Patent Description:
Most air masks, currently in use, employ mechanical filters. These filters have a limited area, provide the user with limited protection, create a significant pressure drop that induces a peripheral leakage of contaminated or infected air, accumulate moisture and bad smell, put strain on the user's lungs causing the user to breathe more heavily, thus shortening the time period the user can suffer the inconvenience of such masks.

It is well-known that air in infected and toxic environments can be treated by either UV radiation, by filtering or by gas absorption. To employ UV radiation in a portable breathing device, extremely high energy efficiency is essential in order to conserve battery power. High energy efficiency implies low power consumption together with high efficacy. To employ a high level of filtering, an increased filter area is required, but it becomes a great challenge as portable breathing devices have only limited surface area. Effective gas absorption requires sufficient contact time, but this can be achieved only if the treated air flow matches the available space in the portable breathing device.

Some of these problems can be resolved by means of a blower that creates an active air flow, which reduces the pressure drop and makes the user's breathing easier. However, active air flow alone does not create a natural cycle of breathing since the volume of air supplied by the blower is not equal to the volume of the inhaled air, and likewise the volume of air drawn by the blower is not equal to the volume of the exhaled air. Active flow alone allows neither UV disinfection efficiency nor gas absorption contact time.

There is therefore a need to provide an inhalation and exhalation air treatment system to overcome the above drawbacks, to provide a high level of protection and to allow monitoring of the air quality, system functionality and the user's health indicators.

<CIT> discloses a mask having a body, an air purifier coupled to or formed on the body and configured to purify and discharge air introduced therein, and a control unit coupled to or formed on the body, and configured to control an air volume of the air purified and discharged through the air purifier.

<CIT> discloses a modular, portable, air purifier device, which may optionally include a UV filter capable of supplying filtered or otherwise conditioned airflow to an individual. It provides a good discussion of known techniques including negative pressure respirators, which typically take the form of either a mask, or a half mask respirator. The mask covers the nose and mouth and air is drawn through a filter by the negative pressure of inhalation. It is suggested that these types of masks increase respiratory stress because the user must overcome the air restriction presented by the air filter. It is further stated that a tight fit is essential to prevent unfiltered air from entering around the mask instead of through the filter. These types of masks also interfere with normal conversation because they cover both the nose and mouth.

<CIT> discloses a mask interface device for a protective mask of the type having a mask filter and a mask expiratory port, the mask expiratory port having an expiratory port valve of the type that is normally closed and openable upon expiration. An expiratory port interface assembly mountable to the mask expiratory port comprises at least one opening for venting expired gas to atmosphere. A one-way valve is positioned to control the flow of expired gas out through the opening, and is set to an opening pressure that provides positive end expiratory pressure.

<CIT> discloses a breathing apparatus comprising a face mask that is coupled to an optional prefilter assembly that includes a housing containing a pre-filter filtration medium.

It is known that the efficiency of conventional face masks is limited owing, in no small part, to their low surface area, which is dictated by the fact that are worn on the face and must be reasonably comfortable. It is therefore known to enhance the filtering efficiency of face masks by coupling them to an external filter. Thus, it is known to adapt face masks for coupling to external elongate filters that are either integrated with the mask assembly or are in the form of cartridges that are worn on the back of the user and are coupled to the mask assembly via a flexible tubing.

Additionally, although it is known to use a one-way valve to control the flow of expired gas that is exhaled, it does not appear to be known to control the flow of air prior to inhalation.

<CIT> discloses a neck-hanging type air purification system comprising a gauze mask and a purification device, wherein the gauze mask covers the face of a human body, the purification device is used for purifying air, and besides, the gauze mask communicates with the purification device through an air inlet pipe.

<CIT> discloses a mask comprising a mask body and a first one-way air valve arranged on the mask body. Ventilation is conducted on the outer side of the mask through the first one-way air valve and is stopped on the inner side. A second one-way air valve is arranged on the mask body, and ventilation is conducted on the inner side of the mask through the second one-way air valve and is stopped on the outer side.

<CIT> discloses breathing apparatus having an elongate filter unit, one or more one-way valves, a mask assembly for covering the oral and nasal passage of a user and an electric blower for delivering a required air pressure and flow to the mask assembly. Air pressure is adjusted by controlling the blower using a breath-responsive flow control algorithm to control the air flow to the mask assembly. The blower can be a separate unit located behind the user's neck and fluidly coupled to the mask assembly by a pipe having a section of bellows at each end which is compressible and extensible to maintain a proper seal regardless of movement of the user's head.

It is therefore one object of the present invention to provide a breathing apparatus that enhances the filtering efficiency of a regular face mask by means of a lightweight external filter cartridge that is coupled to the mask.

