Imported: 13 Feb '17 | Published: 11 Oct '16
USPTO - Utility Patents
Draping particulate filters for use with the nostrils and mouth is disclosed. The draping particulate filters include diaphanous PM filter material, a pair of tabs having a biocompatible skin contact adhesive located on at least a skin contact side of each of the tabs, and multiple creases formed on the diaphanous PM filter material. Methods of making draping particulate filters are also disclosed.
This disclosure relates generally to particulate filters and, more particularly, to particulate filters for the nose and mouth of a user.
The World Health Organization has estimated that about 7 million people died from air pollution in 2012 and that, in general one-eighth of all global deaths are linked to air pollution. Of greatest health concern is pollution made up of fine particulate matter of 2.5 microns in diameter or less (called “PM2.5”), which is typically, but not exclusively, made up of mineral dust, sulfate and soot particles from burning coal, wildfires and volcanic eruptions, and black carbon from agricultural burning and engine exhausts. Colloquially referred to as “haze”, the problem of airborne particulate matter is greatest across a broad swath of the Earth, stretching from the Saharan Desert in Northern Africa through the Middle East, Northern India and into Eastern Asia, in Borneo, Thailand, and with heaviest concentrations being observed in parts of China. When compared with maps of population density, it has been estimated that more than 80% of the world's population breathe polluted air that exceeds the World Health Organization's recommended level of 10 micrograms of particulate matter per cubic meter.
While levels of particulate matter are comparatively low in the United States, pockets have been identified, through satellite analysis, over urban areas in the Midwest and East. Likewise, high levels of particulate matter have been identified through satellite analysis in at least part of the Mexican state of Chihuahua, and to a lesser extent, elevated levels have been detected in pockets of Western Europe as well.
The biggest problem with PM2.5 is that PM2.5 particulates are small enough to bypass the natural filtration provided by nasal hairs and nasal mucus and thereby can enter the lungs, and in some cases, even pass into the bloodstream. As such, PM2.5 can damage lung tissues, cause inflammation that can cause or aggravate respiratory and cardiovascular disease, can cause placental blood toxicity in pregnant women exposed during the first month of pregnancy, and may lead to certain forms of cancer. Adverse health effects have been associated with exposures to PM2.5 over periods as short as a day, with greater affects being seen from longer exposure. People who are most at risk are people suffering from asthma or battling influenza, those with lung, heart, or cardiovascular disease, and particularly the elderly, and children and it is routine for haze warnings to be issued when the outdoor Air Quality Index (“AQI”) exceeds 100. An AQI of 100 roughly corresponds to a PM2.5 level of 40 micrograms per cubic meter of air (averaged over 24 hours), which is slightly more than the short term standard for potentially harmful PM2.5 exposure established by the Environmental Protection Agency (“EPA”) of 35 micrograms per cubic meter of air.
In an attempt to avoid exposure, particularly in Asian countries, people have resorted to wearing low cost surgical face masks widely available from, among other places, convenience stores. However, such masks are generally not effective because they are designed to prevent the spreading of germs and disease through the exhalation and expulsion of germs by the user and the inhalation of most pollens (which are typically larger than PM2.5). Moreover, such masks are uncomfortable, because they require straps that loop around the user's ears to hold them in place and they substantially block the entire lower portion of the user's face. As a result, they are an impediment to, for example, the user eating and/or drinking, blowing their nose, etc., requiring them to remove the mask to perform those activities.
Enhancements to such masks to provide for better filtration of PM2.5 have been attempted, for example, through the addition of a layer of activated carbon or more specialized filters, but such enhancements can significantly increase the cost, size and obtrusiveness of the masks, making them unsuitable for mass use, particularly in poorer areas of the world where the problem is greatest.
