FR3067361A1 - METHOD AND SYSTEM FOR MEASURING THE EFFICIENCY OF A DEVICE FOR DISINFECTING A VEHICLE - Google Patents

Abstract

The present invention relates to a method for measuring the effectiveness of a disinfection device, said measuring method comprising: a step (E2) of contamination by a microbiological solution comprising at least one strain of microorganisms, of at least one sample test and at least one control sample, - a step (E4) of placing said at least one test sample in an enclosure, - after a predetermined operating time of the disinfection device, a measurement step (E6) the concentration of microorganisms present on said at least one test sample and on said at least one control sample, and - a step (E7) for calculating a disinfection device effectiveness rate as a function of the concentration in micro -organisms measured on said at least one test sample and on said at least one control sample.

Description

METHOD AND SYSTEM FOR MEASURING THE EFFICIENCY OF A VEHICLE COCKPIT DISINFECTION DEVICE The invention relates, in general, to the field of cleaning up the interior surfaces of a vehicle interior and more particularly the field of disinfection devices installed in many vehicles.

The invention relates more specifically to a method and a system for measuring the efficiency of a device for disinfecting the surfaces of the passenger compartment of a motor vehicle with regard to microbiological organisms.

In a known manner, a motor vehicle comprises an ambient air management system within the passenger compartment of the vehicle, making it possible in particular to provide sanitation and air pollution control in the passenger compartment. Such an air management system may however prove to be insufficient for cleaning up the interior surfaces of the passenger compartment.

In fact, when a passenger or the driver touches a surface of the passenger compartment, such as the dashboard, the control buttons or even the ventilation nozzles for example, it may happen that there deposits germs or microbes that can proliferate. In order to treat such surfaces infected with microorganisms, certain motor vehicles are thus equipped with a device for disinfecting the surfaces of the passenger compartment.

To this end, document FR 2955031 describes a device for disinfecting a motor vehicle comprising a pneumatic energy module and a module for diffusing a disinfectant substance. The disinfection device makes it possible, by activating the pneumatic energy module, to spread the disinfectant substance over the surfaces of the vehicle interior. Such a disinfection device thus having the function of reducing the concentration of microorganisms on the internal surfaces of the passenger compartment, must follow a series of tests in order to verify its effectiveness.

In accordance with the state of the art relating to the evaluation of the effectiveness of disinfection devices in general, specific standards, such as the Japanese standard JIS Z 2801 or the international standard ISO 22196, allow the production tests on such disinfection devices.

Thus, the Japanese standard JIS Z 2801 describes test methods allowing the verification of the bacterial activity as well as the evaluation of the effectiveness of a disinfection device with regard to such bacteria on various surfaces such as surfaces plastics, metal or textiles. However, such a standard does not apply to all microorganisms. Indeed, the JIS Z 2801 standard does not deal with the evaluation of the effectiveness on fungal organisms, such as molds for example.

Similarly, the international standard ISO 22196 describes methods for measuring the antibacterial action of a disinfection device on plastic surfaces. The ISO 22196 standard does not however deal with the measurement of the effectiveness of the disinfection device on metallic or textile surfaces, however present inside the passenger compartment of a vehicle for example on the seat belt buckles or the seats.

These known standards, not specific to motor vehicles, do not take into account the evaluation of the effectiveness of disinfection devices on any type of microorganism present on different surfaces of a passenger compartment of a motor vehicle , which is a significant gap. These standards do not provide an effective and relevant solution for measuring the effectiveness of a disinfection device mounted in a motor vehicle.

The invention therefore aims to overcome this deficiency by providing a simple, reliable and effective measurement method for measuring the effectiveness of a device for disinfecting the passenger compartment of a vehicle vis-à-vis microorganisms.

