WO2021207675A1

WO2021207675A1 - Sealed air filtering face shield respirator for clean air inhalation and exhalation

Info

Publication number: WO2021207675A1
Application number: PCT/US2021/026682
Authority: WO
Inventors: Effat Emamian
Original assignee: Effat Emamian
Priority date: 2020-04-09
Filing date: 2021-04-09
Publication date: 2021-10-14

Abstract

A lightweight Sealed Air Filtering Face Shield (SAFF Shield) that includes at least one disposable air filter for the purpose of inhalation of clean air and exhalation of filtered air is disclosed, which covers the entire face, shields, and seals the face from the exposure to the airborne particles outside the respirator, while providing full visibility, absorb humidity, and can be sanitized and reused many times.

Description

SEALED AIR FILTERING FACE SHIELD RESPIRATOR FOR CLEAN AIR

INHALATION AND EXHALATION

Claim of Priority

This application claims priority to U.S. Application 63/007,395 filed on April 9, 2020, the contents of which are herein fully incorporated by reference in its entirety.

Field of the Embodiments

The field of the present invention and its embodiments relate to face shielding respirators and practical applications thereof.

Background of the Embodiments

Medical or non-medical grades personal protection equipment (PPE) are a critical component for self-protection against microbial or non-microbial agents that are harmful to human body through inhalation. Moreover, exhalation of microbial agent by patients suffering from contagious lung diseases can expose others and spread the disease. In the case of an epidemic or pandemic of a contagious respiratory infections that have an airborne or droplet way of transmission, having a simple design of lightweight face PPE that can effectively filter the inhaled air from the pathogen, or exclude the pathogen from spreading by infected individuals (Transmission Protection Equipment, i.e., TPE) , can not only be lifesaving equipment, but can also allow people to continue doing their job and prevent the severe economic consequences in such epidemics. While such advanced PPEs are currently present in the Biosafety Level 3 or 4 (BSL-3 or 4) labs, there is currently no simple PPE that can be used by health provides or general population that can deliver full protection. The embodiment of the present invention are aimed to design a single piece lightweight and transparent Sealed Air Filtering Face Shield (SAFF™ Shield, Figures 1-6) as a PPE or TPE that can be easily worn for many hours, sanitized and reused many times.

To cover the face, mouth and nose, a typical PPE in hospitals currently includes a specific mask plus a face shield, and wearing them either together or individually, often have a suboptimal protective effect against the inhalation of microbial agents due to the insufficient face sealing, which results in an ineffective filtration of the inhaled air. Moreover, masks, such as the commonly used N95 mask, are often very difficult to breathe through, very difficult to perfectly fit on different sizes of human faces, they often require multiple adjustments during the time being used, they cannot be sanitized and cleaned multiple times, and they often leave undesirable mask marks on the face’s skin. This utility /design patent discloses an equipment that is uniquely designed to filter the inhaled air more effectively by a combination of a face- shield that seals the face, plus at least one disposable filter, such as a HEPA filter that effectively filter all microbial and non-microbial inhaled air before entering to the lung from the mouth and nasal cavity. Furthermore, it can also trap the pathogens from spreading around by infected individuals. Therefore, SAFF™ Shield can be used effectively as a PPE or TPE.

The concept of having a face shield that is sealed around the face is known, specifically in the design of snorkeling masks or chemical masks. Diving masks create a sealed space around the face underwater, to prevent the entry of water into this space, while creating a breathing area in this space that is attached to a breathing source via some sealed openings in the mask that is attached to a breathing tube. The use of such masks provide clear visibility of the surrounding area. The difficulty, however, is that such masks are not designed to filter the inhaled air and are made of heavier materials because they are supposed to protect against the entry of water. To prevent the inhalation of viruses or bacteria or other infectious particles, or to prevent the transition of a contagious respiratory disease, it is not necessary to utilize the complicated structure of a snorkeling mask or a chemical mask. SAFF™ Shield utilizes a much simpler, yet much more efficient configuration to effectively sterilize the inhaled or exhaled air.

In the biomedical settings, the concept of shielding the face and filtering the air by different type of filters has been heavily used for personal protections. For example, HEPA filters are critical in the prevention of the spread of airborne bacterial and viral organisms and, therefore, infection. Some of the best rated HEPA units have an efficiency rating of 99.995%, which assures a very high level of protection against airborne disease transmission. A variety of filter systems are used in the industry for sterilization of solid, liquid, or gas materials.

