CA3081041A1 - Personal environmental isolation respirator - Google Patents

Abstract

The embodiment of the invention is an article of personal protective equipment (PPE), a reusable respirator. A rigid transparent shell forms a helmet that completely covers the head with a detachable impermeable, elastic diaphragm creating a seal between the helmet's rim and the wearer's neck to completely isolate the wearer's head and respiratory system from environmental pathogens. An externally mounted intake HEPA filter canister is connected to an internal one-way valve located at the back of the helmet permitting only essentially sterile air to enter the respirator and an internal exhaust REPA filter canister is connected to an external exhaust valve at the lower part of the front of the helmet permitting only essentially sterile filtered air to exit the respirator. Air is moved through the helmet by the vacuum and pressure created during breathing. The device can be disinfected while in use and the intake filter replaced while worn. An internal elastic shield isolates the mouth and nose to prevent fogging of the visual field. The device can optionally be fitted with a tube that traverses the diaphragm that can be connected to a vessel to provided the wearer with hydration or nutritional liquids while preserving sterility.

Description

PERSONAL ENVIRONMENTAL ISOLATION RESPIRATOR
TECHNICAL FIELD
The invention described herein pertains to the field of personal protective equipment (herein "PPE") in the prevention of infection from air-born droplets or particles containing pathogens, specifically viruses. It is a device that substantially sterilizes the air that is drawn by respiration negative pressure into the device and also sterilizes the air upon exhalation. These types of devices are known as air purifying respirators (herein "ARPs").
BACKGROUND INFORMATION
The common practice in the medical field and first responders when dealing with people who are infected with a contagious virus is to wear a fiber mask that covers the mouth and nose (typically N95 masks) and transparent face shields intended to protect the wearer from air-born droplets. As recent research has shown, viral particles can remain suspended for long periods of time in rooms where sick patients were housed. It has also been shown that in the case of Covid-19 viral particles can also be shed by speaking and breathing. With the presence of high viral loads in facilities that treat infectious patients, the risk to the health care workers is greatly increased and it becomes necessary to increase the effectiveness of the PPE. Infections have been shown to occur in aeroplanes, pubic transit, restaurants and auditoriums at distances of several meters.
It is generally accepted by the scientific community that most viruses enter the human body through mucous membranes including the mucosa of the mouth and nose and respiratory epithelium, as well as the mucous membranes of the eyes. Shields offer some protection to the eyes from direct contact with projected particles. However, these devices cannot assure complete protection from air-born viruses.
The existing protocols require that the mask or respirator be discarded after each use with a patient or infected person, although some face shields can be disinfected. The single use of masks results in the need for large quantities of masks measured in tonnes and resulting tones of waste matter. Globally, this also costs billions of dollars on products that are used once and discarded. As the masks are made of synthetic materials, they cannot be composted and must be put in land fill or incinerated. The disposal costs contribute to the overall expense of these protocols. The face shields offer some protection to the eyes from splatter and droplets. However, protection is not assured, as demonstrated by the large numbers of health workers who became infected. Only a device that completely isolates the wearer from the environment and provides essentially sterile air can offer assured protection.
This device can also be used by persons with compromised immune systems, persons with allergies to other environmental particles such as pollen, and any other situation where particles in the environment or atmosphere can cause harm to a person. The device is not intended to protect against toxic gasses although specific filtration canisters can be made for that purpose.
PRIOR ART
There are a number of devices, for complete isolation of the wearer including Hazardous Material Suits Date Recue/Date Received 2020-05-20

2/15 for disposal of toxic wastes, and for use with highly contagious agents in biological laboratories, and full head-cover masks for protection from chemical and biological agent primarily provided for the military. Although these devices are effective for protection of the wearer, they are generally very costly, very cumbersome and uncomfortable to wear for long periods and require additional support systems for re-sterilization or providing breathable air. These devices also require considerable time to don and doff Therefore, these devices are not considered practical for common use during a pandemic where massive numbers of people are infected and need immediate medical attention.
Patent #1,410,928, (J.W. Knowblock, issued March 28, 1922) provided full head-coverage extending to the shoulders, with a flexible material and two portals for vision with a single filter. The filter is attached to an internal cup that covers the mouth and nose preventing the fogging of the goggles.
U.S. Patent Numbers 6,277,178 (Holmquist-Brown), and 5,944,873 (Jager), relates to a respirator and filter cartridge that has activated carbon filtering elements. The cartridge fits in a sleeve to prevent unfiltered air from entering the respirator. The head-covers in these respirators are not rigid and tend to contract and expand during breathing cycles with reduced air exchange efficiency.
U.S. Patent Numbers 6,701,925 B 1, and (Renskin, 2004) describes a neck-sealable hood that completely encloses the head. This apparatus is fabricated of an elastomeric material and suffers the same challenges as other elastomeric head covers. This apparatus also has symmetrical front mounted filtering canisters for purifying incoming air. This apparatus also has an internal half mask breathing cup covering the mouth and nose that is mechanically coupled but is not fluidly coupled to the filters and causes the incoming air to be diverted over the visor portion to prevent fogging prior to being inhaled.
Canada patent #1281253, (Greenborough 1991), describes a neck sealable apparatus, that has a full face shield, a rigid hat component and a flexible component that covers the lower half of the back of the head. This device is powered with the motors and batteries housed in the posterior part of the hat section. Air exhausts out the inferior aspect of the anterior part of the face shield. There is no filtering of exhaled air.
Similarly, Canada patent #1165205, (Berg, 1984), the device has a forced air component to deliver air to the face. The face shield adapts to the face at the periphery of the shield. This device relies on excess air flowing out of the face shield to prevent contaminants from entering. The intake filter is housed in the hat portion and there is no exhaust filter.
Canada patent #2520542, (Wang, 2006), describes a forced air full head-cover device with integrated helmet and shield. This device has no neck seal and there is no filtration of exhaled air.
Canada patents #2471429 (Wen, 2009) and #2498620 (Mcfarlane, 2003) are two examples of protective devices that completely cover the head and neck. These devices include a visor or goggle type component and in the case of #2498620 also containing a rigid helmet component and the breathing apparatus is connected by an external hose to a back mounted filtration system. While in #2471429 the filtering components are integrated into the hood covering the head and part of the chest.
Other devices including Canada patent #2706376 (Tilley, 2016) and #2910323 (Bergerson, Del Mistro, Date Recue/Date Received 2020-05-20