More specifically, to achieve this objective, the present invention relates to a method for measuring the efficiency of a disinfection device, intended to be mounted in a motor vehicle, said measurement method comprising:

a step of contamination with a microbiological solution comprising at least one strain of microorganisms of at least one test sample of a part of a passenger compartment of a vehicle and at least one control sample of said part of the passenger

a step of placing said at least one test sample in an enclosure, said enclosure having predetermined environmental conditions,

a step of putting the disinfection device into operation for a predefined operating time, said disinfection device being placed in the enclosure,

a step of preserving said at least one control sample, outside the enclosure, in a safety enclosure, during said operating time of the predefined disinfection device, said safety enclosure having environmental conditions similar to the predetermined environmental conditions of the 'pregnant,

- after the predefined operating time, a step of measuring the concentration of microorganisms present on said at least one test sample and on said at least one control sample, and

a step of calculating an efficiency rate of the disinfection device as a function of the concentration of microorganisms measured on said at least one test sample and of the concentration of microorganisms measured on said at least one control sample , said efficiency rate being equal to: log ^, where C ₅ is the concentration of microorganisms measured on said at least one test sample and C ₆ is the concentration of microorganisms measured on said at least one control sample .

Such a measurement method advantageously makes it possible to evaluate the effectiveness of a disinfection device, making it possible to install an effective disinfection device in a passenger compartment in order to limit possible contamination of the driver or a passenger by a bacteria or an unwanted germ.

According to one embodiment, said concentration of microorganisms present on said at least one test sample and on said at least one control sample is calculated according to the following formula;

n _x + n ₂ H ----- H n _x

Cs> ^ 6 - or:

C ₅ , C ₆ are the respective concentrations of microorganisms, expressed in CFU / ml, present on said at least one test sample or on said at least one control sample;

n, is the number of colonies present in the test sample or in said control sample;

i is a number in the test sample box or in said control sample;

x is the number of test samples or control samples; v is the volume of microbiological solution deposited in the test sample or in said control sample;

D is the level of dilution chosen for said microbiological solutions;

V _T is the respective total volume of test sample (s) or control sample (s) recovered.

Advantageously, microbiological solutions have a concentration of 10 ⁴ CFU / ml and microbiological solutions have a concentration of 10 ⁷

CFU / ml.

Preferably, the measurement method comprises a step of placing said disinfection device in said enclosure, making it possible to use a standard enclosure, suitable for testing any type of disinfection device.

Advantageously, the measurement method comprises, prior to the step of contamination with a microbiological solution comprising at least one strain of microorganisms of said at least one test sample and of said at least one control sample, a step for preparing said microbiological solution, allowing contamination of the samples with a microbiological solution containing a known initial concentration of microorganisms.

Advantageously, the measurement method comprises, prior to the step of contamination with a microbiological solution comprising at least one strain of microorganisms of said at least one test sample and of said at least one control sample, a step of preparing d a treated surface of said at least one test sample and said at least one control sample, said treated surface being adapted to receive said microbiological solution. Such a surface treatment allows better impregnation of the microbiological solution.

Preferably, the measurement method comprises, prior to the step of placing said at least one test sample in the enclosure, a step of decontaminating said enclosure, allowing the test to be carried out in an environment healthy.

Advantageously, the measurement method comprises, at the end of the test, a step of destroying said at least one test sample and said at least one contaminated control sample, so as to subsequently limit the risks of contamination.

Advantageously, the contamination step of the measurement method is carried out on a plurality of test samples and a plurality of control samples from a plurality of parts of the vehicle cabin, making it possible to evaluate the device disinfection on a plurality of surfaces belonging to a plurality of different parts of the passenger compartment.

Preferably, the disinfection device is arranged in the enclosure in a central position above said at least one test sample, allowing, in the case of a plurality of test samples, equivalent treatment of each test sample, equally distributed in the diffusion cone of the disinfection device.

Advantageously, said at least one test sample and said at least one control sample comprise one or more materials, preferably a plastic material and / or a metallic material and / or a textile material, making it possible to evaluate the disinfection device on a plurality of surfaces designed in different materials.

Preferably, the microorganisms included in the microbiological solution belong to one or more of the following strains: Penicillium brevicompactum, Aspergillus niger, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli. Such a variety of strains makes it possible to evaluate the disinfection device on all of the microorganisms potentially present in a passenger compartment of a motor vehicle.

Advantageously, the step of placing in the enclosure is carried out for a plurality of test samples, each test sample comprising a different material contaminated with a microbiological solution comprising a strain of a different microorganism, so as to measure the concentration of microorganisms on a plurality of different test samples.

