Patent Description:
This disclosure relates to personal protective equipment and medical devices.

When dealing with infectious diseases, medical personal often wear personal protection equipment (PPE) to prevent inhaling pathogens from infected patients and exhaling pathogens to susceptible patients and medical personnel. An example PPE is an N95 filter mask. Such a mask fits securely over the nose and mouth and has sufficient filtration to stop pathogens from crossing through the mask. To maintain sanitary practices, such PPE is often discarded after one use to ensure there is no cross contamination between patients and personnel.

<CIT> describes a protective device such as a face mask. The device protects the user from infection and may simultaneously immunise the user against future infection. The document relates to a protective device comprising a disinfection chamber wherein the chamber is arranged to disinfect and/or sterilize fluid in the chamber prior to discharge of the fluid from the chamber such that the fluid discharged from the chamber comprises inactive microorganisms, for example a device comprising a disinfection chamber in fluid communication with a face mask and wherein the chamber is arranged to disinfect and/or sterilize fluid in the chamber prior to discharge of the fluid from the chamber to the mask such that the fluid discharged from the chamber to the mask comprises inactive microorganisms. The document also relates to a method of use of the device.

Document <CIT> describes an embodiment of an air sterilizer that provides for sterilization not only of air from the atmosphere that is to be supplied to a specific user via a face mask but also of air exhaled by the user.

This disclosure relates to an ultraviolet decontaminating mask. A protective mask and a method according to the present invention are defined by the independent claims. Further advantageous developments of the present invention are set out by the dependent claims.

An implementation of the subject matter according to the present invention is a protective mask with the following features. An inlet chamber defines a flow passage leading into a breathing chamber. A first check valve is located between the inlet chamber and the breathing chamber. The first check valve is configured to allow air flow from the inlet chamber into the breathing chamber. A second check valve is located between the breathing chamber and an exhaust chamber. The second check valve is configured to allow air flow from the breathing chamber into the exhaust chamber. An ultraviolet light source is configured to administer a dose of ultraviolet light sufficient to decontaminate gas flowing through the exhaust chamber. The exhaust chamber includes a helical flow passage surrounding the ultraviolet light source. An inlet passage is arranged such that ultraviolet light emitted from the ultraviolet light source is not exposed to skin of a protective mask wearer.

Aspects of the example protective mask, that can be combined with the example mask alone or in combination with other aspects, include the following. An inlet filter is positioned at an inlet of the inlet chamber.

Aspects of the example protective mask, that can be combined with the example mask alone or in combination with other aspects, include the following. The protective mask further comprises an ultraviolet light source configured to administer a dose of ultraviolet light sufficient to decontaminate gas flowing through the inlet chamber.

Aspects of the example protective mask, that can be combined with the example mask alone or in combination with other aspects, include the following. The ultraviolet light source includes a light emitting diode.

Aspects of the example protective mask, that can be combined with the example mask alone or in combination with other aspects, include the following. The ultraviolet light source includes mercury lamps with quartz-doped globes or tubes.

Aspects of the example protective mask, that can be combined with the example mask alone or in combination with other aspects, include the following. The exhaust chamber is a first exhaust chamber, wherein the protective mask further includes a second exhaust chamber.

Aspects of the example protective mask, that can be combined with the example mask alone or in combination with other aspects, include the following. The exhaust chamber is arranged such that little to no moment is exerted against a wearer of the protective mask.

Aspects of the example protective mask, that can be combined with the example mask alone or in combination with other aspects, include the following. A second ultraviolet light source is configured to administer a dose of ultraviolet light sufficient to decontaminate air flowing through the inlet chamber.

