WO2000013715A1

WO2000013715A1 - Device and method for destroying micro-organisms in particular by extra-corporeal process

Info

Publication number: WO2000013715A1
Application number: PCT/FR1999/002094
Authority: WO
Inventors: Eric Ponce
Original assignee: Eric Ponce
Priority date: 1998-09-04
Filing date: 1999-09-02
Publication date: 2000-03-16
Also published as: EP1056479A1; AU5428299A; FR2783427A1

Abstract

The invention concerns a device for treating a liquid against micro-organisms, comprising a cell comprising at least two plates forming electrodes (2, 2') with opposite polarity arranged mutually parallel and towards the cell inside to be in contact with the circulating liquid and generate an electric field between said plates (2, 2'), and an inlet (3) for the liquid to be subjected to said field and an outlet (4) for the treated liquid.

Description

Device and method for destroying microorganisms, especially by extra-bodily route

The present invention relates to a device and a method for destroying microorganisms, in particular by the extracorporeal route.

The various microorganisms, pathogenic or not for humans, can, in part, be destroyed by biological or chemical processes, or else can be stopped by the use of ultrafilters. However, a large number of pathogenic microorganisms resist the various existing processes. In addition, it is known that viruses are capable of mutating, and that microorganisms can acquire resistance, for example to antibiotics. This is why it would be desirable to have a means of destroying microorganisms, in particular pathogens, in particular in infected humans. It would also be desirable to have a device and a method for destroying microorganisms allowing the treatment of different liquids such as water, milk, blood, etc., in order to rid them of micro- potentially pathogenic organisms they contain. The devices and methods should also be able to be used in an industrial environment as well as in a domestic or medical environment.

An advantageous device should also be of simple construction and of limited cost. A particularly advantageous device should moreover totally eliminate the micro-organisms. This is why the present invention relates to a device for treating a liquid against microorganisms, characterized in that it comprises a cell comprising at least two plates constituting electrodes of opposite polarity arranged parallel to each other and towards the 'interior of the cell to be in contact with the circulating liquiαe and to create an electric field between the said plates, constituted as well as a conduit, as well as an orifice ^for admitting the liquid to be subjected to said c ^ amp and qu outlet of the treated liquid

In the context of the present invention, the term “microorganism” means both pathogenic or non-pathogenic bacteria, as well as viruses _{, in} particular retroviruses, particularly HIV 1 and 2 The device of the invention therefore essentially comprises a cell which will be crossed by the liquid to be treated.

The liquid can be for example drinking water or not, milk, generally any drink, blood, etc. Under preferential conditions for using the device described above, the liquid to be treated is blood, in particular human blood. A device according to the present invention is very particularly suitable for the extra-corporeal treatment of blood. Thus, it is possible in particular to draw infected blood from a human organism, for example suffering from sepsis or viremia, in particular by HIV1 or 2 retroviruses, to treat it in a device according to the invention.

Essential elements of the device according to the invention are at least two plates constituting electrodes of opposite polarity. These plates can in particular be flat, corrugated, curved, or even cylindrical. These plates are arranged parallel to each other, so that, when supplied with an electric current, create a regular electric field between them.

When it is indicated that these electrodes are arranged parallel to one another, it is in fact understood that these are regularly spaced from one another. For example, if the electrodes consist of two concentric cylinders, the tangents of the same radius are considered to be parallel to each other.

Among the forms of electrodes of opposite polarity preferred, mention may in particular be made of flat plates and concentric tubes. These forms indeed allow the production of cells that are both efficient and inexpensive.

The plates constituting the electrodes are arranged inside the cell to be in contact with the circulating liquid. When it is indicated that they are located inside the cell, it is meant that the surfaces of the plates located opposite one another are in contact with the circulating liquid. In other preferred conditions for implementing the above device, the plates constituting the electrodes in fact constitute walls of the cell or part of the walls of the cell, the rest of the cell being made of insulating materials such as glass for example, in particular Pyrex glass or a plastic material. Sterilizable materials are also preferred.

The conduit formed by the cell can be, considered in the direction of circulation of the fluid, circular, but preferably rectilinear or formed of a succession of rectilinear parts. A form of the conduit comprising a succession of baffles as illustrated below is preferred.

When you want to obtain the best results, it is useful to avoid that part of the fluid stagnates or is too briefly treated in the cell duct. A shape is therefore advantageously adopted for the conduit, giving a good flow of the fluid to be treated, regular, with for example a constant section all along the conduit.

