EP3991588A1

EP3991588A1 - Face mask system using electrical current for reducing or preventing microbial growth in and/or on a face mask

Info

Publication number: EP3991588A1
Application number: EP20204963.1A
Authority: EP
Inventors: Thomas Andersson
Original assignee: Epff Electrical Pipe For Fluid Transport AB
Current assignee: Epff Electrical Pipe For Fluid Transport AB
Priority date: 2020-10-30
Filing date: 2020-10-30
Publication date: 2022-05-04

Abstract

A face mask system (1) comprising: a face mask (10) comprising a piece of face mask material (12) configured to cover the mouth and nose of a user, the face mask material being electrically conductive, and at least in part air-permeable, and being provided with first and second spaced apart electrodes (30, 32), and an electric power source (50) configured to generate an electric current in the face mask material between the first and second electrodes, is provided. A method of producing the face mask system, as well as a method of preventing or reducing microbial growth in or on a face mask material of a face mask and the use of an electrical current to prevent or reduce microbial growth in or on a face mask material of a face mask, are also provided.

Description

Technical field

The technology proposed herein relates generally to the field of face masks and methods of reducing or preventing microbial growth in and/or on such face masks. More particularly, the technology proposed herein relates to a face mask system using electrical current for reducing or preventing microbial growth in and/or on a facemask, as well as a method of preventing microbial growth in and/or on a face mask by running an electrical current through the face mask material.

Background

With the rise of the COVID-19 pandemic, a worldwide need and interest in face masks have arisen as one tool in preventing the virus infection from spreading. The use of face masks has not only intensified in hospitals and other care settings, also the general public has in many countries been urged or required to wear face masks in public spaces.
In addition to spreading into new sectors of the population, the time each face mask is used has also increased in many cases. It is thus not uncommon that, due to a need or desire to reduce the consumption of face masks, face masks are used for longer periods at a time.
However, with such increased duration of use of a face mask, the effectiveness and safety of the face mask may be diminished. The longer duration of use may in particular cause significant microbiological growth in and/or on the face mask, i.e. in and/or on the material of the face mask.
The problem of microbiological growth can be further aggravated by the increased amount of moisture, from the person wearing the face mask, that becomes trapped in the material of the face mask during use. There is therefore a risk that microbial growth in the face mask, either directly during use, or indirectly after use when the face mask is handled, leads to infection of the person using or handling the face mask.
Bacteria may for example accumulate on or in the face mask material, multiply in the warmth and damp caused by the user's respiration through the face mask materials, and then infect the user of the face mask.
In addition, microbial growth can result in clogging of the face mask material, e.g. when the growth results in a biofilm. Such clogging will reduce the air transport through the face mask material and thereby lead to discomfort and a need for earlier replacement of the face mask.
Thus, there is a need for a face mask which reduces or prevents microbiological growth on and/or in the face mask

Objects of the technology proposed herein

It is accordingly a first object of the technology proposed herein to provide a face mask system reducing or preventing microbial growth in and/or on a facemask.
It is a further object of the technology proposed herein to provide a method of preventing microbial growth in and/or on a face mask.
It is yet a further object of the technology proposed herein to provide a method of manufacturing a face mask reducing or preventing microbial growth therein and/or thereon.

Summary

At least one of the abovementioned objects, or at least one of the further objects which will become evident from the below description, is according to a first aspect of the technology proposed herein obtained by
a face mask system comprising:

a face mask comprising a piece of face mask material configured to cover the mouth and nose of a user, the face mask material being electrically conductive, and at least in part air-permeable, and being provided with first and second spaced apart electrodes, and
an electric power source configured to generate an electric current in the face mask material between the first and second electrodes.