In an effort to avoid some of those issues, attempts have been made to create filtering devices that are inserted as plugs into a user's nostrils to augment or supplant the natural particle catching ability of the nose itself. Thus, while such devices allow for eating and drinking, those filtering devices they do not allow for blowing one's nose without removal and do nothing to prevent particulate matter from entering the body via the mouth. In addition, those devices, being foreign bodies to the nasal cavities and bulky, can themselves trigger sneezing responses in the putative user, rendering them unusable. Even as to users who do not have a sneezing response to such devices, since they must block the nasal passages, they are often uncomfortable to wear and, some types, can be dislodged by strong exhalation or naturally simply through normal breathing over time, leading many users to dispense with using them entirely.
Thus, there is a significant need for a filtration device that can reduce potentially harmful PM2.5 exposure and that does not require insertion into the nostrils, is not as obtrusive as a face mask, and conveniently allows for eating and drinking when necessary.
I have devised a particulate filter for the nostrils and mouth that can reduce potentially harmful PM2.5 exposure in a way that is easy to manufacture, convenient, and less intrusive than a face mask.
One aspect of this disclosure involves a draping particulate filter for use in front of a user's nostrils and mouth. The draping particulate filter includes diaphanous PM filter material, a pair of tabs coupled to the diaphanous PM filter material, a biocompatible skin contact adhesive located on at least a skin contact side of each of the tabs, and multiple creases formed on the diaphanous PM filter material. The particulate filter having an outer peripheral shape bounding the diaphanous PM filter material such that, when the tabs are attached to either side of a user's nose via the biocompatible skin contact adhesive, upon inhalation by the user through their nose, a first portion of the diaphanous PM filter material will act as a nasal filtration region and, upon inhalation by the user through their mouth, a second portion of the diaphanous PM filter material will act as a mouth filtration region and wherein, based upon the creases, the peripheral shape will substantially lie in close proximity to a portion of the user's face.
Another aspect of this disclosure involves a draping particulate filter making method. The method involves forming, on a sheet of diaphanous PM filter material, a peripheral boundary for the particulate filter having therewithin an intended inhalation region; forming a set of creases on the diaphanous PM filter material; and defining an adhesive region on each of a pair of tabs for the particulate filter having a biocompatible skin contact adhesive therewithin, wherein the pair of tabs is connected to the diaphanous PM filter material.
Advantageously, the draping configuration allows the user to perform activities such as eating, drinking, blowing the nose, and sneezing without removing the filter entirely, while not requiring that it be affixed using straps over the ears or behind the head.
Moreover, the draping configuration does not impede exhalation, making it cooler for the user and more beneficial because the user will not re-breathe CO2-laden stale air.
The foregoing has outlined rather generally the features and technical advantages of one or more embodiments of this disclosure in order that the following detailed description may be better understood. Additional features and advantages of this disclosure will be described hereinafter, which may form the subject of the claims of this application.
I have devised a particulate filter configuration for the nostrils and mouth that can be manufactured as a flat sheet, does not need to be inserted into the nostrils at all, is reposition-able, and conveniently allows for activities such as eating, drinking, blowing one's nose while providing greater protection than removal of a face mask would provide.
For simplicity, as used herein, the term “diaphanous PM filter material” is intended to mean any light, floaty, supple, flimsy and/or thin particulate filter material, including nano-fiber or carbon nanotube filter material, that has a filter efficiency of at least PM2.5 and, more ideally, a filter efficiency of at least PM1, and a differential pressure ΔP (“breathability”) measurement of <5 mmH2O/cm2 as measured according to ASTM F2100, European standard EN 14683 or other appropriate alternative standard such that an inhalation-induced pressure differential, or suction caused by inhalation, will cause the material to move in the direction of and with the moving air.
In simplified overview, I have created a draping particulate filter that is made of a diaphanous PM filter material that has a peripheral shape and origami-type folds or living hinges such that, when worn, it lies draping in close proximity to the nostrils and mouth such that inhalation through the nose will cause it to substantially cover the nostrils, and inhalation through the mouth will cause it to substantially cover the mouth, in order to filter out at least PM2.5 matter while being minimally affixed to part of the user's nose in a draping manner. This draping configuration helps ensure that exhaled air is not trapped in front of the nostrils or mouth, so the user does not re-breathe stale exhaled air. Moreover, using a draped configuration allows filters designed according to the teachings herein to more freely move away from the user and thereby reduces the amount of their exhaled CO2 that the user will re-breathe upon inhalation.
