Facial mask

Abstract

To provide a face mask and a method for manufacturing the same.SOLUTION: A face mask comprising a seal member 25 depending from the mask body for stable engagement with the wearer's face, a nose portion 27 for receiving the wearer's nose, a mouth portion 26 for receiving the wearer's mouth, and a cheek portion 28 extending laterally across the wearer's cheeks.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to facial masks, methods of making facial masks, and facial masks made by the disclosed methods. [Background technology]

[0002] Face masks are used for a variety of reasons, including medical treatment and for personal protection (in both medical and non-medical settings).

[0003] Some masks, or filter masks, are needed to filter particulate matter from the air. Such masks are typically one of two types. In particular, a face mask can have a mask body that itself functions to filter particulate matter from the air. This type of filter mask is typically lightweight and relatively inexpensive, being single-use and disposable. Alternatively, a face mask may have a mask body adapted to receive a filter cartridge. Such a filter cartridge may be replaceable, allowing the face mask to be reusable.

[0004] Filter masks can be worn in work or public settings to protect against dust, smoke, and other harmful substances, as well as against pathogens such as viruses or bacteria. For example, in healthcare settings, filter masks are used to prevent inhalation of pathogens from the environment by preventing particulates, such as droplets and aerosols, from passing through the mask. Filter masks can also protect others from pathogens exhaled by the wearer.

[0005] A filter mask typically comprises a filter, such as a sheet of woven or nonwoven filter material, and a means for holding the mask on the wearer's head, for example, by elastic loops placed around the ears. In use, the filter covers the user's mouth and nose or otherwise directs air through the filter, so that all air inhaled by the wearer passes through the filter. To protect others from pathogens exhaled by the wearer, the filter may be positioned so that all air exhaled by the wearer passes through the filter.

[0006] Filtering masks worn in work environments, such as by medical professionals, must remain securely fitted to the face and be comfortable to wear for significant periods of time in environments where the risk of contamination may be high. Such masks must fit snugly against the wearer's face, preferably forming a seal against the face to prevent inhaled and exhaled air from passing around the edges of the mask.

[0007] Filter masks are generally single-use products that are manufactured and sold in large quantities. To make this type of product commercially viable, the cost and complexity of manufacturing must be minimized.

[0008] In many situations, it is desirable for a mask to seal against the wearer's face to prevent air from entering or leaving around the periphery of the mask. Creating an effective seal against the various contours of the face can be difficult, and cushion seals made of elastic materials that compress against the face to form a seal are commonly used. However, such seals can fail during movement of the wearer's face (e.g., during conversation) and can tend to shift laterally across the face. Summary of the Invention [Problem to be solved by the invention]

[0009] SUMMARY OF THE INVENTION A mask and method of manufacturing the same has now been developed that overcomes or substantially mitigates the above-referenced and / or other problems associated with the prior art. [Means for solving the problem]

[0010] SUMMARY OF THE INVENTION According to one aspect of the present invention, there is provided a filter mask comprising a support frame, a filter, and a seal member, the seal member being secured to the support frame and the filter.

[0011] The support frame and filter together may define a mask body that forms a cavity for accommodating the wearer's mouth and nose. The mask body may be curved in at least the transverse plane.

[0012] The support frame may be made from a plastic material such as polypropylene, poly(styrene-butadiene-styrene) (SBS), polycarbonate, plastomer, thermoplastic, thermoplastic elastomer, thermoset, or blends or combinations thereof.

[0013] The support frame may have an outer surface and an inner surface, the inner surface facing the wearer in use and the outer surface facing away from the wearer in use.

[0014] The support frame can support at least a portion of the filter, for example, by preventing distortion of the sheet of filter material. The support frame can provide rigidity to the mask. The support frame can hold the filter media at a distance from the face, thus preventing direct contact of the filter media with the mouth and / or nose, reducing or preventing filter degradation and contamination and improving wearer comfort.

[0015] The support frame can be in the form of a rim, for example, conforming to the shape of the filter material. The rim may have the form of a closed loop. The rim can define an opening through which inhaled and / or exhaled air flows in use. When the filter is placed on the support frame, the support frame can extend around the periphery of the filter. The support frame can include a shoulder extending from the inner edge of the rim, which provides a surface against which the filter can be placed and facilitates retention of the filter within the mold prior to injection molding of the seal member. The filter can be placed on the inner surface of the support frame. The periphery of the filter can be sealed to the support frame, such that air cannot flow between the edge of the filter and the support frame; inhaled air must pass through the filter.

[0016] Instead of or in addition to a rim, the support frame may include one or more ribs, e.g., a plurality of ribs, configured to abut against the surface of the filter, e.g., to provide support to the filter and rigidity to the mask. The one or more ribs may have a shape corresponding to the shape of the surface of the filter. The one or more ribs may be shaped to extend across the surface of the filter. The one or more ribs may extend between two opposing sides of the rim or support frame and be shaped to abut against the surface of the filter. The one or more ribs may have an arcuate shape. Such ribs can provide structure and / or rigidity to the rim or support frame, helping to maintain the shape of the mask and prevent distortion of the filter material.

[0017] The outer surface of the support frame may further comprise a shield extending over at least a portion of the surface of the filter in a filter mask according to the invention. The shield may be separate from the filter or may be positioned in front of the filter so that air can flow between the shield and the filter before being drawn through the filter by the wearer. Thus, a space or gap may exist between the shield and the filter. An inlet opening may be defined between the edge of the shield and the surface of the filter through which air can be drawn by the wearer inhaling. The shield may not contact the filter.

[0018] The shield can provide a barrier against which particles in the environment impinge. Therefore, the shield can reduce the amount of particles that strike the filter during use, thereby extending the useful life of the filter, and therefore the filter mask. The separation between the shield and the filter allows incoming air to flow through the filter across its entire surface, even if the shield is impermeable or substantially impermeable. The shield also provides reinforcement to the mask, preventing it from collapsing longitudinally and keeping the mask positioned correctly against the wearer's nose and chin.

[0019] The shield may be formed from a plastic material, which may form a solid barrier for deflecting particles and may reduce the risk of physical damage to the filter by providing a protective barrier. The shield may form a rigid barrier.

[0020] Alternatively, the shield may be a composite shield formed from two or more components. The composite shield may include a sheet of filter material (shield filter) and a shield frame, with the shield filter overlaid on and attached to the shield frame. The shield frame may be a plastic frame or may form part of the support frame. The shield frame may include a shield rim having substantially the same shape as the intended shield and / or shield filter, with the shield rim attached to the periphery of the shield filter. Such a composite shield can actively absorb and block contaminants and reduce moisture accumulation within the mask, increasing wearer comfort. The composite shield may be removably secured to the mask so that it can be replaced if saturated. Either the entire composite shield or only the sheet of filter material may be removable and replaceable.

[0021] In the following paragraphs, unless otherwise indicated, references to "shield" refer to both shields formed from plastic material and composite shields formed from a shielding frame and a shielding filter. Additionally, unless otherwise indicated, references to "filter" refer to the main filter, i.e., the filter held by the support frame, and references to "shield filter" refer to the filter that forms part of the composite shield.

[0022] The surface area of ​​the shield may be at least 50%, at least 60%, at least 70%, or at least 80%, or at least 90%, or at least 95% of the surface area of ​​the filter. The surface area of ​​the shield may be up to 110%, or up to 105%, or up to 100%, or up to 95% of the surface area of ​​the filter. The shield may extend over at least 50%, at least 60%, at least 70%, or at least 80%, or at least 90%, or at least 95%, or up to 100% of the surface area of ​​the filter.

[0023] The shield may extend over the entire surface area of ​​the filter, or may extend beyond the periphery of the filter so that the shield overhangs the edge of the filter. Alternatively, the shield may extend over less than 100% of the surface area of ​​the filter so that a portion of the filter is exposed at the periphery of the shield. Alternatively or additionally, the shield may include a filter material. The shield may be formed with openings through which the sheet of material is exposed, which openings can aid in air flow to help evenly distribute the particle load on the filter. Alternatively, the shield may not have openings and form a continuous barrier. Thus, the shield may comprise a continuous surface that extends across most of the surface of the filter material.

[0024] The support frame may include a shield extending across at least a portion of the outwardly facing surface of the filter, with at least a portion of the periphery of the shield being separated from the support frame. One or more inlet openings may be defined between the shield and the support frame, through which air is drawn upon inhalation by a wearer.

[0025] The support frame may further include one or more seal support members. The support frame may include one or more seal support members located anywhere the seal requires reinforcement. The support frame may include one or more seal support members in the chin region, nose region, and / or cheek region. In particular, the support frame may include one or more seal support members in the chin region. The one or more seal support members may provide additional support to the seal, help prevent the seal from collapsing, and improve fit. The one or more seal support members may extend outward from the support frame and abut against the seal member, and may have a shape corresponding to the shape of the portion of the abutting seal member. The one or more seal support members may have an arcuate shape.

