Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L2/00—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor
  • A61L2/02—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor using physical phenomena
  • A61L2/14—Plasma, i.e. ionised gases

Definitions

• the present invention relates to a sterilization and cleaning device especially for medical or surgical instruments or devices.
• It also relates to a method of implementing such a device.
• Sterilization is known to destroy in a proportion fixed by the pharmacopoeia, a significant number of microorganisms, viruses or pathogenic proteins present on the surface, internal or external, objects to be treated. There are many methods that can achieve this result more or less satisfactorily.
• the sterilization is usually obtained by means of an autoclave in which the instruments to be sterilized are brought to a determined high temperature, of the order of 12O 0 C, and this for periods of time determined with cycles. imposed by law.
• the autoclaves are limited to the sterilization of small volume objects, which excludes the use to sterilize, for example, appliance lines such as dialyzers or treatment units. dental.
• the application of a temperature greater than 100 ° C. to modern surgical instruments and accessories creates numerous constraints and in particular prevents the subjecting of fragile objects or accessories, for example containing parts made of synthetic polymer materials, by sterilizing them. because of their thermosensitive nature. This is why, in recent years, we turned to methods for performing sterilizations at low temperatures.
• gaseous plasma It has also been proposed to use gaseous plasma. It will be recalled that in these techniques a gas is used which does not itself have bactericidal properties which are subjected to an electric field whose intensity is sufficiently high to cause its ionization and the dissociation of its molecules, if although one thus obtains a plasma which consists of ions and electrons. Plasma has been found to possess high bactericidal properties that have been used to sterilize medical and surgical instruments. For this purpose, the plasma thus produced is admitted into a treatment chamber where it is placed in the presence of instruments that it is desired to sterilize.
• the plasma has high sterilizing properties, it has the disadvantage of also having a destructive effect on certain materials, such as in particular synthetic plastics, which excludes its use for the sterilization of many medical instruments or surgical.
• the gas produced downstream of the plasma hereinafter referred to as "post-discharge gas" has sterilizing properties. This gas which is generated at the end of the plasma is no longer subjected to the effect of the electric field, so that the electrons and the ions which constitute the plasma disappear by recombination in the gas and after diffusion on the walls of the tube.
• the sterilization devices which are intended to be used in the medical field, and in particular in the dental field, must, on a practical level on the one hand not be too sophisticated and on the other hand be of a cost particularly affordable of the order of autoclaves currently used in the field of sterilization of instruments.
• Such specifications therefore exclude the use of materials of the type used in the field of laboratory and forced to use accessories of the type called industrial. Among these accessories there is the vacuum pump.
• vacuum pumps of the so-called "industrial” type have the disadvantage of not providing a sufficiently high vacuum (the residual pressure obtained is of the order of 10 Pa to 100 Pa) to avoid the presence of oxidizing impurities, among which water vapor which produces, during the generation of the plasma, OH " radicals and air residues producing nitrogen oxides which, of course, enter the sterilization chamber and give the post-gas
• oxidizing impurities are fixed on the instruments to be sterilized and therefore engage the corrosion process.
• the present invention aims to improve the prior art by allowing to use in the device according to the invention a vacuum pump of industrial type while further reducing the risk of oxidation instruments and apparatus subject to sterilization.
• the subject of the present invention is thus a device for sterilizing objects, in particular medical or surgical instruments, of the type in which a gaseous flow circulating in a chamber in which an industrial vacuum is created is subjected to the action an electric field so as to create a gaseous plasma whose postdischarge flow resulting therefrom is admitted into a sterilization chamber where it is brought into contact with the surface of the objects to be treated, characterized in that: - the flow gas consists of a mixture of nitrogen and a quantity of hydrogen of less than 5%,
• the walls of the sterilization chamber may be made of a material having a low capacity of recombination of nitrogen and hydrogen atoms, such as for example glass and / or ceramic and / or a polymer.
• the objects to be sterilized may be placed on a metallic object-holder whose nature will be such that, under the effect of the recombination of the nitrogen and hydrogen atoms, this object-holder heats up and ensures the heating of the objects. that it contains.