3/15 et al., 2014) provide examples of full face coverage with an integrated visor and bilateral filtration assemblies. In both cases, the seal is made at the periphery of the face. In the case of #2706376, the filtration canisters have integrated into them fans to force air into the mask, while #2910323 claims to provide attachment to external air supply in addition to the attached filters.
Neither of these examples filter exhaled air.
There are several examples of filtration masks that provide full head cover.
However, in the following examples all are fabricated of a soft or collapsible material that requires some form of inflation by outside air delivery system. The first of these examples is Canada patent #
2700845, Forbes and Hodgeson, 2008) and is intended as an emergency filtration mask which is stored in a collapsed condition until needed. It includes a oral-nasal cup with integral symmetrical filters. This device does not claim to have exhaled air filtration. A similar device having a full hood with visor and oral-nasal cup being attached to an air or oxygen supply is described in Canada patent #1326805, (Brookham, 1994). The design is specific for aircraft use in protection against noxious fumes in the event of an on-board fire. A similar apparatus is Canada patent #2775755 with the notable exception that this device is fitted with an internal active air scrubbing device within the collapsible head-cover. The device requires an external source of air to pressurize and cool the inside of the apparatus. This, too, is designed as an emergency breathing apparatus.
Another full head-cover apparatus is described in Canada patent #2520520 where a rigid component of an inflatable, cylindrical apparatus that fits over a person's head and creates a chamber for the wearer.
A continuous supply of air or oxygen is supplied through rigid piping to prevent collapse. This is primarily used for patients and is impractical for use by healthcare providers.
Canada patent #2625592 is another apparatus that fully encloses the head. The invention includes an apparatus for active scrubbing of the air as well as supplying oxygen to maintain breathable air and the pressure to sustain the inflation of the hood. The oxygen cylinder and its cooling action is used as a heat sink to keep the air inside the inflatable hood cool. The expense of this type of apparatus precludes use by the thousands.
With the examples of protective devices above, there is no filtration of the exhaled air of the wearer and thus makes these devices ineffective for use in pandemic scenarios as there is a potential of the health care worker to infect others in the scenario that the healthcare worker is infected and asymptomatic, and could potentially infect uninfected patients and/or other caregivers.
Only one patent, Canada patent #2510253, was found to describe a device where consideration was given to the exhaled air. This device uses bidirectional HEPA filtration to protect others from the shed viruses of the wearer. The apparatus is non-rigid and there is close contact of the hood material with the skin of the wearer. The apparatus also has a goggle component to isolate the eye field, and an oral-nasal mask component to separate the air exchange from the remainder of the mask and hood. This device would lead to the accumulation of heat and moisture within the hood leading to discomfort and not tolerable for extended periods as required during epidemic conditions.
Although the inventions described above may be suitable for specific applications, they do not fulfill the requirements of a PPE necessary for pandemic conditions of a highly infectious viral agent.
Date Recue/Date Received 2020-05-20

4/15 ADVANTANGES OF THIS INVENTION
The invention described in this document represents major improvements in PPE
and APR and resolves a number of disadvantages of current devices.
Safety: Safety is the primary function of this device. The invention here in described provides superior protection compared to conventional mask and shield PPE because the invention completely encloses the head and the incoming air is essentially filter-sterilized. Furthermore, this invention also protects other persons from potential infection from the wearer because the out going air is also essentially filter-sterilized. It is light and easy to wear compared to conventional PPEs and Advanced PPEs.
Economy: The device is relatively inexpensive to manufacture and can be disinfected numerous times before it loses its serviceability. This consideration alone greatly improves the economy of the protection. The filtering elements can be replaced and also re-sterilized, further improving cost savings over disposable PPE.
Comfort: The device offers adequate space for air circulation within the helmet as breathing within the helmet creates unidirectional flow as it forces fresh air in and used air out with each breath. The continuous flow-through helps cool the inside of the helmet. There is minimal contact between this device and the wearer: at the neck seal, along foam pads at top of head where the helmet rests, and along the nose and cheeks where the fog preventing shield contacts the face.
Further, the device can be fitted with a forced air apparatus. The device is completely transparent and this reduces the sensation of being closed in by the device. The device can optionally be fitted with a tube that traverses the diaphragm seal that can be connected to a vessel to provided the wearer with hydration or nutritional liquids, which is useful when the device needs to be worn for long periods as in emergency shifts, without the need to break the seal of the device.
Date Recue/Date Received 2020-05-20