[0026] At least one seal support member may be disposed in the jaw region, and the jaw region of the support frame may include at least one downwardly depending seal support member. The at least one seal support member may include a tab extending outward from the support frame and may extend downward in a direction substantially perpendicular to the support frame. The at least one seal support member may extend to the distal edge of the seal member or may extend across only a portion of the depth of the seal member. The at least one seal support member may be bonded to the seal and / or the seal may be overmolded onto the seal support member during an overmolding process. The seal support member provides additional reinforcement to the jaw region and helps prevent seal collapse in this region, which helps improve and maintain the seal.

[0027] The support frame is typically formed from a plastic material that retains its shape during use. The support frame may include a rim and / or a shield or shield frame, and / or one or more connecting members and / or one or more seal support members. If multiple components are present, the entire support frame may be integrally formed, for example, by injection molding, or the support frame may be formed of two or more parts that are connected together, for example, by gluing, welding, or mechanical fastening. Thus, if the support frame includes a rim and a shield or shield frame, the rim and shield or shield frame may be integrally formed in a single injection molding step, or the rim and shield or shield frame may be formed separately before being joined together, either chemically or mechanically.

[0028] The filter may be formed from a filter substrate that is dense enough to prevent the passage of most airborne particles, such as dust particles, liquid droplets, and aerosols. The masks of the present invention may filter out at least 80%, or at least 85%, or at least 90%, or at least 95%, or at least 99% of airborne particles.

[0029] In countries including the UK and countries of the European Union, FFP standards specify the requirements for filter masks as respiratory protection devices. The EN149 standard defines three classes of filter efficiency: FFP1, FFP2, and FFP3. The mask of the present invention may, for example, be an FFP3 mask, which, under the EN149 standard, has a minimum filter efficiency of 95 L / min airflow. The mask of the present invention may be an FFP2 mask, which filters out at least 94% of airborne particles at 95 L / min and has a total inward leakage of less than 8%. In the United States, the National Institute for Occupational Safety and Health (NIOSH) provides the N95 classification for air filtration, and the mask of the present invention may be an N95 mask, which means that it filters out at least 95% of airborne particles.

[0030] Materials suitable for use as filter substrates are known in the art, and any suitable material can be used for the sheet of filter material in the present invention. For example, the filter can be a nonwoven material, an electrostatic material, a meltblown material, a spunbond material, a woven material, a nanofiber material, or a nanoweb material, or can be formed from a glass fiber medium. The filter can include multiple layers to enhance its performance and enhance wearer comfort. Thus, the filter can include one or more layers selected from nonwoven materials, electrostatic materials, meltblown materials, spunbond materials, woven materials, nanoweb materials, and / or nanofiber materials. For example, the filter can include layers of nonwoven materials, electrostatic materials, and meltblown materials, along with a fibrous layer, to enhance wearer comfort and provide structure to the filter. The filter can have any suitable configuration; for example, the surface of the filter can be smooth, e.g., flat or planar, or the filter can be pleated. The filter (pleated or non-pleated) may have flat or planar areas around its periphery to facilitate the overmolding process. The filter may further include one or more additives to enhance its effectiveness in reducing or preventing the transmission of pathogens, such as antimicrobial agents.

[0031] The use of pleated filters increases the filter's surface area, improving its effectiveness. Pleating a filter can increase its surface area by 5 to 50%, or 5 to 30%, or 10 to 20% compared to a non-pleated filter. To accommodate a pleated filter, the shape of the support frame can correspond to the shape of the pleated filter, ensuring a tight fit between the two components to prevent leakage. For example, if the filter abuts a shoulder or rim on the support frame, the shoulder or rim can have a series of corrugations that correspond to the pleats of the filter, so that when the filter contacts the shoulder or rim, the corrugations nest with the pleats of the filter to ensure a tight fit. The filter can be pleated before being placed in a mold with the support frame, and a seal member can be overmolded to secure the seal member, support frame, and filter together. Alternatively, pleats may be formed in the filter by compressing an unpleated (i.e., flat or planar) filter between a corrugated rim or shoulder of the support frame and a correspondingly shaped mold before overmolding the seal member to secure the seal member, support frame, and filter together.

[0032] The filter placed in the mold in the method of the present invention may include only a filter substrate and may be flexible in form. The filter may not include a support for the filter substrate until secured to the support frame and seal member.

[0033] The filter may be cut to the correct shape from a larger sheet of filter substrate, for example, using a die. If the filter is formed from multiple layers, the filter may be cut to size and the edges may be sealed in a single hot stamping process, in which heat is used to seal the peripheral edges of the filter during the cutting process. The sealed periphery prevents moisture or contaminants from penetrating into the interior of the filter material between the layers during use. The size and shape of the filter may correspond to the size and shape of at least a portion of the support frame. For example, the size and shape of the filter may correspond to the size and shape of the rim of the support frame, thereby allowing the filter to be held in place by the support frame around the periphery of the filter. It may be positioned on the rim, for example on a shoulder extending inwardly from the rim, so as to extend around the periphery.

[0034] In some embodiments, the filter mask may include a single filter. In some embodiments, the filter mask may include two or more filters. The filter mask may include a first filter on a first side of the mask and a second filter on a second side of the mask. Each of the first and second filters may be brought into contact with the support frame before being secured to both the support frame and the seal member by overmolding the seal member. In this embodiment, the support frame may include a housing having first and second openings into which the first and second filters may be disposed. The size and shape of each filter may correspond to the size and shape of the associated opening in the support frame, thereby allowing the filters to be positioned on the support frame, for example, on a shoulder extending inward from the periphery of the opening, such that the support frame extends around the periphery of each filter.

[0035] The sealing member may be shaped to fit snugly against the wearer's face and seal against the face so that all air inhaled by the wearer passes through the filter material. To enhance comfort and sealing, the sealing member may be in the form of a cushion. That is, the sealing member may form a resiliently compressible area between the support frame and the wearer's face to enhance comfort and improve the seal.

[0036] Additives may be used to increase the effectiveness of the mask in preventing the passage of pathogens. According to a further aspect of the present invention, there is provided a filter mask comprising a support frame, a filter, and a seal member, wherein the seal member is secured to the support frame and the filter, and at least a portion of the filter mask comprises one or more additives selected from antibacterial agents, antimicrobial agents, antiviral agents, and antifungal agents.

[0037] Any embodiment of the support frame and / or seal and / or filter may include one or more additives, including but not limited to antibacterial, antimicrobial, antiviral, and / or antifungal agents, to help enhance the effectiveness of the mask in reducing or preventing the spread of bacteria or other pathogens. In particular, additives containing silver ions (e.g., in the form of Silver Knight™) may be incorporated into the plastic of the support frame and / or seal. Silver ions have been found to catalyze the inactivation of pathogenic bacteria, preventing their proliferation and reducing microbial growth within and on the surface of the mask.

[0038] The seal member, and therefore the face mask, may also extend laterally across the cheeks of the wearer, with a seal being formed between the mask seal and cheek tissue and with the interior cavity of the mask extending across the cheeks.

[0039] During speech, the majority of facial movement occurs within the jaw, including the vertical separation of the nose and chin, while there is a relatively small amount of movement in the cheeks. Additionally, cheek tissue is softer and more compliant than either the nose or chin tissue. This means that a lower degree of flexibility is required for the seal member to achieve an effective seal with the cheek tissue than in other parts of the face. Additionally, the seal and its movement further away from the mouth provides stability and helps maintain a consistent seal.

[0040] According to a further aspect of the present invention, there is provided a face mask comprising a mask body defining a cavity for accommodating a wearer's nose and mouth, and through which, in use, a wearer inhales respiratory gases, and a seal member depending from the mask body for engagement with the wearer's face, the mask body having a nose portion for accommodating the wearer's nose, a mouth portion for accommodating the wearer's mouth ... accommodating the wearer's cheeks. and cheek portions extending laterally across the jaw.

[0041] The seal member may extend around the periphery of the mask such that the seal member includes corresponding cheek portions that extend laterally across the cheeks of the wearer.

[0042] It has been found that when the mask body extends laterally across the wearer's cheeks, the additional lateral stability provided makes it easier for the user to position the mask correctly and helps prevent the mask from sliding to either side during use. This lateral stability, and the effective seal that results, makes the mask body and seal-forming portion suitable for use with other types of masks, including gas delivery masks and gas delivery (e.g., oxygen or aerosol delivery) filter masks.

[0043] The cheek portions may extend laterally across the wearer's cheeks between the upper edges of the wearer's cheekbones and the lower edge of the chin. The laterally extending cheek portions of the mask may form the portions of the mask having the longest dimension in a horizontal direction (i.e., a width direction running from a first side edge of the mask to an opposing side edge of the mask). The distance between the first side edge of the mask body and the opposing side edge of the mask body, measured along the surface of the mask body, may be 1.2 to 2 times, or 1.2 to 1.8 times, or 1.3 to 1.7 times, or 1.4 to 1.6 times greater than the distance between the upper edge of the mask body at the nose region and the lower edge of the mask body at the chin region, measured along the surface of the mask body.