Summary of the Embodiments The present application and its embodiments provide for a first embodiment being a sealed air filtering face-shield respirator that comprises a face shield segment, a disposable filter segment, and a head/neck sealer segment; as described under the SAFFTM Shield General Components 1 to 3.

The present application and its embodiments provide for a second embodiment being a sealed air filtering face-shield respirator that comprises: a face shield segment; a disposable filter segment; a head/neck sealer segment; a shield holder segment; a nose and mouth mask; an inhalation/exhalation canal; and a head attachment segment; as described under the SAFF™ Shield General Components 1 to 7. In at least one embodiment the respirator forms an airtight connection between the face shield segment, the disposable filter segment, and the head/neck sealer segment.

In at least one embodiment the respirator is transparent to facilitate facial communication.

In at least one embodiment the respirator eliminates particles from air before the inhalation or after the exhalation.

In at least one embodiment the respirator prevents the fogging of user’s eyeglasses during the use.

In at least one embodiment the respirator has at least one built-in-valve for the exhaled air to prevents fogging or moisture retention inside the mask. In at least one embodiment the respirator is used for the purpose of clean air inhalation and exhalation.

In at least one embodiment the respirator is used as a personal protection equipment by humans.

In at least one embodiment the respirator is designed as a respiratory protection equipment for animals.

In at least one embodiment the respirator is used as an infection transmission protection equipment by humans.

In at least one embodiment the respirator is used as an infection transmission protection equipment from animals.

Brief Description of the Drawings The disclosed subject matter will be further explained with reference to the attached figures, wherein like structure is referred to by like reference numerals throughout the several views. Number in the parenthesis refer to the structures shown with the same numbers in Fig. 1- 18. Fig. 1: An image of the final production of SAFF™ Shield next to its Computer Assisted

Design (CAD) with parts' description. The parts include SAFF™ Shield Snap-On Shield (11), SAFF™ Shield Front Cover (12), SAFF™ Shield Filter Unit (13), SAFF™ Shield Silicon Face Seal (14), SAFF™ Shield Retainer Seal (15), SAFF™ Shield Head Strap (16) SAFF™ Shield Neck Strap (17), and SAFF™ Shield Strap Ear Strap (18). Fig 2: Two examples of Computer Assisted Design of SAFF™ Shield with (left) or without (right) Snap-On Shield. The only difference between the two version is that the SAFF™ Shield with the Snap-On Shield (left) provides further protection of the eyes and the facial skin, while the SAFF™ Shield without Snap-On Shield (right) only protects the facial structures around the mouth and nose. Both SAFF™ Shield with (left) and without (right) Snap-On Shield create a sealed breathing chamber that filter the air before inhalation and after exhalation. The specific parts shown are as followed: SAFF™ Shield Snap-On Shield (11), SAFF™ Shield Front Cover (12), SAFF™ Shield Filter Unit (13), SAFF™ Shield Silicon Face Seal (14), SAFF™ Shield Retainer Seal (15), SAFF™ Shield Head Strap (16) SAFF™ Shield Neck Straps (17).

Fig. 3. Front and Back view of SAFF™ Shield with the Snap-On Shield. The specific parts shown are as followed: SAFF™ Shield Snap-On Shield (11), SAFF™ Shield Front Cover (12), SAFF™ Shield Filter Unit (13), SAFF™ Shield Silicon Face Seal (14), SAFF™ Shield Retainer Seal (15), SAFF™ Shield Head Strap (16) SAFF™ Shield Neck Straps (17). Fig. 4: Side View of SAFF™ Shield with the Snap-On Shield. The specific parts shown are as followed: SAFF™ Shield Snap-On Shield (11), SAFF™ Shield Front Cover (12), SAFF™ Shield Filter Unit (13), SAFF™ Shield Silicon Face Seal (14), SAFF™ Shield Retainer Seal

(15), SAFF™ Shield Head Strap (16) SAFF™ Shield Neck Straps (17). Fig. 5: Top View of SAFF™ Shield with the Snap-On Shield. The specific parts shown are as followed: SAFF™ Shield Snap-On Shield (11), SAFF™ Shield Front Cover (12), SAFF™ Shield Silicon Face Seal (14), SAFF™ Shield Retainer Seal (15), SAFF™ Shield Head Strap

(16) SAFF™ Shield Neck Straps (17).

Fig. 6: Bottom View of SAFF™ Shield with the Snap-On Shield. The specific parts shown are as followed: SAFF™ Shield Snap-On Shield (11), SAFF™ Shield Front Cover (12), SAFF™ Shield Filter Unit (13), SAFF™ Shield Silicon Face Seal (14), SAFF™ Shield Retainer Seal (15), SAFF™ Shield Head Strap (16) SAFF™ Shield Neck Straps (17).