5/15 PERSONAL ENVIRONMENTAL ISOLATION RESPIRATOR
SUMMARY OF THE INVENTION
The invention is a reusable respirator that completely isolates the wearer's head and respiratory system from environmental pathogens by providing sterile air and preventing the wearer's pathogens from entering the environment by sterilizing expired air. It is formed from four components: 1) a one-piece rigid transparent helmet that completely surrounds the head forming a helmet with an integral transparent face shield (Figure 1 and 2), 2) an impermeable elastic diaphragm creating a seal around the wearer's neck and the outer rim being attached to the lower edge of the helmet also forming a seal, 3) an air intake Filter-Valve Assembly and 4) an exhaust Filter-Valve Assembly.
The transparent helmet completely covers the head and has an integral optically clear visor portion on the front allowing clear vision. The helmet extends from the top of the head down to the inferior border of the chin at the front and along the plane of the inferior border of the mandible to below the occipital bone at the back. The helmet has a number of corrugations at the top of the helmet running from front to back, the inner surface contacting the head and thus stabilizes the helmet and the upper part providing air passages between the corrugations for inspired air. There are vertical corrugations to stiffen the lateral aspects of the helmet.
The impervious elastic diaphragm is stretched and fitted over the head through a hole near it's center and pulled down to the neck so that it creates a seal around the wearer's neck. The helmet is then put on and the outer rim of the diaphragm is attached to the lower rim of the helmet forming a seal. This creates an airtight environment within the confines of the helmet and the diaphragm. The diaphragm has a varying thickness becoming thinnest at the seal around the neck so that circulation of blood is not impeded. The stiffer peripheral aspect of the diaphragm resists flexing during breathing. When worn properly, the only entrance and egress of air into the helmet is through a pair of holes fitted with Filter-Valve Assemblies (Figure 1 and 3). The device can optionally be fitted with a tube that traverses the diaphragm that can be connected to a vessel to provided the wearer with hydration or nutritional liquids. Sterilization protocols must be maintained during connecting of tube to the hydration vessel.
The intake Filter-Valve Assembly allows only essentially filter-sterilized air entry and a reed check valve prevents air exit through the opening creating unidirectional air flow.
The intake Filter-Valve Assembly is located at the back of the helmet with the filter mounted on the external surface with the valve on the internal surface. The Filter canister and Valve assembly are connected by a sealed air conducting conduit formed by the threaded tubes of the Valve assembly and Filter canister (See figure and 8). This arrangement permits the replacement of the main intake filter element (canister) without removing the device.
The exhaust Filter-Valve Assembly, 7, is located at the lower front side of the helmet, with the exhaust Filter canister mounted on the inner aspect of the helmet while the valve assembly is on the external surface of the helmet. The exhaust valve is orientated so that the opening of the guard is facing downward, reducing the risk of contamination of the valve from environmental contaminants. This arrangement permits only filtered, exhaled air to exit. By arranging the filter-valve assemblies as described above, identical filter-valve assemblies can be used for both intake and exhaust.
The filtration elements consist of a radially pleated filter element consisting of one or more HEPA filter Date Recue/Date Received 2020-05-20

6/15 layers forming a closed circle of pleats with a central cavity. The filtration elements are treated with a lipophilic coating designed to trap and kill viruses on the surface of the HEPA filter fibers. The filters can be re-sterilized using 70% alcohol and reconditioned with the application of a lipophilic surfactant.
One side of the pleated filter element is bonded to a flat disc occluding all space openings at the edge between the pleats and the other side is likewise bonded to a disk with a hole in the center to which is attached or integrated an inside-threaded tube, that lines up with the central cavity forming a chamber surrounded by filter material and an air passage through which air can pass and can be connected to the Valve Assembly (Figure 1,5,8). The hole in the disc is connected to a tube or integral with a tube that connects to the valve component. The connection between the valve and filter canister can be threaded, bayonet, or friction Morse-taper.
Air movement through the intake Filter-Valve Assembly is driven by the negative pressure or vacuum created by the inhalation of the wearer. Exhalation forces the air out through the exhaust Filter-Valve Assembly. This arrangement of unidirectional air flow, where the air is essentially filter-sterilized before entering the helmet and essentially filter-sterilized before leaving the helmet, prevents pathogens and contaminants from the environment from entering the device and from the wearer from entering the environment. Thus, the name of the device the "Personal Environmental Isolation Respirator"
(PE1R), as the wearer is isolated from environment The positioning of the filters as described reduces the risk of contamination of the intake air filter during use of the device and facilitates the disinfection of the exposed surfaces of the device without the need to remove the equipment. The device can be comfortably employed for considerable periods.
The (PE1R) respirator can be serviced by replacing the valves and filter canisters as needed (after several days or weeks depending on use and environmental loads). The intake filter can be replaced without the removal of the PE1R. However, the diaphragm seal must be broken to replace the internal exhaust filter and all valves. The external, intake filter can be protected from premature clogging by particulates in dusty environments with an additional particulate pre-filter fitted over the canister filter (not shown on figures).
It is critical that the helmet and diaphragm not yield or flex appreciably during the respiratory vacuum and pressure cycles that would reduce air exchange volume and therefore the efficiency of air exchange and contribute to wearer fatigue. The helmet is made more rigid by strategically placed corrugations on the top running front to back (Figures 1 and 2) and vertically at the sides (Figure 2 and 3). Foam comfort pads are bonded to the inner surface of the top of head corrugations that will rest on and make contact with the head and help position and stabilize the helmet on the head.
When the inner aspect of the corrugations rest on the surface of the head, a channel is created between the head and the space between the corrugations and provide an easy passage for incoming air to pass to the front of the PE1R.
Corrugations on the sides (running vertically) (Figures 2 and 3) provide added stiffness to the lateral walls of the PE1R. Foam pads can also be placed in segments along the inner upper circumference of the helmet to provide lateral stability (not shown).
An elastic shield is positioned on the interior of the front part of the helmet and is attached along its anterior edge to the visor portion in an arc just superior to the filter and the lateral aspects are attached at the inferior border of the helmet (Figure 1 and 2). The distal aspect is free and conforms to the face beginning near the bridge of the nose and continuing laterally and diagonally downward across the cheeks forming a half mask seal when the PEIR is worn. This creates a barrier between the upper Date Recue/Date Received 2020-05-20

