Note: Descriptions are shown in the official language in which they were submitted.
1/15
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
10/15
PERSONAL ENVIRONMENTAL ISOLATION RESPIRATOR
DETAILED DESCRIPTION OF THE INVENTION
FIGURE 1
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
11/15
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
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
12/15
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
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
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
13/15
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
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
14/15
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
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
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
15/15
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
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