The invention also relates to a system for measuring the efficiency of a disinfection device, intended to be mounted in a motor vehicle, said measurement system comprising:

- test means comprising:

an enclosure comprising an opening adapted to allow air circulation, said enclosure being adapted to receive said disinfection device and at least one test sample of a part of a passenger compartment of a vehicle, said at least one sample test being contaminated with a microbiological solution comprising at least one strain of microorganisms,

- at least one temperature sensor and one ozone sensor, so as to control the environmental conditions of said enclosure,

- a safety enclosure, adapted to receive at least one control sample from said part of the passenger compartment, said at least one control sample being contaminated by said microbiological solution,

- motorization means, configured to allow the disinfection device to operate,

measuring means, suitable for measuring the concentration of microorganisms present on said at least one test sample and the concentration of microorganisms present on said at least one control sample, and

- calculation means, configured to calculate an efficiency rate of the disinfection device as a function of the concentration of microorganisms measured on said at least one test sample and of the concentration of microorganisms measured on said at least one control sample.

Such a measurement system advantageously allows the establishment and implementation of the aforementioned measurement method.

Preferably, each test sample and each control sample comprises a different material, preferably a plastic material, a metallic material or a textile material, allowing the introduction into the measurement system of a plurality of samples different test.

Advantageously, each different sample is contaminated with a different microorganism, preferably belonging to one or more of the following strains: Penicillium brevicompactum, Aspergillus niger, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, allowing introduction into the system for measuring a plurality of test samples contaminated with different strains of microorganisms.

Other characteristics and advantages of the invention will appear on reading the detailed description of the embodiments of the invention, given by way of example only, and with reference to the drawings which show:

• Figure 1, a schematic representation of a system for measuring the efficiency of a disinfection device according to an embodiment of the invention, • Figure 2, a diagram of the steps of a measurement method according to an embodiment of the invention, and FIG. 3, a schematic representation of the arrangement of the test samples in a measurement system as described in FIG. 1.

In what follows, the invention is described in particular, without this being able to be interpreted restrictively, with a view to characterizing and measuring the effectiveness of a device for disinfecting surfaces of a passenger compartment intended to be integrated into a motor vehicle.

As described above, certain motor vehicles are equipped with a device for disinfecting the surfaces of the passenger compartment making it possible to decontaminate surfaces infected with one or more strains of microbiological organisms, commonly designated microorganisms. Such surfaces belong to different parts of the passenger compartment such as the dashboard, seats, steering wheel or even the control buttons.

The different parts of the passenger compartment include surfaces designed in different materials, such as metallic surfaces (for example the seat belt buckles), plastic surfaces (for example the coating of the dashboard or control buttons ) or even textile surfaces (for example seats).

As described above, such parts of the passenger compartment can be contaminated with different strains of microorganisms, characteristic of the microorganisms present in a vehicle passenger compartment, such as:

Penicillium brevicompactum,

- Aspergillus niger,

- Staphylococcus aureus,

Pseudomonas aeruginosa,

Escherichia coli.

In order to test the disinfection device 10, the invention provides a measurement method allowing the evaluation of the effectiveness of the disinfection device 10 of the passenger compartment surfaces with regard to such microorganisms.

To this end, Figure 1 shows a measuring system 1, used for the measuring method according to the invention, to assess the effectiveness of a disinfection device 10. To do this, such a system 1 allows measurement of the concentration of microorganisms present on a plurality of samples from different parts of the passenger compartment of the motor vehicle with and without treatment by the disinfection device 10.

In this example, with reference to FIG. 1, the measurement system 1 extends longitudinally along an axis X, laterally along an axis Y and vertically along an axis Z, so as to form an orthogonal coordinate system (X, Y, Z). Thus, by the term horizontal, we mean an object extending in the plane (X, Y). Similarly, the vertical term denotes an object extending in the plane (X, Z) and the transverse term denotes an object extending in the plane (Y, Z).

With reference to FIG. 1, the measurement system 1 comprises, according to a preferred embodiment:

test means 2, configured to receive the disinfection device 10 to be tested,

motorization means (not shown), allowing the disinfection device 10 to operate,

- measuring means (not shown), configured to measure the concentration of microorganisms on a plurality of samples, and

- calculation means (not shown), configured to calculate an efficiency rate T of the disinfection device 10.