It is a further object of the present invention to provide a device and system for air treatment during inhalation or exhalation and for monitoring the air quality, the system functionality and the user health indicators.

These objects are realized in accordance with the invention by a device, system and method for treating the air during inhalation and exhalation having the features of the respective independent claims.

Thus, in accordance with one aspect of the invention there is provided a device for enhancing efficiency of an air mask wearable by a user to cover the mouth and nose of the user, the device comprising:.

The device may be retrofitted to a mask to form an integral unit or the chamber may be adapted for attaching to an existing mask, typically but not necessarily via a screw-coupling. It can also be attached using a bayonet coupling or a push-fit snap connection or may be secured using clasps.

A system according to the invention includes the device with or without an integral mask in combination with auxiliary components as described in detail below.

In order to better understand the invention and its implementation in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, wherein.

In the following description of some embodiments, identical components that appear in more than one figure or that share similar functionality will be referenced by identical reference symbols.

<FIG> illustrates a system <NUM> according to a first embodiment of the invention comprising a chamber <NUM> at least indirectly connected to a mask <NUM> having air openings <NUM> and <NUM>" shown in <FIG>, which serve as an air inlet and an air outlet, respectively. A filter element <NUM> configured to remove viruses and bacteria from either inhaled or exhaled air is mounted in association with the chamber <NUM>. In the embodiment shown in the figures, the chamber is a right-circular cylinder and the filter element is likewise cylindrical and forms a hollow structure that surrounds an outer wall surface of the chamber. However, the geometry and location of the filter are not crucial so long as the filter is able to filter the air prior to its entering the chamber. So it could equally well be located inside the chamber in the form of a hollow tube around the internal wall of the chamber. The filter element <NUM> has a structure of a typical air filter, namely a particulate air filter, and possibly activated charcoal filter and another particulate filter to trap charcoal dust. The filter element <NUM> may also be formed from other filtering materials adapted to remove viruses and bacteria riding on particles. In this embodiment the filter element <NUM> is two dimensional and attached to the portion of the chamber <NUM> structure. In other embodiments (<FIG> and <FIG>) the filter element <NUM> surrounds the chamber <NUM> to achieve a significantly larger filter surface area, thus reducing the velocity of air <NUM> (<FIG>) over the filter material and thereby significantly increasing the filter efficiency.

The system <NUM> comprising the chamber, filter and an expandable member <NUM> described below may be a standalone device adapted for coupling to the mask <NUM>. Alternatively, the device may be coupled to the mask to form an integrated system as shown in the figures and to which additional components may be coupled. For the sake of consistency, in the following description we will refer to the arrangement as a system regardless of whether or not it includes the mask as an integral component. <FIG> illustrates the system of <FIG> with an air blower <NUM>, having blades <NUM> directed toward the interior of the chamber <NUM>.

Both <FIG> illustrate the system <NUM> with a UV source <NUM> exposed to the interior of the chamber <NUM>. The UV source <NUM> is attached to one of the walls of the chamber <NUM> and is driven by a controller <NUM> powered by a battery pack <NUM>. The controller <NUM> and the battery pack <NUM> may be integral with the system <NUM> or may be separate units that are carried by the user and mechanically and electrically coupled to the system via a suitable connector. The controller <NUM> can either switch the blower <NUM> and / or UV source <NUM> ON or OFF or adjust flow rate and power.

In this embodiment, the internal walls of the chamber <NUM> may be covered by a UV reflection layer, to allow multiple reflections <NUM> of the UV source rays <NUM>. To retain the UV radiation energy inside the chamber, a baffle <NUM> and area obstacles <NUM> are located at the inlet and the outlet of the system <NUM> and cooperate to form a labyrinth that serves to reflect UV radiation internally between the inner walls of the chamber. The surfaces of the labyrinth <NUM> and <NUM> directed to the UV source <NUM> are covered by a UV reflecting layer, while the opposite surfaces of the labyrinth are covered by a UV absorption layer.

The surfaces of the blades <NUM> directed to the UV source <NUM> may also be covered by a UV reflection layer, allowing the blower <NUM> to reflect most of the direct rays <NUM> and reflected rays <NUM> hitting the blower blades <NUM> (<FIG>).

<FIG> illustrates the system of <FIG> during inhalation. The air blower <NUM> is configured to provide a steady and continuous airflow <NUM> that meets the maximum breathing demand, thereby avoiding external air intake via the air mask <NUM>. The power of the UV source <NUM> should, therefore, be much higher as the air volume to be disinfected is much larger than the actual air volume entering the lungs. The blower <NUM> creates an overpressure inside the mask, which dispels the entry of ambient air and thus obviates the need for a tight seal between the mask and the user's face.

