KR20200028341A - Protective discharge type medical mask with frame (variant) - Google Patents

Abstract

The group of claimed invention relates to personal protective equipment, in particular masks used primarily in the medical field. The technical results of the claimed group of inventions improve the working conditions of the medical staff during the entire use period of the mask, while not only completely protecting the user from airborne droplet infections in public areas, but also for example from the operating room to the patient, respiratory organs It provides complete protection against infection and penetration of liquid media. The protective-discharge type medical mask with frame includes a hollow frame designed in the form of a channel that forms a mask cavity for the lower part of the face and includes inlets and outlets for passage of air flow. The transparent side of the outside of the frame is airtight, and the side adjacent to the face surface is made of elastic, closed fabric. The frame includes a shield covering a part of the nose, forming a mask cavity for the middle part of the face.

Description

Protective discharge type medical mask with frame (variant)

The group of claimed invention relates to human personal protective equipment, ie face masks used primarily in medicine.

The present invention, represented in three versions, is as follows:

● Universal environmental and hygiene protection for both surgeons and patients while medical support for all levels of complexity is performed, including long-term surgical procedures;

● Civilian protection against air infections, including influenza.

Differences between versions of medical face masks are defined by major applications in the general-purpose, surgical or clinical fields.

Unlike medical filter masks, this relates to protective and vented face masks, ie masks that completely prevent the passage of exhaled air and discharge the exhaled air in the intended direction. Structurally, each version of the mask is a hollow frame.

Various options for the design of protective medical face masks and frame face masks are available from the background art.

From this document [Journal “Surgery Reporter na II Grekov” No.12, 1969, Author: Professor of Private School of Medical Sciences, Professor of SM Kurbangaleyev et al.] As a protective film with a texture that fits the face A protective face mask made of plastic is known. The mask was applied by the I.P. at the First Leningrad Institute (1st St. Petersburg State Medical University). It was tested by Pavlov during 2,000 surgical procedures and showed excellent aseptic properties. In terms of the effectiveness of patient protection against respiratory infections during surgical operations, the undoubted advantage of the protective face mask (air shielding type) compared to filtration (standard medical) masks has been demonstrated experimentally and clinically. .

The disadvantages of the given design are:

-A large amount of exhaled air remains in the area under the mask, causing excessive moisture and overheating of the face.

-The greenhouse effect occurs, the overall mood deteriorates and the productivity of the doctor decreases.

-It is a solid structure that adheres to the face for a long time.

Despite the high level of patient protection during surgical operations, this type of mask is not used in medical practice, as the aforementioned disadvantages significantly affect the surgeon's performance by reducing it to an unacceptable level.

Breathing face masks are known from document CN2162260 Y, published April 20, 1994, for nose and mouth breathing. It consists of two boxed side frames joined in an integral structure with through holes and a sturdy shield positioned between them on the anterior side of the nasal cavity area. The mask is functionally divided into front, right and left sectors, where the left and right sectors represent the side containers containing filtration elements. All exhaled air is removed through valves (similar to the ventilator) and inhaled air is filtered. The partition wall located between the containers acts as a partial protection (shield) to protect the face surface from moisture penetration from outside.

The disadvantages of the given design are:

-Since there is little natural exhaust in the area under the mask, a high level of CO ₂ and moisture accumulates and the wearer's health condition gradually decreases;

-A large number of filtration elements create high resistance to breathing, which significantly affects the wearer's performance;

-It is a solid structure that adheres to the face for a long time.

This general drawback is inherent in two similar things.

To ensure the necessary obstruction, intimate contact of the face surface with a rigid inelastic structure causes long-term compression of nerve fibers and blood vessels, causing pain, local paralysis and significant discomfort, rendering this type of mask unusable.

As the closest analogue, Applicants chose Russian Patent No. 2240160 (November 20, 2004), which is known for its medical framed protective and discharge facial masks.

Similar to the claimed version of the invention:

● Structurally, the mask is a hollow frame;

● The outer part of the frame is made of air impermeable material (medical plastic). The inner part (in contact with the face surface) is made of a soft and elastic fabric that prevents compression of the facial nerve fibers and blood vessels by the mask;

● It performs the protection and discharge functions;

● It is not resistant to breathing.

A number of essential features distinguish similar frames from the claimed invention.

• Firmly secured to the face surface (according to RA. Reiss classification): Cover the floor and middle section from chin to nose level;

● The space under the mask forms a uniform nasal cavity and mouth.