Still with reference to FIG. 1, the test means 2 preferably comprise:

- An enclosure 20, adapted to receive the disinfection device 10 to be tested and at least one test sample 5, corresponding to a sample of part of the passenger compartment of the vehicle; preferably, but not necessarily, the enclosure 20 has an opening 200, configured to allow air circulation, in order to give the enclosure 20 an improved representativeness vis-à-vis a vehicle interior equipped an ambient air management system,

- at least one temperature sensor 22, so as to control the temperature and hygrometry conditions inside the enclosure 20,

- an ozone sensor 23, making it possible to control the ozone concentration inside the enclosure 20, and

a safety enclosure 21, adapted to receive at least one control sample 6 corresponding to a sample of the part of the passenger compartment of the vehicle from which the test sample 5 was taken, the safety enclosure 21 making it possible to ensure the containment of microorganisms and therefore the safety of operators.

According to one embodiment, the enclosure 20 is preferably in the form of a box, typically made of transparent plastic, having a volume sufficient to receive all of the above elements and a plurality of test samples 5 and comprising an opening 200. Thus, the example described in this document, with reference to FIG. 1, presents an enclosure 20, for example with a volume of 9.5 L, with a round opening 200, having a diameter approximately 68 mm, centered on one face of the enclosure 20. The transparent box advantageously allows a user to view the progress of the test samples 5 during the measurement process. It goes without saying that the enclosure 20 could be in a different form and be made of a different material, such as a metallic material for example.

In order to control the environmental conditions of the enclosure 20, a set of sensors is installed inside such an enclosure 20. In fact, the test means 2 comprise at least one temperature sensor 22, that -this extending along the length of the enclosure 20 so as to control the uniformity of the temperature throughout the enclosure 20. Alternatively, the temperature sensor 22 could be in the form of a point sensor, in which case, the test means 2 would comprise a plurality of temperature sensors, for example three, so as to control the temperature at different points of the enclosure 20. Such a temperature sensor 22 also advantageously allows measurement and the control of the hygrometry inside the enclosure 20.

As described above, the test means 2 also comprise an ozone sensor 23 making it possible to control the concentration of ozone inside the enclosure 20. In fact, the test means 2 preferably comprise a hole, allowing the introduction of cables inside the enclosure 20. The presence of such a hole can cause fluctuations in the environmental conditions inside the enclosure 20 which it is therefore necessary to control .

Such environmental conditions such as temperature, hygrometry rate or even the ozone concentration are also checked in the safety enclosure 21, configured to receive all of the control samples 6. Such an enclosure 21, commonly known as Microbiological Safety Post and known by the acronym PSM, ensures the safety of laboratory operators by forming an enclosed space. Preferably, all of the manipulations of the test means 2 are carried out inside the safety enclosure 21. The enclosure 20 is thus also preferably placed inside the safety enclosure 21.

Still with reference to FIG. 1, the measurement system 1 makes it possible to measure the effectiveness of a disinfection device 10 with regard to microorganisms. To do this, the enclosure 20 is adapted to receive, during a test, at least one test sample 5 coming from a part of the passenger compartment of the vehicle and contaminated by one or more micro strain (s). -organisms previously prepared (s). Similarly, a control sample 6 is taken from the same part of the passenger compartment and contaminated with the same strain (s) of microorganisms. The measurement system 1 is configured to preferably receive, in the safety enclosure 21, a plurality of test samples 5 inside the enclosure 20 and a plurality of control samples 6 outside of enclosure 20. Such samples will be described in more detail below.

As described above, the test means 2 are further adapted to receive the disinfection device 10 to be tested. Preferably, such a disinfection device 10 is placed in a horizontal plane in height, so as to be positioned, in the enclosure 20, above a plurality of test samples 5.

To allow the operation of the disinfection device 10, the measurement system 1 comprises motor means (not shown in Figure 1). Such motorization means, for example an electric motor, allow the activation of the disinfection device 10 for a predetermined duration corresponding to the duration of the test necessary for measuring the effectiveness of the disinfection device 10.