An implementation of the subject matter according to the present invention is a protective mask with the following features. An inlet chamber defines a flow passage leading into an accumulation chamber. A first ultraviolet light source is configured to administer a dose of ultraviolet light sufficient to decontaminate air flowing through the inlet chamber. A breathing chamber is configured to enclose a user's nose and mouth. A first check valve is located between the accumulation chamber and the breathing chamber. The first check valve is configured to allow air flow from the accumulation chamber into the breathing chamber. A second check valve is located between the breathing chamber and an exhaust chamber. The second check valve is configured to allow air flow from the breathing chamber into the exhaust chamber. The inlet chamber includes a helical flow passage surrounding the ultraviolet light source, and an inlet passage arranged such that ultraviolet light emitted from the ultraviolet light source is not exposed to skin of a protective mask wearer.

Aspects of the example protective mask, that can be combined with the example mask alone or in combination with other aspects, include the following. The chamber is a first chamber, the protective mask further comprising a second chamber.

Aspects of the example protective mask, that can be combined with the example mask alone or in combination with other aspects, include the following. A second ultraviolet light source is configured to administer a dose of ultraviolet light sufficient to decontaminate air flowing through the exhaust chamber.

Aspects of the example protective mask, that can be combined with the example mask alone or in combination with other aspects, include the following. The exhaust chamber includes a helical flow passage surrounding the ultraviolet light source, and an inlet passage arranged such that ultraviolet light emitted from the ultraviolet light source is not exposed to skin of a protective mask wearer.

An implementation of the subject matter according to the present invention is a method with the following features. Exhaled air is received from a user wearing the protective mask described above. The exhaled air is disinfected. The disinfected air is emitted to a surrounding environment.

Aspects of the example method, that can be combined with the example method alone or in combination with other aspects, include the following. Disinfecting includes emitting a dose of ultraviolet radiation to the exhaled air. The dose is sufficient to disinfect the exhaled air to a level sufficient to reduce transmission of infection.

Aspects of the example method, that can be combined with the example method alone or in combination with other aspects, include the following. A user's skin is shielded from the emitted dose of ultraviolet radiation.

Aspects of the example method, that can be combined with the example method alone or in combination with other aspects, include the following. Fresh air is received. The fresh air is treated prior to the fresh air being inhaled.

Aspects of the example method, that can be combined with the example method alone or in combination with other aspects, include the following. Treating includes removing particulates by a filter.

Aspects of the example method, that can be combined with the example method alone or in combination with other aspects, include the following. Treating includes disinfecting the air by ultraviolet radiation.

Other features, objects, and advantages of the subject matter will be apparent from the description and drawings, and from the claims.

This disclosure describes a protective mask that can be used to reduce an exchange of pathogens between individuals. Such a protective mask can include a filter or other decontamination mechanism on an inlet and can also include a decontamination mechanism on an outlet. As a result, clean, decontaminated air is breathed in by the user, and the exhaled air is decontaminated before being introduced into the surrounding environment. Such a device allows infected individuals to maintain their lifestyle and prevent (e.g. fully prevent or reduce the likelihood of) them from contaminating other individuals that they may interact with. In addition, in implementations where a filter or other decontamination mechanism is used on the inlet, such a device allows susceptible individuals to interact with those that are infected without fear of becoming infected themselves.

<FIG> is a front view of an example protective mask <NUM>. <FIG> is a side view of the inlet chamber of the example protective mask. <FIG> is a top-down view of the example protective mask. The description herein is given in context of <FIG>.

The protective mask <NUM> includes an inlet chamber <NUM> that defines a flow passage leading into an accumulation chamber <NUM>. In some implementations, an inlet <NUM> of the inlet chamber <NUM> has an inlet filter <NUM>. The inlet filter <NUM> can be an antimicrobial or anti-viral filter, such as that used in an N95 filter.