● The face (inner) portion of the frame has a cut portion that is bound around the nasal cavity and mouth;

The disadvantages of the given design are:

-In the area under the large mask (mainly during oral breathing), excessive accumulation of moisture occurs and the CO ₂ level rises, partially reducing the performance of the surgeon.

-The physiological differences in human breathing through the nose or mouth are not taken into account, so the hygienic properties of the mask are improperly reduced;

-Similar to the similar, the shape of the mask is not universal because it depends on the surface relief, which ultimately reduces the consumer's characteristics;

-When wearing a mask, the movement of the lower jaw is hindered, reducing the potential for communication,-which hinders speech.

If the ability of a surgeon to decrease during a surgical procedure due to a sharp deterioration of breathing conditions in a filtration medical mask has a significant impact on the quality of the surgeon's work. In addition, filter medical face masks generally lose their protective properties after 30 minutes of use. As a result, we can observe relatively low-level surgical procedures and high-level postoperative complications worldwide.

Standard filter medical masks lack the potential to protect the public from a number of harmful bacteria associated with viral infections and infectious diseases due to their design features.

Other protection principles for patients and the public are proposed by creating an impermeable barrier to air infections, without disturbing the user's ability to breathe. In addition, a number of other major problems have been solved, for example, to help maintain the ability of the medical staff to perform during the entire working time.

The purpose of this group of inventions for medical face masks is to eliminate the defects of the prior art and achieve the following results:

-Elimination or significant reduction of CO ₂ accumulation in the space under the mask, as well as preventing the increase in moisture and temperature levels, ie solving the basic hygiene problem of the prototype;

-Implementation of various methods of protection against air infection, depending on the environmental conditions and the working characteristics of the wearer;

-Improvement of comfort and efficiency when using a mask due to the appropriateness of protection during oral or nasal breathing;

-Reduced accumulation of airborne infections in the enclosed space (eg operating room) due to full or partial neutralization of the mask compared to similar medical filter masks;

-Universality is achieved because the shape of the mask does not depend on the embossment of the face;

-The mask does not interfere with the mobility of the lower jaw. That is, it does not affect the wearer's ability to communicate.

The technical results of the claimed invention group are as follows:

• The improved working conditions of the medical staff throughout the entire use period of the mask completely protect the infection and infiltration of the liquid medium from the surgical field to the patient's side.

In literal translation, the meaning is slightly distorted. Here's what it actually means:

"The improved working conditions of the medical staff over the entire use period of the mask perfectly protect the penetration of infection and the infiltration of any liquid medium in the area of surgery from both the surgical field and the consumer / surgeon to the user's respiratory system. "

● In addition to protecting the wearer from air infections in public places,

● Protect the human respiratory system from aggressive environments in various areas of professional activity without losing productivity.

The claimed technical results are achieved through a design embodiment of a medical face mask according to three options, each option complementing or concentrating the previous function while providing new consumer characteristics.

All mask options have one common inventive concept; That is, it includes a hollow frame that forms a space under the mask for the lower part of the face made in the form of a channel with an airtight outer surface and an inner surface made of respirable fabric (closest to the face surface). The frame channel includes air inlets and outlets on each side (left and right) for air flow formed during exhalation / exhalation. Typically, the side contacting the face surface has a cut around the mouth.

Structurally, various functional spaces, i.e., oral and nasal breathing regions, are formed in the mask. In the mouth area (lower part of the face), each version of the mask is made in the form of a hollow frame. A separate area for nasal breathing is formed in the middle part of the face (nasal area) depending on the version, which can be open, semi-open or closed.

All versions are secured to the head area using standard means such as straps, elastic bands, and the like.

The face mask is placed on the head in such a way that exhaled air is almost completely backed out into a safe area for people around the wearer.

Since the mask space is divided into two relatively independent zones, optimal breathing conditions taking into account the physiology of nasal and oral breathing are achieved. The presence of cavities in the frame ensures additional venting and adjustment of the space under the mask.

Medical face mask, option 1

Face masks are universal. That is, it is designed for use by the general public and medical institutions. It can be applied as a basic version (the simplest version) or a combination of a frame mask and additional components.