Finally, the measuring system 1 comprises measuring means (not shown in Figure 1), for measuring the concentration of microorganisms present in the plurality of test samples 5 and the plurality of control samples 6 and calculation means (not shown in FIG. 1), making it possible to calculate an efficiency rate T of the disinfection device 10 introduced into the measurement system 1.

There will now be described a method for measuring the effectiveness of a disinfection device 10 according to a preferred embodiment of the invention, using a measurement system 1 as described above.

In order to limit the risks linked to the safety of the operator and the environment, all the steps of the measurement process are preferably carried out in a dedicated laboratory, the environment of which is monitored. According to a preferred embodiment, the steps of the measurement method are thus carried out in a safety enclosure 21, as described above and also known by the acronym BSC meaning Biosafety Cabinet in English. Such a safety enclosure 21 makes it possible to control the environment in which the test is carried out.

FIG. 2 schematically represents the steps of such a measurement method according to an embodiment of the invention. Thus, the measurement method preferably comprises a first step E0 of decontamination of the measurement system 1. Such decontamination can be carried out for example by the application of a disinfectant product such as an alcoholic solution for example and allows the setting in place of the test in a healthy environment.

The measurement method then comprises, in a step E1, the preparation of a microbiological solution comprising one or more strain (s) of microorganisms. A known amount of microorganisms is introduced into the microbiological solution. As described above, such microorganisms consist for example of one or more of the following strains, corresponding to the microorganisms potentially present in a vehicle interior and characteristics in the context of the measurement method according to the invention:

Penicillium brevicompactum,

- Aspergillus niger,

Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli.

Depending on the nature of the strain of microorganisms, two different microbiological solutions can be prepared, a bacterial solution for bacteria, for example Staphylococcus aureus, Pseudomonas aeruginosa or Escherichia coli, and a fungal solution for molds, for example example Penicillium brevicompactu or Escherichia coli. Each microbiological solution typically has a concentration of microorganisms of 10 ⁴ or 10 ⁷ CFU / ml, CFU being the acronym for "Colony-Forming Units" in English, meaning "colony-forming unit", or "strain unipotent >>, the CFU being the unit used in microbiology to qualify the number of viable cells in a sample. Curative test; for 10 ^Λ 4 for periodical test. Both at the same time allows you to test both aspects at once.

According to a preferred embodiment, in order to prepare a microbiological solution, the strains of microorganisms are cultured and incubated for example at 30 ° C for 2 days for bacterial solutions and at 25 ° C for 7 days for fungal solutions. As described above, a microbiological solution having a concentration of 10 ⁴ CFU / ml or 10 ⁷ CFU / ml and / or is prepared for each strain of microorganisms, the concentration of microorganisms being for example evaluated by optical density at using a spectrophotometer. A microbiological solution is thus prepared for each of the above-mentioned strains of microorganisms.

Preferably, several different concentrations of microbiological solutions are used, in order to test the effectiveness of the disinfection device 10 vis-à-vis different contexts. In particular, such a disinfection device can in practice be implemented periodically, to maintain a satisfactory level of air quality in a normal environment, or for curative purposes, when the passenger compartment is particularly polluted. Thus, a first plurality of samples can be contaminated with a microbiological solution having a concentration of 10 ⁴ CFU / ml, to evaluate the effectiveness of the disinfection device 10 implemented periodically, and a second plurality of samples can be contaminated with a microbiological solution having a concentration of 10 ⁷ CFU / ml, to assess the effectiveness of the disinfection device 10 used for curative purposes.

Thanks to the method according to the invention, it is possible to test the disinfection device 10 both as implemented in a "periodic" context and in a "curative" context in a single test, due to the differentiated contamination of different samples.

Furthermore, the measurement method according to the invention preferably makes it possible to evaluate the effectiveness of a disinfection device 10 on a plurality of parts of the passenger compartment of a vehicle comprising different materials, as described previously. Thus a plurality of samples from a plurality of parts of the passenger compartment is taken. Preferably, a plurality of samples is also taken from the same part of the passenger compartment so as to be able to test all the parts of the passenger compartment with regard to all the strains of microorganisms selected.