[0044] The first and second side edges of the mask positioned in the cheek regions may comprise straight or substantially straight or linear edges. The first and second side edges may not be arcuate.

[0045] The cheek portions may each have a first edge extending from the left or right edge of the nose portion, such that the first edge of the cheek portion rests on the wearer's cheekbones. The first edge may extend along an arcuate path. The first edge may be a concave outer edge. The transition between the first edge of the cheek portion and the left or right edge of the nose portion may be arcuate.

[0046] The transition between the first edge (between the nose and cheek portions) and the first and / or second side edges (within the cheek portions) may be angular. The transition between the first edge and the first and / or second side edges may be at an angle of between 70 and 110 degrees, or between 80 and 100 degrees, or about 90 degrees.

[0047] A first side edge may connect the first edge and the second edge at a distal end of the cheek portion (e.g., proximate the wearer's ear), and a second side edge may connect the first edge and the second edge at a distal end of the opposing cheek portion (e.g., proximate the wearer's other ear).

[0048] The cheek portions may each have a second edge extending from the left or right edge of the mouth portion, such that the second edge of the cheek portion is received above the lower edge of the wearer's chin. The second edge may extend along an arcuate path. The second edge may be a concave outer edge. The transition between the second edge of the cheek portion and the left or right edge of the mouth portion may be arcuate.

[0049] The transition between the second edge (between the mouth and cheek portions) and the first and / or second side edges (within the cheek portions) may be angular. The transition between the second edge and the first and / or second side edges may be at an angle of between 70 and 110 degrees, or between 80 and 100 degrees, or about 90 degrees.

[0050] The tangent angle between the tangent to the first and / or second edge of each cheek portion and the x-axis may decrease as the lateral position increases. The angle between the tangent to the first edge and the tangent to the second edge of each cheek portion may decrease as the lateral position increases. At the distal ends of the cheek portions, for example, near the wearer's ears, the first and second edges may be substantially parallel. At the distal ends of the cheek portions, the first edges may be substantially horizontal and / or linear (extending widthwise across the wearer's face in use), while the second edges are arcuate or substantially arcuate. The first and / or second side edges of each cheek portion may be generally linear and aligned with the longitudinal axis (i.e., the y-axis) of the mask. The distal region of each cheek portion may be generally rectangular in shape. This may increase the surface area of ​​the mask body covering the wearer's cheeks.

[0051] The mask body may extend a greater distance transversely across the wearer's face relative to the distance the mask body extends longitudinally across the wearer's face. The greater distance may be relative to the surface of the wearer's face, i.e., the distance may be a dimension along the surface of the face as opposed to a linear dimension.

[0052] The mask body may extend a greater distance in the transverse direction relative to the distance the mask body extends longitudinally. The greater distance may be relative to the surface of the mask, i.e., the distance may be a dimension along or parallel to the surface of the mask, as opposed to a linear dimension.

[0053] The nose and chin portions of the sealing member may seal against or around the nose and chin, while the cheek portions may extend laterally across and seal against the wearer's cheeks. The chin portions may seal against the front of the wearer's chin or may seal under the chin. The chin portions of the sealing member may not extend under the chin. The sealing member may not extend around the wearer's eyes and / or forehead.

[0054] The depth of the seal member in the cheek portions may be less than the depth of the seal member in the nose portion. The depth of the mask body in the cheek portions may be less than the depth of the mask body in the nose portion. Thus, the portion of the internal cavity formed around the cheeks by the cheek portions of the facial mask may be shallower than the portion of the internal cavity formed around the nose and mouth by the nose and mouth portions of the facial mask. The portion of the internal cavity formed around the cheeks by the cheek portions of the facial mask may have a smaller internal volume than the portion of the internal cavity formed around the nose and mouth by the nose and mouth regions of the facial mask.

[0055] The sealing member in the cheek region may comprise a first portion and a second portion, the first portion extending rearward from the peripheral edge of the support frame in use. The first portion may comprise a proximal edge secured to the support frame and a distal edge. The second portion may comprise an outwardly depending lip extending from the distal edge of the first portion. The second portion may define a face-contacting surface. The outwardly depending lip of the second portion may extend from the distal edge of the first portion by 1 to 10 mm, or 2 to 6 mm. The thickness of the material forming the first portion may be greater than the thickness of the material forming the second portion. It has been found that incorporating an outwardly depending lip in the cheek region helps to form an effective seal in this region and maintain the seal even during facial movement.

[0056] At least a portion of the seal member in the jaw region may comprise a first portion and a second portion, the first portion extending rearwardly from a peripheral edge of the support frame in use. The first portion may comprise a proximal edge secured to the support frame and a distal edge. The depth of the first portion may vary along its length. The second portion depends inwardly and outwardly. The second portion may include both an outwardly depending lip and a second portion secured to a distal edge of the first portion. The second portion may define a face-contacting surface. The outwardly depending lip of the second portion may extend from the distal edge of the first portion by 1 to 20 mm, or by 5 to 20 mm. The inwardly depending lip of the second portion may extend from the distal edge of the first portion by 1 to 15 mm, or by 5 to 15 mm. The thickness of the material forming the first portion may be greater than the thickness of the material forming the second portion.

[0057] The portion of the mask body that accommodates the wearer's nose and mouth may have an outer surface that is, for example, substantially arcuate in cross section, while the portion that accommodates the wearer's cheeks may have an outer surface that is, for example, substantially flatter in cross section. The face mask and the internal cavity of the face mask may extend laterally across the wearer's cheeks, such that the edges of the mask are located within 5 cm, 4 cm, 3 cm, or 2 cm of the wearer's ears when in use. The face mask may extend laterally across the wearer's cheeks such that the edges or corners of the mask are located on or around the cheekbones or on or around the malar prominences when in use. Thus, the mask can substantially cover the wearer's cheeks.

[0058] The mask body may include sidewalls extending around at least a portion of its periphery. The sidewalls may form part of the support frame. The sidewalls may have a greater depth in the nose region than in the cheek regions to accommodate the wearer's nose. The sidewalls may have a greater depth in the nose region than in the chin or cheek regions. The depth of the sidewalls in the chin and cheek regions may be substantially the same. The cheek regions may not include sidewalls.

[0059] The depth of the sidewall may gradually decrease between the nose region and the cheek region, such that the region of the sidewall having the greatest depth is in the nose region and the region of the sidewall having the least depth is in the cheek region. The depth of the sidewall may be substantially constant between the chin region and the cheek region. If present, one or more seal support members may extend outward from the sidewall, for example, the seal support member may extend outward from a central point in the chin region.

[0060] The first region of the side wall may extend between the nose region and the cheek region. The first region of the side wall may be generally arcuate in shape and may extend rearward from the rim of the support frame (i.e., toward the wearer's face in use). At least a portion of the first region of the side wall may extend rearward from the rim of the support frame at an obtuse angle relative to the front of the mask. A portion of the first region adjacent to the nose region may extend outward at an obtuse angle relative to the front of the facial mask. At least a portion of the first region of the side wall may extend rearward from the rim of the support frame at a right angle relative to the front of the mask, i.e., in a direction perpendicular to the front of the facial mask. A portion of the first region adjacent to the cheek region may extend rearward from the rim at a right angle relative to the front of the mask.

[0061] The second region of the sidewall may extend between the chin region and the cheek region. The second region of the sidewall may be generally arcuate in shape.

[0062] If the facial mask is a filtering mask, the mask body may be defined by a support frame and a filter. The seal member may extend around a periphery of the support frame, for example, around a rim. The shape of at least a portion of the support frame and the filter may correspond to the shape of a proximal edge of the seal member. The support frame and the filter may extend laterally across the cheeks of the wearer. The portion of the mask body extending across the cheeks of the wearer may form a cavity between the mask and the wearer's face that is shallower than the portion of the mask extending over the wearer's nose and mouth.

[0063] The expansion of the mask over the cheeks increases the surface area of ​​the sheet of filter material and therefore the volume of air that can pass through the filter. The shallower cavity in the mask reduces dead space within the mask.

[0064] Embodiments in which the cheek portions extend laterally across the wearer's cheeks may be advantageous in therapeutic masks, including, but not limited to, nebulizer masks, sleep apnea masks, CPAP masks, oxygen delivery masks, NIV masks, and aerosol masks. The width of the mask in the cheek regions provides a more secure fit to the wearer's face, making the mask less likely to move or become dislodged during use.

[0065] A mask according to this embodiment of the present invention may be particularly advantageous in situations where the user moves significantly, such as for the treatment of sleep apnea and for use in CPAP and non-invasive ventilation. The wearer in such situations is typically a patient who may move or roll, and the increased stability provided by the mask's low profile and lateral expansion of the cheek area allows the wearer to move more easily without removing the mask, even while sleeping. Additionally, for elderly patients or other patient groups who may be missing some teeth, the lateral expansion of the seal over the cheeks allows for a good seal to be obtained with less force in this area. The seal may be overmolded onto the mask body or manufactured as a separate component attached to the mask body. Suitable materials for manufacturing the mask body and seal, and their suitability for overmolding, will be readily apparent to those skilled in the relevant art (e.g., materials science). The mask may not include a filter. The mask may include a filter capable of providing controlled air leakage at a specific pressure. Typically, a controlled leak in a mask can cause noise that can be irritating to the wearer, and the use of a filter or other permeable material, such as a woven material, to provide a controlled leak reduces or prevents the noise.

