WO2022246152A1

WO2022246152A1 - Mask to promote airtight seal

Info

Publication number: WO2022246152A1
Application number: PCT/US2022/030187
Authority: WO
Inventors: William O'brien
Original assignee: The Cleveland Clinic Foundation
Priority date: 2021-05-21
Filing date: 2022-05-20
Publication date: 2022-11-24

Abstract

Masks (100) adapted to form a seal around an airway of a wearer. The masks include a sealing flap (13) configured to seat between the wearer's lower lip and lower gumline to thereby partially provide said seal. The masks are capable of being placed on a typical patient, or may be quickly and easily configured for use in patients having challenging features that otherwise prevent masks from sealing around the patient's airways.

Description

MASK TO PROMOTE AIRTIGHT SEAL

CROSS REFERENCE TO RELATED APPLICATION

[001] This application claims priority to US Provisional Patent Application No. 63/191,444, filed May 21, 2021, the contents of which are incorporated herein by reference.

BACKGROUND

[002] During medical treatment, some patients receive artificial or mechanical ventilation through a mask that is placed over and substantially covers the patient’s mouth and nose (e.g., airways). Many patients experiencing respiratory distress, cardiac arrest or another medical emergency also receive supplemental oxygen through a mask. As is known, masks are generally configured to extend from the bridge of a patient’s nose to below a patient’s mouth and to surround the patient’s airways. Such masks also include an inlet through which oxygen or air (optionally mixed with other therapeutic agents) may be introduced into the mask.

[003] Traditionally, the outer perimeter of the mask is adapted to provide an air-tight seal with the patient’s face around the mouth and nose to prevent leakage. Improper sealing can lead to inadequate ventilation and a loss of airway pressure between breaths. With a bag mask, for example, effective oxygenation can be obtained by delivering small volumes, at slow rates and at low pressures, ideally less than 30 cm FbO or even 20 cm FhO. A compromised seal around the patient’s airways can result in air/oxygen leakage that yields ineffective oxygenation, especially at the very low pressures typically used for ventilation.

At such low pressures, it is important that the mask seal properly to ensure the forced ventilation inflates the lungs and does not escape the mask.

[004] Thus, traditional masks are not ideal for use on patients with challenging features that will negatively impact the desired seal. For example, a patient’s beard or facial hair may prevent medical personnel from establishing a secure seal between the mask and the patient’s face. Medical personnel may also struggle to secure a mask over the patient’s face if the patient has an atypical facial structure caused by, for example, a tumor, swelling, or abnormal bone structure, or if the patient is edentulous (e.g., missing teeth). In these instances, two or more medical personnel are often required to secure the mask over the patient’s airways and provide oxygen, which expends valuable human resources, complicates operating procedures, and occupies otherwise limited physical space over the patient during treatment or in an emergency.

[005] In one non-ideal solution, medical personnel may cover a patient’s entire face, including the nose, in plastic sheeting and then cut an opening for the patient’s mouth in order to isolate the facial hair and provide a smooth and even surface onto which the mask may be sealed. However, the plastic sheeting may be uncomfortable for the patient, awkward to work with, and not routinely available for rapid application in time-sensitive emergency situations.

[006] Another technique sometimes attempted is to use a conventional mask (e.g. a conventional bag mask) and place a lower annular portion 1 of the mask 2 seal (usually an inflated toroid feature) between a patient’s lower lip 3 and gum line, as shown in Fig. 1. This technique aims to promote a seal between the mask and the patient’s airways by pressing the toroidal seal feature against the gumline. However, as the mask is not configured for such a use, it is susceptible to leaks when used in this manner. Moreover, this technique requires the mask to be held in position securely to the patient’s face to ensure it does not move, again often requiring a second person.

[007] Accordingly, it is desirable to provide a mask capable of being secured to the face of a patient and which will provide a reliable seal despite the presence of facial hair or abnormal features. Ideally such a mask will not require the assistance of additional medical personnel or uncomfortable plastic sheeting. It also is desirable to provide a mask that can be quickly and easily applied in an emergency setting and removed when no longer necessary. It is desirable to have a universal mask that is capable of being placed on a typical patient, or which may be quickly and easily configured for use in patients having challenging features that prevent the mask from sealing around the patient’s airways, as well.