Each sample is then prepared so as to obtain a sample of dimensions 5 cm by 5 cm for example. Likewise in the case of an air filter, it is preferably flattened, in order to obtain a sample of thickness between 2 and 3 mm, so as to guarantee the homogeneity of the sample. A surface of each sample is then treated so as to contaminate each sample with a microbiological solution in a step E2.

To do this, an amount equivalent for example to 0.1 ml is taken from one of the microbiological solutions and deposited on the treated surface of a sample of part of the passenger compartment. The microbiological solution is deposited in an equivalent manner, per dose of 10 to 20 μΙ, over the entire surface of the sample so as to cover the entire treated surface of the sample. Such manipulation is carried out on several samples from the same part of the passenger compartment with several microbiological solutions comprising a different microorganism strain. Likewise, this contamination of the samples is carried out for the same microbiological solution (that is to say comprising the same strain of microorganism) on a plurality of different samples.

For example, several samples can be taken from an air filter, from a vehicle seat and from the buckle of a seat belt. Each of these three parts of the passenger compartment would then be contaminated with each of the five aforementioned strains of microorganism. Thus, fifteen test samples 5 would be evaluated during the measurement process.

In order to be able to assess the effectiveness of a disinfection device 10, each sample is doubled. In other words, two samples of the same part of the passenger compartment contaminated with the same bacterial solution or the same fungal solution are taken so as to obtain a test sample 5 and a control sample 6 for each association of a part of a cabin and a microbiological solution. Thus this step E2 results in a plurality of test samples 5 and a plurality of contaminated control samples 6. In the example cited above of three parts of the interior contaminated with five strains of microorganisms, thirty samples would actually be necessary for the measurement process.

The disinfection device 10 to be tested is then positioned in a step E3 preferably in the upper horizontal plane of the enclosure 20 and fixed for example by means of an adhesive tape, so as to be held thereafter at above the test samples 5. Such a disinfection device 10 operates according to a diffusion cone 11 shown in FIG. 3. In other words, the disinfection device 10 is placed in the enclosure 20 so that each sample of test 5 is treated in an equivalent manner by the disinfection device 10.

The aforementioned plurality of test samples 5 is introduced in a step E4 into the enclosure 20 according to a precise positioning, so that the treatment, by the disinfection device 10, undergoes during the measurement process is identical for each test sample 5. The set of test samples 5 is for example arranged in a horizontal plane on the bottom of the enclosure 20 equidistant from the center of the enclosure 20, as shown in the Figure 3, showing a top view of the measurement system 1 (eight test samples 5 are in this example designated A, B, C, E, I, J, K, L). The enclosure 20 then has precise environmental conditions, controlled by one or more temperature and hygrometry sensor (s) 22 and an ozone sensor 23, as described above.

The plurality of control samples 6 is placed outside the enclosure 20, under the same controlled environmental conditions, preferably in the safety enclosure 21 of the PSM type.

In this example the disinfection device 10 is positioned in the enclosure 20 before positioning the test samples 5, but it goes without saying that the disinfection device 10 to be tested could be integrated into the measurement system 1 as soon as it is introduction into the safety enclosure 21 for example or even after positioning the test samples 5.

The measurement method according to the invention then comprises, after the sealed closure of the enclosure 20, a step E5 of operating the disinfection device 10 for a predefined operating time, for example for 8 hours. During this operating time, a regular measurement of the temperature, the humidity level and the ozone concentration is carried out so as to control the environmental conditions inside the enclosure 20.

During this step E5, during this same operating time of the disinfection device 10, the control samples 6 are kept, in a step E5 ′, in the safety enclosure 21 having environmental conditions similar to those of enclosure 20 to ensure that the environmental conditions are identical for the test samples 5 and the control samples 6.

After the predefined operating time, that is to say in our example after 8 hours of operation, the disinfection device 10 is stopped and the test samples 5 are extracted from the enclosure 20 and processed so measuring the concentration C ₅ of microorganisms present in the test samples 5, in a step E6. To do this, preferably, each test sample 5 is first cut into small pieces or ground in order to be placed in a sterile container comprising a liquid recovery solution, for example with 30 ml of liquid solution in which the said pieces are mixed, typically using a vortex for 2 times 2 minutes.