Fig. 7: Separated components of SAFF™ Shield. The unassembled SAFF™ Shield with Snap-On Feature is depicted in this image with separated parts including SAFF™ Shield Snap- On Shield, SAFF™ Shield Front Cover, SAFF™ Shield Silicon Face Seal, SAFF™ Shield Retainer Seal, and SAFF™ Shield Filter Unit, and SAFF™ Shield Head or Neck Straps. The specific parts shown are as followed: SAFF™ Shield Snap-On Shield (11), SAFF™ Shield Front Cover (12), SAFF™ Shield Filter Unit (13), SAFF™ Shield Silicon Face Seal (14), SAFF™ Shield Retainer Seal (15), SAFF™ Shield Head Strap (16) SAFF™ Shield Neck Straps (17). Fig. 8: General Component 1 of SAFF™ Shield (11), the Snap-On Shield, as described below. This SAFF™ Shield has a middle opening (1 la) with several retention clips (1 lb) that enable this part to tightly attach over the SAFF™ Shield Retainer and easily removed from the unit. This is an optional part of SAFF™ Shield. Fig. 9: General Component 1 of SAFF™ Shield, the SAFF™ Shield Front Cover (12), as described below. SAFF™ Shield Front Cover (12) has a posterior outward edge (12a) that fits inside the groove (14b) of the anterior inward edge (14c) of SAFF™ Shield Silicon Face Seal (14), a grilled shaped bottom (12b) with three openings (12c) to allow the attachment of the SAFF™ Shield Filter Unit (13) under the SAFF™ Shield Front Cover (12) by the three Snap-On Features (13e) located on the bottom filter cartridge (13a) of the SAFF™ Shield Filter Unit (13). This is a required part of SAFF™ Shield.

Fig. 10: General Component 2 of SAFF™ Shield, The SAFF™ Shield Filter Unit (13) and its subcomponents. The Filter Unit (13) is composed of a Bottom Cartridge (13a), Filter Medium(s) (13b), a Top Cartridge (13c), and a Filter Seal (13d). The Bottom Cartridge (13a) has three snap on features (13e) for the three openings (12c) on the grilled shape bottom (12b) of the SAFF™ Shield Front Cover (12). This component is further described below. This is a required part of SAFF™ Shield.

Fig. 11: General Component 3 of SAFF™ Shield, the SAFF™ Shield Face Seal (14). This is an elastic face seal that shapes to different facial structures and sits over the skin face from its posterior border via a turning flap (14a). The anterior inward edge (14c) of SAFF™ Shield Silicon Face Seal (14) has a groove (14b) that holds the posterior outward edge (12a) of SAFF™ Shield Front Cover (12). The SAFF™ Shield Face Seal (14) has four strap holders (14d, top right, 14e, top left, 14f, bottom right, and 14g, bottom left) where the end hooks ( 16a, 17a) of the SAFF™ Shield Head Strap (16) and Neck Strap (17) slide in to tightly hold the SAFF™ Shield over the head and neck. This is a required part of SAFF™ Shield.

Fig. 12: General Component 4 of SAFF™ Shield, the shield holder segment or the SAFF™ Shield Retainer Seal (15). Several retention clips (15a) pointed by arrow in Fig. 12, around the interior of the retainer helps the retainer to push over the junction of the SAFF™ Shield Front Cover (12) and the SAFF™ Shield Silicon Face Seal (14). The SAFF™ Shield Snap-On Shield (11) is also designed to click over the exterior of the SAFF™ Shield Retainer Seal (15). Depending on the manufacturing tool used, this part is a required or an optional part of SAFF™ Shield.

Fig. 13: General Component 5 of SAFF™ Shield, the SAFF™ Shield Head Strap (16), and SAFF™ Shield Neck Strap (17), or SAFF™ Shield Ear Strap (18). The SAFF™ Shield Head Strap (16) has two end hooks (16a) that slide in the top right and left strap holders (14 d and 14e) of the SAFF™ Shield Silicon Face Seal (14), and one adjustment hook (16b) for the adjustment of the length of the strap. The SAFF™ Shield Neck Strap (17) has two end hooks (17a) that slide in the bottom right and left strap holders (14 f and 14g) of the SAFF™ Shield Silicon Face Seal (14) and one adjustment hook (17b) for the adjustment of the length of the strap. Instead of using a pair of SAFF™ Shield Head Strap (16), and SAFF™ Shield Neck Strap (17), the user may choose to use a pair of the SAFF™ Shield Ear Strap (18) instead, where each one attach to the top and bottom strap holder on the right (14d, 14f) or left side (14e, 14g) of the SAFF™ Shield Silicon Face Seal (14) via the SAFF™ Shield Ear Strap end hooks (18a).