7/15 portion of the visor and the lower part where the moist air from exhaled breath is expelled directly out of the device through the Filter-Valve Assembly. This arrangement reduces the risk of fogging by decreasing moisture content on the inner surface of the visor portion of the helmet.
It is theorized that the need to force air through filters on inhalation and exhalation could potentially contribute to respiratory fatigue for the wearer when the respirator is used for long periods. A
rechargeable battery powered forced air module delivering 12 liters per minute that attaches directly to the intake canister will also be available (not illustrated).
The PEIR device can be made in a number of sizes, for example small, medium and large, to accommodate various head sizes.
Date Recue/Date Received 2020-05-20

8/15 BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the invitation will become apparent to the reader following the detailed description of the preferred embodiment, together with the drawings in which:
Fig. 1 is a representative view of the lateral aspect of the device as worn by a person and the device is represented in sagittal section.
Fig. 2 is a frontal view of a person wearing the invention.
Fig. 3 is a horizontal cross section along a plane bisecting both Filter-Valve Assemblies in the preferred embodiment of the invention.
Fig. 4 is a view of the embodiment of the invention as seen from above illustrating the position and orientation of the corrugations and other components.
Fig. 5 is an explode view of the Exhaust Filter-Valve Assembly and its relationship to the plastic of the helmet.
Fig. 6 illustrates two orientations of the diaphragm.
Fig. 7 is a detailed cross section illustrating the seal of the diaphragm at the lip of the helmet.
Fig. 8 shows a detailed cross section view of the Filter-Valve Assembly.
Date Recue/Date Received 2020-05-20

9/15 Legend for Figures 1- Transparent full head-cover, the Helmet 2- Top of helmet corrugations.
2a-Air Channels between corrugations 3- Side of helmet corrugations.
4- Diaphragm Retaining Lip of helmet.
5- Front air hole.
6- Back air hole.
7- Exhaust Filter-Valve Assembly.
7a-Exhaust Valve assembly 7b-Exhaust Filter assembly (Filter Canister) 8- Intake Filter-Valve Assembly 8a-Intake Valve assembly 8b-Intake Filter assembly (Filter Canister) 9- Diaphragm.

10- Neck seal.

11- Peripheral Elastic Diaphragm Seal bead.

12- Foam cushion pads.

13- Anti-fogging shield (AFS).

14- Bond line of AFS to inside of helmet.

15- End cap of Filter Canister.

16- Filter element of Filter Canister.

17- End cap with center hole and integral tube for connection to Valve.

18- Canister connection tube with inside-thread

19- Valve connection tube with outside thread.

20- Valve body/backing.

21- Valve seat.

22- Reed valve.

23- Valve Cover/Guard.

24- Valve Cover Guard Opening

25- Seal of Filter-Valve assembly with the helmet

26- Filter element bonding material Date Recue/Date Received 2020-05-20 PERSONAL ENVIRONMENTAL ISOLATION RESPIRATOR
DETAILED DESCRIPTION OF THE INVENTION