By the electric current running through the face mask material microbial growth is reduced and/or prevented. Microbiological growth is here understood to encompass growth of microbial cells such as growth and/or reproduction of bacterial cells or growth of yeast cells. Additionally, reducing or preventing microbiological growth may encompass reducing the viability of microbial cells and/or killing microbial cells. The microbial growth may be reduced by the electric current inhibiting the growth as such, or by the electric current inhibiting cell adhesion on the face mask material.
Additionally, microbial growth may be reduced and/or prevented by an electric field derived from the voltage potential difference between the first and second electrodes required to generate the current in the face mask material between the first and second electrodes.
Further additionally, the electric current and/or the electric field may capture or arrest viruses and particles or droplets carrying viruses. The electric current and/or the electric field may additionally damage or otherwise reduce the infectiousness of viruses and particles or droplets carrying viruses.
The piece of face mask material is configured to cover the mouth and nose of a user and the dimensions of the piece of face mask material may thus vary depending on the dimensions of the face of the user and the distance and between, and dimensions of, the mouth and nose of the user. Typically, the piece of face mask material may thus have a width (i.e. in the direction between the mouth and nose of the user) of from about 5 cm to about 30 cm, such as from about 8 cm to about 16 cm. The height of the face mask material may be from about 8 cm to about 16 cm.
The piece of face mask material may generally be configured to have first and second side edges, which in use generally run vertically along the user's cheeks, as well as a top edge in use running generally horizontally between the eyes and nose of the user, and a bottom edge in use running below the chin of the user.
The user is preferably a human, such as a man, woman, child, or baby, however the user could be another mammal, such as a dog or horse, provided as long as the piece of face mask material is configured to cover the mouth and nose of the mammal.
Preferably the face mask material is configured such that air for inhalation, and preferably also exhaled air, from the user's mouth and/or nose, substantially only passes through the face mask material from and to the environment or atmosphere surrounding the user.
In order to facilitate easier inhalation or exhalation, a one-way valve may be provided in the face mask material to allow air for inhalation, or exhaled air, to pass through the valve instead of through the face mask material.
Preferably the whole of the face mask material is air permeable, however, the face mask material may alternatively be configured with air-permeable and air-impermeable zones as long as the face mask material is at least in part air-permeable.
The face mask material is preferably a filtering face mask material. A filtering face mask material filters the air passing through the material and thereby removes at least some particles from the air. The face mask material may be a mechanical filtering material or an electrostatic filtering material.
The face mask material should be configured at least for hindering at least some droplets or particles in ambient air from being inhaled though the face mask material and thereby entering the mouth and/or nose of the user. Preferably the face mask material is configured for providing a filtration, as determined by the EN 149 standard, of at least FFP1 (corresponding to filtering out at least 80% of airborne particles at 95 L/min air flow) , preferably FFP2 (corresponding to filtering out at least 94% of airborne particles at 95 L/min air flow), more preferably FFP3 (corresponding to filtering out at least 99% of airborne particles at 95 L/min air flow). Alternatively, the face mask material is configured for providing a filtration of at least 95% of airborne particles (also known as U.S. National Institute for Occupational Safety and Health (NIOSH) N95 classification).
The face mask material and the face mask may thus protect a user of the face mask from inhaling one or more of particles, droplets, aerosols, bacteria, viruses, gases, etc., preferably one or more of particles, droplets, aerosols, bacteria, and viruses. Alternatively, or additionally, the face mask material and the face mask may thus protect a user of the face mask from inhaling gases.
The face mask material and the face mask may further prevent or reduce one or more of particles, droplets, aerosols, bacteria, viruses, etc., preferably particles, droplets, aerosols, bacteria, and viruses, from being spread to the environment surrounding the user as the user exhales. Alternatively, or additionally, the face mask material and the face mask may thus prevent or reduce gases being spread to the environment surrounding the user as the user exhales.
The face mask material may be a single layer, or may comprise multiple layers including an inner liner layer providing comfort to the user, a filter or filtering layer providing a filtering of air passing through the face mask material, and optionally an outer layer protecting the filter layer. Suitable face mask materials may comprise fabrics of cotton, silk, polyester, as well as non-woven fabrics of natural or synthetic fibers such a polyethylene, polypropylene, polyamide, or polyester.
In addition to woven and non-woven fabrics, the face mask material may further comprise a membrane made of polyethylene, polypropylene, polyamide, or polyester, in which membrane pores have been provided for rendering the material air-permeable at least in part.
The face mask material may be electrically conductive by being at least partly made of or comprising electrically conductive materials (such as by being made of electrically conductive fibers, including fibers to which electrically conductive particle or fibers have been added), or by being made of materials to which electrically conductive particles or fibers have been added. Such particles or fibers include carbon-black, the nanotubes, graphene, and/or metal fibers or filaments for providing the electrical conductivity. Additionally, the face mask material may be made of or comprise materials such as fibers, fully or partially coated by electrically conductive materials.
Where the face mask material includes a filter layer, an inner liner layer and/or an outer layer, at least the filter layer should be electrically conductive. The inner liner layer and the outer layer may be non-conductive.
The face mask material may have a lower conductivity than the first and second electrodes.
The first and second electrodes may be configured as separate patches or contacts fastened to the face mask material. Alternatively, the electrodes may be formed integral with the face mask material, such as for example by forming the electrodes as part of the printed or coated electrically conductive material. Further alternatively, the first and second electrodes may be releasably attachable to the face mask material, such as for example when the first and second electrodes are configured as first and second clamps.
The electrodes may be formed as point electrodes or may alternatively be formed as linear or patch electrodes. The first and second electrodes may further be formed as interdigitated electrodes which preferably cover at least a majority of the surface area or the face mask material. This provides a uniform flow of current between the electrodes.
The spacing between the electrodes is preferably at least 50, preferably at least 75%, more preferably at least 90% of the largest dimension of the face mask. The larger the separation, the more of the face mask material will be affected by the current between the electrodes, thus providing a more efficient prevention or reduction of microbial growth.
The electrical power source may comprise a battery, a power regulation unit, and a switch for turning on, respectively off, the electric power source. An indicator may be provided to indicate whether the electric power source is on or off, and preferably further for indicate at least one of a status of the battery, a status of the power regulation unit, a status of the circuit formed by the electric power source, and a status of the face mask material. The indicator may thus be configured to indicate the voltage or power reserve of the battery, whether a current runs between the first and second electrodes and whether the circuit is closed, indicate a measure of the output of the power regulation unit, as well as indicating, based on measuring the resistance, inductance and or capacitance between the first and second electrodes, the status of the face mask material between the electrodes. Such status may be determined by comparing the measured resistance, inductance and or capacitance with earlier stored, or pre-set, resistance, inductance and or capacitance measurements to detect a difference, and from comparing the size of the difference with a tolerance threshold, determine and indicate when the face mask, due to use and accumulation of particles and/or moisture, needs to be replaced or cleaned.
The battery is preferably a rechargeable battery, and the electric power source may thus comprise a charging port for receiving electric energy for charging the battery.
The electric power source may be provided separate from the face mask. The electric power source may thus for example be provided in a pocket in the user's clothing or provided in a bag or strap worn by the user. The electric power source may further be provided around the neck of the user and/or attached to, or integrated in, the structure holding the face mask in place during use. In each case the electric power source is configured with suitable electric leads for delivering current to the first and second electrodes.
The electric power source may inter alia comprise contacts for contacting the electrodes. The contacts may further, when the electric power source is provided on a holder structure as described below, serve to attach the face mask to the holder structure. The contacts may therefore be formed as clamps allowing the face mask material to be clamped and attached to the holder structure.
The electric current runs between the first and second electrodes, and thereby runs in the face mask material. The extent of the face mask material that is run through by the current varies depending on the nature of the face mask material and the configuration, size, and placement of the first and second electrodes. Accordingly, the electric current should run through at least part of the face mask material.
The face mask system may further comprise a holder structure holding the face mask in place during use. The holder structure may be formed integral with the face mask or may be separate from the face mask. The holder structure may include one or more ribbons, strings or straps attached to the face mask and allowing the face mask to be fastened to at least a port of the user's head. Such holder structures include ear loops allowing the face mask to be fastened by a ribbon, string, or strap running around the user's ears. Other alternatives include ribbons, strings, or straps running from the side edges of the face mask around the neck or back of the user's head. Additionally, the holder structure may include rigid or semi-rigid material formed to attach to the user's ears, and/or formed as a band extending from one ear to the other along the back side of the user's head. The face mask may be releasably attachable to the holder structure for allowing the face mask to be replaced and disposed of while the holder structure is retained and re-used.
In a preferred embodiment of the face mask system the face mask material comprises a non-woven material. This is advantageous in that non-woven material may be cheaply produced and adapted to provide a range of different filtration efficiencies and air permeabilities. Further, a non-woven material easily incorporates fibers made of conductive materials or the addition of particles of conductive material into the production of the non-woven material.