Alternatively or in addition, in some implementations there is an ultra violet (UV) light source <NUM> configured to emit UV light into the inlet chamber <NUM>. The UV light source <NUM> can be battery powered. Both the inlet chamber <NUM> and the UV light source <NUM> are configured to disinfect any fresh air <NUM> (air from the surrounding environment) flowing through the inlet chamber <NUM> before the air <NUM> is inhaled in by user. The dosage of UV light is dependent upon the wattage of the UV light source <NUM>, the proximity of the UV light source to air <NUM> within the inlet chamber <NUM>, and the exposure/retention time of air <NUM> within the inlet chamber <NUM>. In general, all of these factors are used to ensure a sufficient dosage of UV light decontaminate the air <NUM>. For example, the inlet chamber <NUM> may define a serpentine passage to allow for a greater retention of air <NUM> within the inlet chamber <NUM>. The greater retention time effectively increases the dosage of UV light. In general, the UV light source <NUM> and the inlet chamber <NUM> are configured to decontaminate the air <NUM> at a sufficient rate for a normally breathing individual. For example, a normally breathing individual can inhale/exhale approximately <NUM> Liters (L) or air per breath. The volume of air per breath is often referred to as a "tidal volume. " In some implementations, the UV light source <NUM> and the inlet chamber <NUM> are configured to decontaminate up to four times the estimated tidal volume or breathing rate of air required by a user. This safety margin allows for changes in breathing patterns, for example, when a user is active and or exerting themselves more than usual.

The UV light source <NUM> typically emits a wavelength of approximately <NUM> nanometers (nm) (+ or -<NUM>%); however, certain UV light sources, such as mercury bulbs, can also emit a wavelength at approximately <NUM>. The <NUM> wavelength produces ozone, which is harmful if breathed in by the user. To mitigate this concern, a catalyst can be included within the chamber <NUM>. For example, titanium dioxide (TiO<NUM>) can be used within the inlet chamber <NUM>. In such an implementation, there is sufficient TiO<NUM> surface area to be able to fully catalyze the ozone (O<NUM>) back into oxygen (O<NUM>), which is safe to inhale. Such implementations can include a TiO<NUM> coating along an inner surface of the chamber <NUM>. In some implementations, a mesh or honeycomb-like insert coated with TiO<NUM> can be located within the chamber <NUM> in order to increase the surface area of TiO<NUM>.

In some implementations, a precise UV light source <NUM> can be used. In such implementations, only <NUM> wavelength light is emitted, and as such, ozone is not produced and the catalyst is not required. Such UV light sources can include LEDs and mercury lamps than include quartz-doped globes and/or tubes. As UV light can cause burns on human skin, the inlet chamber <NUM> and the UV light source <NUM> are configured to block UV light from being exposed to the skin of the user and anyone in proximity to the user.

After the air <NUM> has passed through the inlet chamber <NUM>, the air <NUM> enters an accumulation chamber <NUM>. As illustrated, the accumulation chamber <NUM> is behind a face shield <NUM> in front of the user's eyes. In some implementations of face shield <NUM> is not used, and the inlet chamber is connected directly to a breathing chamber <NUM>. The breathing chamber and the transition into the breathing chamber will be discussed later within this disclosure.

From the accumulation chamber <NUM>, fresh air passes into the breathing chamber <NUM>. To go from the accumulation chamber <NUM> to the breathing chamber <NUM>, the air <NUM> passes through at least one check valve <NUM> positioned between the accumulation chamber <NUM> and the breathing chamber <NUM>. As illustrated, two check valves <NUM> are present. Any type of check valve with sufficient sealing and flow characteristics can be uses, for example, a reed valve. This check valve <NUM> only allows air <NUM> to flow one-way through the check valve <NUM>: from the accumulation chamber <NUM> to the breathing chamber <NUM>. As such, as the user inhales, air passes from the accumulation chamber <NUM>, through the check valve(s) <NUM>, and into the breathing chamber <NUM>. Once in the breathing chamber <NUM>, the air <NUM> can be inhaled into the user's lungs. Once the user exhales, the check valve(s) <NUM> close, and the exhaled air <NUM> is unable to flow back into accumulation chamber <NUM>.