Figure 1 Illustrates a person wearing the invention in the preferred embodiment and the figure shows the invention in cross section in the sagittal plane. The invention is a reusable respirator intended to completely isolate the wearer's head and respiratory system from environmental pathogens by providing essentially sterile air and preventing the wearer's pathogens from entering the environment by essentially sterilizing expired air. It is formed from five components.
The first component is a one-piece rigid transparent helmet that completely surrounds the head and has an ovoid opening on the bottom aspect forming a helmet with an integral transparent face shield, 1.
There are a number of corrugations at the upper portion of the dome of the helmet, 2, that run from front to back so that when the inferior aspect of the corrugation rests on the head there are air spaces and channels between the uppermost parts of the helmet and the top of the wearer's head and also function to increase rigidity of the helmet. Foam cushion pads, 12, are attached to the innermost surface of the corrugations to increase stability and comfort and the size of the air channel.
Corrugations on the lateral aspect of the helmet, running in the vertical orientation provide stiffness to side walls of the helmet, not shown on this figure but seen in figures 2, 3, and 4. The material of the inferior border of the helmet is formed with and outward ledge relative to the circumferential plane of the helmet at an approximate angle of 90% forming a lip, 4. The Lip, 4, of the helmet, approximately 5-10mm in width, provides a seat for the bead of the diaphragm, 11 to create a seal. See Figure 7 for details.
The general shape of the Helmet is somewhat conical being smaller at the top of the head, and wider at the bottom, providing enough space for the wearer's head, nose, ears and hair.
The virtual apex of the distally inclined cone is located a point above the helmet, approximately two times the height of the helmet. The shape is such that there are no undercuts on the internal surface of the helmet. All internal shapes as in the case of the corrugations must follow along lines radiating from the virtual apex and the rim at the bottom of the helmet. This aspect is also illustrated in Figure 2.
This figure also shows the position the second component, an impermeable elastomeric diaphragm, 9, creating a seal around the wearer's neck,10, and the outer rim of the helmet at the Lip, 4. The Bead, 11, of the diaphragm attaches to the lower edge of the helmet at the superior aspect of the external part of the Lip, 4, where it wraps around the inferior surface of the lip, 4 and engages the upper surface of the Lip, 4, with its Bead, 11, to create a seal with the helmet. The only openings for air to enter and exit the device are through holes, 5, fitted with the Filter-Valve Assemblies.
The third and fourth components are the air intake and exhaust Filter-Valve Assemblies. This figure also illustrates the preferred position of the Exhaust Filter-Valve Assembly 7, and Intake Filter-Valve Assembly, 8. These are shown in cross section and will be discussed in greater detail in Figure 5 and 8.
The Filter canister and Valve assembly are connected by a sealed air conducting conduit formed by the threaded tubes of the Valve assembly and Filter canister and by their juxtaposition on either side of the plastic where the tube of the Valve assembly passes through the hole, 5, 6, in the plastic of the helmet, creates a sealed passage where only essentially sterile-filtered air can enter or exit the helmet. The Date Recue/Date Received 2020-05-20 positioning and arrangement of the Intake Filter-Valve Assembly, 8, allows air to be drawn into the helmet through the hole, 6, by the negative pressure or vacuum created by inhalation. Before entering the inside of the helmet the air must pass through a HEPA filtering element, 16, that essentially sterilizes the air. Upon exhalation, the positive pressure that is created causes the valve, 22, to close, preventing air from escaping back out through the filter element, maintaining a unidirectional air flow and thus preventing viruses trapped in the filter from being ejected back into the environment. Upon exhalation, air is now forced out through the Exhaust Filter-Valve Assembly, 7, where the air must first pass through a HEPA filtering element, 16, that essentially sterilizes the air before it passes out of the helmet through the exhaust hole, 5. and past the valve, 22. Upon inhalation the negative pressure causes the valve, 22, of the Exhaust assembly to close and prevents air from coming into the helmet through this opening and air must enter through the Intake assembly. This prevents potentially infectious particles from the wearer from entering the environment. This cycle repeats with every breath. This arrangement of the Filter-Valve Assemblies allows a unidirectional flow of fresh essentially sterile air. This arrangement of filters in combination with the transparent helmet that is sealed at the neck, creates a complete isolation of the wearer from the environment. Thus the name of the invention "Personal Environmental Isolation Respirator", abbreviated as PE1R. The arrangement of the Filter-Valve Assemblies as described allows the use of identical Filter-Valve Assemblies for different functions, namely one for intake and one for exhaust, reducing tooling costs for the manufacture of the device.
The fifth component is an anti-fogging shield (AFS) attached to the inner surface of the front of the helmet that separates the upper half to the helmet from the lower part creating a division and passage for air to escape the helmet without causing the moisture laden exhaled air from condensing on the upper, visual field of the visor portion of the helmet.

Figure 2 shows a person wearing the preferred embodiment of the invention and illustrates the transparent helmet that completely covers the head and has an integral optically clear visor portion.
The helmet extends from the top of the head down to the inferior border of the chin at the front and along a plane following the inferior border of the mandible to below the level of the occipital bone at the back. The helmet has a number of corrugations at the top of the helmet running from front to back, 2, the inner surface of the corrugation contacting the head and thus stabilize the helmet on the wearer and providing air passages for inspired air from the back, where the intake Filter-Valve assembly is located, to the front where it is inspired. Foam cushion pads, 12, are attached the the interior surface of the corrugations to create a soft contact with the head. There are vertical corrugations, 3, to stiffen the lateral aspects of the helmet. These are positioned laterally as to not interfere with peripheral vision.
An impervious elastomeric diaphragm, 9, is fitted over the head through a hole near it's center and positioned horizontally approximately at the middle of the wearer's neck so that creates a seal around the neck,10. The helmet is then put on and the outer rim of the diaphragm, 11, is attached to the lower rim of the helmet, engaging the upper surface of the retaining Lip, 4, forming a seal. This creates an airtight environment within the confines of the helmet and the diaphragm. The diaphragm has a varying thickness becoming thinnest at the seal around the neck, minimizing constriction so that circulation of blood is not impeded. When worn properly, the only entrance and egress of air into the helmet is through a pair of holes, not seen in this figure, fitted with Filter-Valve Assemblies, 7, 8. Only the Date Recue/Date Received 2020-05-20 exhaust assembly, 7, is shown in this figure.
This figure also illustrates the preferred location of the exhaust Filter-Valve assembly, 7, at the lower front aspect of the helmet, with the exhaust filter canister, 8a mounted on the inner aspect of the helmet while the valve assembly is on the external surface of the helmet. The exhaust valve is orientated so that the opening of the guard, 23, is facing downward, reducing the risk of contamination of the valve from environmental contaminants and protects the valve proper during disinfection of the apparatus.
This arrangement permits only filtered, exhaled air to exit through the assembly. The location of the Exhaust Filter-Valve assembly, nearest to the mouth and nose when combined with the Anti-Fog Shield, 13, with its attachment, 14, to the inner aspect of the lower front part of the helmet confines moisture laden exhaled breath to the lower part of the helmet where it exits the exhaust Filter-Valve Assembly reducing the possibility of condensation on the visual field portion of the helmet minimizing the possibility of fogging and impairing vision. This figure shows the attachment of Anti-Fog Shield This figure also shows that the general shape of the Helmet is somewhat conical being smaller at the top of the head, and wider at the bottom. The virtual apex of the cone is located a point above the helmet, approximately two times the height of the helmet. The shape is such that there are no undercuts on the internal surface of the helmet. All internal shapes as in the case of the corrugations must follow along lines radiating from the virtual apex and the rim at the bottom of the helmet. The purpose of this shape is that it facilitates the fabrication of the Helmet from a one-piece mold.