FIGS. 1A-1B illustrate, in simplified form, functional examples of two different alternative implementations 100a, 100b of a draping particulate filter 100 constructed according to the teachings herein. As shown, the draping particulate filter 100 has three functional regions, the affixation regions 102, the nasal filtration region 104 and the mouth filtration region 106. These three regions define the operational areas of different embodiments of draping particulate filters 100 constructed according to the teachings herein, irrespective of the shape of the peripheral boundary 108 that any particular embodiment of the draping particulate filter 100 may have.
Functionally, the affixation region is within at least a portion of a pair of tabs 108 or protrusions of the draping particulate filter 100 and contains a biocompatible skin contact adhesive (interchangeably also referred to as a “soft skin adhesive”) that is used to removably and/or reposition-ably affix that portion of the draping particulate filter 100 to the user, as will be described in greater detail below. Advantageously, the tabs 108 may be of any size or shape sufficient to ensure proper adhesion to the user while allowing the diaphanous PM filter material to be positioned such that it drapes in front of, and in close proximity to, the user's nostrils and mouth.
The nasal filtration region 104 defines the area that, when the draping particulate filter 100 is properly applied to a user, is in close proximity to, or covers, at least the nostrils or naris of the user to filter the particulate matter.
The mouth filtration region 106 is similar to the nasal filtration region 104 and defines the area of the draping particulate filter 100 that, when properly applied, will be drawn against the mouth during mouth inhalation to filter particulate matter from the air entering via the user's mouth.
As shown in the example of FIG. 1A, the entire area within the peripheral boundary 110 is made up of the diaphanous PM filter material, whereas, as shown in the example of FIG. 1B, the rectangular boundary area 112 (i.e., exclusive of the tabs) is made up of the diaphanous PM filter material, but the tabs 108 may be made of some other material as will be described in greater detail below. Advantageously, the peripheral boundary shape can be any shape provided that there is a sufficient margin of material around the nasal filtration region 104 and mouth filtration region 106 to allow the diaphanous PM filter material to substantially seal about the nostrils or mouth during inhalation to maximize the amount of air subject to filtration.
In either case, the tabs 108 are used to affix the draping particulate filter 100 to at least a portion of the alar nasal sulcus, the nasal lobule and/or the nasal ala on both sides of the user's nose so that, the remainder of the draping particulate filter 100 is still fairly freely movable with the nasal filtration region 104 being in front of and in close proximity to the user's nostrils, the mouth filtration region 106 being in front of and in close proximity to the user's mouth, and the peripheral edges of the draping particulate filter 100 being in substantially close proximity to the user's face. This is illustrated in FIGS. 2A-2C. Moreover, in some implementations, the shape of the tabs 108, and the space in between them, are formed to help automatically ensure proper placement of the draping particulate filter 100 by the user when applying to, or repositioning it on, their nose.
FIG. 2A illustrates, in simplified form, a front view of one example implementation of a draping particulate filter 100 constructed as described herein, positioned as it would be in use on a representation 200 of a human face. FIG. 2B illustrates, in simplified form, an angled partial side perspective view of the representation 200 of the human face of FIG. 2A showing the draping particulate filter 100 up against the user's mouth while air is being drawn in through the mouth (i.e. in the direction of the arrow during inhalation). As can be seen in FIG. 2B, the suction and/or lower pressure due to the inhalation through the mouth, causes the draping particulate filter 100 to move from its draped position closely in front of the mouth (indicated by the dashed line) to a position up against the mouth. Likewise, FIG. 2C illustrates, in simplified form, an angled partial side perspective view of the representation 200 of the human face of FIG. 2A showing the draping particulate filter 100 up against the user's nostrils while air is being drawn in through them (i.e. in the direction of the arrow during inhalation). As can also be seen in FIG. 2C, the suction and/or lower pressure due to the inhalation through the nostrils, causes the draping particulate filter 100 to move from its draped position closely in front of the nostrils (indicated by the dashed line) to a position up against the nostrils.