Unlike the prototype, the mask frame covers the lower part of the face, providing complete protection only for the mouth area, which is the main cause of air infection and the gateway to the penetration of infection from the outside. In order to maintain the wearer's performance to the maximum, nasal breathing was done completely unobstructed, which is especially important for healthy wearers whose nasal mucosa is intact. The mask frame sides are very short compared to the prototype to minimize breathing resistance.

The hollow mask frame consists of two parts forming an outer part and an inner part in direct contact with the face surface. The outer part of the frame is sealed and is usually made of transparent medical plastic to improve the wearer's ability to communicate. If the mask transparency is not relevant, the outer part can be made of, for example, a dense cloth or paper. The inner part of the frame, i.e. the side contacting the face surface, is made of respirable and generally elastic fabric, e.g., spunbond fabric or medical gauze. To reduce overall breathing resistance, cuts around the mouth area can be placed on the side that contacts the face surface. If a fabric with low breathing resistance is used inside the frame (eg 1-ply or 2-ply gauze), the cut in the mouth area is not suitable.

For transport convenience, the mask may have a special device that folds in dimensions to a flat shape. For example, the outer portion of the frame may have a wavy or pleated fold. With this design, the mask is folded and shaped as a result of forced exhalation.

In the basic version, masks (without additional components) are primarily targeted to the public to prevent the spread of influenza epidemics in public areas.

Additional components of the mask enhance the protective properties and extend the coverage to include medical facilities.

Additional description is provided with reference to FIG. 1 showing the designated locations of structural components, so that experts can better understand all aspects of the disclosure of the essence of version 1 of the claimed technical solution.

The design of the medical protection and discharge facial mask version 1 is shown in FIG. 1.

The frame of the mask for the lower face part 1 comprises, for example, an external air impermeable side (shown transparently) of the frame 2 made of plastic, through which the internal respirable side of the frame 3 is can see. It can be made of fabric, for example, and can come into contact with the face surface. A cut 4 is provided around the mouth area. On both sides of the head, the frame defines a lateral air hole (inlet / outlet) 5 for passage of air flow.

The nasal area is completely open. That is, the inhalation and exhalation of the nose is not damaged. The upper edge of the frame passing directly under the nose partially exhausts the air exhaled through the nose due to its geometric shape.

When inhaling through the mouth, the air from the outside passes through the cavity of the frame through the lateral air holes 5 and then passes through the cut 4 at the side contacting the surface of the face 3. In the absence of cuts, air passes through respirable fabrics.

During oral exhalation, air is initially supplied to the frame cavity and then exhausted through the side air supply opening 5. Due to the air impermeability of the outside of the frame 2, the exhaled air is completely back in the opposite direction with moisture contained therein. Due to the elasticity and hygroscopicity, the side of the frame that comes into contact with the surface of the face 3 prevents the compression of nerve fibers and blood vessels in the face region, does not cause discomfort or pain, and the wetness of the face region (skin tissue Change).

To extend the protection properties of mask version 1, the following additional components are used.

1. The respirable material 6 extends beyond the frame and includes an additional device 7 for partial retention of moisture contained in exhaled air. The device 7 can be made, for example, in the form of a fold or a strip of fabric, and can be immersed in a special disinfectant if necessary. There may be several of these devices 7 on each side of the mask.

2. The air inlets and outlets, ie the side air openings 5 of the frame, comprise additional components 8 in the form of spoilers in the outer (breathable) part, which is the material (6) through which the exhaled air comes into contact with the face surface. ). It extends beyond the frame and includes an additional device 7 for partial retention of moisture contained in exhaled air. The spoiler can be an extension of the outer part 2 of the frame, or it can be a separate part that can be attached, for example, with an adhesive, adhesive tape, or the like. Spoilers can be made of materials with special properties, for example, disinfectants and adhesives.

The respirable material of the mask may be a single layer or may consist of multiple layers, each layer having various useful properties, for example, sterilizing action against different types of microorganisms, and the like. All materials applied (on each floor) are widely used in medical practice and are equivalent to having appropriate certificates.

The plastic and textile parts of the mask can be factory-bonded (stitched, glued), for example, using adhesive tape, or connected by the wearer himself.

The mask is attached / fixed to the wearer's head area using a device 9, for example, a tie, strap, elastic band, or the like.

Medical face mask, option 2

This version of the mask is primarily intended for use in surgery and provides maximum protection for doctors and patients under surgical operation conditions. It aims to preserve medical staff's ability to work as much as possible.