Always when you want to get the best results, it is necessary that all of the fluid is treated. Thus for a cell of very simple shape such as a rectangular parallelepiped, it is desirable that the electrodes protrude relative to the interior walls of the cell to ensure that even the sides thereof are subjected to the action of the field. A series of baffles sandwiched between two planar electrodes advantageously achieves this objective.

Advantageous shapes for a cross section of the cell duct are the rectangular and square shapes. It is thus possible to adopt a configuration in which two opposite sides constitute the electrodes and the other two are insulating.

Because the electrodes of opposite polarity are in contact with the circulating liquid, an electric field is created between said plates when they are supplied, insofar as almost all of the liquids are electrically conductive, exception of organic solvents or fully demineralized liquids However, it will be possible to treat a non-conductive liquid, by making it conductive during its passage through the cell, for example by adding mineral salts, by treating said liquid, then by removing said mineral salts from the liquid thus treated. For certain applications in which the liquid does not circulate naturally, or in cases where it is desirable to force the circulation of said liquid, it is possible to add to the device according to the invention a circulator allowing the liquid to be withdrawn and then discharged after treatment This is why the present invention also relates to a device above, characterized in that it further comprises a circulator allowing the liquid to be withdrawn and then discharged after treatment.

The flow rate in a cell can be for example from 1 to 25 ml / s, in particular from 2 to 10 ml / s, particularly from 2 to 8 ml / s, very particularly from 4 to 5 ml / s. The circulation system may be a simple pump with suitable and adjustable characteristics, so that the flow of the liquid to be treated can be modulated, as a function of the latter and of the number of cells used in parallel.

The present invention relates in particular to a device above, characterized in that it further comprises an electric current generator supplying the at least two plates constituting electrodes of opposite polarity. You can use a single pair of plates but also 2, 3 or more pairs of plates

The current generator will advantageously deliver an alternating current. Preferably, this generator will be provided with one or two settings for the following parameters, potential difference, frequency, as well as, if desired, means for measuring, recording and / or viewing these parameters or others such as the intensity.

A device according to the invention can advantageously be added to or inserted into an existing device for extra-corporeal circulation. It can also be implanted. b

The dimensional characteristics of the devices according to the invention may vary depending on the use which is requested of them. Indicative dimensions will be given below, for a particularly interesting application, namely the treatment of human blood by the extracorporeal route. In such a case, two electrodes of opposite polarity will preferably be spaced from one another by 1 to 5 mm, in particular from 2 to 4 mm, and very particularly from 2 to 3 mm.

In order to obtain the desired efficiency, it is necessary for the electrodes to cover the cell duct over a certain length, so that the liquid is treated for a certain time sufficient for the destruction of the microorganisms. This is why, under preferential conditions of embodiment, the duct will have a length of 50 to 400 mm in the direction of circulation of the liquid, in particular from 80 to 300 mm, and very particularly from 100 to 250 mm. In view of maximum compactness, it is possible to adopt for the conduit a form of multiple contiguous baffles, as will be seen below.

The section of the duct essentially determines the flow rate of the treated liquid and the regularity of circulation of the fluid. Thus, its section can range from 2 to 40 mm ² and more, preferably from 3 to 20 mm ² , in particular from 3 to 10 mm ² and very particularly from 4 to 8 mm ² . It is obvious to those skilled in the art that in the case of blood, it is necessary to best preserve all of the blood cells, in particular of the lymphocyte line. By a few tests, a person skilled in the art can adjust the electrical parameters according to the desired effect, taking into account the benefit for the patient, but for other applications such as sterilization of water where no no such brakes, you can use a much larger field and work at similarly high flow rates.

In some cases, such as blood, it is desirable to avoid excessive heating of the treated fluid. It is possible, if desired, to regulate the temperature of the cell according to well-known techniques such as the addition of radiators, ventilation, circulation of coolant to the heater, or a combination thereof. The present application also relates to a device above which comprises a device for regulating the temperature of the cell.

The present application also relates to a device above which is a device for extra-corporeal blood treatment. The devices which are the subject of the present invention have very advantageous properties. They are endowed in particular with remarkable properties for destroying microorganisms, both pathogenic bacteria or not, and viruses, in particular retroviruses, particularly VI H 1 and 2.

These properties are illustrated below in the experimental part. They justify the use of the devices described above, to reduce or cancel the amount of microorganisms in an infected liquid.