Fig. 14: A sagittal section of the SAFF™ Shield with the Snap-On shield shows the formation of hermetic (airtight) seal between the General Components 1-3 of SAFF™ Shield. To create a sealed space, SAFF™ Shield is designed specifically with several layers of sealing, including the SAFF™ Shield Face Seal (14), SAFF™ Shield Retainer Seal (15), and SAFF™ Shield Filter Seal (13d). The airtight seal formation is further described below.

Fig. 15: Insertion of the SAFF™ Shield Filter Unit (13) under the SAFF™ Shield Front Cover (12). The SAFF™ Shield Filter Unit (13) is designed with three Snap-On features (13e) on the bottom filter cartridge part (13a). Further details for the replacement of SAFF™ Shield Filter Unit (13) structure is described below.

Fig. 16: The side (left) and back (right) view of an alternative computer assisted design of the SAFF™ Shield, including an exhalation valve on the front (19), with an additional seal around the face (20) attached to a different type of head straps (21).

Fig. 17: SAFF™ Shield UVC Disinfection Box

Fig. 18: SAFF™ Shield Pulse Oximeter

Description of the Preferred Embodiments The preferred embodiments of the present invention will now be described with reference to the drawings. Identical elements in the various figures are identified with the same reference numerals.

Reference will now be made in detail to each embodiment of the present invention. Such embodiments are provided by way of explanation of the present invention, which is not intended to be limited thereto. In fact, those of ordinary skill in the art may appreciate upon reading the present specification and viewing the present drawings that various modifications and variations can be made thereto.

The present SAFF™ Shield combines the concept of having a sealed space on or around the face (14, 20), combined with the insertion of at least one highly efficient filter (13, 13b), a HEPA filter or a different easy-to-breathe filter that can effectively filter any type of bacteria or viruses, or air pollutants with submicron particle size (13, 13b). This filter, which can allow the entry or the exit of the air after the filtration, is the sole air entry and exit window in the SAFF™ Shield. Moreover, SAFF™ Shield can also protect the face from the exposure to the pathogens that transmit through droplets, which is a common way of transmission of respiratory infections. Besides the microbial agents such as bacteria and viruses, non-microbial air particles such as allergens or air pollutants with larger particle size can also be effectively frittered by SAFF™ Shield because any such particles can also be trapped in the disposable nano-pore size filter of the sealed mask before the inhalation or after the exhalation.

There are few different non-powered full-face respirators and powered respirators available on the market, but they are completely different products in terms of their utility and design when compared to SAFF™ Shield. Powered respirators are entirely different products because they use a power source to filter the air before inhalation. SAFF™ Shield is a non- powered air purifying respirator that uses the physiological negative pressure during the inhalation for the air filtering.

If we compare SAFF™ Shield with other non-powered respirators, SAFF™ Shield can be easily distinguished in several ways from such product. SAFF™ Shield is fully transparent, therefore facilitate facial communications, and it is lightweight. The shape, the size, and the attachment of its disposable filter unit is unique (13). The sealing mechanisms (14, 14a, 15, 13d) used to ensure a hermetic (air-tight) sealing around the breathing chamber are applied in multiple levels (14, 14a, 15, 13d) and are entirely different from other non-powered air purifying respirators. Furthermore, the types of straps (16, 17, 18), the shape of the straps (16,17,18), and the mechanism of the attachment of the straps to the unit (14d, 14e, 14f, 14g) is entirely different from the existing non-powered air purifying respirators.

To define the components of the SAFF™ Shield, we first describe the following seven general components for the SAFF™ Shield. Later we define the specific components of SAFF™ Shield and describe how these general principles were applied and tested to ensure that the unit serves its function as a non-powered sealed air-purifying respirator.

The following seven General Components of the SAFF™ Shield respirator as defined as:

General Component 1 (11, 12), the face shield segment (Fig. 8, Fig. 9, 11): This segment (11) is composed of light weight transparent materials, such as a polyester film made from stretched polyethylene terephthalate (PET), polycarbonate, or any equivalent transparent hard materials that are used in face shields because of their high tensile strength, chemical and dimensional stability, transparency, reflectivity, gas and aroma barrier properties, and electrical insulation. Instead of having a face cover, this shield can be adjusted to a variety of different sizes to cover a part (12) or the entire face (11) or head. Therefore, this face shield segment can cover the entire head, face (11) or only a part of the face (12) (two examples are shown Figure 2).