SUMMARY

[008] In accordance with one aspect of the present disclosure, a mask adapted to form a seal around an airway of a wearer along a contact portion thereof is provided. The mask includes a sealing flap that extends from an interior of the mask. The flap is configured to seat between a wearer’s lower lip and lower gumline to partially provide the seal. [009] In accordance with another aspect of the present disclosure, a method of forming a seal around an airway of a wearer is provided. The method includes deploying a sealing flap that is that extends from an interior of the mask. The method also includes inserting the sealing flap into the patient’s oral cavity, seating the sealing flap between the patient’s lower lip and lower gumline, and placing a contact portion over the mask over the wearer’s nasal bridge. The sealing flap and contact surface together form said seal around the airway of the wearer.

BRIEF DESCRIPTION OF FIGURES

[0010] Fig. 1 illustrates an alternative method of securing a traditional mask to a patient’s face.

[0011] Fig. 2 illustrates a side view of an embodiment of a mask having a sealing flap in a deployed configuration, wherein the sealing flap is anchored and extends from an interior portion of the mask; i.e. from an interior portion of the toroidal sealing element in the illustrated embodiment.

[0012] Fig. 3 illustrates another side view of the mask in Fig. 2, wherein the sealing flap is only partially deployed.

[0013] Fig. 4 illustrates yet another side view of the mask in Fig. 2, but with the sealing flap in a fully stowed configuration.

[0014] Fig. 5 shows a front perspective view of the mask of Fig. 2, with the sealing flap fully deployed.

[0015] Fig, 6 illustrates a partial cross-sectional view of the mask in Fig. 2, wherein the sealing flap is anchored and extends from an interior portion of the toroidal seal element.

[0016] Fig. 7 illustrates a side cross-sectional view through the head of a patient who is not wearing a mask.

[0017] Fig. 8 illustrates a side cross-sectional view as in Fig. 7, but with the patient wearing a mask as disclosed, wherein the sealing flap has been deployed and is secured in the space between the bottom lip and the gumline. [0018] Fig. 9 illustrates a side view of a second embodiment, wherein a personal-protection mask (such as an N95 mask) includes a sealing flap extending from an interior portion of the mask, wherein the flap is in a deployed configuration.

[0019] Fig. 10 illustrates a side view of the embodiment in Fig. 9, but with the flap in a stowed position.

DESCRIPTION

[0020] Referring first to Fig. 2, an embodiment of a mask 100 is shown. The mask 100 has a mask body 10 typically in the form of a substantially conically shaped membrane configured to be positioned over the patient’s airways when the mask is fitted to the patient’s face. An inlet 11 provides a passage for delivering air, oxygen or other medicinal gases to the patient’s airways disposed beneath the mask body 10 when fitted. Conventional respiratory masks also include an inflatable toroidal seal element 16 at the base of the mask body 10, whose outer surface (facing the patient in-use) provides a contact portion of the mask; i.e. the portion thereof adapted to contact and form a seal with the patient’s face around his/her airway(s). The inflatable toroidal seal element 16 can be deflected to conform to the shape and contour of the patient’s face around his/her airways when fitted. The toroidal seal element 16 is modestly inflated so that it can bend and flex to conform the face and ensure a proper seal when the contact portion thereof is pressed against the wearer’s face surrounding the airways. However, as noted above abnormal facial features as well as facial hair can negatively impact the seal between the patient’s face and the toroidal seal element 16.

