Method and apparatus for the sterilisation of articles

#This application is a national phase filing, under 35 U.S.C. §371(c), of International Application No. PCT/EP2011/052374, filed Feb. 17, 2011, the disclosure of which is incorporated herein by reference in its entirety.

#Not Applicable

#The present invention relates to the sterilisation of articles. In particular, the invention relates to those articles which can not be sterilised through the use of high temperatures, due to the fact that the high temperatures would cause damage and render them useless, such as sterilisation by means of an autoclave for example. In addition, the invention relates to those articles which are not suitable for sterilisation through the use of a vacuum chamber.

#The invention will be more clearly understood from the following description of an embodiment thereof, given by way of example only, with reference to the accompanying drawings, in which:—

#FIG. 1 is a block diagram of an embodiment of the main components of the present invention;

#FIG. 2 is a block diagram of the components of the plasma radical generator;

#As is clear from the background to the invention section, plasma technology offers a simple and effective method to kill all types of bacteria and viruses. The present invention therefore uses plasma technology to kill bacteria and virus, but through a technique which generates plasma products, including oxidizing radicals, at atmospheric pressures at room temperature and exposes them to contaminated surfaces. This approach differs from the current state-of-the-art plasma sterilisation systems, which operate at low pressure (below atmosphere), thus limiting their applicability to articles that can fit in a vacuum chamber. In fact, the present invention is not limited to operation in any particular size of chamber. This is also in contrast to some of the current state-of-the-art systems described above, which, even though operated at atmospheric pressures, must use fixed volume chambers, due to their operation requirements, thus limiting their applicability to articles that can fit in such chambers. These systems also have the further drawback of requiring additional controls and sensors to monitor parameters such temperature, pressure, gas/chemicals/moisture injection and detection of harmful compounds. The system of the present invention also differs from those plasma sterilisation systems which operate at atmospheric pressure and which use a combination of consumables (e.g. gases/chemicals) and/or moisture, and as a result may damage the article, or harmful compounds may form on the article, as previously described.

#By generating a combination of oxidizing radicals using only air, the plasma products attack the bacteria, removing its protective layers and breaking its DNA. The plasma radicals physically remove the bacteria from surfaces by eroding them away, and then kill them by destroying their genetic code. The plasma radicals constitute antimicrobial active species. These species include ozone, atomic oxygen, and free radicals, such as superoxide, hydroxyl and nitric oxygen [T. C. Montie et al., IEEE Trans. Plasma Sci., 28, 41 (2000)]. It should be noted that while ozone and hydroxyl are strong oxidizing agents present in the radical by-product mixture, they are not exclusive to the by-product mix.

#In order to achieve maximum efficiency during the sterilisation process, the generated plasma radicals should be contained in a volume surrounding the article to be sterilised. This ensures a high concentration of radicals, resulting in an increase in the sterilisation action and a reduction of the sterilisation processing time.