In a preferred embodiment of the face mask system the first and second electrodes are attached to the face mask material, such by being printed on or bonded to the face mask material. This is advantageous in that it allows the face mask material to be easily configured, i.e. formed, for covering the mouth and nose of the user, while the electrodes are easily attached after the forming. The electrodes may thus be formed by printing on the face mask material using a conductive ink. Alternatively, the electrodes, which may be formed from metal such as metal foil, are shaped, and bonded to the face mask material using a conductive adhesive.
Further, when the face mask material comprises a filter layer and an inner liner layer and/or outer layer, the electrodes may be sandwiched between the filter layer and the inner liner layer or outer layer.
In a preferred embodiment of the face mask system the first and second electrodes are positioned such that the electric current runs along the width and/or height dimension of the face mask material, preferably wherein the first and second electrodes are positioned at opposite edges of the face mask material. This is advantageous in that it allows the current to pass through a large area of the face mask material, to thereby prevent or reduce microbial growth in that large, while at the same time providing a simple construction of the face mask. The width and the height dimensions, in use of the face mask, correspond to the horizontal dimension from cheek to cheek, and the vertical dimension, from mouth to nose, respectively. Accordingly, the first and second electrodes are preferably positioned at the left and right edges of the face mask material as this position keep the electrodes away from the mouse and nose area.
Alternatively, the electrodes are positioned at the top and bottom of the face mask, i.e. closest to the user's nose and chin when the face mask is worn.
In a preferred embodiment of the face mask system the first and second electrodes are positioned such that the electric current runs in the thickness dimension of the face mask material, preferably wherein the first electrode is formed as a mesh or grid provided on a first side of the face mask material and the second electrode is formed as a mesh or grid provided on an opposite second side of the face mask material. This is advantageous in that it ensures a very uniform current throughout the face mask material. The first side of the face mask material may be the side that is closest to the face of the user when the face mask is worn, and the second side may be the side of the face mask facing away from the user when the mask is worn.
The first and second electrodes may be formed as patches, points, or electrical leads, but is preferably formed as meshes or grids for a uniform distribution of current throughout the face mask material. The mesh or grid may be a deposited or printed directly onto the face mask material, or may alternatively be separately formed, i.e. as a net fabric in which electrically conducting fibers are knitted, knotted, looped or twisted at intersections, or by arranging electrically conducting fibers or threads into a grid shape and fusing them together at the intersections. Alternatively, an electrically conducting mesh may be formed by providing a plurality of apertures in a sheet of conductive material.
Where the face mask material comprises a filter layer and an inner liner layer and/or outer layer, the first and second electrodes are preferably attached on the first and second sides of the filter layer with the inner liner layer and/or outer layer covering the first and second electrodes.
The electrical current may be a DC current.
The power source may additionally or alternatively be configured for changing the polarity between the first electrode and the second electrode. The changing of the polarity may be random in time or follow a predetermined schedule. The polarity may be changed at least once every 12 hours, or at least once every hour. There are indications that the change of polarity will further prevent or reduce microbiological growth.
In a preferred embodiment of the face mask system the electric current is 10 mA or lower, preferably between 0.1 mA and 1 mA, more preferably between 0.4 mA and 0.8 mA. These currents have been shown to prevent or reduce microbial growth.
In a preferred embodiment of the face mask system the electric current is an alternating current having a frequency below 100 Hz, preferably below 10 Hz, more preferably below 1 Hz. An alternating current has been shown to be effective in reducing or preventing microbial growth. The alternating current may have a square wave form. This means that the peak voltage is approximately equal to the root-mean square voltage. It has been found that this type of current inhibits microbiological growth.
Alternatively, the alternating current has a frequency between 1 kHz and 5 kHz, or between 1 kHz and 2 kHz
In a preferred embodiment of the face mask system the electric current is an alternating current having a peak voltage below 80 V, such as below 50 V, preferably between 10 V and 50 V, more preferably between 20 V and 50 V, such as between 30 V and 50 V. Here the voltage refers to the voltage between the first and second electrodes. Alternatively to the abovementioned voltages at which the direct current and the alternating current are supplied, the electric current may be supplied at a voltage between the first and second electrodes that is in the range 1 V and 10 V, 2 V and 8 V, or 3 V and 6. It is contemplated that these voltages will have a sufficient effect on the microbiological growth.
The power source may be further configured for supplying the electric current as a pulsed electric current, both for direct current and alternating current. The pulses of the electric current may have a pulse length in the range 1 ms and 500 ms, 1 ms and 100 ms, or 1 ms and 10 ms. The pulses may have combined pulse length over a period of time that is equal to or less than 50% of the length of the period. It has been found that the microbiological growth is reduced also for pulsed electric currents. The pulsing has the effect of reduced power consumptions, which contributes to a longer battery life when the electric power source comprises a battery.
The power source may be further configured for changing the polarity between the first and second electrode between pulses. There are indications that this will further prevent or reduce microbiological growth.
Additionally, the electric current may be supplied at a voltage between the first and second electrodes that is in the range 0.5 kV and 6 kV, 0.5 kV and 4 kV, 0.5 kV and 2 kV, or 0.5 kV and 1 kV. Additionally, or alternatively, the electric current may be pulsed.
The power source may be configured for varying the electric current and/or the electric potential randomly or according to predetermined values. The varying of the electric current and/or the electric potential may correspond to relative changes in the range 0.01 to 100, or 0.1 to 10.
Additionally, the power source may be configured for varying the electric current and/or the electric potential randomly in time or according to predetermined schedule. The varying may result in a change of the electric current and/or the electric potential at least once every 12 hours, or at least once every hour. It is contemplated that the varying of these parameters will disturb the microbiological growth.
The resistance of the face mask material between the first electrode and the second electrode may be in the range of 8 kΩ to 800 kΩ, such as 8 kΩ to 100 kΩ, such as 8 kΩ to 40 kΩ.
In a preferred embodiment of the face mask system the electric power source is positioned on or in the face mask. This is advantageous in that it makes the face mask system compact to wear.
The electric power source may for example be provided in a pouch or pocket formed in the face mask material or attached directly to the face mask material. The electric power source may further be laminated between layer of the face mask material. The electric power source may be configured to generate an electric current in said face mask material between said first and second contact electrodes by comprising electric leads connecting the electric power source to the electrodes. The electrical leads may be separate from the face mask material or may alternatively be provided laminated into or onto the face mask material or provided as printed or coated circuit leads on or in the face mask material.
In a preferred embodiment of the face mask system the system further comprises a holder structure configured for holding the face mask material in place to cover the mouth and nose of a user during use, wherein the holder structure comprises a generally U-shaped rigid or semi-rigid body having a first end connector configured to be attached to a first edge of the face mask and a second end connector configured to be attached to an opposite second edge of the face mask, the body being configured to extend from the first end connector along the back of the user's head to the second end connector, preferably between the user's outer ears and skull, when used. This is advantageous in that it makes the face mask more comfortable to wear. Further, by having the face mask releasably attachable to the holder structure, the face mask can be replaced and disposed of while the holder structure is retained and re-used.
The generally U-shaped rigid or semi-rigid body is preferably made from a plastics material such as polypropylene or polyamide.
The first and second end connectors may comprise any type of connector suitable for attaching the edges of the face mask to the holder structure. Non-limiting examples include clamps, plug and socket connectors, snap fit fasteners, hook-and-loop connections, hook-and-hole/loop connectors.
The end connectors may be configured to attach directly to the first and second edges of the face mask, i.e. the face mask material, or the face mask material may be provided with an integral attachment tab or attachment structure, such as one of the two members in the above mentioned connections (plug or socket, stud or socket, hook or loop, etc.).
The body may comprise a back portion resting against the back of the user's head in use, first and second side portions resting against the sides of the user's head when in use, as well as first and second ear loop portions each extending from the respective side portion up and around the user's ears (and hence between the user's outer ears and skull) when in use and terminating in first and second end portions at which the first and second end connectors are provided.
Preferably the electric power source is integrated in, or attached to, the holder structure, the first and second end connectors are electrically connected to the electric power source, and the first and second electrodes are configured to be electrically connected to the first and second end connectors when the end connectors are attached to the first and second edges of the face mask. This is advantageous in that it combines the two functions of attaching the face mask to the holder structure and providing the current to the face mask material in the end connectors. Further, where the end connectors are configured as clamps, these clamps can, by engaging the edges of the face mask, further serve as the first and second spaced apart electrodes and thereby further reduce the manufacturing costs and complexity of the face mask.
Electrical leads may be provided in the body for delivering current from the electric power source to the first and second end connectors. It is further contemplated that the body may be formed in two electrically separated parts, wherein the two part of the body itself are used to conduct the current to the first and second end connectors.
In some embodiments of the face mask system the electric power source and the electrodes are configured for contactless transfer of electric power from the electric power source to the electrodes. This may be achieved by configuring the electric power source with a sender coil for converting a alternating current into an alternating magnetic field and by providing the electrodes with a receiver coil for converting the magnetic field to a current between the first and second electrodes. The receiver coil may be formed of electric leads applied, printed, or coated onto or into the face mask material.
At least one of the abovementioned objects, or at least one of the further objects which will become evident from the below description, is according to a second aspect of the technology proposed herein further obtained by a method of producing a face mask system according to the first aspect of the technology proposed herein, comprising the steps of:

i. providing an electrically conductive, and at least in part air-permeable, face mask material and configuring the face mask material so as to be capable of covering the mouth and nose of a user when used, thereby obtaining a face mask,
ii. providing first and second spaced apart electrodes on or in the face mask material, and
iii. providing an electric power source (50) configured to generate an electric current in the face mask material between the first and second electrodes.

The face mask material may be configured for example by cutting, punching, or otherwise forming the face mask material so as to be capable of covering the mouth and nose of a user when used. The face mask material may further be provided with for example a bendable stiffening element at the top edge, provided with rubber lining along the edges to further reduce leakage of air between the edges of the mask and the user's face during use, etc.
At least one of the abovementioned objects, or at least one of the further objects which will become evident from the below description, is according to a third aspect of the technology proposed herein further obtained by a method of preventing or reducing microbial growth in or on a face mask material of a face mask, the method comprising the steps of:

i. providing a face mask system according to first aspect of the technology proposed herein,
ii. actuating the electric power source so as to generate an electric current in the face mask material between the first and second electrodes.

The electric current prevents or reduces microbial growth in or on the face mask material. The terms prevent is to be understood as encompassing the term inhibit. The reduction of microbial growth may be determined by measuring the mass of microbial cells in or on the face mask material, and/or by measuring the number of microbial colonies found in or on the face mask material, or as measured when culturing a sample of the face mask material in a culture medium. Further, reduction of microbial growth may be determined by determining the viability or reproduction of microbial cells in or on the face mask material.
At least one of the abovementioned objects, or at least one of the further objects which will become evident from the below description, is according to a fourth aspect of the technology proposed herein further obtained by the use of an electric current, generated by an electric power source and running between first and second spaced apart electrodes provided in or on an electrically conductive and at least in part air-permeable face mask material of a face mask, for preventing or reducing microbial growth in the face mask material.

Brief description of the drawings and detailed description

A more complete understanding of the abovementioned and other features and advantages of the technology proposed herein will be apparent from the following detailed description of preferred embodiments in conjunction with the appended drawings, wherein:

Fig. 1A shows a first embodiment of a face mask system.
Fig. 1B shows a second embodiment of a face mask system.
Figs. 2A, 2B, 2C, 2D and 2E show different embodiments of the first and second electrodes.
Fig. 3A shows a third embodiment of a face mask system.
Fig 3B, 3C and 3D show different embodiments of the first and second end connectors.