Figure 3 is a horizontal cross section along a plane bisecting the Filter-Valve Assemblies as viewed from above and illustrates the preferred locations of the lateral corrugations at the indicated plane. This figure also shows the preferred position and orientation of the Filter-Valve Assemblies. The intake assembly located at the back of the helmet with the filter canister, 8a, located on the exterior and the valve assembly, 8b, located on the inner aspect. This figure shows the preferred configuration with the exhaust Filter-Valve Assemblies filter canister located on the inner surface of the front of the Helmet and the Exhaust valve located on the outer surface. Details of the Filter-Valve Assembly are seen in Figure 8. This arrangement of the components produces a sealed conduit through the hole in the plastic of the helmet for the passage of essentially sterile air from the inner chamber of the filter canister and out through the valve. The same principle applies to the intake Filter-Valve Assembly where essentially sterile air is brought into the apparatus.

Figure 4 is a view of the preferred embodiment of the invention as seen from above and all of the principle components are illustrated.
As the entire helmet is formed of transparent material, all internal components are visible. The location of the Intake, 8, and Exhaust, 7, Filter-Valve Assemblies are shown. The external location of the Intake Canister, 8a, and internal location of the Valve assembly, 8b, as well as the internal location of the Exhaust Canister, 7a, and external location of the Exhaust valve assembly, 7b, are illustrated in this Date Recue/Date Received 2020-05-20 figure.
The Top of Helmet Corrugations, 2, are seen as well as the Foam Cushion Pads, 12, bonded to the inner surface. The Side of Helmet Corrugations, 3 are also illustrated.
The Anti-Fogging Shield, 13, located at the inner front section of the Helmet is shown as well the areas where it is bonded to the inner aspect of the Helmet, 14.
The Diaphragm, 9, is shown in this figure and is partially obstructed from full view by the non-transparent components of the device, namely the Foam Cushion Pads, 12, Intake Valve Assembly, 8b, the Anti-fogging Shield, 13, and the Exhaust Canister, 7a. The shape of the diaphragm follows the shape of the outline of the lower edge of the helmet and is only slightly smaller so that the elastic tension of the bead of the diaphragm creates a seal at the lip of the helmet, 4. See figure 7 for detail of the diaphragm seal. The Neck seal, 10, is partially obstructed from full view by the Foam Cushion Pads, 12. The preferred position of the hole in the diaphragm for donning and the neck seal are shown and is located slightly towards the back from the center of the diaphragm It is critical that the helmet and diaphragm not yield or flex any significant amount during the respiratory vacuum and pressure cycles. Any flexing of the shell inclusive of the diaphragm would reduce air exchange volume and therefore the efficiency of air exchange and contribute to wearer fatigue. The helmet is made more rigid by strategically placed corrugations on the top running front to back, 2, ( also shown on Figures 1 and 2) and vertically at the sides, 3,(also shown on Figures 2 and 3).
Foam pads, 12, are bonded to the inner surface of the top of head corrugations, 3 that will cushion and position the helmet when resting in contact with the head, a channel is created between the head and the space between the corrugations and provide an easy passage for incoming air to pass to the front of the PEIR. The passage of air along these channels assist in cooling the head and reducing fogging of the visual portion of the helmet. Corrugations on the sides, oriented vertically (also shown in Figures 2 and 3) provide added stiffness to the lateral walls of the PEIR. The increased stiffness to the helmet provided by the strategically placed corrugations allows the helmet to be fabricated from thinner material adding to improved transparency and reduced weight and cost of the device. The contour of the corrugations is a smooth sinuous curve that contributes to the stiffness and are made broad enough to allow access to the bottom of the corrugations as to facilitate the disinfection of all surfaces of the device.

Figure 5 is an exploded diagram of the preferred embodiment of the Filter-Valve Assembly, 7, 8, which consists of a Filter Canister, 7a, 8a, threaded to the Valve assembly, 7b, 8b creating a sealed conduit.
The Filter Canister, 7a, 8a, is composed of 3 elements: a flat disc, End cap of filter canister, 15, a filter element, 16, and an end cap,17, with an approximately 20mm hole at its center and a protruding inside-threaded tube, 18, for connection to the Valve assembly, 7b, 8b.
As most bacteria and viruses can be killed by 70 alcohol, the filter canisters are designed to withstand disinfection by immersion in alcohol, the End Caps of filter canister and connection tube,15, 17, 18, are composed of any material that is insoluble in alcohol, detergents, oils and surfactants and may include metals, plastics or composite materials. The filter element, 16, must also be unaffected by Date Recue/Date Received 2020-05-20 repeated, prolonged immersion in alcohol. The cements that bond the end caps to the filter must also be impervious to alcohol, and may include but not limited to, epoxy, polyester resin, silicone, solvent based bonding agents or thermoplastic cements.
The Filter Element, 16, is composed of one or more layers of HEPA cloth cut in strips approximately 20mm wide and 1000 mm long, pleated at 20mm intervals creating series of connected faces that are 20mm x20mm and arranged radially in a closed circle with an outside diameter of 70mm and an inner diameter and an inner diameter of 30mm, 16. Multiple layers of filtering material, having different desired properties may be employed. The pleated filter element, thus arranged is bonded on both sides along the edges of the pleated strip as to seal the edges of the pleats to the end caps 15 and 17. This is accomplished by placing the filter element in a jig that retains the desired position and orientation of the pleated element, 16, a uniform layer of cement is applied to the entire surface of the end cap,15, and all the edges of the flat side of the pleated filter element contact the cement and are bonded creating a seal between the flat plate and the edge of the filter element. The same is repeated for the end cap, 17, with the inside-threaded connection tube, 18, thus forming a chamber within the filter element. Also see Figure 8.
Air can now be drawn out through the connection tube and the negative pressure causes air to be drawn through the filter element where the viruses are trapped in the filter material leaving essentially sterilized air to come out of the filter canister. The reverse also applies, infected air exhaled by the wearer of the device must pass through the filter where it is essentially sterilized before it can exit out of the connection tube.
Other alternatives for a Filter element include but not limited to open-cell foam.