The two examples of SAFF™ Shield shown in Figure 2 shows how the size of the General Component 1 can be modified significantly, depending on the level of the protection is desired. The only difference between the two version is that the SAFF™ Shield shown in Fig. 2 has the Snap-On Shield (left, 11) provides further protection of the eyes and the facial skin. This is while the SAFF™ Shield without Snap-On Shield (right) only protects the facial structures around the mouth and nose (12). Both SAFF™ Shield with (left) and without (right) Snap-On Shield create a sealed breathing chamber that filter the air before inhalation and after exhalation. Alternative designs of the SAFF™ Shield can be created that have a different shape of the

General Component 1. For example, Fig. 16 shows a different design of the SAFF™ Shield in which the General Component 1 is attached to an additional seal around the face (20). In this design, the seal around the face is attached to a different type of head straps (21). This alternative design also shows an exhalation valve (flutter valve) (19) on the front, which is open only during the exhalation. As the result of this exhalation valve, this version of SAFF™ Shield cannot prevent the transmission of infectious respiratory disease. If protection against the transmission of respiratory infections is desired, this design of SAFF™ Shield can be made without this exhalation valve (19) because the exhaled air can still exit from the SAFF™ Shield Filter Unit (12) located under the SAFF™ Shield.

General Component 2 (13), the disposable filter segment (Fig. 10): This segment includes one or more layers of high efficiency filters of nanometer pore size (13b), which can effectively filter microbial and non-microbial particles. The filter segment can be replaced multiple times, and are made of a biomedical grade HEPA filter, and/or any other effective filter materials used in the P-rated and/or N-rated air masks, such as the electrostatic non-woven polypropylene fibers used in N95, N99, and P95 masks, and/or those used in activated carbon- based filters. The filter segment can be inserted directly on the face shield segment via a built-in valve, a Snap-On feature (13e), or by any type of sealable opening, or can be inserted on a separate segment of the respirator.

General Component 3 (14), The face or neck sealer segment (Fig. 11): This segment is built of elastic materials, such as silicon or elastomers polymer materials with high elastic nature materials, which show high elasticity that can be stretched several times of its original length. This segment seals the face (14a) from exposure to the outside air. The sealer segment is attached to the shield holder segment in front (15) and the head attachment area in the back (16, 17, 18). The sealer segment creates a sealed space on or around the face that prevents the entry or the exit of the unfiltered air from this chamber (Fig 1-6). In cases that the shield is built to cover more areas of the head or the entire head, this sealer can be adjusted accordingly to effectively seal the space inside shield area from the outside air. Alternatively, two sealer segments can be designed, one sealing around the face (20) and the other one seals the area around the nose and mouth (14) (sample shown in Fig. 16).

The General Components 1 to 3 (11, 12, 13, 14) are the required components for the utility and design of the SAFF™ Shield respirator, but components 4-7 below can further augment the unit.

General Component 4 (15): Shield holder segment (Retainer, Fig 12): This segment is composed of lightweight plastic or elastic materials such as TPE (thermoplastic elastomer), LDPE (low density polyethylene), polycarbonate, ABS, or any equivalent materials. This segment holds the front face shield (11) in place and should be tightly attached to the shield and the sealer segment described above. This shield holder segment can be designed as a retainer part (15) that holds the sealer segment (14) and the face shield segment (11, 12) tightly in place.

Unlike General Components 1 to 3 that are the required components for the utility and design of the SAFF™ Shield respirator, this shield holder segment (Retainer) (15) is not considered a required part because attachment of the General Components 1-3 can be achieved by other means, for example by the process of over molding during the injection molding of the General Components 1-3, or via using adhesives to attach these parts together.

General Component 5 (16, 17, 18), the head or neck attachment segment (Fig. 13): This segment can be made of either elastic materials or elastic fabrics, in the form of straps or hats, and can be attached to the shield holder segments (15), the head or neck sealer segment (14), or the shield itself (11, 12). The size of the head or neck attachment segment can vary and adjusted according to the chosen size of the other components of SAFF™ Shield (16, 17, 18). Few examples of the straps are shown in Fig. 13 and Fig. 16). General Component 6: The inside nose and mouth mask (14): This segment is also built from the elastic materials that covers the nose and mouth and cab be attached to an inhalation and exhalation canal. This segment can have a built-in valve for the exhaled air, which prevents fogging or moisture retention inside the mask. This component can be used in addition to General Component 3, when that sealer segment in General Component 3 is extended to seal around the face (20) (Fig. 16).