[0066] The face mask according to this embodiment of the present invention may further include a connector for connecting to a nebulizer. As described above, the cheek portions may extend laterally between the upper edge of the wearer's cheekbones and the lower edge of the chin. The nebulizer is a bulky component of the device, and its weight can cause the mask to slip on the face. The lateral expansion of the cheek portions provides stability, reducing or preventing mask slippage and improving the seal. The nebulizer mask may further include at least one filter. The nebulizer mask may include one filter or two filters. If the nebulizer mask includes two filters, the nebulizer mask may include a first filter disposed on a first side of the mask and a second filter disposed on a second side of the mask, with a connector for connecting to the nebulizer disposed between the two filters. The support frame may include a housing having first and second openings for accommodating the two filters and an integrally formed connector for connecting to the nebulizer.

[0067] Because mask effectiveness improves with improved fit (and reduced leakage), it is useful to have a mask that can adapt to different sized faces and remain effective even when the wearer moves and takes an active role, such as the filtering masks used by medical professionals.

[0068] According to a further aspect of the present invention, there is provided a filtering mask comprising a support frame and a sheet of filtering material, the support frame and the sheet of filtering material defining a mask body adapted to provide a cavity around a wearer's mouth and nose in use, the filtering mask including a seal member depending from at least a portion of a peripheral edge of the mask body, the seal member comprising a lip portion depending both inwardly and outwardly relative to the peripheral edge of the mask body.

[0069] The seal member may extend around the entire peripheral edge of the mask body. The portion of the peripheral edge of the support frame around which the inwardly and outwardly depending lip portions extend may constitute a chin portion. The inwardly depending lip portion may extend around most of the peripheral edge of the support frame. The inwardly depending lip portion may extend around only a portion of the peripheral edge of the support frame. The portion of the peripheral edge of the support frame around which the inwardly depending lip portion extends may constitute a chin portion and / or a nose portion. The portion of the peripheral edge of the support frame around which the inwardly depending lip portion extends may not constitute a cheek portion to facilitate removal of the seal from the mold. The portion of the peripheral edge of the support frame around which the inwardly depending lip portion extends may constitute a cheek portion to provide an improved seal. The outwardly depending lip portion may extend around most of the peripheral edge of the support frame. The outwardly depending lip portion may extend around only a portion of the peripheral edge of the support frame, for example, around the chin and cheek regions. The nose portion of the seal member may not include an outwardly depending lip portion.

[0070] It has been found that the usefulness of the above-described features extends beyond their use in filter masks, and that a seal having the above-described features can be applied to any face mask where an effective seal is required.

[0071] Thus, there is provided a facial mask comprising a seal member depending from at least a portion of the peripheral edge of a mask body, the seal member comprising a chin region, a nose region and a cheek region intermediate the chin and nose regions, the seal member comprising both inwardly and outwardly depending lip portions relative to the peripheral edge of the mask body, the inwardly depending lip portion extending around the chin and nose regions of the seal member and the outwardly depending lip portion extending around the chin and cheek regions of the seal member.

[0072] It is important to form a good seal against the face without increasing cost and manufacturing complexity. It has been found that while inwardly depending lip portions provide a good seal against the face, they can hinder manufacturing by increasing the difficulty of removing the seal from the mold. Providing inwardly depending lip portions in the chin and nose regions, which have the greatest variation in shape / size, improves the seal. Because the cheeks are typically flatter and made of softer tissue, it is easier to form a good seal against the cheeks. Therefore, only outwardly depending lip portions are sufficient in these regions to provide a good seal while facilitating manufacturing.

[0073] The inwardly depending lip portion may be in a generally flat configuration. The inwardly depending lip portion may be in the form of an upstanding wall that follows the contour of the peripheral edge of the body. The inwardly depending lip portion may include a discontinuity that facilitates deformation of the inwardly depending lip portion.

[0074] At least a portion of the outwardly depending lip portion may have a concave contact surface. The outwardly depending lip portion may be shaped to provide a base or shelf formation under the wearer's chin. The outwardly depending lip portion may take the form of an upstanding wall that follows the contours of the peripheral edge of the body. At least a portion of the outwardly depending lip portion may be flat around the wearer's face, for example, in the chin and / or cheek regions. A proximal portion of the outwardly depending lip portion may engage the wearer's chin, while a distal portion may curve and extend under the wearer's chin. The outwardly depending lip portion may be shaped in the form of a chin cup. The chin cup may accommodate at least a portion of the wearer's chin in use. The outwardly depending lip portion may be shaped to provide both a forward lip portion and a lower lip portion.

[0075] The inwardly depending lip portion may contact the lower part of the wearer's face, such as the wearer's chin, to form a seal. For users with larger facial heights, the outwardly depending lip portion may pass just below the wearer's lower chin to provide an additional seal. For all wearers, the outwardly depending lip portion provides an alignment guide for positioning the mask on the face and can help keep the mask in the correct position on the face even if the jaw moves during use.

[0076] The periphery of the support frame near the inner and outer lip portions may be shaped by a first radius from a center point or region of the mask in the chin area. The inwardly depending lip portion typically has an inner edge with a radius smaller than the first radius. The outwardly depending lip portion typically has an outer edge with a radius larger than the first radius.

[0077] The nose portion of the seal member may include an inwardly depending lip portion and may present a convex surface for contact with the wearer's face. The nose portion of the seal member may include reinforcing formations, for example, reinforcing formations on each side of the nose or reinforcing formations around the entire nose region. Reinforcing formations in the nose region have been found to contribute to the formation of a reliable seal by providing stability to the mask and preventing undesired movement and / or collapse of the seal while maintaining the lateral flexibility needed to accommodate different face sizes. This reduces undesired deformation or undesired folding of the seal in this region, improving fit and making it easier to accurately fit the mask.

[0078] Such a filtering mask may include cheek portions that extend laterally across the cheeks of the wearer, as in the previous embodiment, and may include any of the features of that embodiment, wherein the cheek portions extend laterally between the upper edges of the wearer's cheekbones and the lower edge of the chin, thereby enhancing stability of the mask on the face.

[0079] According to a further aspect of the present invention there is provided a facial mask comprising a support frame and a seal member, the support frame defining a mask body adapted to provide a cavity around a wearer's mouth and nose in use, the seal member comprising a nose portion depending from at least a portion of a peripheral edge of the mask body to form a seal against or adjacent the wearer's nose in use, the nose portion comprising at least one reinforcing member.

[0080] The facial mask may be a filter mask or a mask including a filter element. The facial mask may further comprise a sheet of filter material. The support frame and the sheet of filter material together may define a mask body adapted to provide a cavity around the wearer's nose and mouth in use.

[0081] The nose portion of the seal extends over and around the wearer's nose in use to form a seal in the nasal area.

[0082] The at least one reinforcing member may be disposed on an inner wall of the seal member. The at least one reinforcing member may be disposed on an outer wall of the seal member. The at least one reinforcing member may be disposed on both the inner and outer walls of the seal member. The at least one reinforcing member may be integrally formed with the seal member, i.e., injection molded at the same time as the seal member is formed.

[0083] The at least one reinforcing member may comprise one or more ribs positioned on each side of the nasal region of the seal member, such that, in use, one or more ribs are located on each side of the nose. The nasal region may comprise two, or three, or four, or five, ribs located on each side of the nasal region of the seal member. The mask may include six, seven, eight, or more ribs. Each of the one or more ribs may extend substantially perpendicular to the mask body. Each of the one or more ribs may extend from an edge of the seal member proximal to the mask body or to an edge of the seal member distal to the mask body. Each of the one or more ribs may extend only across a central portion of the seal member and may not reach one or both of the proximal and distal edges of the seal member. Each of the one or more ribs may have a consistent depth or a depth that varies along its length, with a greater depth in the central region than in the end regions. Each of the one or more ribs may have a width of 0.5 to 3 mm, or 0.5 to 2 mm.

[0084] The at least one reinforcing member may comprise a corrugated region and / or a scalloped region and / or at least one ridge.

[0085] At least one reinforcing member may include a corrugated region located on each side of the nose portion. The corrugated region may include a series of parallel ridges and grooves, which provide increased rigidity in the area affected by the seal. The corrugations may extend in a direction substantially perpendicular to the mask body. The corrugations may extend from the proximal edge of the seal member to the distal edge of the seal member, or may extend across only a portion of the sidewall of the seal member, e.g., a central portion, and may not reach one or both of the proximal and distal edges of the seal member. Each corrugation may have a proximal end and a distal end, and the proximal and / or distal end of each corrugation has a height relative to the seal member that gradually decreases to zero. Alternatively, the proximal and / or distal end of each corrugation may form a distinct shoulder. The corrugated region may be located on the inner or outer surface of the seal member. The corrugations may include thickened regions of the seal member. The thickened regions may be located on the inner or outer surface of the seal member. The thickened regions may extend through the wall of the seal member, or separate thickened regions may be present on the inner and outer surfaces of the seal member (which may or may not be aligned with one another) so as to be visible on both the inner and outer surfaces of the seal member. Alternatively, the corrugations may be formed from the sidewalls of the seal member such that the sidewalls of the seal member are shaped to form corrugations. Such corrugations are visible on both the inner and outer surfaces of the seal member. The sidewalls of the seal member shaped to form corrugations may have a uniform thickness.

