple structure of the disinfection device, plasma sources with quite a low output may be used to activate the fluid within cavities of the plasma device.

In another embodiment of the invention, the plasma is non-thermal, low-temperature plasma, especially cold atmospheric plasma. This plasma is quite easy to generate and the plasma chamber including the plasma source is characterized by a quite simple structure. Activating the plasma in the cavities of the disinfection appliance is quite easy and cost effective in this way.

In another embodiment of the invention, a gas itself or a gas mixed with atmospheric air is used to produce plasma for special disinfec- tion cases. By this, the disinfection device may be easily adapted to disinfect different objects with special germs or viruses. In another embodiment of the invention, the plasma activated fluid is applied for 10 seconds to 5 minutes, preferably for 60 s to 120 s, to the object which is to be decontaminated and/or disinfected. The disinfection method using the disinfection appliance proved to be very effective and it is possible to reduce the number of germs already within a quite short time of 60 s to 120 s.

In another embodiment of the invention the disinfection method is carried out using a disinfection appliance comprising an energy harvesting device energizing a plasma source to produce plasma for activating the fluid comprised in the cavities of its storage element. Using energy harvesting devices makes it possible to carry out the method independently of known energy sources like batteries or mains.

A detailed description of the invention is given below: The disinfection appliance is characterized by having cavities containing a plasma activatable fluid, a gas and/or a liquid, the cavities being arranged in a storage element. Preferably the storage element itself may be realized in a way to be used as a disinfection appliance.

The storage element of the disinfection appliance or preferably the disinfection appliance itself comprises natural and/or artificial fibres or is made of them. The fibres are woven, knitted or just entangled to produce a piece of fabric having cavities containing the plasma activatable fluid. Fibres themselves produced this way do also comprise cavities which may take up plasma activatable fluid. The volume of fluid the disinfection appliance may take up in this case is defined by the interior volume of the fabrics and by the technique the fibres are connected to each other producing a piece of fabric. Preferably the fibres of the disinfection appliance are inactive with respect to the plasma activatable fluid to make sure that an activated fluid will not be affected negatively before the disinfection appliance may be used. A preferred disinfection appliance comprises or is made of fibres mentioned above to realize a fabric, preferably a cloth, said fabric being folded at least once. Thereby, between the layers of the folded fabric additional cavities are realized which may take up plasma activatable fluid. In other words folding the disinfection appliance or its storage element in a way mentioned above, results in many cavities not only within the fabric but also between the at least two layers of the fabric.

Instead of fibres the disinfection appliance or its storage element comprise a sponge or a sponge-like substance, especially a foamed substance or is made of it. The important aspect is that the disinfection appliance comprises preferably a large number of cavities containing a plasma activatable fluid.

In a preferred embodiment of the disinfection appliance the storage element or the disinfection appliance itself comprises or is made of porous ceramics. The important aspect of the disinfection appliance are the cavities containing a plasma activatable fluid. Using porous ceramics for the storage element or the disinfection appliance itself results in a very wear resistant appliance which may be used many times without deterioration. Fibres of any kind may be damaged when using the disinfection appliance or even by folding the fabriclike storage element of the disinfection appliance or the appliance itself. In the following the use of the disinfection appliance and the novel disinfection method according to the invention will be disclosed more detailed:

Before using the disinfection appliance it is necessary to activate the fluid, i.e. the gas and/or the liquid in cavities of the storage element. A very simple and effective way of using the disinfection appliance is that it itself or its storage element comprises cavities which are filled with air. By applying plasma to the disinfection appliance the air in the cavities will be plasma activated. To activate the fluid comprised in cavities of the disinfection appliance or in its storage element respectively, a known plasma source may be used, preferably a source generating non-equilibrium plasma.

Most preferably the disinfection appliance is placed in a plasma chamber comprising a plasma source producing plasma. A treating device of this kind is clearly disclosed in EP 2 223 704 A1. This publication is incorporated by reference herein. Said treating device meant for treating an object with a non-thermal plasma comprises a housing for temporarily receiving the object to be plasma activated within the housing during the treatment and for applying the plasma to the object within the housing and an inlet opening being arranged in the housing for introducing the object through the inlet opening into the housing. Using said treating device, the disinfection appliance will be placed within the housing realizing the plasma chamber mentioned above to activate the fluid within the cavities. The plasma preferably is as mentioned above non-thermal, low-temperature plasma, especially cold atmospheric plasma. The output of the plasma source of the plasma chamber is chosen within a range of 0,1 W/cm² to 2 W/cm², preferably the output is about 0,5 W/cm². It is possible to use plasma sources having a higher output but this regularly results in the necessity to provide more complex and costly pro- tection means to avoid any negative effects of the plasma in an area outside of the chamber.