In the figures and the description, the same reference numeral is used to refer to the same feature. One or more added to a reference numeral indicates that the feature so referenced has a similar function, structure or significance as the feature carrying the reference numeral without the one or more ', however not being identical with this feature.
Fig. 1A shows a face mask system 1 comprising a face mask 10 comprising a piece of face mask material 12 configured to cover the mouth and nose of a user. The face mask material 12 may, as shown in fig. 1, be generally rectangularly shaped, having opposing first and second edges 14 and 16, as well as opposing top and bottom edges 18 and 20. Other shapes, such as polygonal shapes or round shapes are also possible, it being recognized that the face mask material 12 generally is shaped so as to have opposing side edges or areas, corresponding to the first and second edges 14 and 16 and in use covering at least a part of the user's cheeks, as well as a top edge or side, corresponding to top edge 18 and in use at least partially covering the nose of the user, as well as a bottom edge or side, corresponding to the bottom edge 20 and in use covering at least part of the user's chin. The face mask material 12 is preferably a non-woven material.
Advantageous, as shown in fig. 1A, the face mask 10 is carried by a user by means of first and second loops 22 and 24 of a suitable, preferably elastic, string or ribbon material. Typically, the first and second loops 22 and 24 form ear loops, each passing behind and around a corresponding ear of the user for holding the face mask 10 in position so that the face mask material 12 covers the mouth and nose of the user.
Alternatively, the loops 22 and 24 may be arranged so that the first loop 22 extends from an upper part of the first edge 14 to and upper part of the second edge 16, i.e. around the back of the head of the user, and the second loop 24 extends from a lower part or the first edge 14 to a lower part of the second edge 16, i.e. around the back of the neck of the user.
Accordingly, as the user of the face mask 10 inhales and exhales, air for inhalation, and preferably also exhaled air, substantially only passes through the face mask material 12, which at least in part is air-permeable to allow the air to pass through while filtering and stopping or reducing one or more of particles, droplets, aerosols, bacteria, viruses, gases, etc. are thus by the face mask material 12 from being inhaled by the user from the surrounding environment, and preferably also from being exhaled by the user to the surrounding environment.
Preferably, as shown in fig. 1A, the face mask includes a bendable stiffening element 26, e.g. in the form of metal wire or ribbon attached to, or included in, the face mask material 12 at or adjacent to the top 18. The bendable stiffening element 26, by being bendable by the user, allows the top edge 18 to be bent in order to provide a better seal between the top edge 18 and the user's face in the nose area of the user's face.
The face mask material 12 is further electrically conductive and provided with first and second spaced apart electrodes 30 and 32. These electrodes may each be provided, as in fig. 1, adjacent a corresponding edge of the first and second edges 14 and 16, or alternatively, adjacent the top and bottom edges 18 and 20, respectively. Other placements are possible as long as the electrodes are spaced apart so that an electric current can run in the face mask material between the first and second electrodes. In fig. 1A this electric current is schematically illustrated using broken arrows extending from the vicinity of the first electrode 30 to the second electrode 32.
Additionally, the face mask system 1 comprises an electric power source 50 configured to generate the electric current in the face mask material 12 between the first and second electrodes 30 and 32. As shown in fig. 1A, this electric power source 50 may be configured with first and second electrical leads 52 and 54 providing electrical current to the first and second electrodes 30 and 32, between which a current in the face mask material 12 is then generated.
Electric power source 50 may comprise a battery 56, a power regulation unit 58 providing a suitable voltage and current through the face mask material 12, and a switch 60 for turning on, respectively off, the electric power source 50 and thus turning on, respectively off, the electric current in the face mask material 12 between the first and second electrodes 30 and 32. The electric power source 50 may further comprise an indicator 62, such as a multi color LED, configured to indicate whether the electric power source 50 is on or off, and preferably further configured to indicate at least one of a status of the battery 56, a status of the power regulation unit 58, a status of the circuit formed by the electric power source, the electrical leads 52 and 54, the first and second electrodes 30, 32 and the face mask material 12 between the first and second electrodes 30 and 32, and a status of the mask material 12 between the first and second electrodes 30 and 32.
Preferably the battery 56 is a rechargeable battery. Electric power source 50 may thus further comprise a charging port 64 for receiving electrical energy for charging, for example from an USB type plug or other suitable plug for conducting the electrical energy suitable for charging battery 56.
Fig. 1B shows an alternative embodiment of the face mask system shown in fig. 1B. Accordingly, fig 1B shows a face mask system 1' wherein the face mask 10' and its face mask material 12' has been more extensively configured for covering the mouth and nose of the user. To this effect the face mask 10' and the face mask material 12' has been configured with first and second slanting side edges 14' and 16', as well as a contoured top and bottom edges 18' and 20'. The first and second loops 22 and 24 are however the same as shown in fig. 1B, and also the bendable stiffening element 26, e.g. in the form of metal wire or ribbon and the first and second spaced apart electrodes 30 and 32 are as shown in fig. 1A.
The face mask system 1' of fig. 1B further deviates from that shown in fig. 1A in that an integrated electric power source 50', otherwise corresponding to the electric power source 50, is shown attached to the exterior of the face mask material 12'. Integrated electric leads 52' and 54' thus run along the exterior of the face mask material 12' to the first and second electrodes 30 and 32. The electric leads 52' and 54a may alternatively run inside the face mask material, or on the interior side of the face mask material.
Figs 2A, 2B, 2C, 2D and 2E show different embodiments of the first and second electrodes 30 and 32. Fig. 2A thus shows a face mask 10'' in which the first and second electrodes 30' and 32' are elongated in a direction generally perpendicular to an axis between the spaced apart first and second electrodes. Once more the current between the electrodes is indicated by broken arrows. This may provide a more uniform distribution of current through the face mask material 12.
Fig. 2B shows a face mask 10''' in which the first and second electrodes 30'' and 32'' are configured as interdigitated electrodes, each having a first and second primary electrode 34 and 36, respectively, from which a plurality of first and second secondary electrodes 38 and 40, respectively, extend towards each other in an interdigitated configuration. This may also provide a more uniform distribution of current through the face mask material 12.
Fig. 2C shows a face mask 10'''' in which the first and second electrodes are configured as edge or border electrodes 30''' and 32''', each extending along at least 1/4 of the length of the edge of the face mask material 12. This further increases the effective length of the electrodes and may also provide a more uniform distribution of current through the face mask material 12.
Fig. 2D shows a face mask 10''''' in which the first and second electrodes are configured as first and second electrode layers 30'''' and 32'''' sandwiching between them the face mask material 12. The electrode layers 30'''' and 32'''' are preferably configured as a conductive mesh or conductive fabric. Alternatively, the electrode layers 30'''' and 32'''' may be configured by printing or otherwise depositing a pattern, grid, or mesh of conductive material on the opposite surfaces of the face mask material 12. Accordingly, in the face mask 10''''' in fig. 2D the electrical current generally runs thought the face mask material 12 in the direction of the thickness dimension thereof, in contrast to figs. 1, 2A-2C where the current runs generally in the length and/or width dimension thereof.