<FIG> illustrates the system of <FIG> during exhalation, it being seen that the inlet air blower <NUM> maintains the same rate of airflow as in a previous inhalation. This configuration is therefore is not energy-efficient because the air blower <NUM> draws air into the system when the user inhales, when operation of the air blower is essential, and also when the user exhales, even though during exhalation there is no need for the blower <NUM> to draw air into the system.

To overcome this disadvantage the embodiment of <FIG> integrates an expandable member <NUM> into the system of <FIG>. The airflow <NUM>, previously disinfected by UV source rays <NUM> in the chamber <NUM> inflates the expandable member <NUM> with a sufficient quantity of air ready for inhalation. Whenever the expandable member <NUM> achieves its maximum volume, it engages a sensor <NUM> that is interfaced to the system controller <NUM> and produces a switching signal. The controller <NUM> is responsive to the switching signal for switching OFF the air blower <NUM> and the UV source <NUM>, thus saving the energy required from the battery pack <NUM>. In this embodiment the inlet air blower <NUM> is configured to provide a relatively low and steady rate of airflow (about <NUM>% only), as it should be lower than the maximum breathing flowrate (<NUM> cc per sec), and therefore the power of the UV source <NUM> may be dramatically reduced. To provide the maximum breathing rate, the expandable member <NUM>, previously inflated by the air blower <NUM>, contains a sufficient quantity of already disinfected air and is ready to be deflated, by human inhalation.

<FIG> illustrates the system <NUM> with an expandable member <NUM> at an early stage of exhalation, when the expandable member <NUM> reaches its minimum volume after being deflated by human inhalation. In this embodiment the exhaled air is filtered by the filter layers of the air mask <NUM>, the filter layers being structured to optimize the exhaled air filter.

<FIG> illustrates the system <NUM> with an expandable member <NUM> at a final stage of exhalation, when the expandable member <NUM> has reached its maximum volume.

<FIG> illustrates the system <NUM> with an expandable member <NUM> at an initial stage of inhalation, when the expandable member <NUM> is at its maximum volume.

<FIG> illustrates the system <NUM> at a final stage of inhalation, when the expandable member <NUM> is deflated and reaches its minimum volume.

<FIG> illustrate the system <NUM> of <FIG> having an expandable pipe <NUM> configured for exhalation air UV disinfection. In this configuration the air blower <NUM> is configured for an inverse airflow.

<FIG> shows the expandable member <NUM> at an early stage of inhalation, when it is fully inflated by exhalation of the previous breath, the air blower <NUM> moving possibly contaminated exhaled air via the treatment space of the chamber <NUM> under the UV radiation of the UV source <NUM>.

<FIG> shows the expandable member <NUM> at the final stage of inhalation, when the expandable member <NUM> is fully deflated.

The embodiment of <FIG> and <FIG> achieves high energy efficiency because the lower the air flow rate of the blower <NUM> through the chamber <NUM>, the lower is the power of the UV source <NUM> required to disinfect the air as will now be explained.

Thus, typical inhalation-exhalation cycle time is about <NUM> seconds. Without the expandable member <NUM> the airflow rate would be determined by the nominal inhalation airflow rate, which is around <NUM> cc per sec. With the expandable member <NUM>, there is about twice as much time to inflate the expandable member and therefore the airflow rate through the chamber <NUM> may be reduced by about <NUM>%. If the airflow rate is reduced to half, the UV source <NUM> power may also be reduced by the same ratio.

It should be noted that the system configuration introduced in <FIG> is optimal for uninfected people, as inhalation air quality provided by both the filtering element <NUM> and disinfection light of UV source <NUM> will be beyond the exhalation air quality provided by the air mask <NUM> filtering layers.

For infected people the system configuration of <FIG> may be more suitable, since the quality of the exhaled air provided by both the filtering element <NUM> and disinfection light of the UV source <NUM>, will be higher than the quality of the inhaled air provided by the filtering layers of the air mask <NUM>.

To allow the system <NUM> to be configurable, both for infected and uninfected people, a configurable one-way valve <NUM> shown in <FIG> and <FIG> may be provided. The flow-direction of the valve <NUM> can be easily changed by a user based on whether or not the user is infected. The air flow direction of the air blower <NUM> will be changed by the controller <NUM> accordingly to allow either the configuration of system <NUM> in <FIG>, or the configuration of system <NUM> in <FIG>.

It will be appreciated that the expandable member <NUM> is not limited to the shapes, sizes and materials shown and described with reference to the drawings.