Instead, the exhaled air <NUM> passes through a second check valve <NUM> into an exhaust chamber <NUM>. The second check valve <NUM> is also a one-way valve that only allows the exhaled air <NUM> to pass from the breathing chamber <NUM> into the exhaust chamber <NUM>. The exhaust chamber <NUM>, in some implementations, has a second UV light source (not shown). The second UV light source decontaminates the exhaled air <NUM> exhaled from the user. The exhaust chamber <NUM> and the second UV light source are both configured to supply a sufficient dosage of UV light to the exhaled air <NUM> to decontaminate the exhaled air <NUM> before it is released to the surrounding environment <NUM>. In addition, the exhaust chamber <NUM> and the second UV source are configured to prevent UV light from touching the skin. Decontaminating the exhaled air <NUM> allows for the user to continue interactions with susceptible individuals without fear of infecting other individuals around the user. While the exhaled air <NUM> does not backflow into the breathing chamber, precautions can be taken to ensure that any ozone produced by the second UV light source is reduced. As previously described in the context of the inlet chamber <NUM>, a precise UV light source and/or a TIO<NUM> catalyst can be used within the exhaust chamber to reduce ozone levels in the exhaled air <NUM>. Such a precaution allows the protective mask <NUM> to be used in an enclosed space without increasing ozone levels with the enclosed space to dangerous levels. In some implementations, only exhaled air is exposed to a UV light source.

<FIG> is an example protective mask <NUM> according to the present invention with a battery pack <NUM> connected. In some implementations, additional control and power conditioning circuitry <NUM> can be included to drive the ultraviolet light source <NUM>. <FIG> is a schematic diagram of an example protective mask <NUM> according to the present invention with annotated airflows. In the illustrated implementation, the exhaust chamber <NUM> includes a helical flow passage <NUM> surrounding the ultraviolet light source <NUM>, and an inlet passage <NUM> arranged such that ultraviolet light emitted from the ultra violet light source <NUM> does not contact skin of the wearer. In some implementations, the exhaust chamber <NUM> can be arranged such that the exhaust chamber is substantially balanced. That is, the exhaust chamber is arranged such that the weight/balance of the exhaust chamber does not create a moment on the mask <NUM> significant enough to cause excessive discomfort to the wearer.

While primarily illustrated as a complete unit, the concepts described herein can be applied in whole or in part with other, off the shelf components. For example, helical exhaust chambers and ultraviolet light sources described herein can be attached to a standard ventilator mask without departing from this disclosure. The idea of decontaminating exhaled or exhaust air can be applied to other medical devices as well. For example, ventilators and respirators, in addition to or in lieu of using exhaust filters, can instead use these exhaust chambers with a UV light source to decontaminate any air that may be contaminated with pathogens.

While this disclosure contains many specific implementation details, these should not be construed as limitations on the scope of what may be claimed, but rather as descriptions of features specific to particular implementations. Certain features that are described in this disclosure in the context of separate implementations can also be implemented in combination in a single implementation. Moreover, although features may be described as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

Moreover, the separation of various system components in the implementations previously described should not be understood as requiring such separation in all implementations, and it should be understood that the described components and systems can generally be integrated together in a single product or packaged into multiple products.

Claim 1:
A protective mask (<NUM>) comprising:
a breathing chamber;
an inlet chamber defining a flow passage leading into the breathing chamber;
a first check valve between the inlet chamber and the breathing chamber, the first check valve configured to allow air flow from the inlet chamber into the breathing chamber;
an exhaust chamber (<NUM>);
a second check valve between the breathing chamber and the exhaust chamber, the second check valve configured to allow air flow from the breathing chamber into the exhaust chamber; and
an ultraviolet light source (<NUM>) configured to administer a dose of ultraviolet light sufficient to decontaminate gas flowing through the exhaust chamber;
wherein the exhaust chamber comprises
a helical flow passage (<NUM>) surrounding the ultraviolet light source (<NUM>), and
an inlet passage (<NUM>) arranged such that ultraviolet light emitted from the ultraviolet light source is not exposed to skin of a protective mask wearer.