[0021] In the disclosed embodiment, the mask 100 also includes a sealing flap 13 that extends from an interior of the mask 100. Preferably, as illustrated in Fig. 6, the sealing flap 13 is anchored from a seam 14 that extends at least partially about an interior circumference of the toroidal seal element 16. That is, the sealing flap 13 is attached at an interior portion of the toroidal seal element 16 along an arc-shaped seam 14 that extends circumferentially along an interior surface thereof (i.e. within the space sealed between the mask and the patient in- use). However, it is not critical that the sealing flap 13 be anchored from the toroidal seal element 16. Rather, the sealing flap 13 also could be anchored from (i.e. connected to) an interior surface of the mask body 10; e.g. along a seam between the flap 13 and a membrane defining that body 10. [0022] In any case, generally the sealing flap 13 is made of a flexible material that is safe for use in medical procedures including, but not limited to, medical grade vinyls, gels, silicones, rubbers or plastics. In one embodiment, the sealing flap 13 is made of the same material as the body 10 of the mask 100. In an alternative embodiment, the sealing flap 13 may be made of a different material than the body 10 of the mask 100. The sealing flap 13 desirably is flexible in order that it can be supplied in a stowed configuration (see Fig. 4, discussed below) yet be deployed for use as needed (see Fig. 2, also discussed below).

[0023] The sealing flap 13 may be affixed at an interior portion of the mask (e.g. along a seam 14 between it and the toroidal seal element 16 or the mask body 10), by plastic welding. As shown in Fig. 6, the sealing flap 13 is affixed along an arcuate seam to an interior portion of the toroidal seal element 16, and is configured to be folded conformally over the toroidal seal element 16 when stowed (discussed below) so that the sealing flap 13 effectively extends radially outward over an exterior surface of the toroidal seal element 16 as seen in Fig. 2. In an alternative embodiment of the stowed configuration, the sealing flap 13 extends radially inward and conformally follows an interior surface of a lower portion of the mask body 10.

If desired, the seam 14 from which the sealing flap 13 extends can be common to that between the toroidal seal element 16 and the mask body 10, such that the sealing flap 13 is cantilevered from the same location, along the same seam, where other principal components of the mask 100 are affixed to one another.

[0024] As seen in Fig. 2 (as well as Figs. 3 and 4), the sealing flap 13 is disposed so that it follows a lower circumferential portion of the mask 100 (and in the illustrated embodiment, of the toroidal seal element 16), adjacent to where the mask 100 otherwise would seal against the face between the patient’s chin and mouth. Within this region, and preferably centered with respect to a centerline of the mask 100 along the lower circumferential portion thereof, preferably the sealing flap 13 extends around at least 10%, optionally at least 20%, and up to about 50% the contact portion of the mask 100 — i.e. that portion of the mask 100 that otherwise would contact and seal against the patient’s face in-use, the toroidal seal element 16 in the illustrated embodiment. In this manner, when deployed the sealing flap 13 will be appropriately positioned so that it can be interposed between the lower lip and lower gumline of the patient when the mask 100 is fitted around his/her airways in-use. This way, the sealing flap 13 forms a substantially air-tight seal (at the pressures of interest, e.g. < 30 cm FhO) with the patient’s gumline, thereby circumventing deformity or facial hair that may be disposed at the chin or beneath the lower lip. Together with the seal formed between the toroidal seal element 16 and the patient’s face surrounding the airways above the mouth and over the bridge of the nose, the resulting cooperative sealing flap 13 facilitates a substantially air-tight seal (at pressures < 30 cm H2O) that promotes effective ventilation using the mask 100

[0025] It is contemplated that the sealing flap 13 may extend along greater than 50% (e.g. greater than 60%, 70% or even 80%) of the contact portion of the mask 100. However, a range of along about 10%-50% (and centered along the lower circumferential portion of) of the contact portion of mask is preferred, because this will facilitate seating the sealing flap 13 between the lips at the comers of the patient’s mouth when deployed in-use. This, in-tum, will promote an appropriate air-tight seal in cooperation with the patient’s lips and the portion of the toroidal seal element 16 that contacts (and seals against) the face over the nose.

[0026] Preferably, the sealing flap 13 has an annular terminal edge 15 that is made of or incorporates a material or element that is firmer (i.e. more rigid) than the material used for the greater expanse of the sealing flap 13, but which still possesses flexibility. For example, as shown in Fig. 5, a semi-rigid ring 20 can be provided and adhered to the annular terminal edge 15 of the sealing flap 13, whose elasticity allows it to be compressed from its resting configuration in order to actuate the sealing flap 13 to change (e.g. snap) between the deployed and stowed configurations, and to provide suitable rigidity to enable confident placement and retention between the lower lip and gumline in-use. This ring 20 can be affixed via conventional means, such as plastic welding, medical grade adhesives, etc., or it may be embedded via a fold-over portion of the sealing flap 13 at its annular terminal edge 15 as shown in Fig. 5.