Operation of the system illustrated by <FIG> may be monitored as follows: a) measure the airflow rate using an anemometer <NUM> (<FIG>); b) adjust the UV source <NUM> power based on the direction and flow rate of the breathing: switch the UV source <NUM> OFF at exhalation or adjust the UV source <NUM> power upon inhalation.

The power of the UV source <NUM> may be continuously monitored by a UV sensor (not shown) interfaced to the controller <NUM>. The controller <NUM> may be configured to report system variables (e.g. UV source status, battery status) to a smartphone, computer or router via Bluetooth or WiFi communication to allow preventive maintenance and to allow advanced HMI (human-machine interface) with the system <NUM>.

<FIG> illustrate a system <NUM> according to a second embodiment having a peripheral filter <NUM>. The peripheral filter <NUM> has a significantly larger filter area but does not require additional space beyond that anyway allocated to the expandable member <NUM> shown in <FIG> (deflated) and 5C (inflated). In this embodiment the air velocity over the filter element <NUM> may be as low as <NUM>% relative to commonly used masks. A reduction of this order of magnitude is achieved owing to both the expandable member <NUM> and the peripheral surface area of the filter element <NUM> and assures significantly higher filtering efficiency.

The mask <NUM> may be formed of a material that is impermeable to air or may be of a typical structure adapted for air filter. In this configuration the one-way valve <NUM> blocks the air supply from the flexible pipe <NUM> and the one-way valve <NUM> allows direct access to the filtered air inside the expandable member <NUM>. During the inhalation stage, breathing holes <NUM> allow a space <NUM> between the exterior of the expandable member <NUM> and the interior of chamber <NUM> to be freely filled by ambient air, thus maintaining the air inside the expandable member <NUM> at ambient pressure and avoiding a pressure drop inside the mask <NUM> during inhalation.

A one-way valve <NUM>, such as a membrane valve, allows the flow of inhaled air via a flexible pipe <NUM> into a user's lungs. A one-way valve <NUM>, such as a membrane valve, allows the flow of exhaled air via a flexible pipe <NUM> back to the filter <NUM>. The inhalation and the exhalation portions of the filter <NUM> are separated by a separation wall <NUM>.

The one-way valve <NUM> prevents the exhaled air flow from entering into the chamber <NUM> via pipe <NUM> and forces this air to flow via the pipe <NUM> to the exhaled air filter <NUM> where it is filtered. Simultaneous to the exhalation process, an air blower <NUM> conveys ambient air <NUM> through an outer surface of the filter <NUM> into an expandable member <NUM>, which serves as an air capacitor that continually accumulates sufficient filtered air for the next inhalation. Breathing holes <NUM> maintain the air pressure in a space <NUM> between the exterior of expandable member <NUM> and the interior of the chamber <NUM> equal to the ambient air pressure. During the exhalation stage, the breathing holes <NUM> allow the air in the space between the exterior of expandable member <NUM> and the interior of chamber <NUM> to be freely discharged in order to maintain the air inside the expandable member <NUM> at the ambient pressure and to reduce the airflow resistance over the air blower <NUM> to a minimum.

<FIG> illustrates the filter element <NUM> split into two sections: an inhalation section on the right and an exhalation section on the left. In this embodiment, water vapor content of exhaled air is filtered far away from the mask <NUM> and therefor causes the wearer less discomfort.

The sequence of the breathing cycle introduced by the current embodiment is similar to that described above with reference to <FIG>.

<FIG> is a detailed cross-section portion view of embodiment of <FIG>. As it may be seen from this drawing, blower <NUM> collecting the filtered air from the space in between the filter <NUM> and chamber <NUM> and directs this air into the expandable member <NUM>.

<FIG> illustrates a basic embodiment of a one-way module <NUM>, having an expandable member <NUM> sealed to the base of a chamber <NUM>, in an inhalation stage. A battery <NUM> is mounted on the exterior of the chamber <NUM> and connected to a controller <NUM>, which controls the air blower <NUM>, monitors battery voltage and current to the air blower <NUM> and collects environmental parameters, such as temperature and humidity.

An RFID reader may be interfaced to the controller <NUM> to identify the serial numbers of the filter <NUM> and blower <NUM> and to send this information via an embedded short-range communication (e.g. blue tooth, WiFi) to a service provider database.

In this embodiment the expandable member <NUM> is attached to the chamber <NUM> proximate the outer surface of the filter <NUM>. This proximity may allow interconnection between the filter <NUM> and the expandable member <NUM>, and moreover may allow the functionality of filter <NUM> and the expandable member <NUM> to be realized by a single structure, optionally made of the same material of the filter <NUM>. As shown in the <FIG>, the exterior of the expandable member <NUM> is exposed to ambient air, and therefore inhalation via the short flexible pipe <NUM> should induce negligible pressure drop. By eliminating the pressure drop, the risk of contaminated air leakage of ambient air via the sealing lips of the mask <NUM> is negligible.