In some cases it is necessary to provide disinfection in relation to specific germs. In these cases a additive will be fed to the plasma chamber to produce plasma which is especially adapted to abolish defined species of germs. When generating special plasma, said plasma preferably comprises a partially unitized carrier gas comprising at least one additive, which preferably has a sterilizing effect on the treated object. The generation of a special plasma is clearly disclosed in EP 2 160 081 A1. This publication is incorporated by refer- ence herein. The fluid in the chamber enters the cavities of the disinfection appliance and is stored therein.

Using the disinfection appliance and carrying out the disinfection method it is important to realize a plasma activated fluid within cavities of the disinfection appliance or its storage element. It is not only possible to use external plasma sources to obtain an activated fluid within said cavities as mentioned above. It is also possible to use an energy harvesting plasma generator as disclosed in EP 10013940.1 , which is therefore incorporated by reference therein. In this case it is possible to power a plasma source within the disinfection appliance to plasma activate the fluid within the cavities. The use or energy harvesting techniques in relation to disinfection appliances as mentioned above allows the use of the disinfection appliance and carrying out the disinfection method mentioned above without an addi- tional plasma source, arranged for example in a chamber to activate the fluid within the cavities of the disinfection appliance. In some cases it may be advantageous not to integrate any additional elements, i. e. energy harvesting devices and plasma sources, with the disinfection appliance as said appliance in this case may be smaller and cheaper.

After all, the invention comprises the following embodiments:

The first embodiment of the disinfection appliance does not comprise any plasma source. To activate the fluid within cavities of the disin- fection appliance it is necessary to use either a plasma chamber, as mentioned above, or an energy harvesting plasma generator. Said generator may be integrated for example in a cloth also comprising a plasma source. This cloth may be used to generate plasma to activate the fluid in the cavities of the disinfection appliance. For exam- pie the disinfection appliance may be wrapped in the cloth, the plasma source of it activating the fluid comprised in the cavities of the disinfection appliance.

In both cases the disinfection appliance is quite simple and inexpensive. The second embodiment of the disinfection appliance comprises an integrated energy harvesting plasma generator and a plasma source, resulting in that the appliance itself is able to generate plasma to activate the fluid within the cavities of the disinfection appliance.

In both cases, using an external or internal plasma source, the fluid within the cavities of the disinfection appliance can be activated to disinfect objects. Using an external plasma source, for example a plasma chamber, it is possible to realize one way disinfection appliances which may be thrown away after using them only once.

Most preferably the disinfection appliance is realized as a fabric made of natural fibres, especially of cotton and/or linen. The fabric may be easily replaced after one or more disinfections of an object.

In regular cases there is no need to specially adapt fabrics of natural or artificial fibres or sponges or sponge-like substances to disinfect objects. It is only important that the disinfection appliance comprises cavities containing a plasma activatable fluid. Appliances having a large number of cavities and comprising a relatively high volume of plasma activatable fluid are preferred for carrying out the disinfection method mentioned above.

That is why cheap disinfection appliances having a quite large num- ber of cavities which may be thrown away after one or more uses, are very much preferred.

Disinfection appliances comprising an energy harvesting plasma generator are more expensive. Anyhow, an energy harvesting plasma generator may be integrated into a piece of clothing which then may be used to realize a disinfection appliance and to carry out a disinfection method.

After plasma-activating the fluid within the cavities of the disinfection appliance it is possible to place an object to be disinfected onto the disinfection appliance. The cavities of the disinfection appliance are realized in a way, that the plasma activated fluid may emanate from the disinfection appliance or its storage element to disinfect the object on the disinfection appliance.

On the other hand it is possible to place the disinfection appliance on an object to be disinfected. Also in this case the plasma activated fluid in the cavities of the disinfection appliance or its storage element may emanate from the cavities and reach the object to be disinfected.