This option is a combination of two masks in the shape of a frame and a shield, i.e. a frame and a shield, forming two different mask spaces: a lower frame in the mouth region and a shield in the nose region. A partition wall is formed between the shield and the frame, and includes an air opening for passing air exhaled through the nose into the frame cavity. In this opening, a valve may be installed, if necessary, to direct air exhaled through the nose towards the frame and prevent air exhaled through the mouth from penetrating into the space under the mask.

Since the shield is airtight and located slightly away from the face surface, nasal breathing is virtually unobstructed.

The main purpose of the mask shield is to direct the air exhaled from the nose into the cavity of the frame directly (aerodynamically), thereby completely preventing entry into the operating room. This solution allows surgeons to improve performance while maintaining high-quality primary (nasal) breathing during surgery.

Structurally, the partition wall between the shield and the frame may not have an air opening, but in this case, the aerodynamics of the air flow controlled by the shield become completely irregular, which greatly reduces the consumer properties of the mask.

In addition, the shield protects the nasal region and partially protects the middle part of the face from external pathological factors during surgery, that is, biological fluid, air infection, and the like. This is also related to improving the safety of doctors.

During the operation of the surgical team, the air exhaled by the individual, in contrast to the filter mask, is completely discharged into the non-sterile area of the operating room. This ensures a high level of sterilization in the surgical area itself. In other words, it contributes to reducing the risk of complications after surgery. As a result, the overall quality of care provided by medical facilities is improved.

Further description is provided with reference to FIG. 2 of the drawings showing the designated locations of structural components, so that experts can better understand all aspects of the disclosure of the nature of the technical solutions claimed in accordance with version 2.

The frame of the mask located in the lower face portion 1 comprises an external air-preventing portion of the frame 2 (shown transparently), which can be made of plastic, through which the respirable side of the frame 3 You can see It is made of, for example, textile material and has cuts 4 around the mouth area. On both sides of the head, the frame defines a lateral air hole (inlet / outlet) 5 for passage of air flow.

Contrary to option 1, the sides of the frame are elongated as possible to exhaust as much exhaled air as possible from the operating room.

The frame also has an air impermeable shield 10 covering the lower part of the nose. Between the shield 10 and the frame 11 is a partition wall with an air opening. The partition wall may have several similar openings which may have the same or various shapes.

2 shows that the shield 10 is positioned at a predetermined distance from the face surface to form a slotted space.

When inhaling through the nose, air freely penetrates through this slotted space. When exhaling through the nose, all the air is directed from top to bottom through the air opening of the partition 11 due to the aerodynamic properties of the shield. Air enters the frame cavity and exits through the side air openings 5 for the air flow passages.

Oral breathing occurs similarly to number 1. In order to completely eliminate (if necessary) air inflow from the frame cavity to the space under the mask in the middle of the face, one or more valves can be installed in the air opening of the partition 11.

However, if the inner cavity of the frame is manufactured taking into account the aerodynamics of the air flow through it, the relevance of the valve is reduced or eliminated.

Medical face mask, option 3

The main purpose of this version of the mask is for general clinical use. Masks are used by all types of medical institutions, including the epidemic department, and can be recommended to provide all types of medical services, from outpatient to infectious surgery. This is to maximize the protection of medical staff without significantly losing performance ability. A special feature of this mask option is that it can be modified and adapted to the medical staff's specific working conditions.

This type of mask design is a hybrid consisting of three types of mask: frame, shield shape and filter. Therefore, it combines the functions of well-known medical masks of all types: protection and discharge, protection and filters.

The fundamental differences between Option 3 and the first two are:

1. The mask can have two states: initial and operational. In the initial state, the mask is practically not different from option 2 in terms of functionality.

Breathing is not disturbed in this state. Consequently, in similar locations, it can be used, for example, in conventional surgical procedures. If there is a risk of infection, the mask can be put into operation. In other words, all air flows that occur during inhalation and exhalation of the oral and nasal passages are guided through a built-in filter. Similar risks exist, for example, when healthcare workers move from clean areas to infected wards. When leaving the ward, there is no risk of infection and the mask returns to its initial state with greatly improved breathing conditions. During an emergency operation (immediate emergency), the patient was found to have an infectious disease at the same time. In this situation, the surgeon can put the mask into an operating state without stopping the operation and without removing the mask. In other words, you can protect yourself quickly.