<FIG> illustrates the one-way module <NUM> of <FIG>, during exhalation. The filtered air is conveyed by the air blower <NUM> into the filtered air space captured between the expandable member <NUM> and the interior of the chamber <NUM>. This space expands during the exhalation stage and reaches its maximum value prior to beginning of the inhalation stage.

<FIG> illustrates pictorially an embodiment of the one-way module <NUM> of <FIG>, coupled to a two-way mask <NUM> via a flexible pipe <NUM>.

<FIG> shows a cross-section of the one-way module of <FIG> with a sampling module <NUM> (shown in <FIG>) located inline the blower <NUM> airflow. The sampling module <NUM> can be attached to a mount <NUM> whenever the user or the service provider would like to monitor the system, module or the user's health condition. The sampling module <NUM> is configured to collect particles before or after filtering. When the sampling module <NUM> is located between the flexible pipe <NUM> and the exhalation filter <NUM> (<FIG>), it will collect evidence of the user's health. When the sampling module <NUM> is located between the flexible pipe <NUM> and the inhalation filter <NUM>, it will collect evidence of the performance of the one-way module <NUM>. By attaching the sampling module <NUM> to the exterior of the filter <NUM>, it will collect evidence of ambient air contamination or infection.

The sampling module <NUM> is configured to collect particles on a sampling surface that may be a conventional petri dish (<FIG>), or by a filter membrane, such as nylon membrane (not shown), glass surface or any other collecting surface or material capable of capturing and retaining the particles. The sampling principles of the above-mentioned modules <NUM> are different: a petri dish may capture the particles by its gel agar, while a filter membrane may capture the particles by its structure, glass or other surfaces that allow viruses to survive for a relatively long period, and may capture the particles by moisture condensation taking place in the one-way module during exhalation. The aggregated amount of air washing over the sampling module <NUM> over time, during its operation is significant (typically between <NUM> to <NUM> cc per second - at least <NUM> square meter per <NUM> hours) and therefore the probability of collecting contaminated particles, assuming that such particles are contained in the air, is very high. This allows a comprehensive monitoring process to be established on the following parameters: a) level of contamination of the ambient air; b) level of protection provided by the system <NUM> and its modules <NUM>; c) level of contamination of the exhaled air.

Assuming broad implementation of the system <NUM> by organizations, such as hospitals, an overall contamination map of the entire organization can be established, on departmental and individual levels. The sampling module <NUM> can be configured based on the specific or broad monitoring target. For example, for Covid-<NUM> fast response monitoring the sampling module <NUM> can be configured as a filter membrane capable of collecting particles of <NUM> micron. The sampling module <NUM> at the exhaled air outlet of the one-way module can provide the medical staff with a health indicator in different departments of hospital and trigger a specific investigation whenever desired. The sampling module <NUM> at the inhaled air inlet of the one-way module can provide a department air quality indicator and trigger a specific investigation, whenever desired. For broad monitoring the sampling module <NUM> can be configured as a petri dish.

The analysis of the sampling module <NUM> is derived from its configuration: the petri dish can be analyzed based on already well-established techniques. Filter membrane particulate content can be transferred to a liquid or to air by a back-pressure pulse and then be analyzed using known techniques.

To identify the sampling module <NUM> and to associate the sample with a specific user ID, a RFID chip (not shown) may be attached to the sample module <NUM>. The pairing between the sampling module <NUM> and the one-way module <NUM> may be achieved by an RFID reader onboard the controller <NUM>, or by an external RFID reader that collects the ID of the sampling module <NUM> and the ID of the one-way module <NUM> (also by RFID chip), and links both of them to a user and time stamp in the service provider database.

<FIG> illustrate a basic embodiment of a two-way system <NUM> with expandable members in the inhalation and exhalation one-way modules. In this embodiment the expandable members <NUM> are separated from the filter elements <NUM>. The first air blower <NUM> (<FIG>) inside the box <NUM> conveys inhaled air from the filter <NUM> to an expandable member <NUM> (on the right) and the second air blower (not shown) conveys exhaled air from the filter <NUM> to expandable member <NUM> (on the left).

It will be appreciated that the location of the inhalation and the exhalation one-way modules, on right or left in <FIG>, as well as in the following figures, is arbitrary.