General Component 7: Inhalation or exhalation canal: This canal is attached to the inside nose and mouth mask from one side and the filter opening or the valve located in the face shield holder for the insertion of the disposable filter. It can also be directly attached to the shield or be built as a part of the shield.

Specific Components of SAFF™ Shield: SAFF™ Shield Unit has the General Components 1-5, as explained above, in a specific utility and design depicted in Fig. 1-15. The functional and design specifications of the specific components of SAFF™ Shield are further described below for each part (Fig. 1-15). SAFF™ Shield Snap-On Shield (11) (Fig. 1-6, & Fig. 8): This is a transparent shield that protects user’s eyes. This part (11) is composed of light weight transparent materials, such as a polyester film made from stretched polyethylene terephthalate (PET), polycarbonate, or any equivalent transparent hard materials. It has an opening in the middle (11a) with several retention clips (1 lb) that enable this part to tightly attach over the SAFF™ Shield Retainer and easily removed from the unit. This part goes over the junction of SAFF™ Shield Silicone Face Seal and SAFF™ Shield Front Cover (Fig. 6, Fig. 14). It can be inserted and removed from the unit by releasing the retention clips (lib) located inside the middle opening. Fig. 2, shows a version of SAFF™ Shield without Snap-On Shield (Fig. 2 and Fig. 14). The use of this shield (11) is particularly helpful for the healthcare providers to cover the eyes and the rest of the facial skin when they use the unit as a PPE. However, general population and patients with infectious respiratory disease can choose to take it off and use the rest of the unit, as shown in Fig. 2. If this part is taken off, the SAFF™ Shield provides no protection for the eyes and the rest of the face outside the SAFF™ Shield Silicon Face Seal.

SAFF™ Shield Front Cover (Fig. 1 & Fig. 9): This is a fully transparent cover (12), which can be made with anti-fog coating, to prevent its fogging after expiration. This transparent unit facilitate users’ facial communications.

SAFF™ Shield Front Cover (12) has a posterior outward edge (12a) that fits inside the groove (14b) of the anterior inward edge (14c) of SAFF™ Shield Silicon Face Seal (14), a grilled shaped bottom (12b) with three openings (12c) to allow the attachment of the SAFF™ Shield Filter Unit (13) under the SAFF™ Shield Front Cover (12) by the three Snap-On Features (13e) located on the bottom filter cartridge (13a) of the SAFF™ Shield Filter Unit (13) (Fig. 9 & Fig. 14). SAFF™ Shield Filter Unit (Fig. 1 & Fig. 10): This Filter Unit (13) snaps under SAFF™

Shield Front Cover (12) via three Snap-On features (13e) inserted on the bottom cartridge of SAFF™ Shield (13a) (Fig. 15). It houses a Filter Medium (13b) that is easily breathable and traps over 99% of viruses and bacteria during the inhalation and exhalation. The SAFF™ Shield Filter Unit (13) is composed of the following four components (Fig. 10): 1) Bottom Cartridge (13a): The Bottom Cartridge (13a) has three snap on features

(13e) for the three openings (12c) on the grilled shape bottom (12b) of the SAFF™ Shield Front Cover (12).

2) Filter Medium (13b) 3) Top Cartridge (13c)

4) Filter Seal (13d)

SAFF™ Shield Silicon Face Seal (14) (Fig. 1 & Fig. 11): This is a carefully designed elastic facial seal (14) that covers the area around the nose and mouth and shapes to different face types. Users need to fit it on their face carefully. The SAFF™ Shield Silicon Face Seal is designed to prevent the leakage of exhaled air outside the unit, therefore, it prevents the transmission of a viral or bacterial respiratory disease from a patient by preventing the leakage of unfiltered exhaled air. It also prevents the fogging of the eyeglasses of the user. SAFF™ Shield Silicon Face Seal shapes to different facial structures and sits over the skin face from its posterior border via a turning flap (14a). The anterior inward edge (14b) of SAFF™ Shield Silicon Face Seal (14) has a groove (14c) that holds the posterior outward edge (12a) of SAFF™ Shield Front Cover (12). The SAFF™ Shield Face Seal (14) has four strap holders (14d, top right, 14e, top left, 14f, bottom right, and 14g, bottom left) (Fig. 11 & Fig. 13), where the end hooks ( 16a, 17a) of the SAFF™ Shield Head Strap (16) and Neck Strap (17) slide in to tightly hold the SAFF™ Shield over the head and neck.