The use of the disinfection appliance mentioned above, i. e. positioning an object onto the disinfection appliance or the other way round applying the disinfection appliance on an object, may be carried out if the disinfection appliance is comprising fibres or porous ceramics as there will be no relative movement between the disinfection appliance and the object to be disinfected.

Another way to use the disinfection appliance is to wipe an object to be disinfected with the disinfection appliance after plasma activating the fluid comprised in the cavities of the disinfection appliance or its storage element. Wiping an object or its surface with a disinfection appliance results in a relative movement between the appliance and the object. In many cases a soft disinfection appliance will be pre- ferred when disinfecting an object. That is why this method for disinfecting an object will be preferably carried out if the disinfection appliance comprises fibres or is made of them or a sponge. In cases disinfecting an object with a very wear resistant surface also disinfection appliances comprising ceramics can be used to be moved along the surface of the object to be disinfected. In other cases it might be necessary to grind or polish the surface of an object to be disinfected while disinfecting it. In this case it is very useful, if the disinfection appliance comprises ceramics, as this substance is generally very wear resistant.

Finally, it is possible to wrap an object to be disinfected in the disinfection appliance. To carry out this method it is necessary to realize a soft disinfection appliance which may be adapted to the outer shape of the object to be disinfected and to wrap said object. This method very easily may be realized by using a disinfection appliance comprising natural or artificial fibres or a sponge or sponge-like substances as in this case the disinfection appliance is soft and deform- able to adapt to the outer shape of the object.

On the other hand it is possible to even use porous ceramics in this case, especially if a number of elements made of porous ceramics are connected together in a way that the disinfection appliance may be deformed or folded to wrap an object to be disinfected. For ex- ample it may be possible to use one or more layers of a fabric or a net comprising elements of porous ceramics in between. The ceramic elements will then comprise cavities containing a plasma acti- vatable fluid and also the layers of fabric enclosing the ceramic elements will comprise cavities of this kind. Most preferably the disinfection appliance is made of an elastic material, especially fibres and/or sponge or sponge-like substances in case an object to be disinfected has to be wrapped in the disinfection device. Wrapping an object makes sure that the plasma activated fluid of the disinfection appliance reaches the whole outer surface of the object to be disinfected and may even intrude into pores and cavities of the object. Using the disinfection appliance and carrying out the disinfection method mentioned above the most important aspect is that a plasma activated fluid will be stored within the disinfection appliance until said appliance is used to disinfect an object and by doing so carrying out the disinfection method mentioned above. Additionally, it is important that the cavities are able to include the plasma activatable fluid in a way that said fluid may be stored for a while after plasma activating the fluid in said cavities. By this, a person using the disinfection appliance and carrying out the disinfection method has time to bring the disinfection appliance and the object to be disinfected together in a way that the activated fluid may disinfect the object.

Another important aspect is that the disinfection appliance and the object to be disinfected do not need to be in direct contact with each other to achieve a disinfection effect. The plasma activated gas emanating out of the cavities is able to disinfect a surface being arranged at a distance to the disinfection appliance.

The disinfectant effect of the plasma activated fluid within the cavities of the disinfection appliance will last for a few minutes. Preferably the disinfection appliance will be used within a short time after the fluid has been plasma activated, preferably within 10 s.

The exposure time of the disinfection appliance may be ten seconds or less than five minutes. Preferably the disinfection will be carried out for 60 s to 120 s. Mostly the disinfection time will be adapted to the object which is to be disinfected. If it has a quite porous surface, it will take some more time to obtain a sufficient disinfection of the object, because it takes some time for the activated fluid to enter the cavities. In the following the effectiveness of the disinfection method will be explained:

A disinfection appliance preferably realized as a cloth made of natural fibres is used to carry out the disinfection method. The cloth pref- erably is folded several times, for example three times. An object to be disinfected, for example an agar plate with a bacterial loaded surface, is placed on the folded cloth upside down in a way that only the rim of the agar plate gets into contact with the cloth and its content being arranged at distance from the surface of the cloth. On the sur- face of the agar there is a layer of for example Escherichia coli. It turned out that the plasma activated fluid, i. e. atmospheric gas, emanated from the cavities within the cloth and reached the surface of the agar within the agar plate. The bacterial load on the surface of the agar plate was reduced at least one order of magnitude after leaving the agar plate for 60s to 120s on the cloth. The disinfection method turned out to be very effective, as the reactive gas in the cloth was released, reached the agar surface and reduced the number of E. coli very effectively.