As can be seen in FIGS. 2A-2C, the tabs 108 of the draping particulate filter 100 are arranged such that the dorsum 202 and apex 204 of the nose are not covered, making the draping particulate filter 100 less obtrusive than a conventional face mask that uses ear straps, or straps that fit behind the head, to hold the mask in place.
As can be further seen in FIGS. 2A-2C, the draping particulate filter 100 includes a series of origami-like folds, non-perforating scores or living hinges, or some combination thereof, 206 (interchangeably referred to herein as “creases” and described in greater detail below) that alter the shape during use and/or provide for articulation of a part of the draping particulate filter 100 at specified locations to thereby allow the draping particulate filter 100 to closely conform to a range of user nostril and mouth sizes and shapes when draped.
FIGS. 3A-3C illustrate, in simplified form, three alternative example implementations of draping particulate filters 100 constructed as described herein.
As noted above, and shown more clearly in FIG. 3A, the draping particulate filter 100 is made up entirely of the diaphanous PM filter material 302 (indicated by cross-hatching) and includes the series of creases 206 that create articulation points or shape alterations for the filter 100 when worn. The user makes use of the creases 206 when applying the filter 100, typically by simple application of pressure to the mask over the face once the tabs 108 have been applied to at least a portion of the alar nasal sulcus, the nasal lobule and/or the nasal ala on both sides of the user's nose, so that the nasal filtration region 104 (FIG. 1) lies draping in close proximity to or over the user's nostrils, the region of the filter 100 below the nasal filtration region 104 then lies draping in close proximity to the front of the user's mouth, and the outer periphery 110 of the filter 100 lies in close proximity to part of the user's face. At this point it should be noted that the term “close proximity” is intended to simply mean close enough such that normal inhalation will draw the diaphanous PM filter material to and against the orifice (nostril and/or mouth) and result in the diaphanous PM filter material forming a seal substantially around the periphery of the nostril(s) and/or mouth such that most, if not all, of the inhaled air will pass through the diaphanous PM filter material.
Depending upon the particular implementation, in general, the locations of the creases 206 for different filters 100 can be placed differently to accommodate or allow for nostrils and mouths of different sizes, spacing and/or shapes. Alternatively, a particular filter 100 implementation can have multiple sets of creases 206 such that a single filter 100 can accommodate nostrils and mouths of different sizes, spacing and/or shapes depending upon the particular creases 206 that are used. Moreover, one or more particular creases 206 can be placed so as to allow a user to fold up a part of the filter 100 that is in front of the mouth, for example, to allow for eating and/or drinking, while leaving the portion of the mask that filters PM2.5 from entering the user's nostrils in place or to fold up the filter such that both the mouth and nostrils are exposed to, for example, accommodate blowing the nose, without removing the filter tabs 108. Thus, when the particular activity is done, the user can merely fold back down that portion and filtering will resume.
In other words, there is no requirement that any particular crease 206 be placed in the specific locations shown or must be used for any particular user's face, the particular placement of the creases 206 being an implementation detail.
At this point it is important to note that the draping particulate filters described herein are designed to filter at least PM2.5 during user inhalation and serves little to no purpose during user exhalation, hence the ability to use a draping configuration. Moreover, most people, under normal circumstances, primarily inhale through their nostrils but may inhale through their mouth during certain activities like talking and some aerobic activity. Advantageously, by using a diaphanous PM filter material, because it is so light and floaty, and the creases keep it in close proximity to the user's nostrils and mouth, the beginning of inhalation through the nostrils and/or mouth will draw the diaphanous PM filter material towards the nostrils and/or mouth and cause it to substantially seal against the user such that a substantial portion of the inhaled air will respectively pass through the nasal filtration region 104 and/or mouth filtration region 106 and be filtered thereby.