[0086] At least one reinforcing member may include a scalloped region disposed on each side of the nose portion. The scalloped region may comprise a series of undulations in the wall of the seal member, disposed on either the inner or outer surface of the seal member. The scallops may comprise thickened regions of the seal member. The thickened regions may be disposed on the inner or outer surface of the seal member. The thickened regions may extend through the wall of the seal member, or separate thickened regions may be present on the inner and outer surfaces of the seal member (which may or may not be aligned with each other) so as to be visible on both the inner and outer surfaces of the seal member. Alternatively, the scallops may be formed from the sidewalls of the seal member such that the sidewalls of the seal member are molded to form the scallops. Such scallops are visible on both the inner and outer surfaces of the seal member. The sidewalls of the seal member molded to form the scallops may have a uniform thickness. The scallops may extend in a direction substantially perpendicular to the seal member. The scallops may extend across the inner or outer surface of the seal member from the proximal edge of the seal member to the distal edge of the seal member, or may be formed within the wall of the seal member so that they are visible on both the inner and outer surfaces. Alternatively, the scallops may extend across only a central portion of the seal member (e.g., a sidewall) and may not reach one or both of the proximal and distal edges of the seal member. Each scallop may have a proximal end and a distal end, and each undulating proximal and / or distal end may have a height relative to the seal member that gradually decreases to zero. Alternatively, the proximal and / or distal end of each scallop may form a distinct shoulder. The smooth profile of the scalloped region may facilitate smooth transitions between the seal member and the mold. This can provide the required stability while ensuring that the device can be easily removed from the

[0087] The at least one reinforcing member may comprise at least one ridge. The at least one ridge may be located on the inner surface, the outer surface, or both the inner and outer surfaces of the seal member. The at least one ridge may comprise a thickened portion of the seal member extending circumferentially around the nose region or extending in a direction substantially perpendicular to the seal member. The at least one ridge may extend from the proximal edge of the seal member to the distal edge of the seal member, or may extend across only a central portion of the seal member and may not reach one or both of the proximal and distal edges of the seal member.

[0088] Reinforcing members extending substantially perpendicular to the seal member have been found to act to reinforce the seal member walls, providing a soft cushion that reduces or prevents collapse of the seal member in the nose region, improving the overall seal formed by the seal member. Such reinforcing members have also been found to reduce or prevent inversion. Such reinforcing members may extend across portions of the mask's side walls, e.g., the central portion, and / or may extend to or near the proximal edge of the seal member and / or to or near the distal edge of the seal member. When the reinforcing member(s) extend to or near the distal edge of the seal member, they can also help secure the relative positions of the proximal and distal portions of the seal member, reducing or preventing seal inversion during fitting and / or wear, making it easier to accurately fit the mask. The reinforcing members can also extend toward, to, or near the proximal edge of the seal member to provide additional support.

[0089] Alternatively, the at least one reinforcing member may be a region of increased thickness in the nose region of the seal member. The at least one reinforcing member may, in use, comprise a region of increased thickness on either side of the nose region, i.e., on either side of the nose. Alternatively, it may comprise a continuous region of increased thickness extending around the nose region. The region of increased thickness may comprise a narrow band extending along a central portion of the seal member, or may constitute substantially the entire side wall of the seal member.

[0090] It is important that any additional features, such as reinforcing members, do not inhibit or prevent removal of the seal from the mold. Small and / or narrow raised features can be particularly difficult to remove from the mold and may require manual removal. Larger structures, such as corrugations, scallops, ridges, and thickened areas, are typically easier to remove from the mold without damage using an ejector pin.

[0091] A face mask according to the invention may include means for securing the mask to a wearer in use. Such means may include one or more cords or straps, for example elastic cords or straps, that fit around the wearer's head to press the filtering mask against the wearer's face.

[0092] One or more cords or straps may be formed as separate components and then attached to the filtering mask by inserting through holes or slots and knotting or sealing, or by bonding the cord or strap to the mask. The cord(s) or strap(s) may be bonded to the mask by adhesive or chemical bonding, or by overmolding. The cord(s) or strap(s) may be worn over the wearer's ears or around the back of the wearer's head, thereby preventing the mask from being worn during use. This can help prevent the mask from slipping off and / or riding up the wearer's face.

[0093] Two cords or straps may be provided, passing around each of the wearer's ears, or one cord passing over the wearer's ears and one below the ears and running around the back of the head. A single cord may also be provided, running around the back of the wearer's head.

[0094] Alternatively, a single cord may be passed twice across the back of the wearer's head.

[0095] The elastic cord or strap may include a means for indicating when the desired fit has been achieved. The elastic cord or strap may include indicia that indicate to the user that the desired fit has been achieved. The elastic cord or strap may include a size guide. Once a mask according to the present invention has been donned and adjusted to provide the correct fit, for example using a fit test, the user can use the indicia to adjust any further masks to the correct size without the need for further fit tests.

[0096] If the mask is a filter mask, the mask may include an opening in the filter. The opening may provide a conduit through the filter or may include or be adapted to receive an additional device, such as an exhalation valve. The opening may bypass the filter material. The opening in the filter material may be attached and / or sealed to an opening in the support frame or to a device attached to the support frame. Furthermore, the polymer material injected into the mold to form the seal member may engage with the filter and the opening in the support frame or to a device attached to the support frame during injection molding of the seal member to seal the filter around the opening or device.

[0097] The mask may include one or more vents or valves, such as exhalation valves. Exhalation valves allow exhaled air to escape the filter mask without passing through the filter, thus reducing heat and humidity retained by the filter during use. However, including an exhalation valve may not be desirable when the filter mask is needed to protect others from pathogens exhaled by the wearer, for example, in a medical environment. The vents or valves may be located in the shield or in the rim of the support frame. The valve may be inserted into an opening in the shield or rim, or may form part of the shield or rim. If the valve is inserted into or forms part of the shield, the valve may also extend through the filter material, and an overmolding step to form a seal member may be used to additionally provide a seal between the valve and the filter material and / or between the opening in the support frame for receiving the valve and the filter material. If the valve is inserted into or forms part of the rim, a portion of the rim may be molded to accommodate the valve, for example, in the chin area.

[0098] If a valve is included, the injection molding step for forming the sealing member can also form the valve member. Thus, the sealing member and the valve member may be integrally formed. After molding the sealing member / exhalation valve, the valve may be inserted through the openings in the filter and shield, or through the opening in the rim. Tension between the valve and the surrounding material (shield, filter, or rim) biases the valve to close. This allows exhaled air to flow from the inside to the outside of the mask, but prevents air from flowing in the opposite direction.

[0099] The support frame, e.g., the shield and / or the filter, may be formed with an opening into which either a releasable cover or an exhalation valve can fit. An overmolding step to form a sealing member may be used to additionally provide a seal between the filter material and the opening in the support frame for receiving the valve or cover. For example: The releasable cover may be secured over the opening using a snap-fit ​​or screw-fit connection, and the cover may be removed and replaced with an exhalation valve as needed. This allows for the manufacture of a single mask that can be used with or without an exhalation valve. The size of the opening is appropriate for the installation of an exhalation valve and may be 10 to 50 mm in diameter, or 15 to 40 mm in diameter, or 15 to 30 mm in diameter. Typically, the opening diameter is approximately 20 mm.

[0100] The filtering mask may further comprise a stopcock that can be used to connect the mask to tubing for introducing or removing gas from the mask and / or wearer. Thus, the filtering mask may be used as an oxygen delivery mask or respirator, with the added protection that inhaled and exhaled air (other than the oxygen being delivered) must pass through a filter. In the same manner as an exhalation valve, the stopcock may be releasably attached to an opening in the shield and, optionally, the filter. The opening may be sized to accommodate a stopcock having a diameter of 10-50 mm, or 15-40 mm, or 15-30 mm. Alternatively, the opening may be sized to accommodate a stopcock having a diameter of 2-10 mm, or 2-8 mm, or 4-8 mm. Alternatively, the stopcock may be integrally formed with the shield or another portion of the support frame.

[0101] A filter mask may include a filter and a gas inlet (e.g., a bung) and may be suitable for use as a high-concentration mask, an oxygen mask, a CPAP mask, or a high-flow mask. Conventional masks for use in delivering high-concentration oxygen require a reservoir bag attached to the inlet to provide a reservoir of oxygen to be drawn into if the patient breathes more than the oxygen supply can satisfy. Compared to conventional masks, the larger internal volume of the masks described herein may eliminate the need for an additional reservoir bag, particularly when the mask extends laterally across the wearer's cheeks. Additionally, the need to limit the spread of infection and contaminants means that the inclusion of a filter is highly desirable, protecting both the patient and those providing their care.