Using clothes made of natural fibres, i. e. cotton and/or linen, is a very effective and cheap way to realize disinfection appliances and to carry out the disinfection method very effectively.

Referring to the description of the invention and to the explanation with respect to the invention it is an important aspect, that the fluid of the disinfection appliance contained in its cavities may be a liquid or a gas, preferably air.

The advantage of using the disinfection appliance and carrying out the disinfection method with a gas, especially with air comprised in the cavities is, that there no residue will remain at the surface of the object being disinfected. On the other hand, in case a liquid is used together with the disinfection appliance or when carrying out the disinfection method, it is possible to use special liquids, which, for ex- ample, may be quite easily activated by plasma or which have very good disinfecting properties after being activated by plasma.

It is easily to be seen that the disinfection appliance after all may be used with a liquid or gaseous fluid contained in the cavities.

That is why the disinfection appliance may be easily designed in a way to be used in disinfecting surfaces and/or objects with a dry fluid, for example electronic devices, i.e. keyboards, medical instruments or the like which may not get wet when being disinfected. An additional advantage of dry disinfecting objects is, that there will be no pollution of the surface of the objects by residues which might be disadvantageous especially for ill people or babies.

The disinfection appliance may not only be realized as a cloth but also as a medical element like a bandage, compress, pad, plaster or other. In this case it is very easy to disinfect especially wounds without applying any UV radiation to the patient. Another advantage is, that exposing the disinfection appliance to plasma when activating the fluid within its cavities, the disinfection appliance itself will be disinfected, sterilized and/or decontaminated before using it and before carrying out the disinfection method described above. This is highly advantageous, especially in public ar- eas, restaurants, canteens and especially in hospitals and the like. It is clearly to be seen that after disinfecting an object any pathogens of said object, which might adhere to the disinfection appliance, will be destroyed while activating the plasma in the disinfection appliance and before using it again.

Claims

1. Disinfection appliance comprising a storage element with cavities containing a plasma activatable fluid.

2. Disinfection appliance according to claim 1 characterized in that the storage element comprises or is made of natural fibres.

3. Disinfection appliance according to claim 1 or 2 characterized in that the storage element comprises or is made of artificial fibres.

4. Disinfection appliance according to claim 2 or 3 characterized in that the fibres are inactive with respect to plasma activatable fluids.

5. Disinfection appliance according to one of the preceding claims, characterized in that it is realized by a - preferably folded - cloth, a bandage, compress, pad, plaster or another medical element..

6. Disinfection appliance according to claim 1 , characterized in that the storage element comprises or is made of a sponge or a sponge-like substance, especially of a foamed substance.

7. Disinfection appliance according to claim 1 , characterized in that the storage element comprises or is made of porous ceramics.

8. Disinfection appliance according to one of the preceding claims, characterized in that it comprises an energy harvesting de- vice and a plasma source to produce plasma for activating the fluid comprised in the cavities of the storage element.

9. Disinfection method comprising the following steps: - plasma activating fluid comprised in cavities of a disinfection appliance according to one of the claims 1 to 8;

- applying an object to be disinfected onto the disinfection appliance, or

- applying the disinfection appliance onto an object to be disin- fected, or

- wiping an object to be disinfected with the disinfection appliance, or

- wrapping an object to be disinfected in the disinfection appliance.

10. Method according to claim 9, characterized in that the disinfection appliance is placed in a plasma chamber comprising a plasma source producing plasma to activate the fluid within the cavities of the storage element.

11. Method according to claim 9 or 10, characterized in that the output of the plasma source is 0,1 W/cm² to 2 W/cm², preferably about 0,5 W/cm².

12. Method according to one of the preceding claims 9 to 1 1 , characterized in that the plasma is non-thermal, low-temperature plasma, especially cold atmospheric plasma.

13. Method according to one of the preceding claims 9 to 12, characterized in that a additive is used to produce plasma for special disinfection cases.

14. Method according to claim 9, characterized in that the plasma activated fluid is applied for ten seconds to five minutes, preferably for 60 s to 120 s, to the object which is to be disinfected.

15. Method according to claim 9, characterized in that the disinfection appliance comprises an energy harvesting device energizing a plasma source to produce plasma for activating the fluid comprised in cavities of the storage element.