[0027] In an alternative example, a wire can be provided to the annular terminal edge 15 of the sealing flap 13 to impart rigidity to its annular terminal edge 15 and facilitate a similar snap-back feature between the deployed and stowed configurations of the sealing flap 13, so that in-use the sealing flap 13 can be snapped out of its stowed configuration wherein it conformally follows the outer surface of the toroidal seal element 16 (Fig. 2), into its deployed configuration (Fig. 4). Conversely, it can be snapped back from the deployed configuration to the stowed configuration (though in practice this should be less common). When deployed, the wire (like the aforementioned ring) can facilitate placement and retention between the lower lip and the gumline in-use. The wire may be comprised of metal, plastic or any other conventional material that is both sturdy and flexible. The wire can be affixed to the sealing flap 13 by embedding it within the flexible material of the sealing flap 13 (which may be formed over, and embedded in it), or the wire may be accommodated within a folding-over portion of the sealing flap 13 at a terminal edge 15 thereof as with the ring discussed in the prior paragraph.

[0028] As a further alternative, the sealing flap 13 itself may be manufactured such that it is thicker or possesses a gradient material composition in the terminal -edge region, in order to impart relatively greater rigidity, yet still retain a suitable elastic modulus. The particular material selected for use at the annular terminal edge 15, i.e. to act as or to supply the desired rigidity, is not critical as long as its modulus is higher than that of the major extent of the sealing flap 13. Suitable materials may include high-modulus polycarbonate or PEEK. The thickness of the terminal edge 15 should be sufficiently low in order to ensure patient comfort when installed between the lower gumline and lip, e.g. in the range of 0.5 to 2 mm.

Regardless how provided, it is desirable that the region of the sealing flap 13 adjacent to its terminal edge 15 possesses an increased elastic modulus (i.e. is relatively more rigid, yet still flexible) compared to the major extent of the sealing flap 13, so that the terminal edge region thereof will be effective to act as an insertion tab for the sealing flap 13 that will hold it in- place between the patient’s teeth and lower gumline, as well as to retain it in the stowed configuration (Fig. 4) if it need not be deployed in a given application (i.e. a patient with no deformities and no facial hair to interfere with forming a proper seal).

[0029] When the terminal edge 15 being firmer than the greater expanse of the sealing flap 13, the terminal edge 15 allows the sealing flap 13 to spring between a deployed configuration (e.g. wherein the sealing flap 13 is unfolded so as to be ready to engage between a patient’s lower lip and gumline as shown in Fig. 2, or otherwise within the patient’s oral cavity), and a stowed configuration (e.g. wherein the sealing flap 13 is folded over the toroidal seal element 16 of the mask 100, seen in Fig. 4). Alternatively, the sealing flap 13 may be manually manipulated by a user between the deployed and stowed configurations. As illustrated in Figs. 2 and 3, in deployed or semi-deployed configurations, respectively, the sealing flap 13 extends away from the interior seam 14 of the mask 100 where it is affixed, so that it may be fitted in the patient’s mouth, wherein the terminal edge 15 will facilitate inserting and then securing the sealing flap 13 preferably in a space between a patient’s lower lip and gumline. Alternatively, in the stowed configuration illustrated in Fig. 4, the resting bias of the terminal edge 15 secures the flap 13 conformationally folded over and against a surface of the mask 100.