<FIG> illustrates a basic embodiment of a two-way system <NUM> having separate one-way modules <NUM> for inhalation and exhalation, respectively, each equipped with expandable members <NUM> embedded inside respective chambers <NUM>. The principles of operation of each of the one-way modules are similar to those of the one-way modules shown in <FIG>. In this embodiment the chambers <NUM>, the embedded expandable members <NUM> and the air blowers <NUM> are assembled and inserted inside the envelope of the filter <NUM> (<FIG>). The envelope of the filter <NUM> can be formed from fabric and has a general shape of a neck pillow (flight pillow). To avoid airflow blockage by adhering of the filter fabric to the surface of the chambers <NUM>, the chambers <NUM> are formed with a corrugated outer contour, thus allowing the air blower <NUM> to convey air between the filter element <NUM> and an exterior of the chamber <NUM>, via the longitude tunnels created by the corrugations. The general profile of the chamber <NUM> may be elliptical, with a vertical axis shorter than the horizontal axis. The profile may vary in size from a typical shirt collar dimensions, to a neck pillow dimensions, in the extreme. The overall surface area of the filter element <NUM> of collar/pillow shape is at least twice that of any other face mask filter. The increased filter surface area allows for use of a lower power of air blower and provides improved filter performance.

<FIG> illustrates the system <NUM> of <FIG> with the one-way inhalation module <NUM> shown in cross-section.

Another important aspect of this embodiment is the design - the public may accept the shape, color and texture of the external fabric of the collar-like system <NUM> as a chic fashion item - that may encourage the public to protect itself without paying the penalty of poor appearance. To allow the user to change the appearance of the system <NUM>, the system <NUM> can be inserted into fashion-collars or even into an entire shirt of different color, shape and texture. The fabric of fashion-collars should allow free airflow and low pressure drop. This requirement is easy to achieve because low-density fabrics are abundant at low production cost.

<FIG> illustrates a full cross-section of the system of <FIG> at the end of the exhalation stage and <FIG> illustrates a full cross-section of the same system at the end of the inhalation stage. The principles of operation of each of the one-way modules <NUM> of this embodiment are similar to those of the one-way modules <NUM> shown in the <FIG>. Thus, if we consider the left-hand one-way module <NUM> as the exhalation module, the action of this module is as follows: a) exhaled air inflates the left-hand expandable member <NUM>. During this action, the air in the space outside the expandable member <NUM> and inside the chamber <NUM> is freely discharged into the atmosphere via an opening <NUM> (<FIG>), thus preventing pressure build-up inside the mask <NUM>; b) the left-hand blower <NUM> continually deflates the left-hand expandable member <NUM> and conveys the exhaled air via the left-hand filter element <NUM> out of the system. The specific air flow (the ratio of the volumetric air flow to the area of the filter surface) is extremely low and therefore the power requirement of the blower <NUM> will be significantly lower and the filter <NUM> performance will be significantly higher.

Likewise, considering the right one-way module <NUM> as the inhalation module, its action is as follows: a) inhaled air deflates the right-hand expandable member <NUM>. During this action the air in the space outside the right-hand expandable member <NUM> and inside the right-hand chamber <NUM> freely enters from the atmosphere via the opening <NUM> (<FIG>), thus preventing a pressure drop inside abovementioned space and inside the mask <NUM>; b) the right-hand blower <NUM> continually inflates the right-hand expandable member <NUM> and conveys the air via the right-hand filter element <NUM> into the right-hand expandable member <NUM>. As noted previously, the specific air flow is extremely low thus resulting in improved filter performance at lower power.

It should be noted that the inhalation and exhalation modules may be of similar size, as shown in the <FIG>, or may have different dimensions: a) unequal filter <NUM> area; b) expandable members <NUM> of unequal volume. In other words, the respective volumes of the two halves can be dedicated to expandable members and filters of different relative proportions. So, in one side, more of the available volume or of the available filter area can be allocated to the expandable member or to the filter area of one module at the expense of the other module and vice versa.

Possible examples for unequal allocations of the collar shaped system <NUM> of the embodiment of <FIG> are: a) the whole volume of the expandable members <NUM> being allocated for the inhalation module only; b) the complete area of the filter <NUM> being allocated to inhalation module only; c) other allocations based on functional criteria (system for positively identified users) are valid as well.

<FIG> illustrates in cross-section and <FIG> are detailed views of a power and monitoring module <NUM> integrated into the chamber <NUM>. The power and monitoring module <NUM> shown in this embodiment allows efficient air sampling based on the proximity of the sampling module mount <NUM> to the air stream of the blower <NUM>, thereby allowing measurement of inhalation and exhalation airflow and exhalation air temperature. The continuous operation of the blower <NUM> allows efficient particle collection over the sampling module <NUM>. The power and monitoring module <NUM> is detachable, and therefore enables installation and removal of the sampling module <NUM> in a simple and a convenient way.