Also shown in fig. 2D is an optional liner layer 42. The liner layer 42 is air permeable at least in part and may be made from the same material as face mask material 12 or may be made from an electrically insulating material. Liner layer 42 is, in use, closest to the face of the user of the face mask 10, and accordingly may provide increased comfort to the user of the face mask 10 as it separates the first electrode layer 30'''' from the face of the user. Additionally, the liner layer 42 may protect the first electrode layer 30"", and optionally also the face mask material 12, from abrasion or contamination from the user's face. Liner layer 42 may for example be configured as a mesh fabric layer or net so as to not, or only minimally, impede inhalation and exhalation of the user.
Also shown in fig. 2D is an optional outer layer 44. The outer layer 44 is air permeable at least in part and may be made from the same material as face mask material 12 or may be made from an electrically insulating material. The outer layer 44 is, in use, farthest away from the user's face and may protect the second electrode layer 32'''', and optionally also protect the face mask material 12, from physical damage, such as from e.g. abrasion, as well as from contamination, such as from solid particles and/or liquid contaminants.
Although the liner layer 42 and the outer layer 44 are only shown in fig. 2D in connection with electrode layers 30'''' and 32'''', it should be recognized that the face mask material shown in each of fig. 1A and 1B, and figs 2A-2C, 2D and 3A may comprise a corresponding liner layer and a corresponding outer layer.
Fig. 2E shows a face mask system 1'' with a face mask 10'''''' in which the first and second electrodes 30''''' and 32''''' are connected to a first coil lead 52'' and a second coil lead 54'', so as to be able to receive electric power from an electric power source 50'' which, in addition to the components comprised by the electric power source 50, further comprises a sender coil 66 for transferring electric power from the electric power source 50'' to the first coil lead 52''. In operation the electric power source 50'' energizes the sender coil 66 with an alternating current providing an alternating magnetic field indicated at 68 which impinges on the receiver coil 70 of the first coil lead 52''. The alternating magnetic field 68 thus gives rise to an alternating current in the receiver coil 70 which provides the electric current to the first and second electrodes 30''''' and 32''''' via the first and second coil leads 52'' and 54''.
Fig. 3 shows a further embodiment of a face mask system 1''', in which a rigid or semi-rigid holder structure 100 is provided for holding a face mask 10'''''''. The holder structure 100 is comprises a generally U-shaped body 102 of a rigid or semi-rigid material, such as plastic. The body 102 comprises a back portion 104, first and second side portions 106 and 108, first and second ear loop portions 110 and 112 and terminates in first and second end portions 114 and 116. A first end connector 118 is provided at the first end portion 114, and a second end connector 120 is provided at the second end portion 118. The first and second end connectors 118 and 120 are configured for being attached to the first and second edges 14'' and 16'' of the face mask 10''''''' also shown in fig. 3.
Face mask 10''''''' is similar to face mask 10' shown in fig. 1B, however comprises first and second attachment tabs 30'''''' and 32'''''' which further serves as first and second electrodes. The first and second attachment tabs 30'''''' and 32'''''' may be formed integrally with the face mask material 12', or may alternatively be formed separately from the face mask material 12' and attached to the face mask material. In the former case the face mask material may be formed with the attachment tabs, followed by the application or printing onto the attachment tabs of a conductive material to form the first and second electrodes. In the latter case the first and second attachment tabs may for example be formed of metal foil.
In order to attach the face mask 10''''''' to the holder structure 100, each of the first and second end connectors 118 and 120 are provided with a respective slit 122 and 124 into which the corresponding attachment tab 30'''''' and 32'''''' are inserted for holding the face mask 10''''''' in position. The holder structure 100 further comprises the electric power source 50''' which in fig. 3A is shown integrated in the body 102 of the holder structure 100, but which can alternatively be carried by the body 102. In order to provide the electric current to the face mask 10'''''''. first and second electrical leads 52''' and 54''' run from the electric power source 50''' to the respective first and second end connector 118 and 120, wherefrom the current passes to the first and second attachment tabs 30'''''' and 32'''''' and into the face mask material 12 for preventing microbial growth in the face mask material. A proximity switch 60' is used in the electric power source 50''', the proximity switch 60' being configured to actuate the electric power source 50''' when the holder structure 100 is worn by a user causing the back portion 104 and the proximity switch 60' to be contact or be close to the back of the head of the user.
As an alternative to the slits 122, 124 and the attachment tabs 30'''''' and 32'''''', the first and second end connectors 118 and 120 may be configured in other ways for attaching to the face mask and delivering current to the first and second electrodes.
Accordingly, fig. 3B shows that the first and second end connectors 118 and 120 (only one end connector being shown in fig. 3B) can be configured as a clamp 118'. The clamp 118', by its spring-loaded first and second jaws 126 and 130 provides a universal attachment to the first and second edges of the face mask material, thus allowing the attachment of any of the face masks shown in the preceding figures. Further, by using a clamp 118' made out of a conducting material, e.g. metal, electric current is easily delivered to the first and second electrodes by clamping over the respective electrode. Specifically, it is easily seen that the clamp 118' may easily clamp over the first and second electrodes shown in figs 1A-1B, 2A-C, and also over the first and second attachment tabs 30'''''' and 32'''''' if desired. As regards the first and second electrode layers 30'''' and 32'''' of face mask 10'''' shown in fig. 2D, these electrode layers may be reached by the jaws 126 and 130 of the claim 118' after providing a suitable cutout in, or removing altogether, the outer layer 44 and/or the liner layer 42. Additionally, the clamp 118' may be configured such that the respective jaws 126 and 130 are electrically insulated from each other, thus allowing one clamp to transfer current to both the first and second electrode layers or electrodes.
It may further be recognized that, when clamps like the clamp 118' are used as first and second end connectors, then these clamps may further serve as first and second electrodes when they clamp onto the face mask material.
Further ways of configuring the first and second end connectors 118 and 120 for attaching to the face mask and delivering current to the first and second electrodes include connections such as inter alia plugs and sockets, and snap fasteners, wherein in each case one member of the connection is attached or part of the face mask, and the other member represents the corresponding end connector.
Accordingly, fig. 3C shows a plug and socket connection 118'' including a socket part 126' having locking ledge 132 for cooperation with a snap latch 134 on the plug part 130'.
Further, fig. 3D shows a snap fastener connection 118'' comprising a socket part 126'' and a stud part 130''.
Each of the connections shown in figs 3B and 3C can provide both attachment of the face mask to the holder structure 100, as well as transfer of current from the holder structure to the face mask. Additionally, each of the clamp 118' and the socket part 126'' or stud part 130'' may further serve as electrode when attached to the face mask material. Additionally, each of the socket part 126'' and plug part 130'' may be attached directly to the face mask material and put in electric contact with the face mask material to thereby also serve as an electrode.
Further, if the holder structure is to be used with a face mask such as the face mask 10' shown in fig. 1B, in which the electric power source 50' is carried by the face mask, then additional end connectors are possible, such as hook and loop connections (with one of hooks and loops provided as the end connector and the other attached to or part of the face mask), and hook and hole connection, where the end connectors are configured as hooks and a corresponding hole or loop is attached to or part of the face mask.