2. The hollow frame for the lower part of the face is functionally divided into three sectors: one central sector and two side sectors.

3. The outer wall of the side sector of the frame is an air filter made of material used in the manufacture of standard (filter) medical masks such as spunbond fabrics.

4. The side walls of the frame can be composed of homogeneous or series-connected segments, each segment being a filter of different density, ie a filter designed for different types and levels of infection.

5. The channel of the frame has a device capable of closing and reopening the frame to induce air flow during exhalation and exhalation through an inlet / outlet (side opening) or built-in filter.

6. If the side walls of the frame are composed of multiple segments, each segment can have a separate device for closing, which can be made, for example, in the form of an adhesive tape or a special latch.

7. The mask shield is, in principle, made of filter material used for standard medical masks or consists of a combination of air impermeable material and filter fabric, if it is necessary to provide aerodynamic properties. Similar to option 2, the shield does not contact the face surface.

8. The device is built around the edge of the shield fabric so that it fits the contour of the face around the nostrils. This can be, for example, adhesive strips, flexible wires, elastic brackets, and the like.

9. There is a partition between the frame and the shield that separates the space under the two masks, which can be made without an air opening, as opposed to version 2. If the shield is made entirely of fabric, the aerodynamic properties are not relevant. At the same time, in the working state, if there is no air opening in the partition, the protection level of the mask is increased.

Further description is given with reference to FIG. 3 of the drawings showing the designated locations of structural components, so that the expert can better understand all aspects of the disclosure of the nature of the claimed technical solution according to version 3.

The design of the medical protection and discharge face mask No. 3 is shown in FIG. 3.

The frame of the mask located in the lower face portion 1 comprises an outer air-tight portion (shown transparently) of the frame 2, which can be made of, for example, plastic, through which the frame 3 The respirable side of the can be seen. It is made of, for example, textile material and has cuts 4 around the mouth area. On both sides of the head, the frame defines lateral air holes (inlet / outlet) 5 for passage of air flow.

This mask version is available in two states: initial (open) and actuated (closed).

In the initial position, the shield 10 does not contact the face surface, and the inlet / outlet 5 is opened to allow passage of air flow.

In FIG. 3, the medical mask version 3 is shown in the acting (closed) state.

The shield 10, which is made of filtration and generally single-ply material (eg, spunbond fabric or medical gauze), is securely fixed to the contour of the face around the nose. As a result, the mask space of the nasal region is completely closed, and nasal exhalation / exhalation occurs through the filter fabric of the shield. A partition 11 is formed between the shield and the frame, which, unlike version 2, may not include an air opening.

Unlike options 1 and 2, the outer side of the frame side section consists of segments 12 made of filter fabric (side filter). The walls of each segment 12 can be composed of filters of different densities or different numbers of fabric layers (eg spunbond fabrics). A device 14 for closing the channel is located on the outer boundary 13 of each segment (only shown for the middle segment). Consequently, during oral inhalation / exhalation, air passes only through the side filter 12.

In order to preserve the frame structure (air channels) of the side segments of the frame, molded supports (eg coarse mesh of nylon) can be installed between the fabric layers of the outer part. The mesh may be woven into the fabric furnace in the form of individual fibers, or the fabric itself may be immersed in a molding solution (eg starch).

The respirable material of the frame, the filter and the shield of the side segments can be made of fabric with different functional properties or the same fabric (used as standard in medical practice).

Apart from the prototype in versions 2 and 3 of the mask, the shield does not contact the face surface of the nostril area. The resulting gap is used not only to supply air during inhalation of the nasal cavity, but also to allow free movement of the plastic part to follow the movement of the lower jaw.

Thus, the connection between the mask parts does not interfere with the free movement of the lower jaw, which allows communication, for example, during surgery. In option 3, the shield 10 is made of fabric to the extent that it does not interfere with the movement of the lower jaw during the conversation.

Each version of the mask can have a variety of additional devices or features, and can be made of different materials or using different techniques.

For example:

To further protect the area around the eyes and the rest of the face surface, the plastic part of the mask can have an additional structure in the form of a transparent shield.

To increase the ability to communicate, the outer portion of the mask can be completely or partially transparent; It can be made of plastic as shown in Figs. With the design goals in mind, the colors of the plastics can be different and various inscriptions and images can be printed. Plastics may not be transparent (using any color scheme).