[0102] A filter mask may include a gas inlet (e.g., a plug) and a filter extending through or integrally formed with the support frame or mask body. The gas inlet and filter may be located in different portions of the support frame or mask body. The gas inlet and filter may be located in first and second regions of the support frame or mask body. The first and second regions may be located on different sides of the wearer's nose and mouth during use. The filter may be located in a first cheek region of the support frame and the gas inlet may be located in a second cheek region of the support frame, such that oxygen flows from the gas inlet to the filter and washes over the wearer's mouth and nose, thus providing a continuous flow of oxygen to help draw away exhaled gases.

[0103] The support frame or mask body can include a housing having a first opening capable of receiving a filter and a second opening capable of inserting a gas inlet. Alternatively, the gas inlet may be at least partially integrally formed within the support frame or mask body. It is believed that a reservoir of air held within the filter mask may eliminate the need for an additional reservoir bag. Additionally, if the oxygen supply fails, the wearer can inhale ambient air through the filter, thereby reducing or eliminating the need for an anti-asphyxiation valve. The elimination of the need for a reservoir bag and anti-asphyxiation valve reduces both manufacturing complexity and cost.

[0104] Thus, a facial mask is provided, the facial mask comprising a mask body defining a cavity for accommodating a wearer's nose and mouth, and a seal depending from the mask body for engaging the wearer's face. and a mask body including: a) a filter and a gas inlet, the filter being disposed in a first region of the mask body and the gas inlet being disposed in a second region of the mask body; b) a nose portion for accommodating the wearer's nose, a mouth portion for accommodating the wearer's mouth, and cheek portions extending laterally across the wearer's cheeks; Equipped with.

[0105] The mask body may be transparent, allowing the wearer's face (particularly the lips) to be seen through the mask, allowing for early identification of breathing problems.

[0106] Alternatively, the filter mask may not include a bung, and such a filter mask may not be suitable for use as an oxygen delivery mask or a respirator.

[0107] Additionally or alternatively, a filter mask may include an access port. For example, a filter mask may include an access port for an endoscope, nasal cannula, or high-flow nasal cannula, allowing an endoscopy to be performed or a cannula to be worn while still providing the patient and physician with the protection provided by the filter mask. Masks with cheek portions that extend laterally over the cheeks may be particularly advantageous for use as endoscopy masks due to the additional stability provided by the lateral extension, reducing the need for additional head straps to stabilize the endoscopy mask. Medication or oxygen may be delivered through a high-flow nasal cannula; a characteristic of this type of treatment is that aerosolized particles may be generated and released into the environment. Depending on the nature of the patient's illness, such aerosolized particles may become contaminated and pose a risk to nearby personnel. Allowing access to the airway for delivery of the high-flow nasal cannula while wearing a filter mask to contain any generated aerosols provides a safer environment for clinicians and other nearby personnel. The access port may include an opening in the filter mask. The aperture may comprise a pair of aligned apertures in the support frame, e.g., shield, and sheet of filter material, allowing the cannula to pass through both apertures. An overmolding step to form a seal member may be used to additionally provide a seal between the aperture in the support frame and the filter material. The apertures in the support frame, shield, and / or filter material may be provided with removable covers to cover the apertures when not in use.

[0108] In use, the wearer of the face mask may exhale respiratory gases into the internal cavity. Thus, the face mask according to the present invention, which may be a filter mask, may further comprise a sensor for detecting the CO2 concentration in exhaled breath, such as that described in GB Patent No. 2019236.5 (incorporated herein by reference).

[0109] In this embodiment, the mask body and / or the support frame may be formed of an IR-transparent material. The sensor may be attachable to a sensor portion of the face mask. The sensor may include an electromagnetic radiation transmitter and an electromagnetic radiation receiver, and the mask body's enclosure has a sensor portion including first and second sensor windows, a portion of the interior cavity defined by the enclosure being defined between the first and second sensor windows, and the sensor is attached to the sensor portion of the respiratory mask such that, in use, electromagnetic radiation from the transmitter passes through the first sensor window in the sensor portion of the enclosure, through the portion of the interior cavity defined between the first and second sensor windows, and through the second sensor window to the receiver. A face mask having a sensor as described may be advantageous in that the sensor portion formed within the mask body's enclosure allows the sensor to monitor the patient's respiratory gases before they exit the mask body, reducing the delay between the exhaled gases and measurements being taken. In contrast, using a conventional respiratory mask connected to a sensor via an expiratory or sampling tube Respiratory gases exhaled by the wearer must then travel from the respiratory mask to a sensor, such as a respiratory monitoring unit, before they can be monitored.

[0110] Each of the first and second sensor windows may have an inner surface and an outer surface, and the sensor may be attached to a sensor portion of the respiratory mask with the transmitter disposed adjacent the outer surface of the first sensor window and the receiver disposed adjacent the outer surface of the second sensor window.

[0111] The electromagnetic radiation transmitted by the transmitter and received by the receiver may be infrared radiation, which may refer to radiation having a wavelength between about 700 nm and about 1 mm.

[0112] The first and second sensor windows may be transparent to the electromagnetic radiation transmitted by the transmitter. For example, the first and second sensor windows may be transparent to infrared radiation, i.e., radiation having a wavelength of about 700 nm to about 1 mm. The first and second sensor windows may also be transparent to other wavelengths of light, such as visible light. The first and second sensor windows may be more transparent to the electromagnetic radiation transmitted by the transmitter than the remainder of the mask body, the mask body wall, and / or the sensor portion.

[0113] The first and second sensor windows may be transparent to at least 50%, 60%, 70%, 80%, 90%, or 100% of the electromagnetic radiation transmitted by the transmitter. To obtain an accurate and / or actionable reading, the sensor may require a minimum amount of electromagnetic radiation, or a minimum percentage of the electromagnetic radiation transmitted by the transmitter, to be received by the receiver. Thus, the first and second sensor windows may be transparent to the electromagnetic radiation transmitted by the transmitter such that at least 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% of the electromagnetic radiation is received at the receiver after passing through a portion of the interior cavity defined between the first and second sensor windows.

[0114] The first and second sensor windows may be of reduced thickness relative to the remainder of the mask body, the mask body wall, and / or the sensor portion. The first and second sensor windows may have a thickness of at most 0.5 mm, at most 0.4 mm, at most 0.3 mm, at most 0.2 mm, at most 0.1 mm, or at most 0.05 mm. The thickness of the first and second sensor windows may refer to the distance between the inner and outer surfaces of each sensor window.

[0115] The first and second sensor windows, for example the inner surfaces of the first and second sensor windows, may be spaced apart by a distance of 2 mm to 50 mm, or 5 mm to 30 mm, i.e. the portion of the internal cavity defined between the first and second sensor windows may have a thickness of 2 mm to 50 mm, or 5 mm to 30 mm.

[0116] Alternatively, the face mask may be configured so that the sheet of filter material is replaceable, meaning that the mask frame, including the support frame and seal, can be reused multiple times, while only the filter material needs to be replaced rather than the entire mask having to be replaced after use, thereby reducing both costs and waste.

[0117] A mask with a replaceable filter according to this embodiment can be manufactured using the same principles as described above in a method involving a single overmolding step that fixes the relative positions of the support frame and seal.

[0118] According to a further aspect of the present invention, there is provided a method of manufacturing a filtering mask, the filtering mask comprising a support frame and a seal member, the support frame having a housing for receiving a filter, the method comprising: a) providing a support frame within the mold; b) injecting a polymeric material into a mold to form a first seal member for sealing against the face of a wearer and a second seal member for sealing against a filter received by the housing; The seal member is engaged with the support frame to secure the seal member to the support frame during injection molding of the seal member.

[0119] According to a further aspect of the present invention, there is provided a filtering mask manufactured according to the above-described method. Also provided is a filtering mask comprising a support frame and a seal member, the support frame further comprising a housing for receiving a filter, the seal member being secured to the support frame. Any of the features described above or below in connection with the filtering masks of the present invention may be present in this embodiment, including, but not limited to, a shield, and / or laterally extending cheek portions, and / or one or more reinforcing members, and / or a seal member comprising inwardly and outwardly depending lip portions, and / or the inclusion of a valve or access port, and / or multiple filters.

[0120] The filter may comprise only the filter substrate, which may be releasably attachable to the support frame by any suitable means, for example by clips, or by an interference fit, or by a releasable adhesive, for example an adhesive strip covered by a peelable liner that is removed immediately prior to insertion of the sheet of filter material.