FIG. 3B illustrates, in simplified form, another alternative example implementation draping particulate filter 100, in this case one made of two pieces. As shown, with this configuration draping particulate filter 100, only a portion 304 is made up of the diaphanous PM filter material 302, and the portion 306 containing the tabs 108 is made of a different material which is bonded in some suitable known way to the portion 304 made up of the diaphanous PM filter material 302. With this configuration, the material that is chosen for the tabs 108 can be any material that does not compromise the filtering through the nasal filtration region 104 during inhalation by creating a bypass path.
FIG. 3C illustrates, in simplified form, yet another alternative example implementation draping particulate filter 100. The draping particulate filter 100 of FIG. 3C is made up of a portion 308 that is very light and flimsy, but in this example is substantially air impervious, and a portion 310 made up of the diaphanous PM filter material 302. Depending upon the particular implementation, the portion 310 can be a single area encompassing the nasal filtration region 104 and mouth filtration region 106, it can be separate areas for the nasal filtration region 104 and mouth filtration region 106, or it can be further broken down into discrete diaphanous PM filter material 302 for each nostril and one or more pieces for the mouth inhalation filtration.
Having described different draping particulate filter 100 configurations, examples that are generally representative of the class of particulate filters 100 described herein, materials suitable for manufacture of such filters 100 will now be described.
In general, materials suitable for use as the diaphanous PM filter material include, for example (but are by no means intended to be limited to), Nanovia Dust Protection Membrane NW 70, Nanovia AntiVirus SMNF 57 Membrane, Nanovia Clean Air NW 60, Nanovia Surgical Mask 20 and Nanovia Surgical Mask 40 materials, commercially available from Nanovia Ltd., Podkrusnohorska 271, 436 03 Litvinov-Chuderin, Czech Republic (www.nanovia.cz), as well as carbon nanotube filter sheeting described in O. Yildiz et al., Carbon, Vol. 64, pp. 295-304 (2013) and any other nanofiber HEPA-type filter material that and is sufficiently diaphanous to operate as described herein and can be provided with creases as described herein, while still meeting the definition of “diaphanous PM filter material” provided above.
Materials suitable for the tabs 108, as described herein, if not made of the diaphanous PM filter material, include (but are by no means intended to be limited to), most medical and/or surgical grade pressure sensitive adhesive tapes, for example tapes commercially available from 3M sold under the Medipore™, Medipore™, Micropore™, and Transpore™ brands, and SC Thermoplastic Elastomer Film Tape 2475P or similar tapes from other manufacturers.
Moreover, if enhanced unobtrusiveness is desired, then clear tapes or tapes closely approaching user skin color will be preferable to opaque tapes that likely will contrast highly with a user's skin. Alternatively, as indicated above, other substrates or the diaphanous PM filter material itself can be used for the tabs 108, provided an appropriate skin contact adhesive is applied so that the tabs 108 can be removably adhered to the skin of the nose, such adhesives including (but by no means are intended to be limited to), for example, P_DERM™ brand skin contact adhesives commercially available from Polymer Science Inc., 2787 S. Freeman Rd., Monticello, Ind. 47960, Dow Corning® 7-9700 Soft Skin Adhesive, commercially available from Dow Corning Corp., PO Box 994, Midland, Mich. 48686-0994, skin contact adhesives based upon Baymedix® A, commercially available from Bayer MaterialScience AG, 51368 Leverkusen, Germany (www.baymedix.com), and Silbione® skin adhesives commercially available from Bluestar Silicones, Two Tower Center Blvd., Suite 1601, East Brunswick, N.J. 08816. Thus, it should be understood that the important aspect for the tabs 108 is that they can removably attach the draping particulate filter 100 to the user via an appropriate adhesive, not the particular material or adhesive that is used to do so, the selection of particular material(s) for the tabs being one of implementation design choice. One factor that may influence the particular adhesive used is the way that it will be applied. Some adhesives are best applied through roller or spray application, whereas others are easily applied using, for example, pattern printing.