• This object holder which may in particular be made of brass, may also be provided with its own heating means.
• the electric field will preferably be produced by a microwave generator, but it may also be produced by DC or pulsed discharges or by radio frequencies.
• the sterilization chamber may consist of an autoclave and this autoclave may constitute the heating means of the instruments to be sterilized.
• the means for generating the plasma may be contained in the door of the autoclave.
• the heating of the objects contained in the sterilization chamber will be ensured at least in part by the walls thereof which, for this purpose, will be made of a material suitable for to heat by recombination the nitrogen and hydrogen atoms.
• the heating of objects can also be provided by providing the walls of the sterilization chamber additional heating means, including electrical.
• the present invention is particularly interesting in that it makes it possible to ensure the sterilization of the conduits and internal cavities of apparatuses and even of large volume apparatus such as, for example, dental treatment units, dialysis machines, and the like. To this end, post-discharge flow will be injected through an orifice of this apparatus, through the ducts and internal cavities thereof, which flow will be extracted, for example by suction by another of its orifices.
• the subject of the present invention is also a process for the sterilization of objects, in particular medical or surgical instruments, in which a plasma is created by the action of an electric field on a gaseous flow circulating in an enclosure in which a vacuum is created. of industrial level and the resulting post-discharge flow is brought into contact with the surface of the objects to be treated, characterized in that: a mixture of nitrogen and a quantity of nitrogen is used as a gaseous flow; less than 5% hydrogen,
• a heating objects to be treated at a temperature at least 60 0 C. may raise, during the treatment, the temperature of the instruments, this increase in temperature obtainable by heating the carrier objects, or by heating the sterilization chamber, but also by recombination of the atoms of the post-discharge gas on the surfaces of the carrier and / or the sterilization chamber.
• FIG. 1 is a schematic view of a sterilization device according to the invention.
• FIG. 2 is an alternative embodiment of the sterilization device shown in FIG. 1.
• FIG. 3 is a schematic view of an alternative embodiment of the device according to the invention.
• FIGS. 4 and 5 are schematic views of two applications of the device according to the invention to the sterilization of the ducts and internal cavities of an endoscope and a fiberscope.
• FIG. 6 is a diagrammatic view of an example of sterilization of the external surface and internal conduits and cavities of an apparatus.
• Figure 7 is a schematic view of an application of the device according to the invention to the sterilization of the conduits and internal cavities of a dialysis apparatus.
• FIG. 1 very schematically shows a gaseous plasma sterilization device according to the invention.
• This device comprises an inlet pipe 1 of a gas stream constituted by a a mixture of nitrogen and hydrogen which passes through a vacuum chamber subjected to the action of an electric field generator constituted by a microwave generator 3 at 2.45 GHz, the power of which is regulated by means of 5.
• the post-discharge gas generated by the plasma thus produced (in a known manner) is fed into a treatment chamber 7 via a pipe 9.
• This treatment chamber 7 is disposed in the plasma post-discharge zone. and it is in communication with a vacuum pump 11.
• the latter drives the post-discharge gas into the treatment chamber 7 and ensures the evacuation of the gases outwards through a pipe 13 provided with the appropriate filters 15.
• the treatment chamber 7 comprises a metal object holder 17 which is intended to receive the objects 19 that it is desired to sterilize.
• the object holder 17 is provided with heating means 21 whose temperature is controlled by a control device 23.
• These heating means may in particular consist of an electrical resistance or, as shown in FIG. induction heating 25.
• the treatment chamber may consist of an autoclave of the type used to sterilize medical or surgical instruments.
• the autoclave 30 thus consists of an enclosure 35 of substantially parallelepipedal shape which is closed on one of its sides by a pivoting door 32.
• This pivoting door is sufficiently thick to enclose the various elements necessary for the plasma generation. It comprises, on its front face, a nozzle 34 for exiting the post-gas. discharge intended to supply the interior of the enclosure.
• This nozzle 34 may advantageously end with one or more injectors allowing in particular to homogenize the flow of the post-discharge gas.
• the enclosure 35 is provided on its wall opposite the door 32 with a "reflector" 36 and a fan 38 which contributes to the homogenization of the post-gas.