Airflow measurement can be performed using a miniature flow-meter <NUM> integrated inside the interface pipe <NUM> (<FIG>) of the one-way module <NUM>. To keep the interface pipe <NUM> sealed, the flow-meter blades' rotation velocity can be measured by an interaction between small magnets integrated in the tips of the flow-meter blades and a magnetic sensor interfaced to the controller <NUM> (<FIG>). Another possibility to measure the flow-meter blades' rotation velocity is by a light emitting diode <NUM> (<FIG>) interacting with a reflective surface covering the blades (not shown). In this case the interface pipe <NUM> in the area of the diode <NUM> should be transparent to light.

To allow high sensitivity to extremely low airflow rates of inhalation and exhalation, the flow-meter blades may be rotatable about a thin string <NUM>, in the range of <NUM> to <NUM> diameter, stretched between two mounts <NUM>, along the pipe <NUM> axis, as illustrated in <FIG>.

The temperature of the exhaled air can be measured by a temperature sensor interfaced to the controller <NUM>.

To sterilize the two-way system <NUM> a portable autoclave may be used (not shown). The autoclave may sterilize the system <NUM> by an external heat source (e.g. home oven), or by an embedded heat element configured to raise and maintain the autoclave temperature to a desired level. When an external heat source is used, the autoclave walls should be built from highly thermally conductive materials (e.g. aluminum). When an internal heat source is used, the autoclave walls should be thermally isolated. Another internal, broadly available, heat source is hot water that may be boiled and supplied from various water boiling devices.

<FIG> illustrates use of the embodiment of the system of <FIG> and <FIG>and <FIG>. The air mask <NUM> is adapted to be sealed to the user's face by flexible sealing lips stretched on the perimeter of the mask frame. One-way valves <NUM> and <NUM> have similar functionality to those shown in <FIG>. Flexible pipes <NUM> and <NUM> create a limited coupling force between the mask <NUM> and the face. The headband <NUM> stably supports the weight of the one-directional module <NUM> and system <NUM> over the user's head.

In order to adapt the air mask <NUM> to conduct the user's voice, a communication membrane <NUM> may be fitted at the front end of the mask. Alternatively, the air mask <NUM> may have a microphone, interfaced to an external speaker by wires or wirelessly.

<FIG> illustrates pictorially a detail of the one-way module <NUM> having a contoured neck rest <NUM>, which sits comfortably against the back of the user's neck while being fluidly coupled to the mask at opposite ends via the expandable pipe <NUM> and the flexible pipe <NUM> as best seen in <FIG>. On one end surface of the module <NUM> is an electronic assembly comprising an ON/OFF switch, microphone socket, speaker and USB port for connection of a battery charger.

<FIG> shows a cross-section view of the one-way module <NUM> of <FIG>. The module <NUM> has same structure and functionality as the module <NUM> of <FIG>. A toxic gas absorption charcoal filter <NUM> may be coupled inline with the blower <NUM>. The contact time between the air coming from the filter element <NUM>, and the absorption filter <NUM> will be significantly longer owing to the low air velocity induced by the blower <NUM>. Again, as explained regarding the UV disinfection and air filter, the reduced air velocity allowed by the expandable member <NUM> facilitates significantly higher disinfection, filtering and absorption efficiencies. As was explained with regard to <FIG>, in this embodiment the proximity of the expandable member <NUM> to the filter <NUM> (on the right side of the drawing) allows interconnection between the filter <NUM> and the expandable member <NUM> to form a single structure, which may ease the installation requirements. A typical single structure consists of a cylindrical envelop filter <NUM> attached by either front or rear lips to lips of the expandable member <NUM>,which may be in general a thin plastic bag of the type typically used for food storage.

Typically, the module <NUM>, flexible pipe <NUM> and mask <NUM> are mutually interconnected prior to being worn. In order to create a single structure as shown in <FIG> and <FIG> and 18B, a telescopic link <NUM> is connected to the flexible pipe <NUM> and is snap-fitted to a coupling element <NUM> (shown in <FIG>) on one side of the module <NUM>. The telescopic links <NUM>, on the right and the left side of the system (<FIG>), allow the system <NUM> to be adjusted to fit the user's head.

<FIG> show a perspective and cross-section views of power and monitoring module <NUM> according to another embodiment. The module <NUM> incorporates the controller <NUM>, the battery <NUM>, the ON/OFF switch, the USB charger socket, the speaker and the microphone plug. The absorption filter <NUM> is optional and may be coupled by the user to the module <NUM> prior to being coupled to the module <NUM>.