The liquid solution is then preferably diluted according to a dilution range of 10 ² , that is to say 1/10. In other words, for 1 ml of liquid solution, 9 ml of dilution solution is added.

According to one embodiment, 1 ml of each diluted solution is then placed on a Petri dish, cultured and incubated in a similar manner to the previous incubation, that is to say for example at 30 ° C for bacterial solutions and at 25 ° C for fungal solutions.

During this same step E6, the same treatment is carried out for all of the test samples 5 and all of the control samples 6 so as to measure the concentration C ₅ of microorganisms on each of the samples of test 5 and in parallel the concentration C ₆ of microorganisms on each of the control samples 6. Such a concentration of microorganisms is preferably determined in CFU / ml, as described above. In this example, two measurements are carried out, for example after 1 hour and after 8 hours of incubation so as to obtain two measurements of the concentration of microorganisms, making it possible to confirm the results obtained.

According to a preferred embodiment, said concentrations of microorganisms, respectively in test samples 5 and in control samples 6, are calculated by means of the following formula:

ⁿ i + ⁿ 2 3 ----- L where:

C ₅ , C ₆ are the respective concentrations of microorganisms, expressed in CFU / ml, present on said at least one test sample 5 or on said at least one control sample 6;

n, is the number of colonies present in test sample 5 or in said control sample 6;

i is a number from the box of the test sample 5 or in said control sample 6; x is the number of test samples 5 or control samples 6; v is the volume of microbiological solution deposited in the test sample 5 or in said control sample 6;

D is the level of dilution chosen for said microbiological solutions;

V _T is the respective total volume of test sample (s) 5 or of control sample (s) 6 recovered.

An efficiency rate T of the disinfection device 10 is then calculated in a step E7 as a function of the concentration C ₅ of microorganisms measured on a test sample 5 (having been subjected to the treatment of the disinfection device 10 ) and the concentration C ₆ of microorganisms measured on a control sample 6 (not having been subjected to the treatment of the disinfection device 10), the test sample 5 and the control sample 6 coming from the same part of the passenger compartment and being contaminated with the same microbiological solution.

In particular, according to one embodiment, the efficiency rate T of the disinfection device 10 is calculated as being equal to log ^ where C ₅ is the concentration of microorganisms measured on said at least one test sample 5 and C ₆ is the concentration of microorganisms measured on said at least one control sample 6.

The measurement method then makes it possible to determine the validity of the effectiveness of the disinfection device 10, that is to say to consider its effectiveness as satisfactory, for example when the efficiency rate T is greater than one predetermined threshold.

Finally, the measurement method according to the invention preferably comprises a step E8 of destruction of all of the test samples 5 and of all of the control samples 6, so as to limit any risk of contamination.

Such a measurement method makes it possible to measure the effectiveness of a disinfection device 10 intended to be mounted in a motor vehicle with regard to microorganisms, making it possible to limit the proliferation of germs or bacteria in the passenger compartment of the vehicle . Such a measurement method thus allows the use of effective disinfection devices, making it possible to limit the possible contamination of the driver or of a passenger by an undesirable germ or bacteria which can lead to diseases.

Claims (10)