Figure 6 shows an oblique and cross section view of the diaphragm. The diaphragm is a critical component of the apparatus as it completes the seal to exclude the environment from the interior of the helmet. It is made of an elastomeric material with a high modulus of elasticity. The body of the diaphragm, 9 which is thicker at the periphery and gets progressively thinner nearer to the neck sea1,10. The elasticity is such that it stretches to fit over the head and seals around the mid-section of the neck without restricting blood flow. The peripheral part of the diaphragm which is less elastic due to the greater thickness resists displacement during inhalation and exhalation. The position of the hole for the neck is located about 60% of the distance from the front to the back and in the middle when related to the sides of the helmet. There is a thickened rounded bead, 11, at the periphery of the diaphragm and is integral with the diaphragm and functions to seal the diaphragm to the lip of the helmet.

Figure 7 is a cross section detail of the relationship of the diaphragm, 9, with the lip of the helmet, 4, to create a seal. The diaphragm, 9, is an impervious elastic membrane that forms the closure of the bottom of the helmet by creating a seal around the neck of the wearer, 10, and the inferior edge of the Date Recue/Date Received 2020-05-20 rim or lip of the helmet, 4. The size of the diaphragm, 11, is made slightly smaller that the outer most dimension of the lip of the helmet, 4. To create the seal, the rim of the diaphragm is stretched outward and lifted from the inferior side of the helmet to engage the upper surface of the lip, 4. Tension of the elasticity of the rim, 11, pulls the rim tight against the vertical walls of the helmet creating a seal where the edge of the rim of the diaphragm, 11, against the vertical wall of the helmet, 1, as well as where the diaphragm, 9, is stretched over the lip of the helmet, 4, thus preventing any air to enter or escape along the periphery of the helmet. The lip of the helmet must be of sufficient strength and stiffness to resist collapse by the tension of the diaphragm. The neck seal, 10, fitting snugly around the neck of the wearer prevents air from entering or escaping at the interface between the seal of the diaphragm and the neck.

Figure 8 is a cross section view of the Intake Filter-Valve assembly located at the back of the helmet in the preferred embodiment of the invention. The valve assembly consisting of a connection tube, 19, with external threads, backing plate, 20, valve seat, 21, reed valve, 22, and valve cover, 23. is clearly illustrated. The figure further shows the outside-threaded connection tube, 19, which is an integral part of the packing plate, 20, of Intake valve assembly, 8b, positioned in the hole, 6, in the helmet, 1, where the Intake air Filter canister, 8a is connected to it by inside threaded tube, 18. This figure show the relationship of the parts as they create the seal between the Filter-Valve assembly and the Helmet,l, when inside threaded tube, 18, of the Filter canister, 8b, is threaded onto the outside threaded tube, 19, of the Valve assembly, the plastic at the edge of the hole, 6, is compressed against the backing plate, 20, of the Valve assembly creating a seal, 25.
In this figure the reed valve, 22, is shown in the partially open position as it would be at the beginning of the inhalation cycle.
Note that in the preferred embodiment of the invention, both intake and exhaust Filter-Valve assemblies are identical in design and manufacture and they function differently only due to their orientation on the helmet to achieve the desired air flow. In the case of the Intake assembly, air flows in through the filter element, 16, passes through the conduit created by the threaded tubes, 18 and 19 that are integral parts of the respective components, and passed the valve, 22 and past the valve guard opening, 24 to the inside of the sealed helmet. The Diaphragm is not shown in this figure.
Fresh air enters the back of the helmet flows over and around, the head, is inhaled, and when exhaled exits at the front of the helmet. By continuously directing air flow in this way the inside of the helmet stays relatively cool and dry.
Warning. As this device completely isolates the wearer from the environment, there is a risk of asphyxiation should either of the Filter-Valve Assemblies become obstructed.
The device should be immediately removed and Filter-Valve Assemblies replaced should resistance to normal breathing occur.
Date Recue/Date Received 2020-05-20

Claims (30)

PERSONAL ENVIRONMENTAL ISOLATION RESPIRATOR
What is claimed is:

1) The embodiment of the invention is a reusable respirator to completely isolate the wearer's head and respiratory system from environmental pathogens by providing essentially sterile air and preventing the wearer's pathogens from entering the environment by essentially sterilizing expired air, comprising of: a rigid transparent dome over the entirety of the head forming the helmet, an elastomeric diaphragm that completely seals around the neck and the peripheral lower edge of the helmet, an Air Intake Filter-Valve Assembly, and an Exhaust Air Filter-Valve Assembly.

2) The apparatus in claim 1 further comprising a one-piece rigid transparent helmet that completely surrounds the head forming a helmet with an optically clear transparent visor section, (Figure 1 and 2).

3) The apparatus of claim 2 where there are a number of corrugations at the top of the helmet that run from front to back so that when the inferior aspect of the corrugation rests on the head there are air spaces and channels between the uppermost parts of the helmet and the top of the wearer's head and also function to increase rigidity of the helmet.

4) The apparatus of claim 2 where there are corrugations on the lateral aspect of the helmet, running in the vertical orientation providing stiffness to side walls of the helmet.

5) The apparatus of claim 2 where foam cushion pads are attached to the innermost surface of the corrugations to increase stability and comfort and the size of the air channel, as well as horizontally on the inner surface in the temporal area of the helmet to improve stability and comfort.