[0121] Alternatively, the filter may comprise a filter substrate held in a cartridge or other support connectable to the support frame. For example, the cartridge may be connected to the outer surface of the support frame by one or more snap-fit ​​connectors or clips, or by friction fit, or there may be a port provided in the support frame to accommodate the cartridge. In this embodiment, if the mask comprises a shield, the shield may form part of the cartridge or other support, such that when the cartridge is attached to the outer surface of the mask, the shield is positioned over the outer surface of the filter and at least a portion of the periphery of the shield is separated from the support frame. Alternatively, the shield may be hingedly attached to the support frame, and may be opened to allow insertion of the filter cartridge adjacent to the outer surface of the support frame and then closed. The filter cartridge may be held in place by one or more clips or other attachment members, or a hinged shield may hold the filter cartridge in place.

[0122] Alternatively, the filter cartridge may be connected to the inner surface of the support frame by one or more snap-fit ​​connectors or clips. In this embodiment, the shield (if present) may be present as shown in the drawings and as described above. For example, the filter mask may include a shield that, in use, extends across at least a portion of the outward-facing surface of the filter, with at least a portion of the periphery of the shield being separate from the support frame and / or the shield being integrally formed with the support frame.

[0123] The cartridge may take the form of a plastic, e.g., injection-molded plastic, rim that conforms to the shape and size of the filter substrate and is secured around the periphery of the filter substrate. At least a portion of the cartridge may be overmolded around the periphery of the filter substrate. Alternatively, the entire cartridge may be overmolded around the periphery of the filter substrate. Thus, the cartridge does not restrict the flow of air through the filter substrate.

[0124] Methods for manufacturing seal members are known in the art, and any suitable method may be incorporated into the present invention. In particular, the sealing member may be at least partially manufactured using a gas-assisted injection molding process, such as that described in International Publication No. 2021 / 037768 and GB Patent No. 2013108.2 (both of which are incorporated herein by reference). These documents describe the use of gas-assisted injection molding in the manufacture of sealing members for respiratory devices. Filter masks for personal protection require a highly effective seal, and it has surprisingly been found that sealing members that provide the highly effective seal required in filter masks can be manufactured by this method.

[0125] According to a further aspect of the present invention, there is provided a method of manufacturing a seal member for use in a filtering mask, the method comprising: (a) providing a mold having a cavity, a polymer injection port, and a gas inlet port; (b) injecting a polymer into the mold cavity through a polymer injection port; (c) introducing a gas into the mold cavity through the gas inlet port; Including, This forms a filter mask seal member, wherein at least a portion of the filter mask seal member comprises an internal chamber at least partially bounded by an elastically deformable enclosure formed of a polymer, the enclosure including a face-contacting surface, the face-contacting surface having a shape determined by the mold cavity to provide an anatomical fit with a user.

[0126] When used to manufacture at least a portion of a sealing member for a filter mask, the outer surface of the elastically deformable enclosure can be shaped to provide an anatomical fit with the wearer or the wearer's face, providing an effective seal for the sealing member, while the internal chamber bounded by the enclosure has been found to also allow the sealing member to be pressed against the wearer, e.g., against the wearer's face, if an improved seal is needed. An effective seal is particularly important in filter masks because if a leak exists, air will bypass the filter, causing the mask to lose its effectiveness.

[0127] Only a portion of the sealing member may be manufactured according to the above method. It is particularly advantageous if the nose region of the sealing member of a filtering mask is manufactured using the above method.

[0128] It will be understood that any feature described in relation to one aspect of the invention may be applied to any other aspect of the invention. Thus, any structural feature described in relation to a mask with an integrated filter, such as a shield, first and second attachment formations, an exhalation valve, and / or a bung, may be applied to a mask with a replaceable filter as described above.

[0129] Embodiments of the present invention will now be described, by way of example only, with reference to the following drawings, in which: [Brief explanation of the drawings]

[0130] [Figure 1] 1 is a perspective view of a support frame of a filter mask according to the present invention; FIG. [Figure 2] FIG. 3 is a side view of the support frame of FIG. 2. [Figure 3] 1 is a perspective view of a filter of a filtering mask according to the present invention; FIG. [Figure 4a] 1 is a perspective view of a filter positioned within a support frame in a first embodiment of a filter mask according to the invention during manufacture. FIG. [Figure 4b] FIG. 4a without the filter. [Figure 5] 5 is a perspective view of the support frame and filter of FIG. 4 and a mold core used during the manufacture of a first embodiment of a filter mask according to the invention. [Figure 6] 1 is a side view of a filter mask according to the present invention. [Figure 7] 1 is a perspective view of the rear of a filtering mask according to the present invention; FIG. [Figure 8] 10 is a schematic diagram illustrating the connection between the support frame and the filter material formed by overmolding the seal member. FIG. [Figure 9a] 10A-10C are front and rear perspective views of a further embodiment of a filtering mask according to the present invention. [Figure 9b] 10A-10C are front and rear perspective views of a further embodiment of a filtering mask according to the present invention. [Figure 10a] 10A-10C are front and rear perspective views of a further embodiment of a filtering mask according to the present invention. [Figure 10b] 10A-10C are front and rear perspective views of a further embodiment of a filtering mask according to the present invention. [Figure 11] FIG. 10 is a perspective view of the rear of a filtering mask according to a further embodiment of the present invention. [Figure 12a] 10A-10C are front and rear perspective views of a filtering mask according to a further embodiment of the present invention; [Figure 12b] 10A-10C are front and rear perspective views of a filtering mask according to a further embodiment of the present invention; [Figure 13a] FIG. 1 shows a facial mask according to the present invention having reinforcing members on each side of the nose region. [Figure 13b] FIG. 1 shows a facial mask according to the present invention having reinforcing members on each side of the nose region. [Figure 13c] FIG. 1 shows a facial mask according to the present invention having reinforcing members on each side of the nose region. [Figure 13d] FIG. 1 shows a facial mask according to the present invention having reinforcing members on each side of the nose region. [Figure 14] 1A-1C illustrate configurations of reinforcing members that may be present in a facial mask according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0131] A support frame 10 for use in a filter mask according to the present invention is shown in FIGS. 1 and 2. The support frame 10 has a generally curved shape and includes an integrally formed rim 11, a shield 12, a pair of first attachment formations 13, and a pair of second attachment formations 14. The shield 12 is substantially the same shape as the rim 11, but is smaller and offset from the rim 11 by approximately 1 cm. The shield 12 is attached to the rim 11 by four connecting members 16 evenly spaced around the rim's circumference, attaching to points near the edge of the shield. A space 15 between the shield 12 and the rim 11 extends around the periphery of the shield and is interrupted only by the connecting members 16. A seal support member 31 extends downward from the center of the lower edge of the rim 11. The seal support member 31 is an arcuate tab that depends downward from the rim 11 and curves toward the rear of the support frame 10. The support frame 10 is an integrally formed component with all features manufactured in a single injection molding step.

[0132] A pair of first attachment formations 13 extend outwardly from a first side of limb 11 which, in use, is located near a first ear of the wearer. First attachment formations 13 take the form of keyhole-shaped slots through which a cord or strap (not shown) can be threaded and secured with a knot or clamping device.

[0133] A pair of second attachment formations 14 extend outward from a second side of the rim that, in use, is located near the wearer's second ear. The second attachment formations 14 include a slot (not visible) covered by a tab 17. The tab 17 has a series of teeth 18 that provide a grip. A cord or strap (not shown) is supported between the tab 17 and the edge of the slot. The cord passes from the inside to the outside of the support frame through slots in the mounting formations 14. The teeth 18 grip the cord and reduce or prevent reverse movement of the cord.

[0134] In use, the cord or strap is secured to the upper first attachment formation 13, passes through the upper second attachment formation 14 from inside to outside, passes through the lower second attachment formation 14 from outside to inside, and finally is secured to the lower first attachment formation 13. The strap thus passes behind the wearer's head twice and forms a loop between a pair of second attachment formations 14 on the outside of the support frame. When the wearer applies tension to the loop, for example, by pulling on the loop, the cord is pulled through the opening and passes through the teeth 18 on the tab 17. When this tension is released, for example, by the wearer releasing the cord loop, the teeth 18 are able to grip the cord, thus preventing it from slipping back through the slot unless significant force is applied. In this way, the mask can be easily adjusted to fit the wearer's head with one hand.

[0135] Injection molding is used to manufacture the support frame 10, which is a one-piece unit manufactured from injection molded polypropylene in a single step.

[0136] When filter mask manufacturing is automated, the support frame 10 is ejected from the mold onto a vacuum cup on a robotic arm. A pneumatic die forces a sheet of filter material 22 from a roll of filter material into the support frame 10, and the roll of filter material, containing a continuous series of pre-stamped sheets of filter material, is heat-sealed around its peripheral edges. A sheet of filter material 22 is shown in FIG. 3.

[0137] The sheet of filter material is placed on the inside of the support frame 10, i.e., on the side of the support frame 10 that will face the wearer in use. The sheet of filter material is placed on inwardly extending shoulders and is held in place around its periphery by retention tabs 19 on either side of the rim. This support frame / filter material assembly is shown in Figures 4a and 4b.