SAFF™ Shield Retainer Seal (Fig. 6 & Fig. 12): This retainer is designed to go over the junction of SAFF™ Shield Front Cover (12) and SAFF™ Shield Silicon Face Seal (14) and hold them tightly together. Several retention clips (15a) pointed by arrow in Fig. 12, around the interior of the retainer helps the retainer to push over the junction of the SAFF™ Shield Front Cover (12) and the SAFF™ Shield Silicon Face Seal (14). The SAFF™ Shield Snap-On Shield (11) is also designed to click over the exterior surface of the SAFF™ Shield Retainer Seal (15). SAFF™ Shield Straps (Fig. 1 & Fig. 13) several types of elastic adjustable straps can be designed and used for the attachment of SAFF™ Shield to the user’s head or neck. For example, SAFF™ Shield Ear Straps (~5mm wide), or SAFF™ Shield Head Straps (16) (typically wider and longer, e.g., 18mm wide, with an adjustable length), and SAFF™ Shield Neck Straps (17) (e.g. 18mm wide, with an adjustable length). As shown in Fig. 13, users can chose to use either one pair of SAFF™ Shield Ear Straps (18), when each strap connected to the upper (14d, 14f) and lower (14e, 14g) strap holders on one side of the SAFF™ Shield Silicon Face Seal (14), or one SAFF™ Shield Head Strap (16), connected to both upper strap holders (14d, 14e) of the SAFF™ Shield Silicon Face Seal (14) plus one SAFF™ Shield Neck Straps (17) connected to both lower strap holders (14f, 14g) of the SAFF™ Shield Silicon Face Seal (14). The straps need to be adjusted carefully to ensure that the SAFF™ Shield is fully secured around the face and head.

The SAFF™ Shield Head Strap (16) has two end hooks (16a) that slide in the top right and left strap holders (14 d and 14e) of the SAFF™ Shield Silicon Face Seal (14), and one adjustment hook (16b) for the adjustment of the length of the strap. The SAFF™ Shield Neck Strap (17) has two end hooks (17a) that slide in the bottom right and left strap holders (14 f and 14g) of the SAFF™ Shield Silicon Face Seal (14) and one adjustment hook (17b) for the adjustment of the length of the strap.

Instead of using a pair of SAFF™ Shield Head Strap (16), and SAFF™ Shield Neck Strap (17), the user may choose to use a pair of the SAFF™ Shield Ear Strap (18) instead, where each one attach to the top and bottom strap holder on the right (14d, 14f) or left side (14e, 14g) of the SAFF™ Shield Silicon Face Seal (14) via the SAFF™ Shield Ear Strap end hooks (18a). Achievement of hermetic (air-tight) seal in SAFF™ Shield: Several utility and design considerations enable the hermetic sealing of the SAFF™ Shield to create a sealed breathing chamber that only allows the entry or exit of the air after passing the SAFF™ Shield Filter Medium (13b) (Fig. 14). First, the SAFF™ Shield Silicon Face Seal (14) has a turning flap (14a) that seals the facial skin around the mouth and nose. This turning flap (14a) may bulge out during the exhalation, but it does not separate from the facial skin by normal breathing forces. Second, the junction of the SAFF™ Shield Silicon Face Seal (14) and the SAFF™ Shield Front Cover (12) is specifically designed in a way that the SAFF™ Shield Front Cover’s posterior edge (12a) fits inside a narrow groove (14c) on the anterior edge (14b) of the SAFF™ Shield Silicon Face Shield (14) (see the junction in Fig. 14). Third, The SAFF™ Shield Retainer Seal (15) is specifically designed to push over the junction of the SAFF™ Shield Silicone Face Seal (14) and SAFF™ Shield Front Cover (12), via its several retention clips (15a) located on the inner circle of the SAFF™ Shield Retainer Seal (15). Therefore, insertion of the SAFF™ Shield Retainer Seal (15) over this junction creates a hermetic seal at this junction. Fourth, the design of the inner circle of the middle opening (11a) of the SAFF™ Shield Snap-On Shield (11) (Fig. 8) has several retention clips (1 lb) as well, which facilitate the tight attachment of the shield part over the SAFF™ Shield Retainer Seal (15). Fifth, the SAFF™ Shield Filter Unit (13) has a top Filter Seal part (13d), which seals the connection area between the SAFF™ Shield Filter Unit (13) and the grill shape bottom (12b) of SAFF™ Shield Front Cover (12). This Filter Seal (13d) further blocks the entry or exit of the air into the unit without passing through the Filter Medium (13b) part.