This is why the invention also relates to a process for destroying microorganisms present in a liquid, characterized in that said liquid is circulated through a device above, at a rate allowing the destruction of said microorganisms and by applying a current between the electrodes.

The flow rate allowing the destruction of said microorganisms can be easily determined by a person skilled in the art from a few routine experiments, consisting in taking a sample at the outlet of the cell of the invention and in carrying out a counting. microorganisms. It is also possible, if desired, to count them before processing the liquid.

By way of illustration, for the destruction of microorganisms present in the blood, if a cell is used comprising two rectangular electrodes 50 to 80 mm long by 20 mm wide, and the electrodes being spaced one of the 'other 2 to 3 mm, we will use a blood flow rate of 4 to 5 ml per second through the device according to the invention. This flow is however to be compared with the data indicated below concerning the current used for the treatment. In other preferential conditions of implementation for the destruction of microorganisms present in the blood, if a cell comprising two square electrodes 40 mm side, the electrodes being spaced from each other by 2 mm and encompassing a series of 4 baffles constituting a conduit approximately 250 mm long for a cross section of 6 mm ² approximately, a blood circulation rate of 4 to 5 ml per second will be used through the device according to the invention

The voltage used in the process can be continuous, but it is preferably alternative

This voltage can range, depending on the liquid to be treated, for example from 1 to 100 volts, preferably from 1 to 50 volts, in particular from 1 to 20 volts, particularly from 2 to 17 volts In the case where it is desired to treat water to make it drinkable, we can use high voltages, while for the treatment of blood, we will advantageously use a voltage below 20 volts, preferably from 2 to 17 volts, and very particularly from 15 to 17 volts

The intensity of the circulating current is obviously related, on the one hand, to the potential difference between the electrodes, and the conductivity of the liquid to be treated. As an indication, if one is treating human blood, the intensity of the current will advantageously be established at less than 2 amperes, preferably between 0.5 and 2 amperes, very particularly between 0.5 and 1.5 amperes With regard to the frequency of the current (in this alternating case) supplying the electrodes, this will preferably be less than 1 MHz, in particular between 400 Hz and 1 MHz, and very particularly for the treatment of bacteria in human blood, between 400 Hz and 1 kHz and for the treatment of viruses in the human blood, between 1 Khz and 500 Khz

The present application finally relates to a process for destroying microorganisms present in a liquid, characterized in that it is an extra-bodily treatment of blood

The preferential conditions for implementing the devices described above also apply to the other objects of the invention covered by the present invention. Figure 1 shows a device for treating a liquid against microorganisms, formed of a parailélépipédique cell, seen from above.

Figure 2 is a sectional view along AA 'of Figure 1

FIG. 3 represents a device of the invention seen in section, comprising two concentric cylindrical electrodes.

Figure 4 is a top view in section of a device for treating a liquid against microorganisms, formed of a cell consisting of a series of baffles sandwiched between two square electrodes. Figure 5 is a sectional view along BB 'of Figure 4

FIG. 6, a variant of FIG. 4, is a top view in section of a device for treating a liquid against microorganisms, formed of a cell made up of a series of baffles whose walls constitute the electrodes. Figure 7 is a sectional view along CC of Figure 6

The following examples illustrate the present application

In Figure 1, there is a cell 1 referred to here as a whole comprising two plates 2, 2 ', only the top one being visible in this figure. Each of these two plates 2, 2 'constitutes electrodes of opposite polarity and can be connected to an electric current generator by cords, which are not shown here. On the left, there is an inlet for the liquid 3 and on the right an outlet for the treated liquid 4 In the case where the liquid does not flow naturally, a circulator (or pump). As can be seen more clearly in FIG. 2, in this embodiment of the device according to the invention, the plates 2, 2 ′ are parallel to each other and in fact constitute two opposite walls of the cell The other walls

5 and 6 HERE were made here out of glass All of these walls constitute the chamber 7 which is crossed by the liquid to be treated FIG. 3 represents another embodiment of the invention seen in section. In general, the cell is here formed by two tubes concentric, part of the internal and external walls 2, 2 'of which constitute the electrodes. Chamber 7 here consists of the gap between the two concentric tubes. The rest of the cell was made of plastic.