Claims: 1. Method for measuring the efficiency of a disinfection device (10), intended to be mounted in a motor vehicle, said measurement method comprising: a step (E2) of contamination with a microbiological solution comprising at least one strain of microorganisms of at least one test sample (5) of a part of a passenger compartment of a vehicle and of at least one control sample (6) of said part of the passenger compartment, a step (E4) of placing said at least one test sample (5) in an enclosure (20), said enclosure (20) having predetermined environmental conditions, a step (E5) of putting the disinfection device (10) into operation for a predefined operating time, said disinfection device (10) being placed in the enclosure (20), - A step (E5 ') of storing said at least one control sample (6), outside the enclosure (20), in a safety enclosure (21), during said operating time of the predefined disinfection device (10) , said safety enclosure (21) having environmental conditions similar to the predetermined environmental conditions of the enclosure (20), - after the predefined operating time, a step (E6) of measuring the concentration (C ₅ , C ₆ ) of microorganisms present on said at least one test sample (5) and on said at least one control sample ( 6), and a step (E7) of calculating an efficiency rate (T) of the disinfection device (10) as a function of the concentration (C ₅ ) of microorganisms measured on said at least one test sample (5) and of the concentration (C ₆ ) of microorganisms measured on said at least one control sample (6), said efficiency rate (T) being equal to: log ^, where C ₅ is the concentration of microorganisms measured on said at least one test sample (5) and C ₆ is the concentration of microorganisms measured on said at least one control sample (6). 2. Method according to claim 1, in which said concentration of microorganisms (C ₅ , C ₆ ) present on said at least one test sample (5) and on said at least one control sample (6) is calculated according to the following formula ; ^η ι + ⁿ 2 5 ----- F where: C ₅ , C ₆ are the respective concentrations of microorganisms, expressed in CFU / ml, present on said at least one test sample (5) or on said at least one control sample (6); n, is the number of colonies present in the test sample (5) or in said control sample (6); i is a number in the test sample box (5) or in said control sample (6); x is the number of test samples (5) or control samples (6); v is the volume of microbiological solution deposited in the test sample (5) or in said control sample (6); D is the level of dilution chosen for said microbiological solutions; V _T is the respective total volume of test sample (s) (5) or control sample (s) (6) recovered. 3. Method according to one of the preceding claims, in which microbiological solutions have a concentration of 10 ⁴ CFU / ml and microbiological solutions have a concentration of 10 ^{6 7} CFU / ml. 4. Measuring method according to one of the preceding claims, comprising, prior to step (E2) of contamination with a microbiological solution comprising at least one strain of microorganisms of said at least one test sample (5) and of said at least one control sample (6), a step of preparing a treated surface of said at least one test sample (5) and said at least one control sample (6), said treated surface being adapted to receive said microbiological solution. 5. Measuring method according to one of the preceding claims, comprising, at the end of the test, a step (E8) of destroying said at least one test sample (5) and said at least one contaminated control sample (6). 6. Measuring method according to one of the preceding claims, in which the contamination step (E2) is carried out on a plurality of test samples (5) and a plurality of control samples (6) of a plurality parts of the passenger compartment of the vehicle. 7. Measuring method according to one of the preceding claims, wherein said at least one test sample (5) and said at least one control sample (6) comprise one or more materials, preferably a plastic material and / or a metallic material and / or a textile material. 8. Measuring method according to one of the preceding claims, in which the microorganisms included in the microbiological solution belong to one or more of the following strains: Penicillium brevicompactum; Aspergillus niger; Staphylococcus aureus; Pseudomonas aeruginosa; Escherichia coli. 9. Measuring method according to one of the preceding claims, in which the step (E4) of placing in the enclosure (20) is carried out for a plurality of test samples (5), each test sample (5) comprising a different material contaminated with a microbiological solution comprising a different microorganism strain, so as to measure the concentration (C ₅ ) of microorganisms on a plurality of different test samples (5). 10. System for measuring (1) the efficiency of a disinfection device (10), intended to be mounted in a motor vehicle, said measuring system (1) comprising: - test means (2) comprising: - an enclosure (20) comprising an opening (200) adapted to allow air circulation, said enclosure (20) being adapted to receive said disinfection device (10) and at least one test sample (5) of a part of a passenger compartment of a vehicle, said at least one test sample (5) being contaminated with a microbiological solution comprising at least one strain of microorganisms, - at least one temperature sensor (22) and one ozone sensor (23), so as to control the environmental conditions of said enclosure (20), - a safety enclosure (21), adapted to receive at least one control sample (6) from said part of the passenger compartment, said at least one control sample (6) being contaminated by said microbiological solution, - motorization means, configured to allow the disinfection device (10) to operate, - measuring means, suitable for measuring the concentration (C ₅ ) of microorganisms present on said at least one test sample (5) and the concentration (C ₆ ) of microorganisms present on said at least one control sample (6 ), and 5 - calculation means, configured to calculate an efficiency rate (T) of the disinfection device (10) as a function of the concentration (C ₅ ) of microorganisms measured on said at least one test sample (5) and the concentration (C ₆ ) of microorganisms measured on said at least one control sample (6), said calculation means being configured to compare the efficiency rate of the device 10 disinfection (10) at a predetermined threshold (S).