[0030] The mask 100 as-described (and shown in Figs. 2-5) is designed so that it can be used as a conventional bag mask having a conventional toroidal seal element, in cases when deformities or facial hair will not negatively impact forming a seal with the patient’s face around the airways. In such instances, the mask 100 is used substantially in the configuration shown in Fig. 4, wherein the sealing flap 13 is in the stowed configuration folded conformally over the toroidal seal element 16 of the mask 100. In this configuration, the mask 100 may be used as a traditional mask; i.e. to provide a conventional seal as if the sealing flap 13 were not there. When stowed, the sealing flap 13 effectively forms part of the outer surface of the toroidal seal element 16 and together with the rest of the seal element 16 forms a seal between the mask and the patient’s face about the airways. However, in challenging situations when a patient has a beard or facial deformity, or is edentulous, the sealing flap 13 is deployed for insertion into the patient’s mouth to facilitate forming an air tight seal suitable for bag-ventilation, for delivery of air/oxygen, etc.

[0031] The following will describe how the mask 100 may be secured to the face of a patient under challenging circumstances with the sealing flap 13 deployed. Fig. 7 illustrates a side cross-sectional view through the head of a patient who has not yet been fitted with a mask. The patient has a bottom lip 17 and a gumline 18, with a space 19 disposed between. Now referring to Fig. 8, with the sealing flap 13 in the deployed configuration, it is inserted into the patient’s mouth using the terminal edge 15 thereof as a tab to guide the sealing flap 13 into the patient’s oral cavity, over the bottom lip 17 and into the space 19 between the bottom lip 17 and the gumline 18, where it may be secured and held in-place via the elastic tendency of the terminal edge 15 to return to its resting conformation once external forces are removed.

[0032] When inserted and positioned as shown in Fig. 8, the sealing flap 13 effectively relocates a portion of the path of contact with the patient’s face along which a seal will be established between the mask and the patient. Instead of a lower portion of the toroidal seal element 16 (or other circumferential seal) contacting the face and forming an air-tight seal below the patient’s lower lip and over the lower cheek-portions adjacent to the chin, the sealing flap 13 effectively short-circuits that lower seal-path segment and relocates it to between the flap 13 and the patient’s lower gumline, terminating at the corners of the mouth between the lips. This avoids positioning the seal along locations where the presence of facial hair or atypical features would inhibit a proper seal. Notably, the sealing flap 13 extends circumferentially about a proportion of the mask sufficient to engage between the lower lip and the gumline, but stopping at opposing locations approximating where the lower and upper lips would intersect. In this manner the sealing flap 13 is insertable between the lips at a location where they meet; i.e. at the corners of the mouth, as opposed to continuing upward along the mask seal in which case the flap may need to be folded over itself to avoid engaging against the upper jaw. From the corners of the mouth upward, the conventional seal between the toroidal seal element 16 and the patient’s face, extending over the bridge of the nose, can complete the circumferential seal about the patient’s airways — wherein the sealing flap 13 provides the lower portion of that seal (in cooperation with the patient’s gumline), and the toroidal seal element 16 provides the upper portion of that seal (in cooperation with the patient’s skin over his/her nose).

[0033] With the mask 100 seated around the patient’s airways in this manner, a compressible bag, for example, can be affixed to the inlet 11 of the mask 100 and used to provide artificial, mechanical ventilation. The composite seal around the patient’s airways provided between the sealing flap 13 and the patient’s lower gumline from the comers of the mouth downward, and between the toroidal seal element 16 and the patient’s skin from the comers of the mouth upward, together are effective to sustain a positive pressure of not less than 5 cm FhO, preferably not less than 10 cm FhO, preferably not less than 15 cm FhO, preferably not less than 20 cm FhO, and most preferably not less than 30 cm FhO.

[0034] As will be appreciated, using a mask 100 as herein disclosed a seal between the mask 100 and the patient’s face may be obtained without requiring additional personnel to hold the mask in place on the patient’s face or having to cover the patient’s face in uncomfortable plastic sheeting in situations where excessive facial hair or other atypical features would result in an inadequate seal.