In the case where two different materials are used to make particulate filters 100 as described herein, e.g., the diaphanous PM filter material and some other material are to be joined together, any appropriate method for doing so that does not adversely affect the diaphanous PM filter material from filtering or moving as described herein may be used.
Having described different materials suitable for manufacture of particulate filters 100 as described herein, various example methods of manufacture of such filters 100 will now be described.
Depending upon the particular implementation, the creases 206 can be formed in, for example, any one or more of the following ways. The creases 206 can be formed using origami and/or oribotics techniques involving repeated folding and unfolding that weaken the areas along the fold lines such that movement will more easily occur along those lines. The creases 206 can be formed by slightly scoring or cutting into one or both sides of the surface of the diaphanous PM filter material provided that the filtration efficiency in the area of the cuts (i.e. caused by the depth of the score(s) or cut(s)) does not cause that area to not meet the diaphanous PM filter material definition, even though the efficiency may be degraded in those areas. The creases 206 can be formed by application of localized pressure and/or heat that compresses or otherwise deforms the fibers of the diaphanous PM filter material so as to weaken that area and/or thin the material in one area relative to the surrounding material and thereby form living hinge-type flex points. Other methods of crease 206 creation can also be used, the important aspect being the creation of the creases 206, not the manner in which they are created.
The overall creation of the particulate filters 100 can follow any of several approaches, bearing in mind that the specific ordering of the steps may be varied in different implementations that still result in a draping particulate filter 100 as described herein, the important aspect being the performance of the steps, not any particular ordering thereof.
In some cases the draping particulate filters 100 will be individually manufactured purely from the diaphanous PM filter material, the process involves: (a) cutting the specific peripheral shape so as to form the tabs 108 and encompass the nasal filtration region 104 and mouth filtration region 106 with sufficient material border around them to allow for drawing against part of a user's face during inhalation while minimizing infiltration of unfiltered air from the periphery, forming the creases 206, and (c) applying the appropriate adhesive to what will be the affixation regions 102 of the tabs 108, with (a) through (c) occurring in any order.
In other cases the filters 100 will be created in a strip configuration. FIG. 4 illustrates, in simplified form, a strip 400 of particulate filters 100 constructed according to the teachings herein. As shown, the strip 400 is made up of a single row of individual 402-1, 402-2, 402-3, 402-n particulate filters 100. The filters are created by, in appropriate order, (a) forming the creases 206, (b) applying the selected adhesive to the area for the tabs 108 on the tab side of the lowermost (in the figure) crease 206-1, (c) removing the areas 404 that would impact the apex of a user's nose so as to intrinsically form the tabs 108. Once steps (a)-(c) are complete, depending upon the particular implementation, cuts can be made to separate the individual filters 100 402-1, 402-2, 402-3, 402-n. Alternatively, perforations can be made between the individual filters 100 402-1, 402-2, 402-3, 402-n so that they can be provided in an accordion folded strip or roll form and easily separated later.
For a strip of this type where the tabs will be a separate piece, in appropriate order, steps (a)-(c) would be performed on the diaphanous PM filter material. The tabs 108 would be formed and then joined to the diaphanous PM filter material, or the material for the tabs would be joined to the diaphanous PM filter material and then formed. If the material for the tabs is not a tape or other material that comes with adhesive already applied, then the adhesive could be applied before or after forming the tabs 108 or joining of the tab material to the diaphanous PM filter material, depending upon the particular implementation. To join the tab material to the diaphanous PM filter material any appropriate method may be used including, for example, heat bonding or adhesive.