For additional ventilation, the outer portion of the frame in front of the mouth area may be a movable wall in the form of a membrane capable of vibrating in synchronization with breathing.

Some of the frames in contact with the face surface are, for example, cotton fabrics, or transparent or translucent natural fabrics (eg silk, batiste, chiffon, etc.) or rigid fabrics of synthetic polymers (eg nylon, capron, etc.) Or it can be made of nets (fine or coarse mesh).

For greater strength and better adaptation to the face surface, components for forming and strengthening marks (such as meshes, threads, elastic bands and straps that act as a tie-through mask) will pass between the layers of respirable material. You can.

Due to the presence of a frame in all versions of the mask, various devices and equipment can be installed in the channel for further treatment of the air used for breathing (cleaning, drying, disinfection, cooling, heating, deodorization, etc.).

By taking into account the different properties of the air flow formed during inhalation / exhalation through oral or nasal breathing, the mask frame cavity is provided with at least one device for optimization and separation of air flow, for example one or more bulkheads, air channels, etc. It may include.

The at least one filtration component can be installed along the air flow path in the frame channel, for example, further treated with a preservative or developed with a filtration material (eg, spunbond fabric) used in the manufacture of medical masks. Can.

Also, at least one air channel in the mask frame may include at least one moisture absorbing element.

Any air channel in the mask frame can include at least one inlet or outlet valve.

At least one tube for forced supply of the air mixture from the external source to the respiratory tract and / or forced discharge of exhaled air from the space under the mask can be attached to at least one air channel in the mask frame.

The at least one air channel in the mask frame may further include at least one compressed air bottle to enhance the composition of the inhaled air in standalone mode or field (combat) conditions.

The at least one air channel in the mask frame may also include at least one fan.

The at least one air channel can be made into a spiral shape, which allows foreign particles in the inhaled air to move in a rotating (centrifugal) manner and settle on the walls of the channel.

The at least one air channel in the mask frame may include at least one zero resistance filter.

The inner surface of the frame channel can be treated with a special adhesive that promotes surface adhesion of various biological aerosols contained in dust and air.

The mask frame can be further electrostatically treated to ensure the surface settling of dust particles and other foreign matter that is accommodated in the passing air stream and has opposite potential.

Claims (11)

In the medical frame-type protective and discharge face mask which is a hollow frame forming a space under the mask in the face area,
The medical mask is in the form of a channel that includes an air inlet and an outlet, and the hollow frame forms a space under the mask for the lower part of the face and at least one inlet and at least one outlet for passage of air flow. A medical mask, taking the form of at least one channel comprising, and the outer part of the frame is air-impermeable and the side contacting the face surface is made of a respirable material. According to claim 1,
A medical mask with a side portion of the frame in contact with the face surface having a cut around the mouth. According to claim 1,
The respirable material extends beyond the frame, a medical mask. According to claim 1 and 3,
The at least one inlet and / or outlet includes an additional component that directs exhaled air to a material contacting the face surface, the component extending beyond the frame. The method of claim 3,
The respirable material extending beyond the frame comprises an additional device for maintaining moisture in the exhaled air. According to claim 1,
The outer portion of the frame is a medical mask having folds of wrinkles or wrinkles. According to claim 1,
And at least one device for securing the mask to the head region. A medical frame-type protective and discharge facial mask, which is a hollow frame formed in the form of a channel under the mask in the face region and including air inlets and outlets,
The hollow frame forms a space under the mask for the lower part of the face and takes the form of at least one channel comprising at least one inlet and at least one outlet for passage of air flow, the frame also comprising at least one of the nose A medical mask comprising a shield that can close a lower portion and form a partition wall with the frame, wherein the partition wall includes at least one air opening. The method of claim 8,
A medical mask, wherein at least one valve is provided in the at least one air opening. A medical frame-type protective and discharge facial mask, which is a hollow frame formed in the form of a channel under the mask in the face region and including air inlets and outlets,
The hollow frame forms a space under the mask for the lower part of the face and takes the form of at least one channel comprising at least one inlet and at least one outlet for passage of air flow, the frame also being around the nostrils. It is formed to be able to contact along the contour of the face and comprises a shield forming a partition wall with the frame, and in the oral cavity area, the outer portion of the frame is air impermeable, the other part is made of filter material, and at least one The channel is provided with at least one device capable of closing the channel, a medical mask. The method of claim 10,
The frame is made of filter material, a medical mask.

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