Feasible modifications

The technology proposed herein is not limited only to the embodiments described above and shown in the drawings, which primarily have an illustrative and exemplifying purpose. This patent application is intended to cover all adjustments and variants of the preferred embodiments described herein, thus the present invention is defined by the wording of the appended claims and the equivalents thereof. Thus, the equipment may be modified in all kinds of ways within the scope of the appended claims.
For instance, it shall be pointed out that structural aspects of embodiments of the method according to the first aspect of the technology proposed herein shall be considered to be applicable to embodiments of the system according to the second aspect of the technology proposed herein, and conversely, methodical aspects of embodiments of the system according to the second aspect of the technology proposed herein shall be considered to be applicable to embodiments of the method according to the first aspect of the technology proposed herein.
It shall also be pointed out that all information about/concerning terms such as above, under, upper, lower, etc., shall be interpreted/read having the equipment oriented according to the figures, having the drawings oriented such that the references can be properly read. Thus, such terms only indicate mutual relations in the shown embodiments, which relations may be changed if the inventive equipment is provided with another structure/design.
It shall also be pointed out that even though it is not explicitly stated that features from a specific embodiment may be combined with features from another embodiment, the combination shall be considered obvious, if the combination is possible.
Throughout this specification and the claims which follows, unless the context requires otherwise, the word "comprise", and variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or steps or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