[0138] The support frame / filter material assembly is transferred into a first half of a mold and mounted on a mold core 30. The second half of the mold is sealed to the first half of the mold to form a mold cavity. In an injection molding step, a seal member 25 is overmolded onto the support frame / filter material assembly, surrounding the periphery of the sheet of filter material 22 and adhering it to the support frame 10 in a single overmolding step to form the seal member 25. The filter mask 20 is removed from the mold using, for example, a 20 mm pin to peel the filter mask 20 from the core 30 and transferred for manual attachment of an elastic cord and subsequent packaging.

[0139] The connection between the filter, seal member, and support frame is shown schematically in FIG. 8. The periphery of filter 91 is positioned against shoulders 94 extending laterally from the rim of support frame 93, either before or after the support frame is placed in the mold. Thermoplastic elastomer (TPE) 92 is injected into the mold to form the seal member. The portion of TPE 92 shown in FIG. 8 represents only the proximal edge of the seal member. TPE 92 is forced by the mold between the peripheral edge of filter 91 and the rims and shoulders of support frames 93, 94. TPE 92 surrounds and impregnates the peripheral edge of filter 91, and the impregnated area of ​​the periphery, designated 95, is bonded to the rims and shoulders of support frames 93, 94.

[0140] As shown in FIG. 8, the tool shutout prevents the TPE 92 from entering the filter 91 beyond its perimeter 95, and the filtering action of the filter 91 is prevented by the TPE. In addition to assisting in adhering the support frames 93, 94 to the filter, the impregnation of the periphery 95 of the filter 91 with TPE may contribute to the seal at the edges of the filter formed by the heat seal, preventing moisture or other contaminants from penetrating into the structure of the filter.

[0141] A side view of a filtering mask 20 according to the present invention is shown in Figure 6. The support frame 21 is the same as that described in connection with Figures 1 and 2. A sheet of filtering material 22 is positioned behind the support frame 21 and is visible around the periphery of the shield 23 in the gap between the shield 23 and the rim 24. This allows air to easily flow past the shield 23 and through the filtering material 22 while still benefiting from the protection of the shield over the filtering material.

[0142] The seal member 25 is overmolded onto the support frame 21 and the filter material 22 to secure their relative positions. The seal member 25 includes a chin engaging portion 26, a nose engaging portion 27, and a cheek engaging portion 28. The cheek engaging portion 28 extends laterally across the cheeks to form a seal against the softer skin on the cheeks, improving the overall seal of the mask.

[0143] The seal member 25 is formed of an elastomeric material, thereby providing a compressible area between the support frame 21 and the wearer's face, allowing the elastomeric material to conform to the contours of the wearer's face and provide a good seal thereagainst.

[0144] The downwardly depending seal support member 31 abuts the seal in the chin area and reinforces the seal in this area to enhance the seal against the wearer's chin.

[0145] 4a and 4b show a support frame / filter element assembly with and without the presence of filter material, respectively. Support frame 10 includes rim 11. Rim 11 has an inwardly extending shoulder 41 upon which a pre-cut sheet of filter material 22 is placed. Extending from a first side of the rim is a first mounting formation 13, and a second mounting formation 14 extends from a second side of the rim. Support frame 10 also includes shield 12. A series of vertical ribs 29 across the rear of shield 12 ensure that spacing between shield 12 and filter material 22 is maintained.

[0146] A further embodiment of a filter mask according to the present invention can be seen in Figures 9a and 9b and is generally designated 100. The structure of the mask is substantially the same as that described in connection with the first embodiment shown in Figures 6 and 7, except that the mask 100 further comprises a mushroom valve 101 (shown in the closed position). In the chin area, the rim 102 of the support frame comprises an upwardly protruding portion 103, and the shapes of the shield 104 and the filter material 105 correspond to the shape of the inner periphery of the rim 102 so that they accommodate the upwardly protruding portion 103. The filter material 105 is sealed along the periphery of the rim 102 of the support frame, including the upwardly protruding portion 103, by a peripheral rim of TPE 106. The upwardly protruding portion comprises an opening, and the mushroom valve 101 is formed within the opening as part of an overmolding step that also forms the seal member 107. The mushroom valve 101 allows exhaled air to escape without passing through the filter material 105. Alternatively, the mushroom valve 101 can be housed within a shield 104 .

[0147] A further embodiment of a filtering mask shown in Figures 10a and 10b is generally designated 110 and has substantially the same structure as that described in the second embodiment in relation to Figures 9a and 9b, but instead of the mushroom valve shows an elbow connection 111. The elbow connection 111 allows the mask 110 to be connected to other medical equipment such as a nebulizer.

[0148] A further embodiment of a filtering mask of the present invention is shown in Figure 11. The filtering mask has all of the features described in connection with Figures 6 and 7, but further includes a series of corrugations 121 on each side of the nose portion of the seal member to provide reinforcement to the seal. The corrugations 121 extend in a direction perpendicular to the support frame and across a central portion of the seal. The corrugations 121 are integrally formed into the wall of the seal member so that they are visible from both the inside and outside of the seal member.

[0149] 12A and 12B show a filter mask 140 including a filter 141, a gas inlet 142, a mask body 143, a seal member 144 extending from the periphery of the mask body 143, and first and second pairs of attachment members 145, 146, as described in connection with FIGS. 4A-4B. The gas inlet 142 may be a plug. An opening in a first side of the mask body 143 houses the filter 141, while the gas inlet 142 is inserted through or integrally formed with the second side of the mask body 143, such that the filter 141 and the gas inlet 142 are positioned on different sides of the wearer's nose and mouth during use. During use, oxygen flows from the gas inlet 142 to the filter 141, rinsing over the wearer's mouth and nose and providing a continuous flow of oxygen to help dislodge exhaled gases.

[0150] Figures 13b-13d show a cross section of the mask 150 along line XX marked in Figure 13a, showing the reinforcing members in the nose area.

[0151] Figure 13b shows a series of ribs 151 on either side of the nose region of the seal member 152. The ribs 151 extend perpendicular to the mask body and are located on the interior sidewall of the seal member 152. The ribs provide reinforcement to the seal member 152 and prevent distortion of the seal member 152 in the nose region.

[0152] Figures 13c and 13d show reinforcing members 153, 154 integrally formed within the wall of seal member 152. Reinforcing members 153, 154 take the form of corrugations or scallops on the side walls of the seal member, with each corrugation 153 or scallop 154 ​​extending in a direction perpendicular to the mask body. The wall of seal member 152 in the region of reinforcing members 153, 154 maintains a uniform thickness. Reinforcing members 153, 154 support seal member 152 in the nose region. Another arrangement of reinforcing members is shown in Figure 14.

Claims

1. 1. A facial mask comprising: a seal member depending from at least a portion of a peripheral edge of a mask body, the seal member including a chin region, a nose region, and cheek regions intermediate the chin and nose regions; the seal member further comprising both inwardly and outwardly depending lip portions relative to the peripheral edge of the mask body, the inwardly depending lip portion extending around the chin and nose regions of the seal member, and the outwardly depending lip portion extending around the chin and cheek regions of the seal member.

2. 10. The facial mask of claim 1, wherein the outwardly depending lip formation has a concave contact surface in the chin region.

3. 3. The facial mask of claim 2, wherein the outwardly depending lip portion is shaped to provide a base or shelf formation under the wearer's chin in the chin region.

4. The facial mask of any one of claims 1 to 3, wherein the cheek regions extend laterally across the cheeks of the wearer.

5. 5. The facial mask of claim 4, wherein the cheek regions may extend laterally across the wearer's cheeks between an upper edge of the wearer's cheekbones and a lower edge of the wearer's chin.

6. 6. The face mask of claim 4, wherein a distance between a first side edge of the mask body and an opposing side edge of the mask body, measured along a surface of the mask body, can be 1.2 to 2 times larger than a distance between an upper edge of the mask body in the nose region and a lower edge of the mask body in the chin region, measured along the surface of the mask body.

7. a mouth portion for accommodating the wearer's mouth; 7. The face mask of claim 4, wherein the cheek regions each have a first edge extending from a left or right edge of the nose region and nested over the cheekbones of the wearer, and a second edge extending from a left or right edge of the mouth region, the second edge of the cheek regions nested over a lower edge of the wearer's chin, and an angle between a tangent to the first edge and a tangent to the second edge of each cheek region decreases as the lateral position increases.

8. 8. The facial mask of claim 7, wherein the cheek regions each further comprise side edges extending between a distal end of the first edge and a distal end of the second edge.

9. 9. The facial mask of claim 8, wherein the side edges comprise substantially linear edges.

10. 10. The facial mask of claim 8 or claim 9, wherein the angle between the side edge and the first edge is between 70 degrees and 110 degrees, or between 80 degrees and 100 degrees, or about 90 degrees.

11. The facial mask of any one of claims 7 to 10, wherein the first edge is concave.

12. A facial mask according to any one of claims 1 to 11, further comprising a port, said port being an inlet for breathing or inhaled gases.

13. The facial mask according to any one of claims 1 to 12, further comprising an additive containing silver ions.

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