6) The apparatus of claim 2 where the material of the inferior border of the helmet is formed with and outward ledge relative to the circumferential plane of the helmet at an approximate angle of 90 degrees forming a lip that will become the seat of the peripheral seal of the diaphragm.

7) The apparatus of claim 2 where the general shape of the Helmet is somewhat conical being smaller at the top of the head, and wider at the bottom, providing enough space for the wearer's head, nose, ears and hair. The shape is partially defined by a distally inclined cone with a virtual apex located a point above the helmet, approximately two times the height of the helmet.

8) The apparatus of claim 2 where the shape is such that there are no undercuts on the internal surface of the helmet. All internal shapes as in the case of the corrugations must follow along lines radiating from the virtual apex and the rim at the bottom of the helmet

9) The apparatus of claim 1 where an impermeable elastomeric diaphragm creates a seal between the wearer's neck and the outer rim, at the Lip of the helmet, forming a space within the helmet that is sealed from the external environment.

10) The apparatus of claim 1 where all components are fabricated of materials that are insoluble in 70% alcohol.
Date Recue/Date Received 2020-05-20

11) The apparatus of claim 9 where the diaphragm when seen in cross section has a varying thickness beginning with a round bead at the outermost periphery gradually becoming thinner and becoming thinnest at the seal around the neck, minimizing constriction so that circulation of blood is not impeded.

12) The apparatus of claim 9 where the seal is formed between the diaphragm and the helmet when the peripheral bead of the diaphragm is attached to the lower rim of the helmet, engaging the upper surface of the retaining Lip, and the elastic tension retains the bead tight to the helmet.

13) The apparatus of claim 9 where the apparatus is donned by fitting the elastomeric diaphragm over the head through a hole near it's center and positioned it horizontally approximately at the base of the wearer's neck so it that creates a seal around the neck. The helmet is then put on and the bead of the diaphragm is attached to the upper surface of lip at the lower part of the helmet as in Claim 11, thus forming a hermetically sealed environment within the apparatus.

14) The apparatus of claim 1 where two Filter-Valve Assemblies are mounted on the helmet to provide essentially sterile-filtered intake and exhaust air, permitting the wearer to breath continually and comfortably.

15) The apparatus of claim 14 where the Intake Filter-Valve Assembly is located at the back of the helmet and the Exhaust Filter-Valve Assembly is located at the lower part of front of the helmet.

16) The apparatus of claim 14 where the Filter canister and Valve assembly are connected by a sealed air conducting conduit formed by the threaded tubes of the Valve assembly and Filter canister and by their juxtaposition on either side of the plastic where the tube of the Valve assembly passes through the hole in the plastic of the helmet, creates a sealed passage where only essentially sterile-filtered air can enter or exit the helmet, respectively.

17) The apparatus of claim 14 where the Intake and Exhaust Filter-Valve Assemblies are identical but function differently. The Intake Filter Canister is mounted at the back of the helmet and positioned on the external aspect of the helmet and the Valve is located on the internal aspect connected by a sealed air conduction conduit, while the Exhaust Filter is mounted internally at the lower front of the helmet and the valve is located on the external aspect of the helmet. By this arrangement the air must flow through the Filter element of the intake Filter-Valve Assembly before it can enter the internal space of the apparatus and that similarly the wearer's exhaust air is filtered before exiting the apparatus.

18) The apparatus of claim 14 where the filter-assemblies are fabricated from HEPA filter fabric or material.

19) The apparatus of claim 14 where the valve assembly consisting of a backing plate, a reed valve and a guard and has integrated a tube with an outside-thread that connects to the Filter canister to form a sealed conduit where the action of the reed valve controls the airflow in a unidirectional manner.

20) The apparatus of claim 18 where one or more layers of filter material can be used.

21) The apparatus of claim 18 where a Lipohilic surfactant is applied to the one or more of the layers .
Date Recue/Date Received 2020-05-20

22) The apparatus of claim 18 where the Filter-assembly can be disinfected with 70% alcohol.

23) The apparatus of claim 18 where the filter fabric is pleated and arranged radially in a closed circle forming a central cavity or chamber, and sealed between two discs one of which has a centrally located, protruding, cylindrical tube with inside-thread that will form part of the air-conducting conduit when attached to the valve assembly.

24) The apparatus of claim 1 and 2 where an impervious elastomeric shield is positioned on the interior of the front part of the helmet and is bonded to the visor portion in an arc immediately superior to the exhaust filter canister and the lateral aspects are bonded the inferior border of the helmet functioning to reduce the risk of fogging.

25) The apparatus of claim 24 where the unattached or free end of the shield is shaped to conform to the bridge of the nose and cheeks to form a partial cup around the mouth and nose forming an internal barrier between the upper and lower halves of internal front part of the apparatus.

26) The apparatus of claim 24 where the shield causes the moisture-laden exhaled air to be immediately expelled out of the apparatus through the exhaust Filter-Valve assembly preventing condensation of moisture on the visual field.

27) The apparatus in claim one where there is no internal shield where fogging is not critical.

28) The apparatus in claim 1 where the device can be made in a number of sizes, for example small, medium and large, to accommodate various head sizes.

29) The apparatus in claim 1 where an alternative embodiment of the invention is fitted with a tube that passes through a small hole in the anterior part of the diaphragm from the outside to the inside and functions to bring hydration or nutritional fluids from a container or vessel outside the device to be consumed by the wearer, so that the sterile function of the device is not broken.

30) The apparatus in claim 1 where the intake Filter-Valve Assembly can be located elsewhere on the helmet.
Date Recue/Date Received 2020-05-20