Item list

1: face mask system
10: face mask
12: face mask material
14: first edge
16: second edge
18: top edge
20: bottom edge
22: first loop
24: second loop
26: bendable stiffening element
30: first electrode
32: second electrode
34: first primary electrode
36: second primary electrode
38: first secondary electrode
40: second secondary electrode
42: liner layer
44: outer layer
50: electric power source
52: first electric lead
54: second electric lead
56: battery
58: power regulation unit
60: switch
62: indicator
64: charging port
66: sender coil
68: magnetic field
70: receiver coil
100: holder structure
102: body
104: back portion
106: first side portion
108: second side portion
110: first ear loop portion
112: second ear loop portion
114: first end portion
116: second end portion
118: first end connector
120: second end connector
126: first jaw
130: second jaw
132: locking ledge
134: snap latch

Claims

A face mask system (1) comprising:
- a face mask (10) comprising a piece of face mask material (12) configured to cover the mouth and nose of a user, the face mask material being electrically conductive, and at least in part air-permeable, and being provided with first and second spaced apart electrodes (30, 32), and

- an electric power source (50) configured to generate an electric current in the face mask material between the first and second electrodes.
The face mask system (1) according to claim 1, wherein the face mask material (12) comprises a non-woven material.
The face mask system (1) according to any of the preceding claims, wherein the first and second electrodes (30, 32) are attached to the face mask material (12), such by being printed on or bonded to the face mask material (12).
The face mask system (1) according to any of the preceding claims, wherein the first and second electrodes (30, 32) are positioned such that the electric current runs along the width and/or height dimension of the face mask material, preferably wherein the first and second electrodes (30, 32) are positioned at opposite edges of the face mask material (12) .
The face mask system (1) according to any of the preceding claims, wherein the first and second electrodes (30, 32) are positioned such that the electric current runs in the thickness dimension of the face mask material, preferably wherein the first electrode (30'''') is formed as a mesh or grid provided on a first side of the face mask material (12) and the second electrode (32'''') is formed as a mesh or grid provided on an opposite second side of the face mask material (12) .
The face mask system (1) according to any of the preceding claims, wherein the electric current is 10 mA or lower, preferably between 0.1 mA and 1 mA, more preferably between 0.4 mA and 0.8 mA.
The face mask system (1) according to any of the preceding claims, wherein the electric current is an alternating current having a frequency below 100 Hz, preferably below 10 Hz, more preferably below 1 Hz.
The face mask system (1) according any preceding claim, wherein the electric current is an alternating current having a peak voltage below 80 V, such as below 50 V, preferably between 10 V and 50 V, more preferably between 20 V and 50 V, such as between 30 V and 50 V.
The face mask system (1) according to any preceding claim, wherein the electric power source (50) is positioned on or in the face mask (10).
The face mask system (1) according to any preceding claim, further comprising a holder structure (100) configured for holding the face mask material (12') in place to cover the mouth and nose of a user during use, wherein the holder structure comprises a generally U-shaped rigid or semi-rigid body (102) having a first end connector (118) configured to be attached to a first edge (14'') of the face mask (10'''''') and a second end connector (120) configured to be attached to an opposite second edge (16) of the face mask, the body being configured to extend from the first end connector along the back of the user's head to the second end connector, preferably between the user's outer ears and skull, when used.
The face mask system according to claim 10, wherein the electric power source (50''') is integrated in, or attached to, the holder structure (100), the first and second end connectors (118, 120) are electrically connected to the electric power source, and wherein the first and second electrodes (30'''''', 32'''''') are configured to be electrically connected to the first and second end connectors when the end connectors are attached to the first and second edges (14", 16") of the face mask.
The face mask system (1) according to any preceding claim, wherein the electric power source (50") and the electrodes (30'''''', 32'''''') are configured for contactless transfer of electric power from the electric power source to the electrodes.
A method of producing a face mask system (1) according to any of the preceding claims, comprising the steps of:
i. providing an electrically conductive, and at least in part air-permeable, face mask material (12) and configuring the face mask material so as to be capable of covering the mouth and nose of a user when used, thereby obtaining a face mask (10),

ii. providing first and second spaced apart electrodes (30, 32) on or in the face mask material, and

iii. providing an electric power source (50) configured to generate an electric current in the face mask material between the first and second electrodes.
A method of preventing or reducing microbial growth in or on a face mask material (12) of a face mask (10), the method comprising the steps of:
i. providing a face mask system (1) according to any of the claims 1-12,

ii. actuating the electric power source (50) so as to generate an electric current in the face mask material (12) between the first and second electrodes.
Use of an electric current, generated by an electric power source (50) and running between first and second spaced apart electrodes (30, 32) provided in or on an electrically conductive and at least in part air-permeable face mask material (12) of a face mask (10), for preventing or reducing microbial growth in the face mask material.