[0035] The preceding embodiment has been described in relation to a bag mask, where a compressible bag is affixed to the inlet 11 of the mask 100 to provide artificial, mechanical ventilation — often in an emergency. Alternatively, the mask can be a CPAP mask used by patients who suffer from sleep apnea, or any other respiratory mask used to administer gases (such as air or oxygen) to a patient in a setting where a seal between the mask and the patient’s face around the airways is desirable. [0036] It also is to be appreciated that a sealing flap 13 as disclosed herein may be integrated into other types of masks where forming a seal between the mask and a person’s face about the airways is desirable. For example, personal protective masks (such as conventional N95 respirator masks) also benefit from providing a substantially airtight seal about the wearer’s airways. Figs. 9 and 10 illustrate a personal protective mask 200, such as an N95 respirator), which has been fitted with a sealing flap 23 analogous the flap 13 described above in an earlier embodiment. The protective mask 200 has a cup-shaped body 21 to be fitted over a wearer’s airways to provide efficient filtration of airborne particles or contaminants, such as dust, bacteria or viruses. Unlike the mask 100 described in the prior embodiment, a protective mask 200 typically omits both the inflatable toroidal seal element 16 and the inlet 11 configured to deliver air, oxygen, or medicinal gases. Optionally, however, a conventional expiratory check valve (not shown) may be positioned in the cup-shaped body 21 of the protective mask 200 in order to reduce breathing resistance during expiration. An adjustable noseclip 22 typically is included and configured to provide a customizable and secure seal around the bridge of the wearer’s nose adjacent to an upper circumferential edge 26 of the protective mask 200. The protective mask 200 may also contain one or more securing elements 24 (e.g. drawstrings or elastic bands as shown) configured to be placed over or to extend around the wearer’ s head to secure the protective mask 200 and compress it against the wearer’s face to ensure a proper seal about the airways. The securing elements 24 may be made of elastic, fabric, plastic or any other conventional material known in the art.

[0037] The cup-shaped body 21 of the protective mask 200 can be made of one or more layers of non-woven fabric, such as polypropylene, suitable to filter out contaminants of predetermined size and/or composition. The non-woven fabric is durable enough to maintain its cup-like shape, while being flexible enough to conform around the facial anatomy and form a seal around the airways.

[0038] Similarly as in the prior embodiment, a sealing flap 23 is provided extending from an interior surface of the mask and is anchored at an interior surface of the cup-shaped body 21 along a seal 27 therewith. The sealing flap 23 is centered relative a centerline of the mask 200 and follows a pathway extending along a circumference of the mask 200 adjacent to its lower edge, again so that in-use a terminal edge 25 thereof can be inserted into the wearer’s mouth between the lower lip and lower gumline to form a seal therebetween. Again in this embodiment the sealing flap 23 preferably extends along about 10%-50% of a contact portion of the mask 200 (which in this embodiment would comprise a perimeter region along the interior surface of the cup-shaped body 21 that is fitted against the wearer’s face in-use). The sealing flap 23 also preferably is disposed adjacent to and centered at the base (lower portion) of the cup-shaped body 21, so that the sealing flap 23 will be emerge between the upper and lower lips at the comers of the mouth in-use, to promote a proper seal.

[0039] The sealing flap 23 extends from an interior seam 27 along an interior surface of the cup-shaped body 21. Preferably, the interior seam 27 is located in the lower circumferential half of the cup-shaped body 21, consistent with where the sealing flap 23 is to be located with respect to the mask. Except as otherwise described, the sealing flap 23 in this embodiment can be configured and made of the same materials as the flap 13 in the earlier described embodiment. The sealing flap 23 here thus may be affixed to the interior portion of the cup shaped body 21 with an adhesive configured to adhere medical-grade flexible materials, such as medical grade vinyls, gels, silicones, rubbers or plastics, to fabrics, such as a polyvinyl adhesive. The sealing flap 23 may also be affixed to the fabric of the cup-shaped body 21 by, for example, heat-welding, sewing, or any other conventional means known in the art.

[0040] As described herein, the sealing flap 23 is configured to alternate between a deployed configuration (see Fig. 9), wherein the sealing flap 23 is unfolded so as to be ready to engage between a patient’s lower lip and gumline, and a stowed configuration (see Fig. 10), wherein the sealing flap 23 conformally follows a surface of the mask body 21 when not in-use, so as not to interfere with otherwise conventional use and sealing of the protective mask 200. In the illustrated embodiment of Fig. 10, in the stowed configuration the sealing flap 23 conformally follows an interior surface of a lower portion of the cup-shaped body 21, within the mask. It can be unfolded from this conformal configuration when it is desired to deploy it to the configuration shown in Fig. 9. Alternatively, the stowed configuration in this embodiment may be similar to that in the earlier embodiment, wherein the sealing flap 23 will be folded conformally over a lower circumferential edge 28 of the cup-shaped body 21, to follow the contour of the exterior surface of the protective mask 200.