FIG. 5 illustrates, in simplified form, a sheet 500 of particulate filters 100 constructed according to the teachings herein. As shown, the sheet 500 is made up of an array of four by “n” individual filters 100. The manufacturing process for such a sheet is similar to that of the strip, except that, the edge areas 404 and the analogous internal areas 504 will need to be removed. Advantageously, the sheet approach allows a large number of filters 100 to occupy a relatively small volume. For example, a 9″ by 12″ (˜23 cm by 30.5 cm) sheet can contain an array of twelve filters 100, so only about 31 sheets, at about the thickness of a published magazine, would contain an entire year's supply of filters 100 for one person and a year's supply of filters 100 for a family of four would not be much thicker than the thickness of a typical hardcover novel. This is valuable because, in poor areas where the PM2.5 particulates are a significant problem, storage space may be at a premium.
Depending upon the particular implementation, particulate filters 100 constructed as described herein can be packaged individually or packed together in larger quantities as desired. Ideally, whatever the configuration, prior to distribution they will be packaged in sealed sterile packages. The creation of individual or bulk sterile packages for distribution is well known, so that aspect will not be discussed herein.
As a final matter, it should be noted that, while the foregoing filters 100 provide significant advantages, there are circumstances where they may not be fully effective, for example, if used by people with beards, thick moustaches and/or other facial hair around the mouth area. Nevertheless, the foregoing design, if applied properly, can still provide significant nasal filtration, even if less than optimal. Given the potentially harmful nature of PM2.5 particulates, even partial filtration is better than no filtration at all.
Usage of the Particulate Filter
A significant advantage to the draping particulate filters 100 constructed as described herein is their ease of use and comfort relative to filters that must be inserted into the nostrils or face filters 100 that are held on via straps fitted behind the user's ears or head.
To use the particulate filters 100 constructed as described herein, the user takes a filter and places it so that the bottom of the cutout area 404 is just below the apex of the user's nose with the user's nose apex between the tabs 108 within the cutout area 404 and applies the tabs 108, via the adhesive, over the outside of the nose (the ala of the nose), such as previously shown in FIGS. 2A-2B, so that the nasal filtration area 104 is draped in front of and is either in close proximity to, or in some cases covers, the users nostrils. The user then manipulates the filter 100, visa the creases 206, such that the mouth filtration area 106 lies in close proximity to (or touches) the user's mouth and, ideally is in close proximity to the user's face all around the peripheral edge so as to enhance the “draw” of the diaphanous PM filter material towards the mouth during mouth inhalation. Note here that, since the filter 100 is only affixed to the ala of the nose and the remainder of the mask hangs free in a draping configuration such that it can “flap” inwards and outwards as the user inhales and exhales, providing significant comfort for the user.
In addition, if the user needs to eat, drink, smoke, expectorate, etc, they can merely fold the lower portion of the filter (i.e., containing the mouth filtration area 106) up, depending upon the particular implementation and user, on the outside of the filter or under on the inside of the filter along a crease, which will leave the nasal filtration area 104 relatively unaffected. FIG. 6 illustrates, in simplified form, the filter 100 of FIG. 2A when the lower portion has been folded up and under (i.e. between the upper portion and the user's face).
Likewise, if the user needs to blow their nose or sneeze, they can fold the lower portion up entirely such that both the nostrils and mouth are exposed. Advantageously, in doing so, the tabs 108 of the filter 100 need not be removed and when the user is done, that portion of the filter can be lowered and re-draped and resume filtering during inhalation. FIG. 7 illustrates, in simplified form, the filter of FIG. 2A after part of the filter has been folded up to uncover the nostrils for blowing the nose or sneezing without removing or repositioning the filter tabs.
It should be understood that this description (including the figures) only includes some illustrative embodiments. For the convenience of the reader, the illustrative embodiments of the above description is a representative sample of all possible embodiments, a sample that teaches the principles of the invention. The description has not attempted to exhaustively enumerate all possible variations. That alternate embodiments may not have been presented for a specific portion of any variant, or that further non-described alternate embodiments may be available for a portion of a variant, is not to be considered a disclaimer (intentional or unintentional) of those alternate embodiments. One of ordinary skill will appreciate that many of those non-described embodiments incorporate the same principles of the claimed invention and that others are equivalent thereto.