• Such an arrangement is advantageous in that it allows the user to have a multi-function autoclave, namely a conventional autoclave function and a function in which it is sterilized by gas. post-discharge and low temperature.
• a multi-function autoclave namely a conventional autoclave function and a function in which it is sterilized by gas. post-discharge and low temperature.
• the autoclave may be used to bring the objects to be sterilized to the desired temperature. It has indeed been found that it is possible to obtain a post-discharge gas having bactericidal properties from a feed gas stream consisting of a mixture of nitrogen and hydrogen without necessarily involving atomic oxygen as taught in the state of the art.
• the present invention makes it possible to increase the efficiency of plasma sterilization devices using nitrogen as a plasma generating gas.
• the hydrogen atoms thus produced serve a dual function, namely on the one hand they generate a reduction reaction of the gaseous oxidative impurities associated with the instruments to be sterilized, and whose decomposition by the plasma could corrode these instruments, and on the other hand
• These atoms as well as the NHx radicals that are added to the nitrogen atoms produce a surface chemistry on the instruments to be sterilized. It was found that this surface chemistry disorganized organic macromolecules and, associated with a small temperature increase of the order of 60 0 C, destroyed the microorganisms by decomposing them. The resulting desorption gases being evacuated out of the chamber by pumping.
• the present invention also makes it possible to sterilize parts of apparatus which, because of their nature or their dimensions, are not sterilizable in sterilizers of conventional type.
• the sterilization device represented in FIG. 1 has thus been applied to the sterilization of an endoscope 40.
• an inlet 42 thereof is connected by means of a connector 41 to a 9 'line connected to the exit of the plasma generator 3, so that the post-discharge gas is formed inside a sterilization chamber formed by the conduits and internal cavities of the endoscope 40.
• the output 43 thereof is likewise connected, by means of a connector 41 ', to a pipe 9 "connected to a vacuum pump 11.
• the post-discharge gas which passes through the interior of the cavities of the endoscope will ensure the sterilization of the latter.
• a sterilization chamber 7 ' which is in communication via a pipe 9' with the plasma generator 3, this pipe being connected to an input of the endoscope by a connector 41 and also being in communication with a nozzle 45 with the interior of the sterilization chamber 7 'in which the post-discharge gas is formed, the exit 43 of the endoscope 40 and the internal volume of the sterilization chamber being connected to a vacuum pump 11 as shown in FIG. 7.
• the device according to the invention to ensure sterilization of the pipes and internal volumes of a dental treatment unit by connecting an inlet of the pipes of this unit to the arrival of the post-discharge gas, and out of it to a vacuum pump.
• FIG. 8 Another particularly interesting application of the invention consists in the sterilization of dialysis machines, as shown in FIG. 8.
• the dialysis apparatus 50 is thus connected by its inlet to an inlet pipe 9 'of the gas of post-discharge and its output is connected to a vacuum pump 11.

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• Health & Medical Sciences (AREA)
• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Plasma & Fusion (AREA)
• Epidemiology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Apparatus For Disinfection Or Sterilisation (AREA)

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• 2004
  • 2004-12-28 FR FR0413984A patent/FR2879933B1/fr not_active Expired - Fee Related
• 2005
  • 2005-12-27 WO PCT/FR2005/003287 patent/WO2006070138A1/fr active Application Filing
  • 2005-12-27 BR BRPI0519668-0A patent/BRPI0519668A2/pt not_active IP Right Cessation
  • 2005-12-27 CN CNA2005800452173A patent/CN101124000A/zh active Pending
  • 2005-12-27 CA CA002592618A patent/CA2592618A1/fr not_active Abandoned
  • 2005-12-27 US US11/794,354 patent/US20080112846A1/en not_active Abandoned
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  • 2005-12-27 EP EP05850620A patent/EP1841469A1/fr not_active Withdrawn
  • 2005-12-27 KR KR1020077017665A patent/KR20070110013A/ko not_active Application Discontinuation
  • 2005-12-27 JP JP2007548868A patent/JP2008525141A/ja active Pending
• 2007
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