[0041] Although the invention has been described with respect to select embodiments, it shall be understood that the scope of the invention is not to be thereby limited, and that it instead shall embrace all modifications and alterations thereof coming within the spirit and scope of the appended claims.

Claims

1. A mask adapted to form a seal around an airway of a wearer, the mask comprising a sealing flap configured to seat between the wearer’s lower lip and lower gumline to thereby partially provide said seal.

2. The mask of claim 1, said sealing flap extending from an interior of the mask.

3. The mask of claim 1, wherein when said sealing flap partially provides said seal, the seal will be airtight up to a pressure of at least 5 cm TbO.

4. The mask of claim 1, the sealing flap extending along about 10%-50% of a contact portion of the mask, centered at a lower portion thereof.

5. The mask of claim 1, wherein the flap is configured to be actuatable between a deployed configuration wherein the flap can be fitted between the wearer’s lower lip and lower gumline, and a stowed configuration wherein the flap will not interfere with a contact portion of the mask forming said seal.

6. The mask of claim 5, wherein said flap in said stowed configuration forms a part of said contact portion configured to seal against the wearer’s face below a mouth of the wearer.

7. The mask of claim 5, said sealing flap having a terminal edge or edge region configured to secure the sealing flap conformally against a surface of the mask in the stowed configuration.

8. The mask of claim 1, said sealing flap having a terminal edge or edge region that is relatively more rigid than a greater expanse of the sealing flap, said terminal edge or edge region being thereby configured to secure the flap in a space between the wearer’s lower lip and lower gumline.

9. The mask of claim 1, further comprising a mask body comprising a conically shaped membrane, an inlet providing a passage for delivery of a gas to an interior of the mask, and a toroidal seal element secured to said mask body and comprising a contact portion, wherein the sealing flap is attached to and extends from a surface of said toroidal seal element at the interior of the mask, said sealing flap configured to be actuatable between a deployed configuration wherein the flap can be fitted between the wearer’s lower lip and lower gumline, and a stowed configuration wherein the sealing flap is retained conformally against said toroidal seal element.

10. The mask of claim 9, wherein when said sealing flap in the deployed configuration thereof partially provides said seal, the seal will be airtight up to a pressure of at least 5 cm H2O.

11. The mask of claim 1, said mask being a personal protective mask comprising a cup shaped body comprising at least one fabric layer, the sealing flap extending from an interior surface of said cup-shaped body, wherein a perimeter region along the interior surface of the cup-shaped body is the contact portion of said mask.

12. The mask of claim 11, the sealing flap extending along about 10%-50% of a contact portion of the mask, centered at a lower portion thereof.

13. The mask of claim 11, said protective mask being an N95 respirator.

14. The mask of claim 11, wherein the sealing flap is configured to be actuatable between a deployed configuration wherein the sealing flap can be fitted between the wearer’s lower lip and lower gumline, and a stowed configuration wherein the sealing flap will not interfere with a contact portion of the mask forming said seal.

15. The mask of claim 14, wherein a terminal edge of said sealing flap is configured to secure the sealing flap in a space between the wearer’s lower lip and lower gumline in the deployed configuration.

16. A method of forming a seal around an airway of a wearer comprising: deploying a sealing flap extending from the mask; inserting the sealing flap into the wearer’s oral cavity; seating the sealing flap between the wearer’s lower lip and lower gumline; and placing the mask over the wearer’s nasal bridge; wherein said sealing flap and said contact surface together form said seal around the airway of the wearer.

17. The method of claim 16, further comprising attaching a compressible bag to an inlet of the mask; and compressing the compressible bag to provide artificial ventilation to the wearer.

18. The method of claim 17, wherein the seal is airtight up to a pressure of at least 5 cm H2O while compressing the bag to ventilate the wearer.