Sanitization and reuse of SAFF™ Shield: SAFF™ Shield can be sanitize and reused as a non-powered air purifying respirator. All parts, except the Filter Medium (13b) of the SAFF™ Shield, which by itself is a disposable filter, can be washed and cleaned by detergents. Other sanitization method, such as UV-sterilization can be also used. More specifically, a specific UV box equipped with UVC LED lights of 260-280 nm can be used for the sterilization of SAFF™ Shield. Chemical disinfection of SAFF™ Shield is also a possible sanitization method for the SAFF™ Shield. Fig. 17 shows a custom made UVC LED box for the disinfection of SAFF™ Shield following each use.

Besides a disinfection box, other additional items can be included with each SAFF™ Shield Unit. For example, a pulse oximeter (Fig. 18) can be added to measure the blood oxygen level and the pulse rates of the users. Monitoring of blood oxygen levels reflects the function of the lungs and can help the users to know when they are required to get assistance from their healthcare provider if they are suffering from an infectious lung disease. An anti-fog spray or an anti-fog wipe can also be supplied with the unit to refresh the anti-fog coating of the SAFF™ Shield Front Cover when needed.

SAFF™ Shield is designed as a lightweight non-powered respirator: During the long- term design and development of SAFF™ Shield, specific attention was given to make the unit as lightweight as possible. Unlike other non-powered air purifying respirators that typically weigh over 400 grams, SAFF™ Shield including its Filter Unit weight less than 190 grams. For example, 3M Full Face Respirator 6000 Series weight without the filter units is 405 grams. SAFF™ Shield is designed as a lightweight respirator weights approximately between 100-182 grams depending on using the SAFF™ Shield Snap-On Shield or the type of straps used.

SAFF™ Shield without the Snap-On shield (Fig. 2, right side), weight only 100 grams without the SAFF™ Shield Filter Unit, SAFF™ Shield with the Snap-On shield (Fig. 2 left) weight 172 grams without the SAFF™ Shield Filter Unit. The SAFF™ Shield Filter Unit weight only lOgrams. Therefore, one important advantage of the SAFF™ Shield over similar available products is its lightweight.

The facial size consideration in the design of SAFF™ Shield. During the design of the SAFF™ Shield it was very important to choose a size that fits different shapes and types and sizes of human face. The study published in 2017 by Yi-Chun Lin & Chen-Peng Chen was used carefully to select a size that fits the different facial structures (link: https://doi.org/10.1371/ioumal.pone.01886381. Due to the elastic nature of the materials used to make the SAFF™ Shield Silicon Face Seal (14), this respirator can easily adopt to different facial shape and sizes described in the study of Yi-Chun Lin and Chen-Peng. Although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made only by way of illustration and that numerous changes in the details of construction and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention.

Claims

What is claimed is:

1) A sealed air filtering face-shield respirator that comprises: a face shield segment; a disposable filter segment, and a head/neck sealer segment; as described under the SAFF™

Shield General Components 1 to 3.

2) A sealed air filtering face-shield respirator that comprises: a face shield segment; a disposable filter segment; a head/neck sealer segment; a shield holder segment; a nose and mouth mask; an inhalation/exhalation canal; and a head attachment segment; as described under the SAFF™ Shield General Components 1 to 7.

3) A sealed air filtering face-shield respirator of claims 1 or 2, that forms an airtight connection between the face shield segment, the disposable filter segment, and the head/neck sealer segment.

4) A sealed air filtering face-shield respirator of claim 1 or 2 that is transparent to facilitate facial communication. 5) A sealed air filtering face-shield respirator of claim 1 or 2 that eliminate particles from air before the inhalation or after the exhalation. 6) A sealed air filtering face-shield respirator of claim 1 or 2 that prevents the fogging of user’s eyeglasses during the use.

7) The sealed air filtering face-shield respirator of claim 1 or 2, when the said respirator has at least one built-in-valve for the exhaled air to prevents fogging or moisture retention inside the mask.

8) The sealed air filtering face-shield respirator of claim 1 or 2, when the said respirator is used for the purpose of clean air inhalation and exhalation.

9) The sealed air filtering face-shield respirator of claim 1 or 2, when the said respirator is used as a personal protection equipment by humans.

10) The sealed air filtering face-shield respirator of claim 1 or 2, when the said respirator is designed as a respiratory protection equipment for animals.

11) The sealed air filtering face-shield respirator of claim 1 or 2, when the said respirator is used as an infection transmission protection equipment by humans. 12) The sealed air filtering face-shield respirator of claim 1 or 2, when the said respirator is used as an infection transmission protection equipment from animals.