According to the design of Figure 4, the electrodes shown in dotted lines are two in number, with a dimension of 40 x 40 mm and spaced apart from them by 2 mm; they constitute opposite internal walls of the cell in contact with the liquid to be treated. Partitions 8 made of resin (but it is also possible, for example, to use porcelain, ceramic, glass, etc. as insulating material), staggered between these walls form a duct 7 (equivalent to the chamber in FIG. 1 ) of continuous circulation in a series of baffles, of homogeneous section with a width of 3 mm, bringing the liquid from the inlet to the outlet of the cell after crossing the successive baffles.

In FIG. 5, one can observe the electrodes 2, 2 ′ encompassing the conduit 7 winding between the walls 8. The electrodes 2, 2 ′ are connected to a generator not shown in FIG. 4. The arrows in the conduits represent the direction electric current.

According to the variant of FIG. 6, the liquid to be treated always circulates in parallel and adjacent conduits in baffles, but this time the electrodes 2, 2 ′ constitute the partitions, the other walls of the cell being made of insulating material. The electric current this time flows through the liquid from the partitions and no longer from the walls of the cell. A current generator is installed between points A and B.

In FIG. 7, one can observe the electrodes 2, 2 ′ constituting the partitions. If the shape of the cell is externally in the case of FIGS. 6 and 7 the same as that of FIGS. 4 and 5, on the other hand the electrodes are installed perpendicular to those of said FIGS. 4 and 5.

The cells described above can be used in any orientation, vertical, horizontal, oblique. Example 1. Human blood was treated using the device illustrated in Figure 4 connected to an alternating current generator with frequency and voltage settings.

The device was made of plastic resin for the insulating parts, and of stainless steel for the electrodes.

Human blood was treated at a rate of 4 ml per second. The Echerichia coli count in the blood before treatment was 1 colony / 4 ml. Analysis of the blood taken at the outlet of the device of the invention, after treatment, showed a total absence of viable Echerichia coli. The electrical parameters used during blood processing were as follows: voltage 13 volts, frequencies: 400 Hz and 1 Khz.

We also checked the effect of treatment on other blood parameters: classic NFS. These were not affected by the treatment.

Example 2:

Physiological saline was treated, to which Staphylococcus epidermidis was added at the concentration of 1 colony / 4 ml. This liquid was treated at a flow rate of 5 ml per second using a device illustrated in Figure 4, of identical dimensions. The electrical parameters used are as follows: alternating voltage of 20 volts, frequency of 1 Khz and 10 Khz. After treatment, the saline was free from the above viable microorganisms.

Claims

1 A device for treating blood against microorganisms, characterized in that it comprises a cell constituting a conduit comprising at least two plates constituting electrodes (2, 2 ') of opposite polarity arranged parallel to each other and towards the inside the cell to be in contact with the circulating liquid and to create an electric field between said plates (2, 2 '), as well as an inlet orifice (3) for the liquid to be subjected to said field and an orifice outlet (4) of the treated liquid, said plates being supplied by an alternating electric current generator, the geometry of the electrodes being such that even the sides of the cell are subjected to the action of the electric field created by the current

2. A device for treating a liquid according to claim 1, characterized in that it further comprises a circulator allowing the liquid to be withdrawn and then discharged after treatment

3 A device for treating a liquid according to one of claims 1 and 2, characterized in that two electrodes (2, 2 ') of opposite polarity are spaced from one another by 1 to 5 mm

4 A device for treating a liquid according to one of claims 1 to 3 characterized in that two electrodes (2, 2 ') of opposite polarity have a length of 20 to 200 mm in the direction of circulation of the liquid

5 A device for treating a liquid according to one of claims 1 to 4 characterized in that two electrodes (2, 2 ') of opposite polarity are flat plates or concentric tubes

6 A device for treating a liquid according to one of claims 1 to 5 characterized in that the cell forms a conduit (7) comprising a succession of baffles

7 A method of destroying microorganisms present in the blood, characterized in that the blood to be treated is circulated through a device according to one of claims 1 to 6, at a rate allowing the destruction of said microorganisms and by applying an alternating current between the electrodes (2, 2 ').

8. A method of destroying microorganisms according to claim 7, characterized in that the voltage applied between two electrodes (2, 2 ') arranged parallel to each other is from 1 to 20 volts.

9. A method of destroying microorganisms according to one of claims 6 to 8, characterized in that the frequency of the applied current is 400 Hz to 1 MHz.

10. A method of destroying microorganisms according to one of claims 6 to 9 characterized in that the current delivered has an intensity of

0.5 to 2 A.