<FIG> show the entire assembly of the system <NUM> over the user's head. To provide a soft and comfortable contact between the module <NUM> and the user's neck, a flexible support <NUM> can be coupled to the front side of the module <NUM>. The support <NUM> and mask <NUM> mutually cooperate with the headband <NUM> to stabilize the system <NUM> on the user's head.

Real time monitoring of the system illustrated in any of <FIG> may be performed as follows: a) actuating the air blowers <NUM>; b) measuring inhalation and exhalation airflows; c) measuring the exhalation and inhalation temperatures; d) sampling the blower current; e) uploading the collected data by Bluetooth™ communication to a user's smartphone; f) uploading the data from the smartphone to a cloud application; e) analyzing the breathing profile of the user and defining the normal breathing flow-temperature profile; and g) looking for deviations and sending the user a message, if such deviation were detected.

Explanation: a) airflow increase may indicate an increase in the demand for higher amount of flow; b) airflow decrease may indicate a blocked filter <NUM> or degradation of lung functionality; c) exhalation air temperature increase indicates higher temperature of the user's body; d) frequent breathing, derived from the airflow measurement, may indicate a general condition of the user and together with the exhalation air temperature more significant indication of user health deviation.

Advanced monitoring can be achieved by transmitting the module <NUM> measurements, via the communication link, to a heart rate monitoring device (not shown), such as smart-watch, chest strip, or other, and synchronizing, in real-time, the transmitted data with the heart rate measurements. The combined measurements may then be analyzed and displayed to the user (e.g. on the smartphone). The analysis of the combined data can provide the user with heart-lung functionality indications in different situations, including sport activities, emergency activities and health monitoring activities. The added value of the system with the advance monitoring is dual: protecting the user and providing the user with health indicators. This is extremely important, especially during the pandemic periods, when fast detection of health conditions is required.

An alternative way is to adapt the system controller <NUM> to receive, via the communication link, the heart rate measurements from a heart rate monitoring device and to synchronize the measurements onboard the controller <NUM>. In this case, the measurements can be analyzed and displayed over the user's smartphone and can be uploaded into the service provider's cloud database.

Note: in all embodiments, the service provider can be an employer organization (e.g. hospital) or a company selling the systems or a monitoring center that receives measured data from remote sources.

Off-line monitoring of the air quality may be performed as follows: a) actuating the air blowers <NUM>; b) collecting infection particles by the sampling module <NUM> washed over by the blower air stream; c) associating the ID of the sampling module <NUM> with the user ID; d) removing the sampling module <NUM> and analyzing the collected content; e) associating the analysis with the user ID.

The description of the above embodiments is not intended to be limiting, the scope of protection being provided only by the appended claims.

In particular it should be noted that features that are described with reference to one or more embodiments are described by way of example rather than by way of limitation to those embodiments. Thus, unless stated otherwise or unless particular combinations are clearly inadmissible, optional features that are described with reference to only some embodiments are assumed to be likewise applicable to all other embodiments also.

It should also be noted that the claims constitute an integral part of the description and are intended to provide support for features that are recited in the claims but are not described in detail in the foregoing description.

Claim 1:
A device for enhancing efficiency of an air mask (<NUM>) wearable by a user to cover the mouth and nose of the user, the device comprising:
an elongated chamber (<NUM>) fluidly couplable at a proximal end thereof to an air opening (<NUM>, <NUM>') of the mask (<NUM>),
a filter element (<NUM>) formed of flexible material that is wrapped around a sidewall of the chamber either internally or externally for filtering air flowing through the chamber in either direction,
a one-way valve (<NUM>, <NUM>) mounted in association with the opening,
an air blower (<NUM>) configured to continuously supply air for inhalation or to discharge exhaled air,
characterized in that:
an expandable member (<NUM>) is fluidly coupled to the chamber:
the one-way valve (<NUM>, <NUM>) is configured for allowing treated air inhaled by the user to pass from the chamber to the mask or for allowing air exhaled by the user to pass from the mask to the chamber,
the expandable member (<NUM>) is operably coupled to the one-way valve for directing air through the filter during inhalation or exhalation;
whereby if the opening is configured to be an air inlet, then during inhalation air is constrained to flow into the chamber and inflate the expandable member (<NUM>) with treated air ready for inhalation prior to flowing out through the opening into the user's lungs; and
if the opening is an air outlet, then during exhalation air is constrained to flow from the user's lungs into the chamber and inflate the expandable member (<NUM>) with exhaled air prior to being discharged as treated air into the environment.